A New Seismic Hazard Map for Greenland

A probabilistic seismic hazard analysis (PSHA) was carried out for Greenland based on the revised earthquake catalogue of GEUS for the period 1974-2022. The analysis is based on more than 5.000 earthquakes. For the analysis Greenland has been divided into 9 areal zones, identical to the zones used in a previous study by Voss et al (2007). The zones are defined based on seismicity and geological provinces. The seismic network in Greenland is sparse and the configuration of the network changes significantly with time. During periods with large international projects the station network is densified, but hundreds of km between neighbouring stations is not uncommon. Some areas experience frequent earthquakes, especially in SE Greenland around the town of Tasiilaq, but most earthquakes in Greenland are less than Magnitude 4.5. The hazard analysis has been carried out using HAZ45.3 for Windows and the code has been validated against the 2007 study. Lacking local information on attenuation a global reference model for normal faults in hard rocks has been applied. Sufficient data were available to obtain robust hazard levels for 7 out of 9 areal zones. One zone in NW Greenland had too few recorded earthquakes for the analysis, and the zone defined by the inland ice was omitted as well. Most of coastal Greenland has peak ground acceleration (PGA) hazard values around 0.04g, with slightly higher values up to 0.06g in SE Greenland for a return period of 475 years.