Calibration Of Volcflow Models Using Thermal Images: The December 2010 Eruptions Of Tungurahua Volcano (Ecuador)

Abstract:

Pyroclastic and lava flows represent a potential hazard at Tungurahua volcano that can cause negative impacts on the productive capacity of the local population. Big challenges have been surmounted in modeling these types of phenomena during the last decades in order to understand and characterize their physical behavior. Nevertheless, just a few of the models have been controlled by specific data that contribute to knowing their cinematic and rheological properties. In order to generate realistic models we focused on the calibration of the numerical model “VolcFlow” using information obtained by sequences of thermal images of lava and pyroclastic flows of Tungurahua volcano (Ecuador). Those models helped to determine the rheological properties. We focused on studying the lava and pyroclastic flows generated on December 4th–5th and 10th 2010, respectively. The work was divided into two basic parts: 1) analysis of lava and pyroclastic flows using sequences of thermal images, and 2) modeling lava and pyroclastic flows with calibrated VolcFlow models. The analysis of thermal images provide input about the spatial location of the flows, the length, area, inferred volume and flow velocity, using the timing of those images. With the aim of modeling both flows with VolcFlow we calibrated it using the volume, velocity, length of the deposit and timing of the inception and deposition of the flows. The results of the calibrated model show that it is possible to obtain values of viscosity and yield strength, which are characteristics for a specific rheology for both flows. This is the first time that a calibration with data measured from lava and …

Año de publicación:

2012

Keywords:

Fuente:

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