How hot do Groningen faults get?
An earthquake is the result of fast slip along faults in the Earth鈥檚 crust at depth where stresses are large. The friction on the fault results in the generation of heat which raises the temperature and can weaken faults. This frictional heat is a major factor in the total earthquake energy budget. Therefore, understanding the physical mechanisms of fast fault slip is of great importance for understanding induced seismic, such as that in Groningen.
In this DeepNL project, we will develop a method to identify and measure temperature anomalies in ancient natural faults, currently exposed at the surface. This is done by measuring a magnetic signature present in each rock, but which is locked in at a specific temperature. In this way, the peak temperatures in small earthquakes can be estimated and seismic faults can be distinguished from aseismic faults.
In addition, we will experimentally determine the effect of small-scale frictional heating on pore fluid pressure and frictional behaviour. In this way weakening mechanisms operating in small slip events will be identified. The combined outcomes will provide the crucial input parameters for numerical modelling studies of small earthquake rupture.
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About DeepNL
The aim of the research programme is to improve the fundamental understanding of the dynamics of the deep subsurface under the influence of human interventions.
With DeepNL, NWO is giving a concrete response to the advice of the Dutch Safety Board: ensure that there is a structural and long-term research programme into the gas-extraction related problems in Groningen. This NWO research programme has been made possible in part by a financial contribution from NAM. DeepNL will be realised in accordance with the usual NWO procedures and quality standards and is entirely independent. NAM is not involved in the decision-making or the specific management of the programme. DeepNL is part of NWO's contribution to the Top Sector Energy.