A shallow slow slip event in 2018 in the Semidi segment of the Alaska subduction zone detected by machine learning
Document Type
Article
Date of Original Version
6-15-2023
Abstract
Slow slip events (SSEs) have been discovered at shallow depth near the trench in some subduction zones and have been linked to the triggering of large earthquakes and the absence of tsunami. These shallow SSEs are invariably submarine, making it difficult to observe their temporal and spatial extent. Here, we report a shallow SSE in late 2018 near the west Semidi segment of the Alaska subduction zone, up-dip of and preceding the Mw 8.2 Chignik earthquake on July 29th, 2021. The SSE was detected in data from an offshore array of seafloor pressure gauges by a machine learning method. This detection is supported by the spatial pattern of simulated SSE deformation, the increased seismicity after the SSE in the positive Coulomb stress change area, the lack of shallow slip in Chignik earthquake, and the absence of a sizable tsunami following the Chignik earthquake. Our method has the potential to transform the way offshore SSEs are detected and to improve tsunami hazard assessment in subduction zones.
Publication Title, e.g., Journal
Earth and Planetary Science Letters
Volume
612
Citation/Publisher Attribution
He, Bing, Xiao Zhuo Wei, Meng Wei, Yang Shen, Marco Alvarez, and Susan Y. Schwartz. "A shallow slow slip event in 2018 in the Semidi segment of the Alaska subduction zone detected by machine learning." Earth and Planetary Science Letters 612, (2023). doi: 10.1016/j.epsl.2023.118154.