TY - JOUR
T1 - Improved seismic monitoring with OBS deployment in the Arctic
T2 - A pilot study from offshore western Svalbard
AU - Jeddi, Zeinab
AU - Ottemöller, Lars
AU - Sørensen, Mathilde B.
AU - Rezaei, Sara
AU - Gibbons, Steven J.
AU - Strømme, Marte L.
AU - Voss, Peter H.
AU - Dahl-Jensen, Trine
N1 - Publisher Copyright:
© 2021 Seismological Society of America. All rights reserved.
PY - 2021/9
Y1 - 2021/9
N2 - The mid-ocean ridge system is the main source of earthquakes within the Arctic region. The earthquakes are recorded on the permanent land-based stations in the region, although, smaller earthquakes remain undetected. In this study, we make use of three Ocean Bottom Seismographs (OBSs) that were deployed offshore western Svalbard, along the spreading ridges. The OBS arrival times were used to relocate the regional seismicity, using a Bayesian approach, which resulted in a significant improvement with tighter clustering around the spreading ridge. We also extended the regional magnitude scales for the northern Atlantic region for OBSs, by computing site correction terms. Besides location and magnitude improvement, the OBS network was able to detect hundreds of earthquakes, mostly with magnitude below Mw 3, including a swarm activity at the Molloy Deep. Our offshore observations provide further evidence of a low-velocity anomaly offshore Svalbard, at the northern tip of Knipovich ridge that was previously seen in full-waveform inversion. We conclude that even a single permanent OBS near the ridge would make a significant difference to earthquake catalogs and their interpretation.
AB - The mid-ocean ridge system is the main source of earthquakes within the Arctic region. The earthquakes are recorded on the permanent land-based stations in the region, although, smaller earthquakes remain undetected. In this study, we make use of three Ocean Bottom Seismographs (OBSs) that were deployed offshore western Svalbard, along the spreading ridges. The OBS arrival times were used to relocate the regional seismicity, using a Bayesian approach, which resulted in a significant improvement with tighter clustering around the spreading ridge. We also extended the regional magnitude scales for the northern Atlantic region for OBSs, by computing site correction terms. Besides location and magnitude improvement, the OBS network was able to detect hundreds of earthquakes, mostly with magnitude below Mw 3, including a swarm activity at the Molloy Deep. Our offshore observations provide further evidence of a low-velocity anomaly offshore Svalbard, at the northern tip of Knipovich ridge that was previously seen in full-waveform inversion. We conclude that even a single permanent OBS near the ridge would make a significant difference to earthquake catalogs and their interpretation.
UR - http://www.scopus.com/inward/record.url?scp=85114600951&partnerID=8YFLogxK
U2 - 10.1785/0220200471
DO - 10.1785/0220200471
M3 - Article
AN - SCOPUS:85114600951
SN - 0895-0695
VL - 92
SP - 2705
EP - 2717
JO - Seismological Research Letters
JF - Seismological Research Letters
IS - 5
ER -