Continuation of Events Detection with Global Long-Period Seismic Data: An Analysis from 2010 to 2022

Abstract

Abstract We develop an algorithm to detect and locate sources of long-period (25–100 s) seismic signals. Our method is based on the analysis of seismological data recorded at global networks, plus all available stations at latitude larger (smaller) than 60° (−60°). We use a delay and stack method to identify coherent Rayleigh waves generated at the free surface of the Earth. The application of our approach to 13 yr of continuous data permitted us to detect more than 36,000 events. After a precise analysis to classify known events and to remove spurious detections, we report more than 1700 previously unidentified source of long-period seismic signals. Each source is characterized by its location (with associated uncertainty) and moment magnitude. This new catalog mainly reveals sources in the polar regions likely associated with glaciers dynamics but also volcanic activity, landslides, and regular earthquakes located in remote areas of the planet. Our study reveals the importance of maintaining global seismic networks and exploring the recorded data, beyond providing new observations that can be the basis to future studies to better characterize physical processes occurring at the free surface of our planet.