ANSS Seminar Series: 9/18 Thomas Goebel, University of Memphis
Barnhart, William D
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Hello Network Seismology Community and Beyond! Join us for our next seminar! September 18th, 11 am Mountain Time: Thomas Goebel - University of Memphis - A community seismic network for the early detection of seismic activity close to active volcanoes in western El Salvador Click this link to join!
Abstract: Seismic monitoring can provide key constraints on volcanic processes, magma migration and preparatory processes before volcanic eruptions. Nevertheless, the high cost of broadband networks limits the number of volcanoes that are actively monitored. Here, we test the capability of a network of raspberry shake (RS) seismographs to monitor volcanoes in El Salvador and characterize associated seismicity sequences in real time. We deployed seven three component, short-period RS velocity seismometers around Santa Ana volcano which has a long history of phreato-magmatic eruptions as recently as 2007. The new network primarily supports training, research and outreach activities but also has the potential to provide early alerts before volcanic unrest. The seismometers were installed at schools, a university campus and hotels within 20 km of Santa Ana volcano. We recorded an accelerating seismicity sequence within 15 km distance from the volcano between 12/28/2023 and 02/01/2024. Both magnitudes and seismicity rates increased systematically, culminating in two events above ML4 on January 28th, 2024 without causing detectable changes in temperature or gas emissions at the summit of Santa Ana. Detailed space-time clustering analyses reveal dominant mainshock-aftershock triggering at local to regional distances, similar to tectonic earthquake sequences. The new RS network around Santa Ana volcano demonstrates the ability of low-cost seismometers to improve seismic event detection, location, and classification. The observations suggest that dense volcano monitoring networks facilitate an early detection of unfolding seismicity sequences and improve tectonic vs. volcanic event classifications - a key component of reliable eruption alerts.
Bio:
Thomas Goebel is an Associate Professor of Seismology at the University of Memphis. He studies induced seismicity, lab-quakes, and volcanos and is particularly interested in how differences in fault zone properties affect permeability, stress transfer, earthquake magnitudes and aftershocks. Goebel received his PhD from the University of Southern California and worked at Caltech and UC Santa Cruz before joining the University of Memphis. He received an UofM research foundation professorship and the Ascending to Excellence Award. He currently leads a group of seven students and postdocs with projects in central and western U.S., El Salvador, central Europe, Hawaii and Alaska. |
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William Barnhart, PhD
Assistant Coordinator
USGS Earthquake Hazards Program
c: 319-834-0674
o: 303-273-8591