ERC FUNDED PROJECTS

The rise of atmospheric O2 ~2,500 million years ago is one of the most profound transitions in Earth's history. Yet, despite its central role in shaping Earth's surface environment, the cause for the rise of O2 remains poorly understood. Tight coupling between the O2 cycle and the biogeochemical cycles of redox-active elements, such as C, Fe and S, implies radical changes in these cycles before, during and after the rise of O2. These changes, too, are incompletely understood, but have left valuable information encoded in the geological record. This information has been qualitatively interpreted, leaving many aspects of the rise of O2, including its causes and constraints on ocean chemistry before and after it, topics of ongoing research and debate. Here, I outline a research program to address this fundamental question in geochemical Earth systems evolution. The inherently interdisciplinary program uniquely integrates laboratory experiments, numerical models, geological observations, and geochemical analyses. Laboratory experiments and geological observations will constrain unknown parameters of the early biogeochemical cycles, and, in combination with field studies, will validate and refine the use of paleoenvironmental proxies. The insight gained will be used to develop detailed models of the coupled biogeochemical cycles, which will themselves be used to quantitatively understand the events surrounding the rise of O2, and to illuminate the dynamics of elemental cycles in the early oceans. This program is expected to yield novel, quantitative insight into these important events in Earth history and to have a major impact on our understanding of early ocean chemistry and the rise of O2. An ERC Starting Grant will enable me to use the excellent experimental and computational facilities at my disposal, to access the outstanding human resource at the Weizmann Institute of Science, and to address one of the major open questions in modern geochemistry.

1 472 690 €

Start date: 2013-09-01, End date: 2018-08-31

Alkenones are algal lipids that have been used for decades to reconstruct quantitative past sea surface temperature. Although alkenones are being discovered in an increasing number of lake sites worldwide, only two terrestrial temperature records have been reconstructed so far. The development of this research field is limited by the lack of interdisciplinary research that combines modern biological and ecological algal research with the organic geochemical techniques needed to develop a quantitative biomarker (or molecular fossil) for past lake temperatures. More research is needed for alkenones to become a widely used tool for reconstructing past terrestrial temperature change. The early career Principal Investigator has discovered a new lake alkenone-producing species of haptophyte algae that produces alkenones in high abundances both in the environment and in laboratory cultures. This makes the new species an ideal organism for developing a culture-based temperature calibration and exploring other potential environmental controls. In this project, alkenone production will be manipulated, and monitored using state-of-the-art photobioreactors with real-time detectors for cell density, light, and temperature. The latest algal culture and isolation techniques that are used in microalgal biofuel development will be applied to developing the lake temperature proxy. The objectives will be achieved through the analysis of 90 new Canadian lakes to develop a core-top temperature calibration across a large latitudinal and temperature gradient (Δ latitude = 5°, Δ spring surface temperature = 9°C). The results will be used to assess how regional palaeo-temperature (Uk37), palaeo-moisture (δDwax) and palaeo-evaporation (δDalgal) respond during times of past global warmth (e.g., Medieval Warm Period, 900-1200 AD) to find an accurate analogue for assessing future drought risk in the interior of Canada.

940 883 €

Start date: 2015-04-01, End date: 2020-03-31

The onset of the systematic consumption of marine resources is thought to mark a turning point for the hominin lineage. To date, this onset cannot be traced, since classic isotope markers are not preserved beyond 50 - 100 ky. Aquatic food products are essential in human nutrition as the main source of polyunsaturated fatty acids in hunter-gatherer diets. The exploitation of marine resources is also thought to have reduced human mobility and enhanced social and technological complexification. Systematic aquatic food consumption could well have been a distinctive feature of Homo sapiens species among his fellow hominins, and has been linked to the astonishing leap in human intelligence and conscience. Yet, this hypothesis is challenged by the existence of mollusk and marine mammal bone remains at Neanderthal archeological sites. Recent work demonstrated the sensitivity of Zn isotope composition in bioapatite, the mineral part of bones and teeth, to dietary Zn. By combining classic (C and C/N isotope analyses) and innovative techniques (compound specific C/N and bulk Zn isotope analyses), I will develop a suite of sensitive tracers for shellfish, fish and marine mammal consumption. Shellfish consumption will be investigated by comparing various South American and European prehistoric populations from the Atlantic coast associated to shell-midden and fish-mounds. Marine mammal consumption will be traced using an Inuit population of Arctic Canada and the Wairau Bar population of New Zealand. C/N/Zn isotope compositions of various aquatic products will also be assessed, as well as isotope fractionation during intestinal absorption. I will then use the fully calibrated isotope tools to detect and characterize the onset of marine food exploitation in human history, which will answer the question of its specificity to our species. Neanderthal, early modern humans and possibly other hominin remains from coastal and inland sites will be compared in that purpose.

1 361 991 €

Start date: 2019-03-01, End date: 2024-02-29

Fluids play an important role in fault zone and in earthquakes generation. Fluid pressure reduces the normal effective stress, lowering the frictional strength of the fault, potentially triggering earthquake ruptures. Fluid injection induced earthquakes (FIE) are direct evidence of the effect of fluid pressure on the fault strength. In addition, natural earthquake sequences are often associated with high fluid pressures at seismogenic depths. Although simple in theory, the mechanisms that govern the nucleation, propagation and recurrence of FIEs are poorly constrained, and our ability to assess the seismic hazard that is associated with natural and induced events remains limited. This project aims to enhance our knowledge of FIE mechanisms over entire seismic cycles through multidisciplinary approaches, including the following: - Set-up and installation of a new and unique rock friction apparatus that is dedicated to the study of FIEs. - Low strain rate friction experiments (coupled with electrical conductivity measurements) to investigate the influence of fluids on fault creep and earthquake recurrence. - Intermediate strain rate friction experiments to investigate the effect of fluids on fault stability during earthquake nucleation. - High strain rate friction experiments to investigate the effect of fluids on fault weakening during earthquake propagation. - Post-mortem experimental fault analyses with state-of-art microstructural techniques. - The theoretical friction law will be calibrated with friction experiments and faulted rock microstructural observations. These steps will produce fundamental discoveries regarding natural earthquakes and tectonic processes and help scientists understand and eventually manage the occurrence of induced seismicity, an increasingly hot topic in geo-engineering. The sustainable exploitation of geo-resources is a key research and technology challenge at the European scale, with a substantial economical and societal impact.

1 982 925 €

Start date: 2018-03-01, End date: 2023-02-28

Whether and where clouds consist of liquid water, ice or both (i.e. their thermodynamic phase distribution), has major impacts on the clouds’ dynamical development, their radiative properties, their efficiency to form precipitation, and their impacts on the atmospheric environment. Cloud ice formation in the temperature range between 0 and -37°C is initiated by aerosol particles acting as heterogeneous ice nuclei and propagates through the cloud via a multitude of microphysical processes. Enormous progress has been made in recent years concerning the understanding and model parameterization of primary ice formation. In addition, high-resolution atmospheric models with complex cloud microphysics schemes can now be employed for realistic case studies of clouds. Finally, new retrieval schemes for the cloud (top) phase have recently been developed for various satellites, including passive polar orbiting and geostationary sensors, which provide a good spatial and temporal coverage and a long data record. We propose here to merge the bottom-up, forward modeling approach for the cloud phase distribution with the top-down view of satellites. C2Phase will conduct systematic closure studies for variables related to the cloud phase distribution such as the cloud ice area fraction, its distribution as function of temperature and its temporal evolution, with a focus on Europe. For this, we will (1) use clustering techniques to separate different cloud regimes in model and satellite data, (2) explore the parameters and processes which the simulated phase distribution is most sensitive to, (3) investigate whether closure is reached between state-of-the art cloud resolving models and satellite observations, and how this closure can be improved by consistent and physically justified changes in microphysical parameterizations, and (4) use our results to improve the representation of mixed-phase clouds in weather and climate models and to quantify the impacts of these improvements.

1 499 549 €

Start date: 2017-04-01, End date: 2022-03-31

"Ice-core records show that glacials had lower atmospheric pCO2 and cooler temperatures than today and that the last deglaciation was punctuated by large, abrupt millennial-scale climate events. Explaining the mechanism controlling these oscillations remains an outstanding puzzle. The ocean is a key player, and the Atlantic is particularly dynamic as it transports heat, carbon and nutrients across the equator. This project proposes to consolidate my research through a focused study of present and past ocean chemistry in the Equatorial Atlantic and to assess the impact of ocean chemistry on fragile deep-sea ecosystems. Despite decades of research there are distinct gaps in our knowledge of the history of the deep and intermediate ocean. Major hurdles include access to suitable archives, development of geochemical proxies and analyses that are sufficiently precise to test climate hypotheses. Through a combination of ship board field work, modern calibrations and cutting-edge geochemical analyses this project will produce samples and data that address each of these gaps. A particular focus will be on using the skeletons of deep-sea corals. Research using deep-sea corals as climate archives, and indeed research into their habitats, environmental controls and potential threats to their survival are still fields in their infancy. The expense and logistics of working in the deep ocean, the complexity of the ecosystem and the biogeochemistry of the coral skeletons have all proved to be significant challenges. The potential payoffs of high-resolution, dateable archives, however, make the effort worthwhile. There have been no studies that attempt to match up co-located deep-sea coral, seawater and sediment samples in a single program, so this would be the first directed study of its type, and as such promises to provide a substantial step in quantifying the fluxes and transport of mass, heat and nutrients across the equator in the past."

