Low Magnitude Seismicity in the Vicinity of the North Korean Test Site

Session: Waveform Cross-Correlation-Based Methods in Observational Seismology [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Non-nuclear sources of seismicity that originate near known nuclear test sites present a continuing risk of source misidentification in test-ban treaty monitoring operations. To quantify such seismicity near the North Korean Test Site (NKTS), Lamont-Doherty Observatory researchers assembled and prepared six years of seismographic data collected from the 17- element Dongbei Seismic Network (DBSN 2004-2010) for processing. We supplement these data with nine years of International Monitoring System (IMS) records to characterize local, low- magnitude seismicity recorded tens of km from the NKTS test site. The temporal coverage of our data precedes, coincides with and follows the testing program of North Korea. To build an event catalog, we applied noise-adaptive, digital power and correlation detectors against our data streams and subsequently identified waveform phases, associated events and located sources where possible. Three channel sensors deployed within the DBSN recorded low magnitude seismic events from the pre-testing through the testing epoch. Array data from the IMS recorded events from the testing through the post-testing epoch. Both datasets reveal sources with epicentral solutions located within 10s of km of the test site with source-receiver distances ranging from 90-450km. These data reveal the history of tectonically-sourced low magnitude events that locate near the NKTS. We propose that further analyses of these data will help develop methods to distinguish between tectonic events (including explosion-induced shearing) from explosive events and will improve our physical understanding of natural seismic behavior in a post-testing era.

Presenting Author: Christine N. L. Gammans

Authors