Long Swarms and Short Swarms at Volcanoes: Evidence for Different Processes (part 1) and Estimates of Water in the Hunga Tonga plume (part 2)

 Presented by Dr. Steve McNutt | Professor, University of South Florida

Talk Abstract:

Volcanoes often show earthquake swarms of different durations. Long swarms (weeks to months) are characterized by a low b-value, suggesting increased pressure at depth. These are followed by short swarms (hours-days) with higher rates and 30-50 percent VLP events, suggesting pulses of magma injection. A case study of Hunga Tonga estimates the amount of water in the enormous plume and uses this to determine energetics of the eruption.

Biography:

Steve McNutt is a volcano seismologist who has spent over two decades working with the Alaska Volcano Observatory, studying some of the world's most active and unpredictable volcanic systems. His research spans an unusually wide range of volcanic phenomena, including the source and propagation of volcanic tremor, low-frequency events, and explosion earthquakes; the mechanical behavior of volcanoes (from eruption periodicity to how earth tides, sea level changes, and tectonic stress can trigger eruptions); volcano infrasound and volcanic lightning.

Today, Dr. McNutt coordinates volcano seismology research in the Department of Geosciences at the University of South Florida and has served as Secretary-General of the International Association of Volcanology and Chemistry of the Earth's Interior, helping shape the field on a global stage.