1 998 833 €

Start date: 2011-10-01, End date: 2017-09-30

Clouds and precipitation play a crucial role in the Earth's energy balance, global atmospheric circulation and the water cycle. Despite their importance, clouds still pose the largest uncertainty in climate research. I propose a new approach for studying anthropogenic effects on cloud fields and rain, tackling the challenge from both scientific ends: reductionism and systems approach. We will develop a novel research approach using observations and models interactively that will allow us to “peel apart” detailed physical processes. In parallel we will develop a systems view of cloud fields looking for Emergent Behavior rising out of the complexity, as the end result of all of the coupled processes. Better understanding of key processes on a detailed (reductionist) manner will enable us to formulate the important basic rules that control the field and to look for emergence of the overall effects. We will merge ideas and methods from four different disciplines: remote sensing and radiative transfer, cloud physics, pattern recognition and computer vision and ideas developed in systems approach. All of this will be done against the backdrop of natural variability of meteorological systems. The outcomes of this work will include fundamental new understanding of the coupled surface-aerosol-cloud-precipitation system. More importantly this work will emphasize the consequences of human actions on the environment, and how we change our climate and hydrological cycle as we input pollutants and transform the Earth’s surface. This work will open new horizons in cloud research by developing novel methods and employing the bulk knowledge of pattern recognition, complexity, networking and self organization to cloud and climate studies. We are proposing a long-term, open-ended program of study that will have scientific and societal relevance as long as human-caused influences continue, evolve and change.

1 428 169 €

Start date: 2012-09-01, End date: 2017-08-31

The water cycle in the Himalaya is poorly understood because of its extreme topography that results in complex interactions between climate and water stored in snow and glaciers. Hydrological extremes in the greater Himalayas regularly cause great damage, e.g. the Pakistan floods in 2010, while the Himalayas also supply water to over 25% of the global population. So, the stakes are high and an accurate understanding of the Himalayan water cycle is imperative. The discovery of the monumental error on the future of the Himalayan glaciers in the fourth assessment report of the IPCC is exemplary for the scientific misconceptions which are associated to the Himalayan glaciers and its water supplying function. The underlying reason is the huge scale gap that exists between studies for individual glaciers that are not representative of the entire region and hydrological modelling studies that represent the variability in Himalayan climates. In CAT, I will bridge this knowledge gap and explain spatial differences in Himalayan glacio-hydrology at an unprecedented level of detail by combining high-altitude observations, the latest remote sensing technology and state-of-the-art atmospheric and hydrological models. I will generate a high-altitude meteorological observations and will employ drones to monitor glacier dynamics. The data will be used to parameterize key processes in hydro-meteorological models such as cloud resolving mechanisms, glacier dynamics and the ice and snow energy balance. The results will be integrated into atmospheric and glacio-hyrological models for two representative, but contrasting catchments using in combination with the systematic inclusion of the newly developed algorithms. CAT will unambiguously reveal spatial differences in Himalayan glacio-hydrology necessary to project future changes in water availability and extreme events. As such, CAT may provide the scientific base for climate change adaptation policies in this vulnerable region.

1 499 631 €

Start date: 2016-02-01, End date: 2021-01-31

The ubiquity of arsenic resistant genes across all of life’s variety suggests a close intimacy between arsenic biogeochemistry and evolution, over geological time scales. However, the behaviour of arsenic in past environments where life originated and its impact on our evolution is essentially unknown. Arsenic is of particular importance because of its toxic properties, prevalence in tight association with ubiquitous iron and sulfide minerals and as a major component of sulfide-rich waters, all common features of Precambrian oceans. Arsenic obstructs the synthesis of the building blocks of life, exhibiting both chronic and acute toxicity at very low concentrations. These properties make arsenic an agent capable of exerting strong selective pressure on the distribution, success and diversity of life. This is exemplified by when the release of arsenic into groundwater following rock-weathering processes results in widespread poisoning. Using the state of the art stable isotopes tools, coupled to biomass production, bacterial iron, arsenic and sulfur cycling under ancient oceanic conditions, this project will open a new discussion on the much debated relationship between ocean chemistry and evolution, by introducing a new arsenic framework. This will be achieved under three majors themes: 1) Does there exist a biogeochemical connection between arsenic and the timing and transition from the iron-rich to the hypothesized sulfide-rich oceans that are linked to the rise of atmospheric oxygen? 2) Does arsenic and sulfide show concomitant cyclicity during the Precambrian? 3) Could arsenic thus serve as a proxy for the calibration of key transitional steps in the timing of biological innovation?

1 486 374 €

Start date: 2013-09-01, End date: 2018-08-31

Few geophysical phenomena are as spectacular as tropical cyclones, with their eye surrounded by sharp cloudy eyewalls. There are other types of spatially organised convection (convection refers to overturning of air within which clouds are embedded), in fact organised convection is ubiquitous in the tropics. But it is still poorly understood and poorly represented in convective parameterisations of global climate models, despite its strong societal and climatic impact. It is associated with extreme weather, and with dramatic changes of the large scales, including drying of the atmosphere and increased outgoing longwave radiation to space. The latter can have dramatic consequences on tropical energetics, and hence on global climate. Thus, convective organisation could be a key missing ingredient in current estimates of climate sensitivity from climate models. CLUSTER will lead to improved fundamental understanding of convective organisation to help guide and improve convective parameterisations. It is closely related to the World Climate Research Programme (WCRP) grand challenge: Clouds, circulation and climate sensitivity. Grand challenges identify areas of emphasis in the coming decade, targeting specific barriers preventing progress in critical areas of climate science. Until recently, progress on this topic was hindered by high numerical cost and lack of fundamental understanding. Advances in computer power combined with new discoveries based on idealised frameworks, theory and observational findings, make this the ideal time to determine the fundamental processes governing convective organisation in nature. Using a synergy of theory, high-resolution cloud-resolving simulations, and in-situ and satellite observations, CLUSTER will specifically target two feedbacks recently identified as being essential to convective aggregation, and assess their impact on tropical cyclones, large-scale properties including precipitation extremes, and energetics of the tropics.

1 078 021 €

Start date: 2019-06-01, End date: 2024-05-31

Key words: Atmospheric secondary organic aerosol, chemical ionization mass spectrometry The increase in anthropogenic atmospheric aerosol since the industrial revolution has considerably mitigated the global warming caused by concurrent anthropogenic greenhouse gas emissions. However, the uncertainty in the magnitude of the aerosol climate influence is larger than that of any other man-made climate-perturbing component. Secondary organic aerosol (SOA) is one of the most prominent aerosol types, yet a detailed mechanistic understanding of its formation process is still lacking. We recently presented the ground-breaking discovery of a new important compound group in our publication in Nature: a prompt and abundant source of extremely low-volatility organic compounds (ELVOC), able to explain the majority of the SOA formed from important atmospheric precursors. Quantifying the atmospheric role of ELVOCs requires further focused studies and I will start a research group with the main task of providing a comprehensive, quantitative and mechanistic understanding of the formation and evolution of SOA. Our recent discovery of an important missing component of SOA highlights the need for comprehensive chemical characterization of both the gas and particle phase composition. This project will use state-of-the-art chemical ionization mass spectrometry (CIMS), which was critical also in the detection of the ELVOCs. We will extend the applicability of CIMS techniques and conduct innovative experiments in both laboratory and field settings using a novel suite of instrumentation to achieve the goals set out in this project. We will provide unprecedented insights into the compounds and mechanisms producing SOA, helping to decrease the uncertainties in assessing the magnitude of aerosol effects on climate. Anthropogenic SOA contributes strongly to air quality deterioration as well and therefore our results will find direct applicability also in this extremely important field.

1 892 221 €

Start date: 2015-03-01, End date: 2020-02-29

How do erosion rates in glacial landscapes vary with climate change and how do such changes affect the dynamics of mountain glaciers? Providing quantitative constraints towards this question is the main objective of COLD. These constraints are so important because mountain glaciers are sensitive to climate change and their deposits provide a unique history of Earths terrestrial climate that allows reconstructing leads and lags in the climate system. The climate sensitivity of mountain glaciers is influenced by debris on their surface that impedes ice melting. Theoretical models of frost-related bedrock fracturing predict that rates of debris production are temperature-sensitive and that its supply to mountain glaciers increases during warming periods. Thus a previously unrecognized negative feedback emerges that lowers ice melt rates and potentially buffers part of the ice retreat due to warming. However, the temperature-sensitivity of debris production in glacial landscapes is poorly understood. Specifically, we lack robust erosion rate estimates for these landscapes, which are key for testing models of frost-related bedrock fracturing. Here, I propose an innovative combination of new tools that capitalize on recent developments in cosmogenic nuclide geochemistry, landscape evolution modelling, and planetary-scale remote sensing analysis. I will use these tools to quantify headwall erosion rates in mountainous glacial landscapes and to gauge the sensitivity of mountain glaciers to variations in debris supply. Expected results will provide a basis for assessing the impacts of global warming, for improved predictions of valley glacier evolution, and for palaeoclimate interpretations of glacial landforms. COLD will focus on glacial landscapes, but the inverse modelling approach I will develop is applicable to any landscape on Earth and has the potential to fundamentally transform how we use cosmogenic nuclides to constrain Earth surface dynamics.

