Challenges on Characterizing a Low-Magnitude Seismic Sequence with a Sparse National Network

Session: Regional Earthquake Centers: Highlights and Challenges [Poster]
Type: Poster
Date: 4/28/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Mexico is a highly active country. Most of the seismicity is concentrated at the plate boundaries, which has dictated the evolution of the national seismic network and other regional and local networks. However, it was until the last decade, when the national network expanded to the north of the country, that it became evident the occurrence of low-magnitude seismic sequences far from the plate limits. The national network is still sparse, and there are only a few regional/local networks, forcing to use sometimes a single station for the events' characterization. We present the analysis of three swarms: 1) El Cuchillo, Nuevo León, 2013-2014; 2) Parral, Chihuahua, 20??; and 3) Ixtlán del Río, Nayarit, 2018-2019. Some of them have caused minor damage in communities near the epicentral area. Therefore, improving their locations will allow us to understand the mechanisms that originate these sequences. In all cases, we apply an automatic detection algorithm (STA/LTA, cross-correlation, or fingerprint) in one, two or more stations of the national network to identify more events than those reported by the Servicio Sismológico Nacional (SSN, National Seismological Service, Mexico). For the first sequence, the SSN reported 139 events, while we identify 2611, analyzing data from a single station; for the second, the SSN reported 160, while we identify 300 at a single station; and for the third one, the SSN reported 60, while we identified 132. For the last one, we were able to use more than one station of the national network and benefited from a station of a regional network.

Presenting Author: Xyoli Perez-Campos

Authors