Abstract
Abstract We show two examples of how integrated analysis of thermal and infrasound signal can be used to obtain, in real time, information on volcanic activity. Soufrière Hills Volcano (SHV) on Montserrat offers the opportunity to study a large variety of processes related to lava-dome activity, such as pyroclastic density currents (PDCs) and large Vulcanian eruptions. Infrasound and thermal analysis are used to constrain the propagation of PDCs and their velocities, which are calculated here to range between 15 and 75 m s −1 . During the Vulcanian eruption of 5 February 2010, infrasound and thermal records allow us to identify an approximately 13 s seismic precursor possibly related to the pressurization of the conduit before the explosion onset. The associated very long period (VLP) seismic signal is correlated with the gas-thrust phase detected by thermal imagery, and may reflect a change in the upward momentum induced by the mass discharge. Moreover, from infrasound and thermal analysis, we estimate a gas-thrust phase lasting 22 s, with an initial plume velocity of approximately 170 m s −1 and a mean volumetric discharge rate of 0.3×10 5 –9.2×10 5 m 3 s −1 . This information provided in real time gives important input parameters for modelling the tephra dispersal into the atmosphere.
Highlights
ObjectivesOur aim is to give an estimate of the plume exit velocity and volume flux that are important input parameters for the tephra dispersal predictive models evaluating the amount of volcanic ash emitted into the atmosphere
The associated very long period (VLP) seismic signal is correlated with the gas-thrust phase detected by thermal imagery, and may reflect a change in the upward momentum induced by the mass discharge
Extrusion of andesite lava at Soufriere Hills Volcano (SHV) is associated with violent Vulcanian explosions that transport large quantities of tephra to heights of tens of kilometres into the atmosphere
Summary
Our aim is to give an estimate of the plume exit velocity and volume flux that are important input parameters for the tephra dispersal predictive models evaluating the amount of volcanic ash emitted into the atmosphere
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
