Did the 1999 earthquake swarm on Gakkel Ridge open a volcanic conduit? A detailed teleseismic data analysis

International audience In 1999, a seismic swarm of 237 teleseismically recorded events marked a submarine eruption along the Arctic Gakkel Ridge, later on also analyzed by sonar, bathymetric, hydrothermal, and local seismic studies. We relocated the swarm with the global location algorithm HYPOSAT a...

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Bibliographic Details
Published in:Journal of Seismology
Main Authors: Riedel, Carsten, Schlindwein, Vera
Other Authors: Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI), Helmholtz-Gemeinschaft = Helmholtz Association
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2009
Subjects:
Gakkel Ridge
HYPOSAT
Relocation
Station residuals
Spatiotemporal organization
1999 swarm
Polar research
Double difference
Cross-correlation
Magma ascent
Oden volcano
Ultraslow-spreading ridge
Arctic
Online Access:https://hal.science/hal-00537995
https://hal.science/hal-00537995/document
https://hal.science/hal-00537995/file/PEER_stage2_10.1007%252Fs10950-009-9179-6.pdf
https://doi.org/10.1007/s10950-009-9179-6
Description
Summary:International audience In 1999, a seismic swarm of 237 teleseismically recorded events marked a submarine eruption along the Arctic Gakkel Ridge, later on also analyzed by sonar, bathymetric, hydrothermal, and local seismic studies. We relocated the swarm with the global location algorithm HYPOSAT and analyzed the waveforms of the stations closest to the events by cross-correlation. We find event locations scattered around 85°35 N and 85° E at the southern rift wall and inside the rift valley of the Gakkel Ridge. Waveforms of three highly correlating events indicate a volumetric moment tensor component and highly precise referenced double-difference arrival times lead us to believe that they occur at the same geographical position and mark the conduit located further southeast close to a chain of recently imaged volcanic cones. This result is supported by station residual anomalies in the direction of the potential conduit. Seismicity is focused at the crust–mantle boundary at 16–20 km depth, but ascending toward the potential conduit during the beginning of April 1999, indicating an opening of the vent.

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