1 499 308 €

Start date: 2018-01-01, End date: 2022-12-31

The core-mantle interface is the central cog in the Earth's titanic heat engine. As the boundary between the two major convecting parts of the Earth system (the solid silicate mantle and the liquid iron outer core) the properties of this region have a profound influence on the thermochemical and dynamic evolution of the entire planet, including tectonic phenomena at the surface. Evidence from seismology shows that D" (the lowermost few hundred kilometres of the mantle) is strongly heterogeneous in temperature, chemistry, structure and dynamics; this may dominate the long term evolution of the Earth's magnetic field and the morphology of mantle convection and chemical stratification, for example. Mapping and characterising this heterogeneity requires a detailed knowledge of the properties of the constituents and dynamics of D"; this is achievable by resolving its seismic anisotropy. The observation of anisotropy in the shallow lithosphere was an important piece of evidence for the theory of plate tectonics; now such a breakthrough is possible for the analogous deep boundary. We are at a critical juncture where developments in modelling strain in the mantle, petrofabrics and seismic wave propagation can be combined to produce a new generation of integrated models of D", embodying more complete information than any currently available. I propose a groundbreaking project to build such multidisciplinary models and to produce the first complete image of lowermost mantle anisotropy using the best available global, high resolution seismic dataset. The comparison of the models with these data is the key to making a fundamental improvement in our understanding of the thermodynamics and composition of the core-mantle interface, and illuminating its role in the wider Earth system.

1 639 615 €

Start date: 2009-09-01, End date: 2015-08-31

"Leaf wax n-alkanes are long-chained lipids that are vital components of plant cuticles. What makes leaf wax n-alkanes unique is that their stable hydrogen isotope composition (δD) contains information on precipitation and plant water relations. In addition, leaf wax n-alkanes are abundant in leaves, soils, sediments and even the atmosphere and can persist with their δD values over millions of years. With this exceptional combination of properties, leaf wax n-alkanes and their δD values are now being celebrated as the much-needed ecohydrological proxy that provides information on the hydrological cycle and plant water relations across spatial and temporal scales that range from leaves to biomes and from weeks to millions of years. Despite the enormous potential that leaf wax n-alkanes have as ecohydrological proxy for a range of different research areas, the exact type of hydrological information that is recorded in the δD values of leaf wax n-alkanes remains still unclear. This is because critical mechanisms that determine the δD values of leaf wax n-alkanes are not understood. This proposal will perform the experimental work that is now needed to resolve the key mechanisms that determine the δD values leaf wax n-alkanes. These experiments will set the basis to develop a new numerical model that will allow to ultimately test what the exact hydrological signal is that leaf wax n-alkanes record in their δD values: a mere hydrological signal reflecting the amount or origin of precipitation or, a plant-shaped signal indicating plant water relations such as evapotranspiration. Building on this new model, COSIWAX will set out to test the potential that leaf wax n-alkane δD values hold as new ecohydrological proxy for ecology and ecosystem sciences. If successful, COSIWAX will establish with this research leaf wax n-alkanes δD values as a new and innovative ecohydrological proxy that has extensive possible applications in paleoclimatology, ecology, earth system sciences."

1 496 342 €

Start date: 2011-10-01, End date: 2016-09-30

Seismic tomography images of the Earth's interior are key to the characterisation of earthquakes, natural resource exploration, seismic risk assessment, tsunami warning, and studies of geodynamic processes. While tomography has drawn a fascinating picture of our planet, today's individual researchers can exploit only a fraction of the rapidly expanding seismic data volume. Applications relying on tomographic images lag behind their potential; fundamental questions remain unanswered: Do mantle plumes exist in the deep Earth? What are the properties of active faults, and how do they affect earthquake ground motion? To address these questions and to ensure continued progress of seismic tomography in the 'Big Data' era, I propose new technological developments that enable a paradigm shift in Earth model construction towards a Collaborative Seismic Earth Model (CSEM). Fully accounting for the physics of wave propagation in the complex 3D Earth, the CSEM is envisioned to evolve successively through a systematic group effort of my team, thus going beyond the tomographic models that individual researchers may construct today. I will develop the technological foundation of the CSEM and integrate these developments in studies of large-earthquake rupture processes and the convective pattern of the Earth's mantle in relation to surface geology. The CSEM project will bridge the gap between regional and global tomography, and deliver the first multiscale model of the Earth where crust and mantle are jointly resolved. The CSEM will lead to a dramatic increase in the exploitable seismic data volume, and set new standards for the construction and reproducibility of tomographic Earth models. Beyond this project, the CSEM will be openly accessible through the European Plate Observing System (EPOS). It will then offer Earth scientists the unique opportunity to join forces in the discovery of multiscale Earth structure by systematically building on each other's results.

1 367 500 €

Start date: 2017-01-01, End date: 2021-12-31

DEEP TIME will unearth a record of geological time that is buried thousands of kilometres deep. The seafloor that covers two-thirds of the earth's surface is a tiny fraction of all seafloor created during its history – the rest has sunk back into the viscous mantle. Slabs of subducted seafloor carry a record of surface history: how continents and oceans were configured over time and where their tectonic plate boundaries lay. DEEP TIME will follow former surface oceans as far back in time as the convecting mantle system will permit, by imaging subducted slabs down to the core with cutting-edge seismological techniques. Current tectonic plate reconstructions incorporate little if any of this deep structural information, which probably reaches back 300+ million years; they are based on present-day seafloor, which constrains only the past 100-150 million years. DEEP TIME will match deep slab structure to the geological surface record of subduction – volcanic arcs and other crustal slivers that stayed afloat, survived collisions, and form the world’s largest mountain belts. Integrating these two direct records of subduction, the project will * Add paleo-trenches to existing plate reconstructions and extend them 2-3 times longer into the past. * Produce a 3-D atlas of the mantle that matches subducted seafloor with paleo-oceans inferred by land geology. * Rigorously test the hypothesis of vertical slab sinking, which may yield an absolute mantle reference frame. Tomographic models and geological land records will be synthesized into quantitative and testable paleogeographic reconstructions that complement and extend existing ones, especially in paleo-oceanic areas. This is likely to transform our understanding of the earth’s physical surface environment and biosphere during Mesozoic times, as well as the formation of natural resources. It also will put observational constraints on elusive mantle rheologies. Nearly every subdiscipline of the earth sciences could benefit.

1 438 846 €

Start date: 2015-08-01, End date: 2020-07-31

I propose to develop and apply a novel method for the integrated reconstruction of past changes in carbon cycling and climate change. This method will be based on combining a well-established sensitive paleoclimate proxy with a recent discovery: the stable carbon isotopic composition (δ13C) of marine dinoflagellates (algae) and their organic fossils (dinocysts) reflects seawater carbonate chemistry, particularly pCO2. Biological (culture) experiments will lead to new insights in dinoflagellate carbon acquisition, and enable quantification of the effect of carbon speciation on dinoflagellate δ13C. The rises in CO2 concentrations during the last century, and at the termination of the last glacial period will be used to test and calibrate the new method. The δ13C of fossil dinoflagellate cysts will subsequently be used to reconstruct surface ocean pCO2 and ocean acidification during a past analogue of rapidly rising carbon dioxide concentrations, 55 million years ago. My research will shed new light on processes such as ocean acidification and the marine carbon cycle as a whole. Past analogues of rapid carbon injection can aid in the quantification of climate change and identification of vulnerable biological groups, critical to identify ‘tipping points’ in system Earth. The study of dinoflagellate carbon isotopes comprises the initiation of a new research field and will provide constraints on ocean acidification in the past and its consequences in the future.

1 498 800 €

Start date: 2010-09-01, End date: 2016-08-31

This project aims to directly constrain the melting history and composition of the mantle of the Earth for the first 750 Ma of its history. So far, our limited knowledge hinges on isolated detrital zircons from Archean crustal rocks. They indicate crustal extraction as early as 4.4 Ga with peaks at 4.0 and 4.3 Ga but reveal conflicting models for the composition of the Hadean mantle. Both the timing and extent of these early crust formation events and the composition of the Hadean mantle have crucial implications for our understanding of the Early Earth’s chemical evolution and dynamics as well as crustal growth and thermal cooling models. Sulfides (BMS) and platinum group minerals (PGM) may hold the key to these fundamental issues, as they are robust time capsules able to preserve the melting record of their mantle source over several billion years. I propose to perform state-of-the-art in-situ Pt-Re-Os isotopic measurements on an extensive collection of micrometric BMS and PGM from Archean cratonic peridotites and chromite deposits, and paleoplacers in Archean sedimentary basins. For the first time, < 20 μm minerals will be investigated for Pt- Re-Os. The challenging but high-resolution micro-drilling technique will be developed for in-situ sampling of the PGM and BMS with subsequent high-precision 187Os-186Os isotopic measurements by NTIMS. This highly innovative project will be the first to constrain Hadean Earth history from the perspective of the Earth’s mantle. By opening a new window towards high-precision geochemical exploration for micrometric minerals, this project will have long-term implications for the understanding of the micro to nano-scale heterogeneity of isotopic signatures in the Earth’s mantle and in extra-terrestrial materials.

