Seismic hazard assessment of Greenland

Abstract

Earthquake activity in Greenland has been registered and mapped since 1907 (Larsen et al. 2006) and thus a long (albeit relatively sparse) record of seismic activity is available for evaluation of seismic hazard and risk. Seismic hazard assessment is carried out by judging the probability of future earthquakes in a given region and is based on statistic treatment of earthquake data. The determination of the seismic hazard is the first step in an evaluation of seismic risk, i.e. the possible economic costs and loss of human life after an earthquake. The motivation for this seismic hazard study is the registration of four significant earthquakes in Greenland in 2005. The Geological Survey of Denmark and Greenland (GEUS) received reports of all four earthquakes from residents who had felt the shaking. The 2005 earthquakes were located at or near Qeqertarsuaq on 30 March, Sisimiut on 23 July, Station Nord on 30 August and Attu on 23 October (Fig. 1), with magnitudes on the Richter scale of 4.3, 4.1, 5.1 and 2.5, respectively. The earthquake in Attu led to the inhabitants fleeing in their boats.

Stress and fault parameters affecting fault slip magnitude and activation time during a glacial cycle

“…Earthquake hazard due to GIA does not only affect formerly glaciated areas but also currently glaciated regions that are undergoing rapid ice melting, e.g., Greenland and Alaska [e.g., Sauber and Molnia , ; Larsen et al , ; Voss et al , ; Dahl‐Jensen et al , ]. Stress changes induced in these regions can generate earthquakes if the background regime favors the additional stresses [e.g., Wu and Hasegawa , ].…”

Moment tensors, state of stress and their relation to post-glacial rebound in northeastern Canada

“…Basham et al 1977; Quinlan 1984; Adams 1989a; Adams et al 1991; Henderson 1991; Arvidsson & Kulhanek 1994; Bent 1994; Adams 1996; Johnston 1996; Uski et al 2003; Steffen & Wu 2011), and around the current ice margin of the Greenland and Antarctic ice sheets (e.g. Okal 1980; Adams & Akoto 1986; Gregersen 1989; Chung & Gao 1997; Tsuboi et al 2000; Chung 2002; Gregersen 2006; Reading 2007; Voss et al 2007). As several parts of the Earth remain covered by ice sheets, the relationship between deglaciation and seismicity is important for the understanding of the trigger mechanism of intraplate earthquakes, the mitigation of seismic risk for infrastructure planning and design, and the understanding of climate change and Heinrich events (Hunt & Malin 1998), which were possibly triggered by ice‐load‐induced earthquakes.…”

Transferability of a calibrated numerical model of rock avalanche run‐out: Application to 20 rock avalanches on the Nuussuaq Peninsula, West Greenland

“…These conditions are thought to be particularly favourable for the generation of rock avalanches along Vaigat's coastal slopes, especially where erosion exposes the underlying soft units (Strom, ). Given that active faulting in Vaigat is minimal (Voss et al, ), the rock avalanches are thought to have been triggered by progressive deformation of the valley side‐walls in response to glacial over‐steepening (Pedersen et al, ). Climatic controls are considered to have acted as a direct trigger of the 21 November 2000 Paatuut rock avalanche, where a particularly deep active layer of permafrost was present (Buchwał et al, ) and fluctuations in air temperature in the days prior to the event drove the repeated melting and refreezing of water in surface cracks (Dahl‐Jensen et al, ).…”