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

发震断层对地球表面自然和人为引起的载荷变化的响应 - 一种数值模拟方法

• 批准号: 15109242
• 负责人: Professorin Dr. Andrea Hampel
• 金额: --
• 依托单位: Institut für Geologie
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/15109242?language=en
• 关键词: response; seismogenic; faults; natural; human

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.

发震断层上弹性应变能的反复释放早期激发了地震重现的准周期模型。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，尽管它们可能与地壳中随时间变化的应力场有关。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集）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于海平面变化、山体滑坡或冰川进退等自然过程以及采石场挖掘和水坝建设等人类活动造成的。这些过程可能会改变地壳应力状态，从而促进或延迟地震。三维有限元模型包括流变层状岩石圈中的离散断层，将能够量化表面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并应用创新技术来模拟失效和故障传播。