1 306 743 €

Start date: 2010-10-01, End date: 2016-09-30

The origin of oxygenic photosynthesis is one of the most dramatic evolutionary events that the Earth has ever experienced. At some point in Earth’s first two billion years, primitive bacteria acquired the ability to harness sunlight, oxidize water, release O2, and transform CO2 to organic carbon, and all with unprecedented efficiency. Today, oxygenic photosynthesis accounts for nearly all of the biomass on the planet, and exerts significant control over the carbon cycle. Since 2 billion years ago (Ga), it has regulated the climate of our planet, ensuring liquid water at the surface and enough oxygen to support complex life. The biological and geological consequences of oxygenic photosynthesis are so great that they effectively underpin what we think of as a habitable planet. Understanding the origins of photosynthesis is a paramount scientific challenge at the heart of some of humanity’s greatest questions: how did life evolve? how did Earth become a habitable planet? EARTHBLOOM addresses these questions head-on through the first comprehensive scientific study of Earth’s first blooming photosynthetic ecosystem, preserved as Earth’s oldest carbonate platform. This relatively unknown, >450m thick deposit, comprised largely of 2.9 Ga fossil photosynthetic structures (stromatolites), is one of the most important early Earth fossil localities ever identified, and EARTHBLOOM is carefully positioned for major discovery. EARTHBLOOM will push the frontier of field data collection and sample screening using new XRF methods for carbonate analysis. EARTHBLOOM will also push the analytical frontier in the lab by applying the most sensitive metal stable isotope tracers for O2 at ultra-low levels (Mo, U, and Ce) coupled with novel isotopic “age of oxidation” constraints. By providing new constraints on atmospheric CO2, ocean pH, oxygen production, and nutrient availability, EARTHBLOOM is poised to redefine Earth’s surface environment at the dawn of photosynthetic life.

1 848 685 €

Start date: 2017-02-01, End date: 2022-01-31

Tracking the early traces of life preserved in very old rocks and reconstructing the major steps of its evolution is an exciting and most challenging domain of research. How amazing it is to have a cell that is 1.5 or 3.2 billion years old under a microscope! From these and other disseminated fragments of life preserved along the geological timescale, one can build the puzzle of biosphere evolution and rising biological complexity. The possibility that life may exist beyond Earth on other habitable planets lies yet at another scale of scientific debates and popular dreams. We have the chance now to live at a time when technology enable us to study in the finest details the very old record of life, or to land on planets with microscope and analytical tools, mimicking a geologist exploring extraterrestrial rocky outcrops to find traces of water and perhaps life. There is still a lot to be done however, to solve major questions of life evolution on Earth, and to look for unambiguous life traces, on Earth or beyond. The project ELiTE aims to provide key answers to some of these fundamental questions. Astrobiology studies the origin, evolution and distribution of life in the Universe, starting with life on Earth, the only biological planet known so far. The ambitious objectives of the project ELiTE are the following: 1) The identification of Early traces of life and their preservation conditions, in Precambrian rocks of established age 2) The characterization of their biological affinities, using innovative approaches comprising micro to nanoscale morphological, ultrastructural and chemical analyses of fossil and recent analog material 3) The determination of the timing of major steps in evolution. In particular, the project ELiTE aims to decipher two major and inter-related steps in early life evolution and the rise of biological complexity: the evolution of cyanobacteria, responsible for Earth oxygenation and ancestor of the chloroplast, influencing drastically the evolution of life and the planet Earth, and the evolution of the domain Eucarya since LECA (Last Eucaryotic Universal Ancestor). 4) The determination of causes of observed pattern of evolution in relation with the environmental context (oxygenation, impacts, glaciations, tectonics, nutrient availability in changing ocean chemistry) and biological innovations and interactions (ecosystems evolution). Objective 1 has implications for the search for unambiguous traces of life on Earth and beyond Earth. Objectives 2 to 4 have implications for the understanding of causes and patterns of biological evolution and rise of complexity in Earth life. Providing answers to these most fundamental questions will have major impact on our understanding of early life evolution, with implications for the search for life beyond Earth.

1 470 736 €

Start date: 2013-01-01, End date: 2018-12-31

It is ozone that primarily heats and therefore creates the stratosphere. Human emissions of ozone-depleting substances (ODSs) have however led to dramatic stratospheric ozone losses for decades. This global problem is ongoing and of renewed concern due to recent unexpected changes. It is also likely affecting the nature of the stratosphere itself, with implications for global health and economy. In addition, emissions of greenhouse gases have been proposed to lead to a long-term acceleration of the stratospheric overturning circulation. In summary, significant stratospheric changes are to be expected from both, ozone losses and global warming. Indications for such changes have been reported, but there are substantial uncertainties and limitations connected with these studies. In addition, current technologies to explore stratospheric composition and chemistry are very expensive and often offer only infrequent data. There is clearly a need for new and improved tools to correctly detect and quantify changes from observations. This project will open 3 novel avenues to explore stratospheric chemistry, composition and circulation: 1) A newly developed low-cost technology to retrieve and analyse air from the stratosphere. This will be a new way to derive budgets of all important and newly emerging ODSs directly in the stratosphere; while at the same time providing observations of many strong greenhouse gases. 2) I have found new evidence for substantial past changes in stratospheric chemistry and circulation. An unprecedented investigation of stratospheric air archives spanning 40 years and >50 trace gases will allow new insights into these changes 3) New diagnosis tools and a detailed comparison with state-of-the-art models will identify the implications for future climate. The EXC3ITE project will result in a breakthrough in the understanding of stratospheric changes which are of high importance for society through their impact on climate prediction and ozone recovery.

1 496 439 €

Start date: 2016-04-01, End date: 2021-03-31

Volcanic eruptions occur with a frequency that is inversely proportional to their magnitude. Datasets of natural volcanic events, currently used to determine the recurrence rate of volcanic eruptions are intrinsically biased. Combining physical modelling of processes with detailed statistical analysis has been demonstrated essential for assessing reliably the recurrence rate of natural hazards, such as floods and earthquakes. This would be the first attempt to apply a similar, integrated approach to explosive volcanic eruptions. The high-gain final target of FEVER is to produce a physically based statistical model able to ForEcast the recurrence rate of Volcanic Eruptions both at regional and global scale. This is the first project of this kind and consequently involves a significant risk. Because 500 million people live in proximity of volcanoes and eruptions have a significant social and economical impact, forecasting the recurrence rate of volcanic eruption remains a great challenge in Science. This project builds on two main directions of my research: a) Thermo-mechanical and statistical modelling targeting the identification of the main physical factors controlling the recurrence rate of volcanic eruptions. We showed that the flux of magma from depth directly controls the magnitude of the largest possible eruptions. Thus, b) we developed a novel method to determine such magma fluxes. These two lines of research combine perfectly in FEVER and will be integrated to answer questions such as: What is the probability of an eruption similar to the Tambora 1815 to occur in the next 100 years on Earth or in Europe? What is the largest physically possible eruption that can occur in Europe? The high-gain target of FEVER is to mitigate the impact of volcanic eruptions on our society, by producing research of interest for governmental agencies dealing with location of strategic infrastructures, and for businesses such as aviation.

1 458 192 €

Start date: 2016-04-01, End date: 2021-03-31

Anomalies in surface temperatures, winds, and precipitation can significantly alter energy supply and demand, cause flooding, and cripple transportation networks. Better management of these impacts can be achieved by extending the duration of reliable predictions of the atmospheric circulation. Polar stratospheric variability can impact surface weather for well over a month, and this proposed research presents a novel approach towards understanding the fundamentals of how this coupling occurs. Specifically, we are interested in: 1) how predictable are anomalies in the stratospheric circulation? 2) why do only some stratospheric events modify surface weather? and 3) what is the mechanism whereby stratospheric anomalies reach the surface? While this last question may appear academic, several studies indicate that stratosphere-troposphere coupling drives the midlatitude tropospheric response to climate change; therefore, a clearer understanding of the mechanisms will aid in the interpretation of the upcoming changes in the surface climate. I propose a multi-pronged effort aimed at addressing these questions and improving monthly forecasting. First, carefully designed modelling experiments using a novel modelling framework will be used to clarify how, and under what conditions, stratospheric variability couples to tropospheric variability. Second, novel linkages between variability external to the stratospheric polar vortex and the stratospheric polar vortex will be pursued, thus improving our ability to forecast polar vortex variability itself. To these ends, my group will develop 1) an analytic model for Rossby wave propagation on the sphere, and 2) a simplified general circulation model, which captures the essential processes underlying stratosphere-troposphere coupling. By combining output from the new models, observational data, and output from comprehensive climate models, the connections between the stratosphere and surface climate will be elucidated.

1 808 000 €

Start date: 2016-05-01, End date: 2021-04-30

Atmospheric aerosol particles impact Earth’s climate, by directly scattering sunlight and indirectly by affecting cloud properties. The largest uncertainties in climate change projections are associated with the atmospheric aerosol system that has been altered by anthropogenic activities. A major source of that uncertainty involves the formation of secondary particles and cloud condensation nuclei from natural and anthropogenic emissions of volatile compounds. This research challenge persists despite significant efforts within recent decades. I will build a research group that aims to resolve the atmospheric oxidation processes that convert volatile trace gases to particle precursor vapours, clusters and new aerosol particles. We will create novel measurement techniques and utilize the tremendous potential of mass spectrometry for detection of i) particle precursor vapours ii) oxidants, both conventional but also recently discovered stabilized Criegee intermediates, and, most importantly, iii) newly formed clusters. These methods and instrumentation will be applied for resolving the initial steps of new particle formation on molecular level from oxidation to clusters and stable aerosol particles. To reach these goals, targeted laboratory and field experiments together with long term field measurements will be performed employing the state-of-the-art instrumentation developed. Principal outcomes of this project include i) new experimental methods and techniques vital for atmospheric research and a deep understanding of ii) oxidation pathways producing aerosol particle precursors, iii) the initial molecular steps of new particle formation and iv) mechanisms of growth of freshly formed clusters toward larger sizes, particularly in the crucial size range of a few nanometers. The conceptual understanding obtained during this project will open multiple new research horizons from oxidation chemistry to Earth system modeling.

