We know and think a lot about carbon and its atmospheric cycle, but part of this cycle is hidden in so-called subduction zones. How much carbon is lost to the deep Earth or escapes back into the atmosphere over millennia is hotly debated. This is because we know very little about when carbon is released and whether subduction zones scrub carbon. Within the Vidi project 'Release', we will couple geological observations, experiments and numerical models to understand these processes.
I am the facility manager and main contact of the community-driven project "The EXCITE Network", a European infrastructure initiative for scientists working on unravelling the secrets of Earth materials by using some of the world’s best electron and X-ray imaging facilities. Want to learn more? Visit out excite-network.eu.
Fluid-driven mineral reactions chemically modify enormous portions of the Earth’s crystalline lithosphere. These reactions drive fluid-mediated rock transformation processes that govern the stability of mountain belts, the formation of hydrothermal mineral deposits and the sequestration of anthropogenic CO2 as well as many other processes. We propose that contrary to our current thinking, the reactions themselves are driven by self-promoting nanoscale transport phenomena. Existing geological frameworks lack a quantitative understanding of mechanisms that control the rates of reactive fluid-rock interaction. This is because they do not account for the pervasive influence of nanoscale dynamics on the redistribution of elements within geological materials. The nanoEARTH project will solve this by defining the predominant transport processes occurring in mineral nanopores and the dynamic behaviour of fluid-rock interaction. To achieve the nanoEARTH aims and breakthrough current limitations in our understanding of fluid-rock interaction, we will use my expertise in the multi-scale physics of geological processes. We will combine (1) novel nanoscale experiments that will establish transport mechanisms through natural and synthetic mineral nanopores and (2) unique in operando observations of fluid-driven mineral transformations at multiple length scales with (3) molecular-to continuum-scale transport modelling that is (4) constrained by geological observations. Through this integrative strategy, we will deliver new knowledge to redefine how the reaction of fluids with minerals self-generates a mode of transport that mobilises elements and controls the rates of fluid-driven transformation. This will impact geoscience research well beyond the project duration and bring the nanoscience of geological processes a quantum-leap forward in defining it as an integral part of solid Earth science.
DeepNL: Ongoing surface subsidence: how low can it go?
Extraction of fluids, like natural gas, from the Earth’s crust frequently results in surface subsidence and tremors. The cause lies in reservoir compaction, driven by the increase in effective overburden stress due to decreasing reservoir fluid pressure. However, the long-term surface impact of fluid production cannot be predicted confidently. The key barrier to obtaining appropriate models is that the physical and chemical mechanisms responsible for reservoir compaction are poorly known and quantified at realistic subsurface pressure and temperature conditions. We will quantify these mechanisms causing long-term subsidence and seismicity, to enable prediction via computer modelling.
Earthquakes constitute one of the most pronounced natural disasters affecting thousands to millions of people each year. To further improve seismic hazard evaluation it is of utmost importance to understand the underlying nucleation mechanisms that lead to seismicity and earthquakes. This is also of rapidly growing importance in the industrial sector where gas/oil extraction, deep geothermal energy production and underground storage of carbon dioxide leads to human-induced seismicity. Although earthquakes occur on very large scales the processes leading to them take place within fault rock volumes that are only several hundred microns to tens of millimetres in size. Recent studies focusing on these fault rocks have identified nanogranular and/or amorphous pulverized rock materials (fault rock gouge), where the nanoscale processes within these gouges may control the overall macroscopic deformation behaviour. Although, while the EU identified the “exploration of the nanoworld” as one of the new science and technology frontiers for the 21st century, no integrated approach has yet been undertaken to decipher the formation and deformation mechanisms of natural nanograins and their influence on the behaviour of fault rocks prone to nucleate earthquakes. The research project proposed here will use next-generation nano-analytical techniques to decipher the nanoscale processes within fault zones to develop a mechanism-based understanding of how the behaviour of nanograins may influence the macroscopic behaviour of fault rocks thus processes leading to seismicity and earthquakes.
The reactions of fluids with rocks are fundamental for Earth’s dynamics as they facilitate heat/mass transfer and induce volume changes, weaknesses and instabilities in rock masses that localises deformation enabling tectonic responses to plate motion. Fluid-rock interactions also play a key role in industries such as geothermal energy, hydrocarbon production and CO2 sequestration. However, most terrestrial rocks of geological and industrial importance have very low permeability suggesting that fluid migration through them should be nearly impossible. Nevertheless, considerable evidence from natural observations suggests that mineral reactions can ‘eat’ their way through rocks by generating permeable fracture networks, opening the solid rock reservoir to fluid-rock interaction. Little is known about the actual mechanism of this reaction-induced fracturing or the forces produced by (re-)crystallization, and whether such a system can be self-sustaining.