Infrasound Waveform Classification and Emissions Correlation at Karymsky and Sakurajima Volcanoes
Tuesday, 16 December 2014
Infrasound (sound between ~0.01-20 Hz) is often used to monitor volcanoes and provide insight into eruption dynamics. Of the main goals in the volcano infrasound community, associating volcanic emissions with specific infrasound features remains of importance. Here we focus on infrasound collected during two separate field campaigns at Karymsky Volcano, Kamchatka, Russia and Sakurajima Volcano, Japan. Both volcanoes are andesitic and produce frequent eruptions. Recent Karymsky eruptions have been classified into four main eruption types: discrete ash explosions, pulsatory gas emissions, gas jetting, and quiescence followed by an explosion. Sakurajima eruptions are typically ash-rich and are dominantly Vulcanian in character. We use a waveform cross correlation scheme to identify infrasound waveform families from recent eruptions at each volcano. We also identify changes in eruption dynamics by tracking the number and occurrence of these families though time. This can be done on a large scale (changes in relation to the families) as well as on a smaller scale (changes in relation to the subfamilies). During these field campaigns volcanic emissions data were also collected using ground-based sampling, and visual, ultraviolet, and infrared remote sensing techniques. The infrasound waveform families are then correlated with volcanic emissions data to determine unique signatures of volcanic emissions. By comparing model calculations and physical data, this information will hopefully lead to improved monitoring and characterization of volcanic eruptions using infrasound in particular at remote, difficult to monitor volcanoes.