1 953 790 €

Start date: 2017-02-01, End date: 2022-01-31

For decades the Holocene has been considered a flat and “boring” epoch from the standpoint of paleomagnetism, mainly due to insufficient resolution of the available paleomagnetic data. However, recent archaeomagnetic data have revealed that the Holocene geomagnetic field is anything but stable – presenting puzzling intervals of extreme decadal-scale fluctuations and unexpected departures from a simple dipolar field structure. This new information introduced an entirely new paradigm to the study of the geomagnetic field and to a wide range of research areas relying on paleomagnetic data, such as geochronology, climate research, and geodynamo exploration. This proposal aims at breaking the resolution limits in paleomagnetism, and providing a continuous time series of the geomagnetic field vector throughout the Holocene at decadal resolution and unprecedented accuracy. To this end I will use an innovative assemblage of data sources, jointly unique to the Levant, including rare archaeological finds, annual laminated stalagmites, varved sediments, and arid playa deposits. Together, these sources can provide unprecedented yearly resolution, whereby the “absolute” archaeomagnetic data can calibrate “relative” terrestrial data. The geomagnetic data will define an innovative absolute geomagnetic chronology that will be used to synchronize cosmogenic 10Be data and an extensive body of paleo-climatic indicators. With these in hand, I will address four ground-breaking problems: I) Chronology: Developing dating technique for resolving critical controversies in Levantine archaeology and Quaternary geology. II) Geophysics: Exploring fine-scale geodynamo features in Earth’s core from new generations of global geomagnetic models. III) Cosmogenics: Correlating fast geomagnetic variations with cosmogenic isotope production rate. IV) Climate: Testing one of the most challenging controversial questions in geomagnetism: “Does the Earth's magnetic field play a role in climate changes?”

1 786 381 €

Start date: 2018-11-01, End date: 2023-10-31

The Earth formed ~ 4.5 billion years ago, from accreting particles of dust and primitive meteorites. It is the only habitable planet in our solar system and has a unique history of extended accretion and core formation coupled with active plate tectonics. Accretion and core formation would have defined the initial elemental composition of the Earth’s interior whereas plate tectonic processes controlled chemical exchange between the Earth’s surface and interior and the distribution of elements between major geochemical reservoirs. The overarching goal of this proposal is to define the roles of these processes in the chemical evolution of the Earth and hence in the creation of a habitable planet. In order to achieve this goal I propose to investigate the partitioning of new stable isotope systems such as Ge and Se in high-pressure experiments that simulate core formation. This novel, multidisciplinary approach will provide some of the first direct constraints on the extent to which these volatile elements were partitioned into the core. We will use this information to address the fundamental issue of whether the Earth acquired its volatile elements inventory early, during core formation, or subsequently, as part of a “late veneer”. The second major theme of the proposed research uses Fe, Zn, Mo and Se stable isotopes to trace the cycling of Fe and S during subduction, the tectonic process where one plate sinks beneath another and is recycled into the Earth’s deep interior. The goal of this project is to understand the impact of subduction on the chemical and redox evolution of the Earth’s interior and the relationship between tectonic recycling and the rise of oxygen in the Earth’s atmosphere ~ 2.5 billion years ago. This theme will focus on samples of relict subducted plate material and of the Earth’s interior, obtained as fragments sampled by lavas or as ancient minerals trapped within diamonds.

1 999 975 €

Start date: 2013-01-01, End date: 2018-12-31

In spite of their small areal extent, inland waters play a vital role in the carbon cycle of the continents, as they emit significant amounts of the greenhouse gases (GHG) carbon dioxide (CO2) and methane (CH4) to the atmosphere, and simultaneously bury more organic carbon (OC) in their sediments than the entire ocean. Particularly in tropical hydropower reservoirs, GHG emissions can be large, mainly owing to high CH4 emission. Moreover, the number of tropical hydropower reservoirs will continue to increase dramatically, due to an urgent need for economic growth and a vast unused hydropower potential in many tropical countries. However, the current understanding of the magnitude of GHG emission, and of the processes regulating it, is insufficient. Here I propose a research program on tropical reservoirs in Brazil that takes advantage of recent developments in both concepts and methodologies to provide unique evaluations of GHG emission and OC burial in tropical reservoirs. In particular, I will test the following hypotheses: 1) Current estimates of reservoir CH4 emission are at least one order of magnitude too low, since they have completely missed the recently discovered existence of gas bubble emission hot spots; 2) The burial of land-derived OC in reservoir sediments offsets a significant share of the GHG emissions; and 3) The sustained, long-term CH4 emission from reservoirs is to a large degree fuelled by primary production of new OC within the reservoir, and may therefore be reduced by management of nutrient supply. The new understanding and the cross-disciplinary methodological approach will constitute a major advance to aquatic science in general, and have strong impacts on the understanding of other aquatic systems at other latitudes as well. In addition, the results will be merged into an existing reservoir GHG risk assessment tool to improve planning, design, management and judgment of hydropower reservoirs.

1 798 227 €

Start date: 2013-09-01, End date: 2019-08-31

The formation of ice particles in the Earth s atmosphere strongly affects the properties of clouds and their impact on climate. However, our basic understanding of ice nucleation and crystallisation is still in its infancy. Despite the importance of ice formation in determining the properties of clouds, the Intergovernmental Panel on Climate Change (IPCC) was unable to assess the impact of atmospheric ice formation in their most recent report, because our basic knowledge is insufficient. In this proposal plans are described to establish a laboratory dedicated to improving our fundamental understanding of ice nucleation and crystallisation. It is proposed to develop a series of laboratory experiments designed to quantify atmospherically relevant processes at a fundamental level. In work package 1 the role of glassy solids and ultra-viscous liquids in cloud formation will be investigated; in work package 2 the rate at which various mineral dusts nucleate ice in the immersion mode will be quantified; the phase of ice that deposits onto frozen solution droplets or heterogeneous ice nuclei will be determined in work package 3; and in work package 4 the laboratory data from work packages 1-3 will be used to constrain ice nucleation in numerical clouds models in order to assess radiative forcings. The instrumentation and modelling experience gained in this five year project will provide a lasting legacy and open doors to new research areas in the future. As an international hub of atmospheric and climate science, the University of Leeds is a unique and ideal institute in which to bridge the gap between fundamental studies and the cloud/climate modelling community.

1 664 190 €

Start date: 2009-11-01, End date: 2015-04-30

Diamonds and their inclusions are the deepest materials originating from the Earth’s interior reaching the surface of our planet. Their study plays a key role in understanding and interpreting the geodynamics, geophysics, petrology, geochemistry and mineralogy of the Earth’s mantle and those processes which governed trough the time the evolution of the Earth. The most abundant mineral inclusions in diamonds are olivines, orthopyroxenes, clinopyroxenes, garnets, spinels, and sulfides. All of these mineral phases have been identified by X-ray diffraction or electron microprobe analysis since the 1950’s almost always after their extraction from the diamonds. However, a non-destructive in-situ investigation of an inclusion in diamond is useful and important because: (a) some mineral inclusions under pressure could have a different crystal structure, and thus different petrologic significance compared to that at ambient pressure; (b) the internal pressure on the inclusion can provide information about the formation pressure of the diamond; (c) the morphology and growth relationships of the inclusion with the host diamond can provide indications about its protogenetic vs. syngenetic and/or epigenetic nature. In this project a new experimental approach, based on X-ray diffraction technique, will be used in order to determine, for the first time, the crystal structure of the inclusions still trapped in their host diamonds allowing to obtain chemical information capable to provide the inclusion remnant pressure and, from this, the pressure of formation of the diamond-inclusion pair. At the same time, our approach will allow to obtain any possible epitaxial relationship between diamond and its inclusions in order to provide strong constraints about the syngenetic or protogenetic nature of minerals included in diamond solving a 50 years old debate. Several geochemical and geodynamical models are based on the assumption of syngenesis but this has yet to be demonstrated.

1 423 464 €

Start date: 2013-01-01, End date: 2018-12-31

Ocean waves are the essential gearbox between the atmosphere and ocean and also consitute a very peculiar prism through which most satellite sensors see the ocean. IOWAGA proposes a systemic investigation of ocean waves for improving the ocean surface wave compartment of Earth system models. The project will integrate in a coherent manner exisiting and new wave-related observations from multiple sources, including remote sensing, seismic records, and in situ measurements, from climate and global scales to coastal scales and single events. Going through several cycles from observations to numerical modelling via theory and parameterizations, a consistent numerical model will be refined. This modelling tool will be exploited for multi-scale hindcasts and analyses of wave related parameters, with applications to geophysics at large, in particular remote sensing, air-sea interactions, coastal hydrodynamics and seismic studies, and practical applications with associated societal benefits (ocean energy planning and management, marine safety, pollution mitigation &amp;). The consistency between the various wave observations and the numerical modelling efforts is essential to constrain and advance better understandings of wave-related processes, to improve the accuracy of the wave-related parameters to be estimated, but also to help instrumental designs and future ocean surface remote sensing space observations. IOWAGA will be a focal point for ocean wave research, with close connection to other efforts in Europe that are focused on other compartments of the Earth system models.

