Imaging evolution of Cascadia slow-slip event using high-rate GPS

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1038/s41598-022-10957-8. This is version 1 of this Preprint.

Downloads

Download Preprint

Authors

Yuji Itoh , Yosuke Aoki, Junichi Fukuda

Abstract

The slip history of short-term slow slip event (SSE) is typically inferred from daily Global Positioning System (GPS) data, which, however, cannot image the sub-daily processes, leaving the underlying mechanisms of SSEs elusive. To address the temporal resolution issue, we attempted to employ the kinematic subdaily GPS analysis, which has never been applied to SSE studies because its signal-to-noise ratio has been believed too low. By carefully post-processing sub-daily positions to remove non-tectonic position fluctuation, our 30-minute kinematic data clearly exhibits the transient motion of a few mm during one Cascadia SSE. A spatiotemporal slip image by inverting the 30-minute data exhibits a multi-stage evolution; it consists of an isotropic growth of SSE followed by an along-strike migration and termination within the rheologically controlled down-dip width. This transition at the slip growth mode is similar to the rupture growth of regular earthquakes, implying the presence of common mechanical factors behind the two distinct slip phenomena. The comparison with a slip inversion of the daily GPS demonstrates the current performance and limitation of the subdaily data in the SSE detection and imaging.Better understanding of the non-tectonic noise in the kinematic GPS analysis will further improve the temporal resolution of SSE.

DOI

https://doi.org/10.31223/X5J91V

Subjects

Earth Sciences, Geophysics and Seismology, Tectonics and Structure

Keywords

GPS, GNSS, slow earthquake, SSE, slow slip, tremor, cascadia, kinematic GPS

Dates

Published: 2021-12-24 16:07

License

CC BY Attribution 4.0 International

Additional Metadata

Conflict of interest statement:
None

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.