DEPLOYMENT OF OBS IN THE ARCTIC SEAS: APPLYING FINDINGS TO THE STUDY OF MARINE GEOHAZARDS

Abstract

The Arctic Seas are of particular interest now in connection with the prospects for their development. At the same time, the construction of critical and industrial infrastructure at sea must be preceded by a thorough assessment of possible geohazards, including dangerous landforms, earthquakes, geofluid outflows, marine landslides, soil liquefaction, tsunamis, etc. The purpose of the study is to highlight various seismological applications of the records obtained recently in the Laptev Sea and other Arctic Seas of the Russian sector by OBS network based on broadband MET sensors, including the analysis of ambient seismic noise, registering the signals of large remote earthquakes and weak local microearthquakes, instrumental approach of the site response assessment. The Laptev Sea is of particular interest as the most seismically active water area of the Russian Arctic. The main characteristics of the OBS architectures turned out to be suitable for obtaining high-quality records under the Arctic conditions to solve seismological problems. For example, the OBS data confirm a general shift of the epicenters cloud towards the eastern part of the Laptev Sea, which was observed according to regional catalogs. This shift can serve as an argument in favor of the hypothesis of the existence of the transcurrent fault zone in this area. The approximate location of this shift is also characterized by a significant number of methane seeps. The confinement of the provinces of gas seeps to large fault areas is possibly also characteristic of other Arctic seas.