1 099 040 €

Start date: 2010-01-01, End date: 2013-12-31

The vast boreal forests play a critical role in the carbon cycle. As a consequence of increasing temperature and atmospheric CO2, forest growth and subsequently carbon sequestration may be strongly affected. It is thus crucial to understand and predict the consequences of climate change on these ecosystems. Stable isotope analysis of tree rings represents a versatile archive where the effects of environmental changes are recorded. The main goal of the project is to obtain a better understanding of δ13C and δ18O in tree rings that can be used to infer the response of forests to climate change. The goal is achieved by a detailed analysis of the incorporation and fractionation of isotopes in trees using four novel methods: (1) We will measure compound-specific δ13C and δ18O of leaf sugars and (2) combine these with intra-annual δ13C and δ18O analysis of tree rings. The approaches are enabled by methodological developments made by me and ISOBOREAL collaborators (Rinne et al. 2012, Lehmann et al. 2016, Loader et al. in prep.). Our aim is to determine δ13C and δ18O dynamics of individual sugars in response to climatic and physiological factors, and to define how these signals are altered before being stored in tree rings. The improved mechanistic understanding will be applied on tree ring isotope chronologies to infer the response of the studied forests to climate change. (3) The fact that δ18O in tree rings is a mixture of source and leaf water signals is a major problem for its application on climate studies. To solve this we aim to separate the two signals using position-specific δ18O analysis on tree ring cellulose for the first time, which we will achieve by developing novel methods. (4) We will for the first time link the climate signal both in leaf sugars and annual rings with measured ecosystem exchange of greenhouse gases CO2 and H2O using eddy-covariance techniques.

1 814 610 €

Start date: 2018-01-01, End date: 2022-12-31

There are essentially two approaches to climate modelling. Over the past decades, efforts to understand climate dynamics have been dominated by computationally-intensive modelling aiming to include all possible processes, essentially by integrating the equations for the relevant physics. This is the bottom-up approach. However, even the largest models include many approximations and the cumulative effect of these approximations make it impossible to predict the evolution of climate over several tens of thousands of years. For this reason a more phenomenological approach is also useful. It consists in identifying coherent spatio-temporal structures in the climate time-series in order to understand how they interact. Theoretically, the two approaches focus on different levels of information and they should be complementary. In practice, they are generally perceived to be in philosophical opposition and there is no unifying methodological framework. Our ambition is to provide this methodological framework with a focus on climate dynamics at the scale of the Pleistocene (last 2 million years). We pursue a triple objective (1) the framework must be rigorous but flexible enough to test competing theories of ice ages (2) it must avoid circular reasonings associated with ``tuning&apos;&apos; (3) it must provide a credible basis to unify our knowledge of climate dynamics and provide a state-of-the-art ``prediction horizon&apos;&apos;. To this end we propose a methodology spanning different but complementary disciplines: physical climatology, empirical palaeoclimatology, dynamical system analysis and applied Bayesian statistics. It is intended to have a wide applicability in climate science where there is an interest in using reduced-order representations of the climate system.

1 047 600 €

Start date: 2009-09-01, End date: 2014-08-31

The vegetation of Central Europe has been directly influenced by humans for at least eight millennia; the original forests have been gradually transformed into today’s agricultural landscape. However, there is more to this landscape change than the simple disappearance of woodland. Forests have been brought under various management regimes, which profoundly altered their structure and species composition. The details of this process are little known for two main reasons. The greatest obstacle is the lack of cooperation among the disciplines dealing with the subject. The second major problem is the differences in spatio-temporal scaling and resolution used by the individual disciplines. Existing studies either concern smaller territories, or cover large areas (continental to global) with the help of modelling-based generalizations rather than primary data from the past. Using an extensive range of primary sources from history, historical geography, palaeoecology, archaeology and ecology, this interdisciplinary project aims to reconstruct the long-term (Neolithic to present) patterns of woodland cover, structure, composition and management in a larger study region (Moravia, the Czech Republic, ca. 27,000 km2) with the highest spatio-temporal resolution possible. Causes for the patterns observed will be analyzed in terms of qualitative and quantitative factors, both natural and human-driven, and the patterns in the tree layer will be related to those in the herb layer, which constitutes the most important part of plant biodiversity in Europe. This project will introduce woodland management as an equal driving force into long-term woodland dynamics, thus fostering a paradigm shift in ecology towards construing humans as an internal, constitutive element of ecosystems. By integrating sources and methods from the natural sciences and the humanities, the project will provide a more reliable basis for woodland management and conservation in Central Europe.

1 413 474 €

Start date: 2012-01-01, End date: 2016-12-31

Magmas, i.e. silicate melts, have played a key role in the chemical and thermal evolution of the Earth and other planets. The Earth's interior today is the outcome of mass transfers which occurred primarily in its early history and still occur now via magmatic events. Present day magmatic and volcanic processes are controlled by the properties of molten silicate at high pressure, considering that magmas are produced at depth. However, the physical properties of molten silicates remain largely unexplored across the broad range of relevant P-T conditions, and their chemical properties are very often assumed constant and equal to those known at ambient conditions. This blurs out our understanding of planetary differentiation and current magmatic processes. The aim of this proposal is to place fundamental constraints on magma generation and transport in planetary interiors by measuring the properties of silicate melts in their natural high pressures (P) and high temperatures (T) conditions using a broad range of in situ key diagnostic probes (X-ray and neutron scattering techniques, X-ray absorption, radiography, Raman spectroscopy). The completion of this proposal will result in a comprehensive key database in the composition-P-T space that will form the foundation for modelling planetary formation and differentiation, and will provide answers to the very fundamental questions on magma formation, ascent or trapping at depth in the current and past Earth. This experimental program is allowed by the recent advancements in in situ high P-T techniques, and comes in conjunction with a large and fruitful theoretical effort; time has thus come to understand Earth's melts and their keys to Earth's evolution.

1 332 160 €

Start date: 2011-06-01, End date: 2017-05-31

Volcanic eruptions are driven by the exsolution and escape of dissolved volatiles. Fast and efficient escape of volatiles leads to a lower potential for an explosive eruption: defusing it. Yet, despite recognition of the importance of volatile escape, the mechanisms and kinetics of degassing remain unclear. This study aims to use a pioneering approach to reconstruct the escape of volcanic gases. Exsolved gases are ephemeral and do not survive eruption. However textural evidence such as vesicles, fractures and veins in erupted magma lingers. Moreover, new data shows that chemical signals of degassing endure, not only in minerals, but also in quenched melt. Volcanic gases are enriched in metals such as Hg, Tl, and Cu resulting in ore deposits and contributing to global metal emissions. Such enrichment is based on the preference of these metals for a gas phase. This project will establish how metals partition between volcanic gas and melt (basalt and rhyolite), how quickly such equilibrium partitioning is reached, and what can be learned regarding magma degassing from gas emissions and melt compositions as measured at volcanoes. The first part of the project focuses on obtaining gas-melt partition coefficients and diffusivities of metals. The second part of the project involves comparison to natural samples. Metal concentration variations will be mapped within an exposed magmatic conduit and in recent explosively erupted volcanic rocks. The third part of the project aims to model the escape of volcanic gases using reactive flow modeling. The combined results of this project will not only show how and how fast volcanic gases escape, but also form the basis of a new approach to quantifying historic (from glass shards) and future (from gas emissions) magmatic metal release to potential ore forming systems as well as to the atmosphere. Moreover, linking gas chemistry to dynamic degassing processes in a quantitative model will aid prediction of eruption style and timing.

1 604 211 €

Start date: 2013-05-01, End date: 2018-04-30

"Today, subduction dominates the Earth’s appearance: it drives plate tectonics, and plays a dominant role in continental crust formation. If and how subduction operated 2.5-4 billion years ago, in the Archaean, is debated, primarily on the basis of the sparse Archaean geological record. It seems likely that some form of subduction occurred at least by the late Archaean, but may well have looked different from today’s. A proper understanding of this Archaean ‘subduction’ is essential, since so many processes are likely to depend on it. Observations of the geological (mostly isotope-geochemical) record have provided an invaluable window to peer into the Archaean world. But inferred Archaean geodynamics from these observations are non-unique. Various models fit the same data within uncertainty, and often lack a firm physical basis. To overcome these shortcomings, I propose a novel, forward approach of predicting synthetic geochemical fingerprints from numerical, geodynamically consistent physical models, and comparing those with geochemical observations. This will be used to constrain and better understand the two most pressing questions in Earth sciences: How did plate tectonics evolve, and how did continents form? In particular, this project aims to: 1) assess quantitatively the geodynamical and geochemical viability of intermittent plate tectonics; 2) test the various proposed models for the formation of Archaean continental crust; Comparison of calculated synthetic geochemistry (e.g. Re-Os data, rare-Earth element data) from geodynamical models with available datasets will provide powerful diagnostics to distinguish viable models. In addition, this work will also directly relevant for the evolution of the Earth’s surface, and to the differences with the other terrestrial planets. Finally, there are potential economic benefits, since the world’s largest mineral deposits (e.g. gold) occur in Archaean terrains and have been associated to subduction."

1 490 738 €

Start date: 2012-01-01, End date: 2016-12-31

Atmospheric concentration of the strong greenhouse gas methane (CH4) is rising with an increased annual growth rate. Biosphere has an important role in the global CH4 budget, but high uncertainties remain in the strength of its different sink and source components. Among the natural sources, the contribution of vegetation to the global CH4 budget is the least well understood. Role of trees to the CH4 budget of forest ecosystems has long been overlooked due to the perception that trees do not play a role in the CH4 dynamics. Methanogenic Archaea were long considered as the sole CH4 producing organisms, while new findings of aerobic CH4 production in terrestrial vegetation and in fungi show our incomplete understanding of the CH4 cycling processes. Enclosure measurements from trees reveal that trees can emit CH4 and may substantially contribute to the net CH4 exchange of forests. The main aim of MEMETRE project is to raise the process-based understanding of CH4 exchange in boreal and temperate forests to the level where we can construct a sound process model for the soil-tree-atmosphere CH4 exchange. We will achieve this by novel laboratory and field experiment focusing on newly identified processes, quantifying CH4 fluxes, seasonal and daily variability and drivers of CH4 at leaf-level, tree and ecosystem level. We use novel CH4 flux measurement techniques to identify the roles of fungal and methanogenic production and transport mechanisms to the CH4 emission from trees, and we synthesize the experimental work to build a process model including CH4 exchange processes within trees and the soil, transport of CH4 between the soil and the trees, and transport of CH4 within the trees. The project will revolutionize our understanding of CH4 flux dynamics in forest ecosystems. It will significantly narrow down the high uncertainties in boreal and temperate forests for their contribution to the global CH4 budget.

