USGS Mendenhall seminar: Mariana Islands seismicity & infrasound

Mendenhall Postdoctoral Research Seminar

John Lyons, USGS – Anchorage, AK

When: Monday, May 18, 2015 – 12 Noon

Where: Via WebEx and National Center, Room 3A409 (Chief Geologist’s Conference Room)


Long-period seismicity and infrasound driven by shallow magmatic degassing at Mount Pagan, Mariana Islands

Mount Pagan (570 m) is the currently active vent on the north end of Pagan Volcano, Mariana Islands.  Since the establishment of a monitoring network in 2013, a persistent degassing plume, long-period (LP) seismicity and infrasound, and infrequent small degassing explosions have dominated activity. The current low-level, open vent activity provides an ideal platform for studying the source processes of LP events, and how they relate to degassing. Many active volcanoes display LP (0.2-5 Hz) seismicity and because variations in LP activity often herald changes in eruption behavior, understanding the source mechanisms that generate LP events is a primary goal of volcano seismology. Expanding observations to include other data types greatly facilitates the interpretation of LP events. Studies correlating seismic and infrasound data have revealed important linkages between shallow LP seismicity and the generation of LP infrasound at other open vent, basaltic systems. Some form of degassing often accompanies LP activity, and integrating seismic and infrasound data with plume observations or gas chemistry allows further refinement of source models. In this study, we focus on characterizing the LP activity and interpreting the source processes generating the seismic and infrasonic signals through waveform modeling. The results are combined with gas emission and composition data and information about the shallow geologic structure to develop a model of shallow degassing for Mount Pagan.

WebEX Info

Topic: Mendenhall research Seminar
Date: Monday, May 18, 2015
Time: 11:00 am, Eastern Daylight Time (New York, GMT-04:00)
Meeting number: 714 351 061
Meeting password: (This meeting does not require a password.)
Host Key: 237217

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Teleconference: National Center in Reston, VA Dial In: x4848
DOI Dial In Number: 703-648-4848
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