Glacial and seismic events investigation from a single-station record at Severnaya Zemlya archipelago (Arctic region)

Abstract

The new permanent seismic station SVZ started working in Arctic (Severnaya Zemlya archipelago, Bolshevik Island), we discuss the first results of the local seismicity study. We have processed 46 local seismic events for 2017–2022. Data processing using a single seismic sensor is difficult, but using waveforms and spectral-temporal analysis of P, S, and surface waves, it is possible to separate shallow earthquakes from glacial events. We distinguish two types of icequakes—glacier-related events and pulses. An increase in seismic background noise is related to processes of glacial nature in summertime. Data processing allows to obtain the main peculiarities of local seismicity, i.e., mutual connection of glacial processes and crustal seismicity. We show the presence of icequakes induced by local crustal events; their epicenters confined to the ice domes edges. Spatio-temporal sequence and the rate of events migration show that the glacial events are a result of the defusing deformations process in the glaciers caused by the impact of shallow tectonic earthquakes. Thousands of pulsed and high-frequency micro-oscillations associate with the sea ice sheet or lake ice. The temporal variation of events’ number and energy per day correlates with air temperature temporal variations. Moreover, there is a sharp increase in the number of pulses with sharp temperature changes. The greatest activity of this pulsed events is in winter and especially in March, connected with ice surface destruction. In case a network deployment is not feasible, even a single seismic station allows to get a useful information about the glacial and seismic processes.