Modelled depth and thermal history for sediments offshore Sumatra (NERC grant NE/P012140/1)

The thermal state of marine sediments controls a range of potential dehydration reactions as sediments are subducted. In thick sediment sections it is possible that reactions that would normally occur within a subduction zone start offshore of the deformation front. This scenario may be occurring at the Sumatra subduction zone (e.g. Geersen et al., 2013; Huepers et al., 2017). We have investigated this possibility by modelling the thermal and depth history of sediments offshore Sumatra. We have used a range of different assumptions about how the sediments decompact with depth, as well as testing the dependence on the seismic velocities used for depth conversion of the horizons.

海洋沉积物的热状态控制着一系列潜在的脱水反应，这些反应随着沉积物的俯冲而发生。在厚沉积层中，原本应在俯冲带内发生的反应可能始于变形前沿的近海区域。这一情形可能在苏门答腊俯冲带中发生（例如，Geersen 等人，2013；Huepers 等人，2017）。我们通过模拟苏门答腊近海沉积物的热历史和深度历史，对此可能性进行了研究。我们采用了一系列关于沉积物随深度减密的不同假设，以及测试了用于深度转换的地震波速对界面依赖性的影响。