Seismic and Acoustic Signals Generated from Explosive Volcanic Eruptions: A Numerical Investigation of a Potential Monitoring Tool

Colorado School Of Mines, Golden CO

Investigators

Abstract

Morrissey EAR-0003470 The objective of this project is to continue investigating the near-field (3-4 km from source) seismic and acoustic response of a volcano to the explosive discharge of ash and gas. We propose to develop a computer model that simulates the motion in the fluid and rock associated with the discharge of a pressurized mixture of ash and gas through the volcano and atmosphere. Discrete, explosive eruptions are commonly accompanied by shallow volcanic earthquakes and initiate atmospheric sound waves. Existing near-field seismic and acoustic models of volcanic eruptions are either formulated for incompressible, steady flowing ash-steam mixture or are one dimensional. The proposed model will simulate the 3 dimensional explosive discharge of an ash-gas mixture through a crater (filled with either air, steam or water) and into the atmosphere. Applications of the computer code will include modeling the acoustic and earthquake signals associated with eruptions at Sakurajima volcano in Japan and Ruapehu volcano in New Zealand. The merit of this project pertains to the improvement of volcano monitoring capabilities by identifying physical processes related to fluid transport from characteristic features of acoustic and seismic signals.