The response of seismogenic faults to natural and human-induced changes in loads on Earth's surface - a numerical modelling approach

发震断层上弹性应变能的反复释放，早期启发了地震复发的准周期模型。然而，越来越多的古地震学研究表明，尽管板块构造边界条件不变，但许多断层在地震复发方面表现出明显的时间变化。这种断层行为的根本原因仍然是个谜，尽管它们很可能与地壳中临时变化的应力场有关。初级研究小组的主要目标是评估断层行为的变化，特别是地震的时间聚类，在多大程度上是由地球表面质量的重新分布引起的。质量的重新分配可能是由自然过程造成的，如海平面变化、山体滑坡或冰川的进退，也可能是人类活动造成的，如采石场的开挖和水坝的建设。这些过程可能会改变地壳的应力状态，从而促进或延缓地震的发生。包括流变层状岩石圈中离散断层在内的三维有限元模型将允许量化地表变化对单个断层和相互作用断层阵列行为的影响。重点将放在实现现实流变学和应用创新技术来模拟故障和故障传播。

The repeated release of elastic strain energy on seismogenic faults has early inspired quasiperiodic models of earthquake recurrence. An increasing number of palaeoseismologic studies have revealed, however, that many faults exhibit pronounced temporal variations in earthquake recurrence despite unchanged plate-tectonic boundary conditions. The underlying causes for such a behaviour of faults remain enigmatic, although they are likely related to a temporally changing stress field in the crust. The main goal of the Junior Research Group will be to evaluate to what extent variations in fault behaviour ¿ in particular the temporal clustering of earthquakes ¿ are provoked by the redistribution of mass on Earth`s surface. Redistribution of mass may result from natural processes such as sea level changes, landslides, or the advance and retreat of glaciers and from human activity like excavation of quarries and construction of dams. These processes may alter the crustal state of stress such that earthquakes are either promoted or retarded. Three-dimensional finite-element models including discrete faults in a rheologically layered lithosphere will allow to quantify the effects of surface changes on the behaviour of single faults and arrays of interacting faults. Emphasis will be put on implementing realistic rheologies and applying innovative techniques to model failure and fault propagation.