Earth's surface and interior

Unraveling the Dynamics of Our Planet

Our research investigates the dynamic and intricate systems that govern our planet, from the deep interior to the surface landscapes. Our work combines advanced computational modeling, sophisticated seismic observation, detailed rock and mineral analysis, and extensive field campaigns to uncover the processes that have shaped Earth over geological time.

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A major focus lies in understanding Earth's Deep Interior and the mechanisms that drive its evolution. Scientists develop and apply complex numerical methods—requiring high-performance computing—to create time-dependent mantle flow models. These models simulate mantle convection, the slow, viscous movement of rock that dictates plate-tectonic dynamics, controls the global distribution of lithospheric stress, and influences long-term changes like sea-level variations. A key challenge is connecting these geodynamic models with real-world observations. This is achieved through virtual seismology, where model results are transformed into theoretical seismic signals using mineral-physics relations, allowing researchers to evaluate if a specific model of mantle structure is compatible with actual seismic data. Further work addresses the inherent uncertainties in seismic imaging, exploring how the limited resolution of tomographic models affects reconstructions of past mantle flow and predictions of surface dynamic topography.

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Our department also delves into the mysteries of the Earth’s magnetic field, generated by the thermochemical convection of molten iron-nickel in the fluid outer core—the process known as the geodynamo. Researchers use magnetohydrodynamics to simulate this process over millions of years, yielding predictions about the frequency and duration of geomagnetic polarity reversals and the field's behavior during these events. By analyzing the paleomagnetic record preserved in volcanic rocks from diverse regions, scientists seek correlations between the field's strength, directional fluctuations, and reversal frequency to determine if the Earth’s dynamo has changed its mode of operation over geologic time. This analysis also provides crucial temporal constraints on the eruptive histories of large igneous provinces, which are massive volcanic events with significant consequences for the global biosphere.

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Connecting the interior to the crust, other research explores the behavior of rocks under stress. The rheology of rocks is a vital area of study, as the way materials deform governs plate tectonics, volcanism, and the occurrence of earthquakes. This involves comparing experimentally deformed rocks with the natural deformation record found in fault rocks, which carry information about deep-seated deformation processes in the crust. In subduction zones, researchers investigate the transformation and flow of materials at extreme pressure and temperature conditions, addressing questions about how subduction earthquakes are generated and how rocks are exhumed from depths greater than 100 kilometers on very fast geological timescales. Further research in rock and mineral analysis focuses on ophiolitic complexes, exploring the formation and evolution of Earth's mantle and the mobility of critical metals in various tectonic settings.

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The study of the subsurface is greatly enhanced by advanced observational techniques. Seismology is a central theme, encompassing the operation and analysis of global and local seismic networks and arrays. This includes specialized areas like volcano seismology and cryo seismology, as well as the seismic monitoring of geothermal systems. Researchers are also pushing the boundaries of seismic observation through rotational seismology, integrating all aspects of rotational ground motion into Earth System Monitoring. This involves the use and development of high-precision rotation sensors, such as ring lasers, with applications in seismology, volcanology, geodesy and even structural health monitoring. Furthermore, computational seismology aims to make simulations of seismic wave propagation ever more realistic by incorporating complex, nonlinear rock rheologies. This work extends beyond Earth into planetary seismology, focusing on instrumentation and experimental strategies to characterize ground motion on planetary bodies like the Moon and Mars.

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We study magmatic processes, exploring the origin, evolution, and emplacement of magma within the Earth’s crust. Petrological reactions in silicate and carbonatitic rocks are central to understanding how minerals crystallize, melt, and/ or re-equilibrate under varying pressures and temperatures. These reactions control magma composition, texture, and the formation of igneous and metamorphic rocks, as well as the evolution of volatile and rare earth elements. We study differentiation processes such as fractional crystallization, magma mixing, assimilation, partial melting, and volatile transfer between magma and hydrothermal fluids using a combination of field research, experimental investigations and analytical work. This interdiscilinary efforts is applied to the Earth as well as planetary bodies in our solar system and beyond.

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Geothermal energy is rising as a necessary solution to improve sustainability, and meet the energy transition. We study fluid properties, how hydrothermal fluids react with rocks, prompting mineral reactions, and how cooling (both natural or due to fluid injection during geothermal operation) leads to contraction and fractures (e.g., columnar joints) of magma and hot rocks, which modify the permeable patways for fluid flow and the local stress that may induce seismicity and earthquakes.

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Finally, the department’s work extends to the Earth’s Surface, focusing on the physical and chemical processes that shape landscapes. Research combines field observations, analogue experiments, and sophisticated geochemical analyses to quantify the erosion, transport, and deposition of sediments. By measuring and modeling how rivers build valleys and how sediment transitions through river corridors, scientists seek to understand the time and spatial scales of sediment flux. These studies are essential for understanding how global fluxes of sediment, nutrients, and carbon modulate Earth's climate and how river systems react to changes in climate and erosion rates.