Characterization of seismicity at Volcan Baru, Panama: May 2013 through April 2014

Volcan Baru, in the western province of Chiriqui, is Panama's youngest and most active volcano. Although Baru has experienced no historic eruptions there have been four eruptive episodes in the last 1600 years, the most recent occurring 400-500 years ago (Sherrod et al., 2007). In addition, there have been four reported earthquake swarms in the last 100 years. The most recent swarm occurred in May of 2006, prompting a USGS hazard assessment (Sherrod et al., 2007). In order to characterize local seismicity and provide a reference for future monitoring efforts, we established a seismic network that operated from May 2013 through April 2014. The network consisted of eight temporary single-component, short-period sensors loaned by OSOP Panama, and three permanent stations distributed over a 35 by 15 km area. During operation of the network a catalog of 91 local events were detected, located and then used to calculate a minimum 1-D velocity model for Baru. Of particular interest were a cluster of events west of the town of Boquete. A template matching detection technique was used to identify another 47 smaller magnitude events in the area of this cluster. Spectrograms for the largest events in the cluster show a broad band of frequencies up to ∼20 Hz suggesting a predominantly tectonic source while eight focal mechanisms were calculated which suggest strike-slip and reverse faulting may be the predominant source processes. Further study is encouraged to better constrain the source processes and investigate how volcanic processes might affect local tectonics. 1.;1The material contained in this thesis is intended for submission to the Journal of Volcanology and Geothermal Research .