Physical volcanology studies form one of the major research activities
within HIGP, and is done both in support of our remote sensing activities
as well as basic research on its own. Over the last decade, HIGP members
have visited over a dozen active volcanoes around the world, and have
active collaborations with faculty within the UH Department of Geology and
Geophysics, and with other organizations around the world. Some of our
on-going volcanology efforts include:
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Geologic Mapping.
At HIGP volcanological research is a natural outgrowth of the remote sensing studies undertaken on various volcanoes around the world. Dr. Scott Rowland has been using remote-sensing data to gain a better understanding of the Galápagos volcanoes. These shield volcanoes have some similarities to those found in Hawai'i but some striking differences as well. For example, Galápagos calderas are very large with respect to the volcanoes so they exert a significant structural control on magma migration and eruption location. Only by detailed mapping of lava flows, vents, and slopes is it possible to start to unravel this complexity. The map at left shows the distribution of young (orange), medium-aged (green) and old (gray) lava flows on Fernandina, the most active of the Galápagos volcanoes.
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Emplacement of Basaltic Lava Flows.
Dr. Andy Harris leads the HIGP efforts to understand the structure and emplacement of basaltic lava flows. Part of this effort is to constrain the thermal signal received by remote sensing instruments but a significant additional goal is to gain a better understanding of how, why, and where basaltic flows are emplaced. Much of this work is field-oriented and involves careful monitoring of the surface thermal structure and cooling histories of active flows. By making repeat measurements of a flow as it cools, a better understanding of the cooling mechanism and physics of surface crust formation can be gained. Simultaneous measurements of small areas of the surface (with spectrometers), large areas of the surface (with radiometers, such as at left), and the interior of active lava (with thermocouples) provide important information about what remote measurements are actually "seeing". Collaboration with HIGP faculty members Luke Flynn and Peter Mouginis-Mark, students and faculty in the Department of Geology and Geophysics, and the staff of the Hawaiian Volcano Observatory is a strong component of this work.
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FLOWGO.
Combining knowledge about the heat loss that an active lava flow undergoes and rheological properties of lava has allowed Andy Harris and Scott Rowland (Department of Geology and Geophysics) to derive a self-adaptive numerical model of lava flowing in a channel. This model, named FLOWGO, considers 1-m packets of active lava and takes into account all the heat loss and heat gain processes that are occurring, some of which are obvious and others of which are not. By combining these and including the ways in which they interact, Drs. Harris and Rowland are able to replicate the flow conditions that have been observed in the field. They are currently collaborating with Harold Garbeil to produce a lava flow model that is able to follow digital topography. This work has obvious applications to lava hazard mitigation efforts as well as to deriving the eruption characteristics of lava flows, both terrestrial and planetary, that were not observed.
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Mt. Pinatubo, the Philippines.
Since the major eruption of Mt. Pinatubo in June 1991, this volcano has been an ideal location for remote sensing studies of topographic change on a volcano. Pete Mouginis-Mark and Harold Garbeil have been studying radar and multispectral images of the volcano. They also started a field program on Mt. Pinatubo to better understand the erosional processes that are still taking place on the flanks of the volcano. The degree of erosion of some of the river valleys on the western flanks of Mt. Pinatubo is extreme. In some places, more than 20 meters of erosion have been recorded with the passage of a single typhoon.
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Other Volcanoes.
Luke Flynn and Andy Harris have on-going collaborative
efforts on several Central American volcanoes. They have made recent field
visits to Pacaya and Santa Maria volcanoes in Guatemala in support of their
satellite investigations of volcanic thermal anomalies. They also
collaborate with Mexican volcanologists on the analysis of Popocatepetl
volcano. Pete Mouginis-Mark and Harold Garbeil have maintained a low-level
research interest in Taal volcano (Philippines) in collaboration with
members of the Department of Geology and Geophysics.
Sarah Fagents is interested in the physics of eruptive processes, and the influence that planetary environment has on the style of eruption and resulting landform. Her research includes lava fluid dynamics and heat transfer, the role of thermomechanical erosion, and lava-water interactions.
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For more information on volcanology at HIGP contact:
Sarah Fagents,
Luke Flynn,
Andy Harris, and
Peter Mouginis-Mark.
Text and images courtesy Scott Rowland, and Peter Mouginis-Mark.
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