Response of faults to climate‐induced changes of ice sheets, glaciers and lakes

Abstract

Glacial–interglacial cycles are characterized by strong variations in climatic conditions, which affect the size of continental ice sheets, glaciers and lakes. Such climate‐triggered fluctuations in ice and water masses lead to transient stresses in the Earth's crust, which can be large enough to affect the slip behaviour of faults. In particular, postglacial unloading may increase the slip rate of active faults or re‐activate dormant faults. In the past, numerical modelling has helped to better understand the response of faults to mass fluctuations on Earth's surface. This article provides an overview of the mechanisms and controlling parameters of climate‐induced variations in fault slip as derived from the numerical models. Geological records of postglacial faulting from Scandinavia, the European Alps and the Basin‐and‐Range Province (western USA) are presented. Taken together, modelling and case studies provide a basis for evaluating the future seismic potential in regions that are currently experiencing ice loss or lake regression.

Spatial Changes in Late Quaternary Slip Rates Along the Gyaring Co Fault: Implications for Strain Partitioning and Deformation Modes in Central Tibet

“…Such temporal changes in fault activity have already been evidenced in other slow‐rate faults, for instance, in Mongolia, where an increase in fault activity at 16 ka has been discovered (Ritz et al., 2003, 2006). Other authors have shown that climate‐controlled changes in loads at the Earth's surface may exert a fundamental control on the slip history of individual faults (e.g., Hampel, 2017; Hetzel & Hampel, 2005). The middle‐west segment of the Gyaring Co fault experienced considerable load variations mainly from Gyaring Co Lake and the surrounding mountain glaciers, and the changes in these loads were imposed by climate change (Figures 2 and 11c; Dong et al., 2018; Gu et al., 1993; Shi et al., 2017).…”

“…The middle‐west segment of the Gyaring Co fault experienced considerable load variations mainly from Gyaring Co Lake and the surrounding mountain glaciers, and the changes in these loads were imposed by climate change (Figures 2 and 11c; Dong et al., 2018; Gu et al., 1993; Shi et al., 2017). According to the model of Hampel (2017), the effects of load changes on accelerating fault activity probably began at late MIS 2 and lasted until the early Holocene. After this period, the slip rate of the middle‐west segment of the Gyaring Co fault started to decrease due to lake loading and probably lasted until the middle Holocene (Figure 11c).…”

Evaluation of deep crustal earthquakes in northern Germany – Possible tectonic causes

“…A potential trigger of these events is stress change due to GIA. Numerical simulations are able to quantify the interplay of glaciation‐induced stress changes and fault activity (Hampel, ; Hampel & Hetzel, ; Hampel et al., ; Hampel et al., ; Hetzel & Hampel, ; Steffen, Steffen, Wu, & Eaton, 2014c; Steffen, Wu, Steffen, & Eaton, ,b; Turpeinen, Hampel, Karow, & Maniatis, ; Wu, , ; Wu & Hasegawa, ,b; Wu & Johnston, ). Modelling results of Grollimund and Zoback () and Hampel et al.…”

Interactions between active tectonics and gravitational deformation along the Billecocha fault system (Northern Ecuador): Insights from morphological and paleoseismological investigations

“…Concerning the post-glacial unloading hypothesis, favored by Ego et al, (1996a), it is known to result in fault slip along inherited discontinuities during single or multiple seismic events (e.g. Ustaszewski et al, 2008 ;Mattila et al, 2019) or in transient fault slip-rates increases along active faults (Hampel, 2017 andreferences therein, DuRoss et al, 2020). However, the influence of post-glacial unloading on fault activity is generally thought to be restricted to some thousands of years after the deglaciation, being as short as the original ice-cap thickness is limited (Hampel and Hetzel, 2006).…”