Volcanic Domes
DB: This is Earth and Sky. Most volcanos don’t have fast–flowing lava like the famous volcanoes in Hawaii.
JB: Instead, most volcanos erupt explosively – like Mount Saint Helens in Washington. The lava that creeps out onto the surface is sticky – at least 1,000 times thicker than Hawaii’s more liquid lavas. The thicker lava moves more like hot asphalt, pushing upward to form a pile of rock called a dome. These lava domes are difficult to study.
Michael Ramsey: The only real good way to do that is with satellite data because you don’t want to send somebody up on top of an active lava dome – it’s incredibly dangerous work.
DB: That’s Michael Ramsey, a volcanologist at the University of Pittsburgh. He’s using the ASTER instrument on NASA’s Terra satellite to study the infrared energy from lava domes.
Michael Ramsey: During the time of the eruption, that lava dome can change – in chemistry, it can change in texture… and those types of changes signal something very important about what’s going on further down in the volcano – and especially whether the volcano is pressurizing and is going to erupt large again, or if it’s just passively sitting there – the dome is kind of the last gasp, and it’s just cooling and settling back down again.
JB: Ramsey hopes to find indicators that could help predict when volcanoes are likely to erupt. Special thanks today to NASA Earth Science Enterprise. We’re Block and Byrd for Earth and Sky.
The following individual was interviewed for today’s show. Our thanks to:
Dr. Michael Ramsey
Assistant Professor
Department of Geology & Planetary Science
University of Pittsburgh
and Director of the Infrared Spectroscopy Laboratory,
U. of Pittsburgh
Ramsey is a member of the science team for ASTER (Advanced Spaceporne Thermal Emission and Reflection Radiometer), an instrument aboard the Terra satellite.
More Resources:
Domes of Destruction (NASA’s Earth Observatory)
ASTER homepage (NASA’s Jet Propulsion Laboratory)
NASA’s Terra Satellite homepage
