Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

mechanical modelling, seismological and geological reviews (for example SSM 2013:34). The expert consultation included several workshops which also included the seismic hazard at Forsmark (for example SSM 2014:22,) witch brought together several experts in seismology and adjacent disciplines. R E S U LT S / D I S C U S S I O N The conclusions from the field excursion were that the various observations claimed by Mörner to indicate paleoearthquakes are likely linked to other processes. Such as shoreline regression and glacial erosion. The deformed post-glacial sequences, including folding and water escape or liquefaction structures, claimed by Mörner to relate to seismic events, could also be explained with for example gravity driven syn-sedimentary deformation caused by non-uniform loading, slope gradients and reverse density differences arising during the sedimentation (SSM 2009/493). Conclusions that have been verified by later studies (Hall et al.,2020; Smith and Öhrling, 2022). As pointed out in SSM 2017:35, the margins of temperate glaciers are tremendously dynamic geological environments. The terrain is unvegetated, and sediments are often saturated with meltwater. Mass movements are common, and sedimentation rates can be extreme (Benn and Evans, 2007, p. 262), Both mass movements and rapid sedimentation can create increased pore pressures that lead to water- escape or liquefaction structures (Collinson and Thompson, 1989, p. 45) that are often pointed to as evidence of paleoseismicity. Sediments supported by ice, such as esker deposits, are prone to collapse as the ice melts (Benn and Evans, 2007, p. 247, p. 243. Such collapse creates faults within the sediments that are entirely unrelated to paleoseismicity. Additional faulting or folding of glacial sediments is done by the flow of the ice itself (Benn and Evans, 2007, pp. 249- 255). The expert panel elicitation, even though they used different approaches, gave approximately 0,1 earthquakes greater than magnitude 6 within