Provenance of Nicobar Fan sediments from IODP Expedition 362, offshore Sumatra

俯冲带是一个板块被迫压在另一个板块之下的地方，是最大规模地震的发生地，通常与构成自然灾害的海啸的产生有关。这类海啸地震是由在所谓的“孕震区”内的俯冲板块上部沿着的滑动事件引起的。进入板块及其沉积物覆盖层（“俯冲输入”）的物质特性，可能与不同沉积物来源或物源（本研究建议的重点）随时间推移而改变的沉积物类型有关，在海啸地震的产生中发挥着关键作用。沉积物类型和它们在三维空间中的堆积方式（称为“岩石地层学”）对俯冲带的物质性质和构造行为产生了一级影响2。岩土工程师和地质学家都很欣赏粗粒与细粒深海沉积物的3D位置和比例，以影响俯冲输入的摩擦系数和渗透率。这项拟议中的研究将有助于改善对这些问题的理解，重点是厚沉积桩进入俯冲带3，并提供了一个比较研究的IODP远征322，日本近海（PI是船上的科学家），调查输入材料的俯冲运输朝向和下方的正面所谓的南开增生棱镜。

Subduction zones, where one plate is forced beneath another, are the locations of the largest-magnitude earthquakes, often associated with the generation of tsunamis that pose a natural hazard. Such tsunamigenic earthquakes are caused by slip events along the upper part of the subducting plate in the so-called "seismogenic zone". The material properties of the incoming plate and its sediment cover ("subduction inputs"), likely linked to changing sediment types over time from different sediment sources or provenances (the focus of this research proposal), play a critical role inthe generation of tsunamigenic earthquakes. The sediment types and the way in which they are stacked in three dimensions (called "lithostratigraphy") exerts a first-order influence over the material properties and tectonic behaviour of subduction zones2. The 3D location and proportion of coarse- versus fine-grained deep-marine sediments are appreciated among geotechnical engineers and geologists to affect coefficients of friction and permeability of the subduction inputs. This proposed research will contribute significantly to an improved understanding of these problems by focussing on the thick sedimentary pile entering a subduction zone3, and provide a comparative study to that of IODP Expedition 322, offshore Japan (on which the PI was a shipboard scientist), that investigated input materials transported by subduction toward and beneath the frontal so-called Nankai accretionary prism.