Automated Detection and Characterization of Swarms and Mainshock-aftershock Sequences in Nicaragua and Costa Rica
Description:
A new methodology for the automated identification and characterization of swarms and Mainshock-Aftershock (MsAs) sequences was recently developed and applied to seismicity in the Mexico subduction zone (Ventura-Valentin et al., in review). This method uses a nearest neighbor approach to identify clusters (Zaliapin & Ben-Zion, 2013) and then integrates five quantitative characteristics derived from Omori, Båth, and Gutenberg-Richter laws to differentiate swarms from MsAs. Specifically, the algorithm calculates these attributes: magnitude difference, mainshock order, rate decay, magnitude decay, ratio of magnitude range to number of events. Intriguingly, the analysis in Mexico found twice as many swarms as MsAs. Our project is investigating whether this method produces a similar result in the nearby portion of the Central American subduction zone in Nicaragua and Costa Rica.
Using publicly available catalogs for this region, our preliminary results indicate the opposite: there were about twice as many MsAs as swarm sequences in Nicaragua and Costa Rica. Individual sequences were manually reviewed to confirm that automated ratings of sequence types was appropriate. MsAs were more common offshore and associated with the subducting plate interface, although some were also common near inland volcanoes. Alternatively, swarms were more common along the inland sliver fault and also near some volcanoes such as Poas in Costa Rica. Swarms were also more common along sliver faults in Mexico, indicating some similarity in origin but there is notable a difference in swarm productivity between the two regions.
Session: Advanced Geophysical Observations, Analytical Methods, and New Insights for Earthquake Swarms [Poster]
Type: Poster
Date: 4/15/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Lina
Student Presenter: Yes
Invited Presentation:
Poster Number: 115
Authors
Lina Miesse Presenting Author miesselr@miamioh.edu Miami University |
Michael Brudzinski Corresponding Author brudzimr@muohio.edu Miami University |
Wilnelly Ventura-Valentin venturwa@miamioh.edu Miami University |
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Automated Detection and Characterization of Swarms and Mainshock-aftershock Sequences in Nicaragua and Costa Rica
Category
Advanced Geophysical Observations, Analytical Methods, and New Insights for Earthquake Swarms