1 908 652 €

Start date: 2018-02-01, End date: 2023-01-31

Observation and Modelling of Radiocarbon in Atmospheric Methane for Methane Source Identification Greenhouse gas emissions are the primary cause of global climate change, and methane (CH4) is the second most important contributor after carbon dioxide (CO2). Major sources of methane are both natural (wetlands) and anthropogenic (agriculture, landfills and fossil fuels). Current efforts to assess the anthropogenic CH4 influence on climate change and the effectiveness of mitigation policies for CH4 are limited by large uncertainties in estimates of total methane emissions and their attribution to various sources by accounting-based techniques. This project will pioneer and apply innovative techniques for atmospheric observation and modelling of radiocarbon in CH4 that will enable unique quantification of fossil fuel vs. biogenic CH4 sources at regional and global scales, thereby improving the estimation and attribution of CH4 emissions of different types. The proposed work will significantly advance the frontier of current research on atmospheric methane and the characterization of anthropogenic sources on policy-relevant scales, and it has the potential to influence climate policy and industrial practices over the next 10-20 years.

1 500 000 €

Start date: 2016-06-01, End date: 2021-05-31

"Iron minerals are ubiquitously present in the environment. Their formation is linked to the global C and N cycle and they control the fate of nutrients, metals, and greenhouse gases. My recent work, published in international journals including Nature Geoscience, showed that Fe(II)-oxidizing bacteria form Fe(III) minerals and suggested that such bacteria were involved in the deposition of Precambrian Banded Iron Formations, the world’s largest iron mineral deposits. Three neutrophilic microbial groups contribute to Fe(III) mineral formation: microaerophiles, phototrophs and nitrate-reducing Fe(II)-oxidizers. However, as previous studies have always solely focused on only one particular Fe(II) metabolism, the contribution of the different Fe(II)-oxidizing groups to overall Fe(III) mineral formation in nature and the competition among them for Fe(II) within Fe(II)-oxidizing communities is still unknown. I propose to use an innovative and holistic approach to study for the first time the abundance, activity and spatial distribution of all three Fe(II)-oxidizing bacterial groups in one habitat in different environments. Quantification of microbial activity and both nutrient and metal sorption under varying geochemical conditions will allow us to study competition among the Fe(II)-oxidizing groups and evaluate the ecological importance of microbial Fe(III) mineral formation in both early Earth and modern environments. This requires an interdisciplinary frontier research effort at the scale of an ERC grant integrating microbiology, biogeochemistry and mineralogy. Central to this is the cultivation and characterization of Fe(II)-oxidizing bacteria and their mineral products, a research area spearheaded by my group. This frontier research will define the role of microbial iron mineral formation in modern and ancient Earth systems, open doors to new biotechnology applications and advance the search for life on the Fe-rich planet Mars."

1 499 000 €

Start date: 2013-01-01, End date: 2017-12-31

Despite large progress in modelling of atmospheric processes and computing capabilities and concentrated efforts to increase complexity of the atmospheric models, the assessment of accuracy of natural atmospheric climate variability, its predictability and interaction with anthropogenic influences is far from well understood. This project aims to advance scientific understanding of dynamical properties of the atmosphere and climate systems over many spatial and temporal scales. It is proposed to study atmospheric balance and predictability in terms of the energy percentage which is associated with various types of motions, balanced or Rossby-type of motions and unbalanced or inertio-gravity motions. This representation of the atmosphere is called the normal-mode function representation and it is a heart of methodology proposed in this project. The projects is built on theoretical foundation set in 1970s at the National Center for Atmospheric Research in USA and with the support of original developers it will apply normal-mode function representation tool to issues for which it could not have been reliably applied earlier. The project relies on accomplishments of the proposal’s PI in weather and data assimilation modeling which this project will extend to new research areas. The project will quantify balance in analysis datasets and ensemble forecasting systems and use the results as a starting point for climate model assessment for their ability to represent the present climate and possible changes of balance in model simulations of future climate scenarios. Results will allow dynamical classification of climate models based on their balance properties. Predictability issues will be studied by comparing temporal variability of balance in the forecasts in terms of various spatial scales. An important project outcome will be a free-access, user-friendly tool for carrying out a physically-based analysis of weather and climate model outputs.

495 482 €

Start date: 2011-12-01, End date: 2016-11-30

MUSICA aims to understand the atmospheric water cycle and its interplay with climate change applying unique long-term high quality and global remote sensing observations of tropospheric stable water vapour isotopologues. It is well established that water in its various forms plays a dominant role in nearly all aspects of the Earth s climate system. Understanding the full cycle of evaporation, cloud formation, and precipitation is of highest scientific priority for predicting climate change. The ratio of the isotopologues (e.g. HD16O/H216O) is affected by evaporation, condensation, and cloud processes, and offers a unique opportunity for investigating how water moves through the troposphere. Incorporating isotopologues in atmospheric general circulation models (AGCM) and comparing the isotopologue simulations to observations has the potential to test the models ability of reproducing the global atmospheric water cycle and its interplay with climate change. So far this research field has not been explored due to the lack of consistent, long-term, high-quality, and area-wide observational data. MUSICA will for the first time combine long-term ground- and space-based remote sensing measurements in a consistent manner, and will generate novel tropospheric HD16O/H216O data, taking benefit from both the high and well documented quality of the ground-based observations and the wide geographical coverage of the space-based observations. This unique observational data set will allow a new dimension of water cycle research. MUSICA will collaborate with the Stable Water Isotope Intercomparison Group (SWING) in order to improve current state-of-the-art water isotope AGCMs. MUSICA will investigate and improve the understanding of tropospheric water vapour sources and transport pathways, and empirically assess how well climate feedbacks are captured by current climate models and thereby it will constrain a major uncertainty of climate projections.

1 500 000 €

Start date: 2011-02-01, End date: 2016-07-31

Comprehensive seismic programs undertaken in the past few years, combined with emerging new numerical technologies now provide the potential, for the first time, to explore in detail the Earth’s interior. However, such an integrated approach is currently not contemplated, which produces physical inconsistencies among the different studies that strongly bias our understanding of the Earth’s internal structure and dynamics. Of particular concern are nowadays apparent thermo-petrological anomalies in tomographic images that are generated by the unaccounted-for anisotropic structure of the mantle and that are commonly confused with real thermo-petrological features. Given the diffuse mantle seismic anisotropy, apparent thermo-petrological anomalies contaminate most tomographic models against which tectono-magmatic models are validated, representing a critical issue for the present-day window. Here we aim to develop a new methodology that combines state-of-the-art geodynamic modelling and seismological methods. The new methodology will allow building robust anisotropic tomographic models that will exploit anisotropy predictions from petrological-thermomechanical modelling to decompose velocity anomalies into isotropic (true thermo-petrological) and anisotropic (mechanically-induced) components. As a major outcome, we expect to provide a new, geodynamically and seismologically constrained perspective of the current deep structure and tectono-magmatic evolution of different tectonic settings. This new methodology will be applied to the Mediterranean and the Cascadia subduction zone where, despite the abundant seismological observations, large uncertainties about the subsurface structure and tectono-magmatic evolution persist. Furthermore, we plan to develop a new inversion technique for seismic anisotropy, and release an open source, sophisticated code for mantle fabric modelling, which will allow coupling geodynamic and seismological modelling in other tectonic settings.

1 466 030 €

Start date: 2018-03-01, End date: 2023-02-28

Antarctic ice sheets are destabilizing because Southern Ocean warming causes basal melt. It is unknown how these processes will develop during future climate warming, which creates an inability to project ice sheet melt and thus global sea level rise scenarios into the future. Studying past geologic episodes, during which atmospheric carbon dioxide levels (CO2) were similar to those projected for this century and beyond, is the only way to achieve mechanistic understanding of long-term ice sheet- and ocean dynamics in warm climates. Past ocean-induced ice sheet melt is not resolved because of a paucity of quantitative proxies for past ice-proximal oceanographic conditions: sea ice, upwelling of warm water and latitudinal temperature gradients. This hampers accurate projections of future ice sheet melt and sea level rise. OceaNice will provide an integral understanding of the role of oceanography in ice sheet behavior during past warm climates, as analogy to the future. I will quantify past sea ice, upwelling of warm water and latitudinal temperature gradients in three steps: 1. Calibrate newly developed dinoflagellate cyst and biomarker proxies for past oceanographic conditions to glacial-interglacial oceanographic changes. This yields quantitative tools for application further back in time. 2. Apply these to two past warm climate states, during which CO2 was comparable to that of the future under strong and moderate fossil fuel emission mitigation scenarios. 3. Interpolate between new reconstructions using high-resolution ocean circulation modelling for circum-Antarctic quantification of past oceanographic conditions, which will be implemented into new ice sheet model simulations. The groundbreaking new insights will deliver mechanistic understanding and quantitative estimates of ice-proximal oceanographic changes and consequent ice sheet melt during past warm climates, which will finally allow accurate future sea level rise projections given anticipated warming.

