Friday Seminar (9 September 2022) David Fee (Univ. Alaska Fairbanks)

Title: Seismo-acoustic observations of the remarkable atmospheric waves from the January 2022 Hunga, Tonga volcanic eruption

Abstract:  The 15 January 2022 volcanic eruption of Hunga, Tonga produced atmospheric waves that stunned both scientists and the general public. These waves were observed globally by a multitude of instruments and technologies. The most notable atmospheric wave was an acoustic-gravity “Lamb” wave that was detected globally on barometers, infrasound sensors, seismometers, and satellites. This Lamb wave propagated across the globe numerous times and contributed to fast-arriving, hazardous tsunamis that were not forecasted. The Hunga Lamb wave resembled the Lamb wave produced by the 1883 Krakatau eruption, but was observed by a much denser instrument network. Notably, infrasound waves also propagated around the globe numerous times, and audible acoustic waves were heard out to an unprecedented 9000 km. Current wave propagation models do not sufficiently explain these observations. Here I present some notable observations of the atmospheric waves from the Hunga eruption, many of them detailed in a recent highly collaborative manuscript. I focus on the Lamb, infrasound, and acoustic wave observations, including some surprising observations made near the source as well as across the dense geophysical network in Alaska. The atmospheric waves from this eruption provide a landmark dataset for scientists to study for many years.