The 2013 Slab‐Wide Kamchatka Earthquake Sequence

Abstract Studies of initiation of large earthquakes are usually focused on frictional instabilities occurring in the near vicinity of the future rupture. Possible contributions of long‐distance interactions with large‐scale tectonic instabilities remain unknown. Here we analyze seismic catalogs and...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: B. Rousset, M. Campillo, N. M. Shapiro, A. Walpersdorf, N. Titkov, D. V. Chebrov
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2023
Subjects:
Online Access:https://doi.org/10.1029/2022GL101856
https://doaj.org/article/241d6c3fe0c64cd2b4f789574569c434
Description
Summary:Abstract Studies of initiation of large earthquakes are usually focused on frictional instabilities occurring in the near vicinity of the future rupture. Possible contributions of long‐distance interactions with large‐scale tectonic instabilities remain unknown. Here we analyze seismic catalogs and geodetic time series during a few months preceding the 2013 M = 8.3 deep‐focus Okhotsk earthquake. This deep‐focus event is preceded by four intense seismic clusters in the seismogenic zone. GNSS time series in Kamchatka revealed a transient landward motion episode 1 month prior to the mainshock, consistent with an increase of seismogenic zone loading. This transient loading episode is accompanied by a doubling of the intermediate depth seismicity rate suggesting a transient slab pull as the origin. These observations question the constant subducting velocity hypotheses and may have implications in the understanding of the long‐distance along‐slab stress interactions and in their contribution to initiation of large deep‐focus earthquakes.