1 500 000 €

Start date: 2019-02-01, End date: 2024-01-31

The isotopic composition of O in seawater is a fundamental property of Earth's oceans, key to paleoclimate reconstructions and to our understanding of the origin of water on Earth, the water-rock reactions that govern seawater chemistry, and the conditions under which life emerged. Despite more than five decades of research, the geologic history of seawater 18O/16O remains a topic of intense debate. Without exception, well-preserved 18O/16O records from marine precipitates reflect both the minerals' formation temperature, and the isotopic composition of seawater. This duality has prevented unique interpretation of a long-term secular trend, in which 18O/16O in sedimentary rocks (e.g., carbonates, cherts) has increased by ~15 ‰ since the Archean. Here I outline an inter-disciplinary research program to address this fundamental problem, which integrates new geochemical observations, laboratory experiments, and numerical models. We will generate geologic records of 18O/16O in two previously untapped repositories: iron oxides and iron-bearing authigenic clays. Several characteristics of both, and preliminary results, suggest that these repositories hold the potential to settle the long-standing debate about seawater 18O/16O. We will determine the temperature dependence of mineral-water O isotope fractionation in laboratory experiments and observations of natural systems. We will experimentally test the resistance of these minerals to O isotope exchange under geologically-relevant conditions, with the aim of evaluating the potential for late-stage isotopic resetting. Finally, we will develop models of the marine O isotope cycle, which account for the processes that govern seawater 18O/16O over long timescales, and which will be used to provide a quantitative understanding of the new records. With these new insights, we will explore implications for the geologic history of seawater chemistry, atmospheric composition, climate and biology.

1 490 596 €

Start date: 2018-09-01, End date: 2023-08-31

Atmospheric oxygen is fundamental to life as we know it, but its concentration has changed dramatically over Earth’s 4.5 billion year history. An amazing qualitative story has emerged, in which Earth’s atmosphere was devoid of free oxygen for the first 2 billion years of planetary history, with two significant increases in concentration at ~2.4 and ~0.55 billion years ago. Both oxygenation events were accompanied by extreme climatic effects – the “snowball earth” episodes – and paved the way for massive reorganization of biogeochemical cycles such as the Cambrian radiation of macroscopic life. Despite these profound influences on the Earth system, we currently lack fundamental quantitative constraints on Earth’s atmospheric evolution. I am poised to add substantial quantitative rigor to Earth’s atmospheric history, by constraining the concentrations of important gases (e.g., O2, O3, CO2, CH4, organic haze) in ancient atmospheres to unprecedented accuracy. I will accomplish this via an innovative interdisciplinary program focused on the unusual mass-independent isotope fractionations observed in sedimentary rocks containing sulfur and oxygen. These signals are direct remnants of ancient atmospheric chemistry, and contain far more information than can currently be interpreted. This project combines novel experimental and methodological approaches with state-of-the-art numerical modelling to significantly advance our ability to decipher the isotope records. A unique “early Earth” UV lamp coupled to a custom-built photocell will enable direct production of isotope signals under Earth-like conditions, with time-dependent sampling. Groundbreaking analytical methodologies will vastly increase the global geochemical database. The experimental results and data will provide ground-truth for next-generation atmospheric models that will constrain atmospheric composition and its feedbacks with the Earth-biosphere-climate system during key points in our planetary history.

1 767 455 €

Start date: 2016-06-01, End date: 2021-05-31

The Earth’s oceans absorb about 11 billion tonnes of carbon dioxide (CO2) each year, about 25% of all anthropogenic CO2. The oceans are huge reservoirs of CO2, and a better understanding on how the oceans absorb CO2 is critical for predicting climate change. The sea-surface microlayer (SML), the aqueous boundary layer between the ocean and atmosphere, plays an important role in the exchange of gases between the ocean and atmosphere. The effects of the SML on air-sea gas exchange have been widely ignored by past and current research efforts due to uncertainties to what extent the SML covers the oceans. However, we recently reported the ubiquitous coverage of the oceans with SML, which pushes the SML into a new and wider context that is relevant to many ocean and climate sciences. I propose experiments at multiple scales, i.e. in laboratory tanks, wind wave tunnel, mesocosm and during a long-term field study. I propose a systematic field study measuring air-sea CO2 fluxes and mapping chemical, biological and physical properties of the SML. With the experiments on smaller scales, such measurements will allow for the first time (i) to define new parameters controlling gas fluxes, (ii) to quantify short-time and seasonal variability, (iii) to define global proxies for the effects of the SML, and (iv) to develop and apply a new parameterization for the correction of global CO2 flux data. For the first time, biogeochemical processes relevant to carbon cycling are investigated on the ocean’s surface at an interfacial level. Furthermore, I aim to reconstruct the natural composition of the SML in a wind-wave tunnel to study its ability to modify the ocean’s surface at well-defined wind regimes. The results from the proposed studies can form the basis for an improvement of current assessments of CO2 fluxes, and oceanic uptake rates. A better understanding in the oceanic uptake of atmospheric CO2 is critical in predicting climate trends and establishing policies.

1 485 797 €

Start date: 2014-04-01, End date: 2019-03-31

Phosphorus (P) is a key and often limiting nutrient for phytoplankton in the ocean. A strong positive feedback exists between marine P availability, primary production and ocean anoxia: increased production leads to ocean anoxia, which, in turn, decreases the burial efficiency of P in sediments and therefore increases the availability of P and production in the ocean. This feedback likely plays an important role in the present-day expansion of low-oxygen waters (“dead zones”) in coastal systems worldwide. Moreover, it contributed to the development of global scale anoxia in ancient oceans. Critically, however, the responsible mechanisms for the changes in P burial in anoxic sediments are poorly understood because of the lack of chemical tools to directly characterize sediment P. I propose to develop new methods to quantify and reconstruct P dynamics in low-oxygen marine systems and the link with carbon cycling in Earth’s present and past. These methods are based on the novel application of state-of-the-art geochemical analysis techniques to determine the burial forms of mineral-P within their spatial context in modern sediments. The new analysis techniques include nano-scale secondary ion mass spectrometry (nanoSIMS), synchotron-based scanning transmission X-ray microscopy (STXM) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). I will use the knowledge obtained for modern sediments to interpret sediment records of P for periods of rapid and extreme climate change in Earth’s history. Using various biogeochemical models developed in my research group, I will elucidate and quantify the role of variations in the marine P cycle in the development of low-oxygen conditions and climate change. This information is crucial for our ability to predict the consequences of anthropogenically-enhanced inputs of nutrients to the oceans combined with global warming.

1 498 000 €

Start date: 2012-01-01, End date: 2016-12-31

Atmospheric CO2 concentrations have risen rapidly since pre-industrial times and our current climate is not yet in equilibrium with this; it will change. To obtain insight in the type and magnitude of this change and to validate climate models used to project these changes, we need to look back at past climates. The most recent time in Earth history with CO2 levels that were similar to today is the Pliocene. The Pliocene thus provides a unique window into a world that exhibited many of the climate characteristics that we might experience. These are documented by proxies locked into sedimentary archives, especially marine sediments. It remains a challenge for palaeoclimatologists, however, to quantify past terrestrial temperatures. I have recently developed a novel proxy for quantitative annual mean air temperature reconstruction, which is based on the distribution of membrane lipids synthesised by soil bacteria. Upon soil erosion these molecules are transported to the marine realm where they become part of the marine sedimentary archive. The PlioProx project aims at a quantitative reconstruction of continental temperatures and latitudinal temperature gradients for the Pliocene. This will be achieved by applying this new palaeothermometer to high resolution marine sediment records near river outflows to generate river-basin integrated records of continental air temperature. This approach also allows for a direct comparison to reconstructed sea surface temperatures. Using globally distributed sediment records, latitudinal temperature gradients will be constructed which will be compared to moisture transport and rainout, reconstructed using stable hydrogen isotopes from plant wax lipids. Results will provide vital new insights in climate evolution on land under elevated atmospheric CO2 concentrations. It will also contribute to improving the next generation earth system models that are used to predict future climate.

1 500 000 €

Start date: 2012-10-01, End date: 2017-09-30

How do earthquakes begin? Answering this question is essential to understand fault mechanics but also to determine our ability to forecast large earthquakes. Although it is well established that some events are preceded by foreshocks, contrasting views have been proposed on the nucleation of earthquakes. Do these foreshocks belong to a cascade of random failures leading to the mainshock? Are they triggered by an aseismic nucleation phase in which the fault slips slowly before accelerating to a dynamic, catastrophic rupture? Will we ever be able to monitor and predict the slow onset of earthquakes or are we doomed to observe random, unpredictable cascades of events? We are currently missing a robust tool for quantitative estimation of the proportion of seismic versus aseismic slip during the rupture initiation, cluttering our attempts at understanding what physical mechanisms control the relationship between foreshocks and the onset of large earthquakes. The current explosion of available near-fault ground-motion observations is an unprecedented opportunity to capture the genesis of earthquakes along active faults. I will develop an entirely new method based a novel data assimilation procedure that will produce probabilistic time-dependent slip models assimilating geodetic, seismic and tsunami datasets. While slow and rapid fault processes are usually studied independently, this unified approach will address the relative contribution of seismic and aseismic deformation. The first step is the development of a novel probabilistic data assimilation method providing reliable uncertainty estimates and combining multiple data types. The second step is a validation of the method and an application to investigate the onset of recent megathrust earthquakes in Chile and Japan. The third step is the extensive, global use of the algorithm to the continuous monitoring of time-dependent slip along active faults providing an automated detector of the nucleation of earthquakes.

1 499 545 €

Start date: 2019-01-01, End date: 2023-12-31