EAPS

Michael Poland
Research Geophysicist
US Geological Survey


The effusion rate of lava is a parameter of critical importance given its direct association with volcanic hazard. For example, high effusion rates at basaltic volcanoes can result in long lava flows, and at silicic volcanoes are associated with dome collapse and the generation of destructive pyroclastic density currents. Despite its importance, however, lava effusion can be difficult to quantify, and mostly involves indirect measurements. At Kīlauea Volcano, Hawaiʻi, effusion-rate measurement methods include gas emissions, electromagnetic induction over lava tubes, geologic mapping, modeling of thermal radiance, and quantification of topographic change. None of these techniques, however, have consistently yielded reliable results since about 2008, due to the expense associated with data collection or changes in the character of volcanism. The TanDEM-X satellite mission offers a potential solution to this problem by using two satellites to simultaneously collect radar data of the surface that can be merged to form digital elevation models (DEMs). Differencing DEMs from temporally sequential radar images provides measure of the increase in volume due to accumulation of lava across Kīlauea’s >100 km2 East Rift Zone lava flow field over time. During 2011-2014, the effusion rate derived via this method was 1–2 m3/s, which is about half the long-term average rate over the course of Kilauea’s 1983–present East Rift Zone eruption. This result implies an increase in the rate of lava storage at Kilauea, a decrease in the magma supply rate, or some combination of both with respect to previous years. Since June 27, 2014, lava flows have been advancing on island’s Puna district, threatening to inundate or isolate communities that are home to several thousand people. After an initially rapid advance downslope, the flows have repeatedly stalled about 20 km from the vent—perhaps a consequence of the relatively low effusion rate.

Hosted by Taylor Perron


A reception in Building 54, Room 923 precedes the talk.

All are welcome.

If you have any questions regarding the lecture, please contact Jen Fentress at 617.253.2127 or jfen@mit.edu. Reservations not required.

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