ĭark Oligotrophic Volcanic Ecosystems (DOVEs) in Fumarolic Ice Caves of Mt. The image was acquired December 31, 2013, covers an area of 63 x 73 km, and is located at 77.5 degrees south, 167.1 degrees east. Continuous lava-lake activity with minor explosions, punctuated by occasional larger strombolian explosions that eject bombs onto the crater rim, has been documented since 1972, but has probably been occurring for much of the volcano's recent history. The glacier-covered volcano was erupting when first sighted by Captain James Ross in 1841. An elliptical 500 x 600 m wide, 110-m-deep crater truncates the summit and contains an active lava lake within a 250-m-wide, 100-m-deep inner crater. The 3794-m-high Erebus is the largest of three major volcanoes forming the crudely triangular Ross Island. The process to create these little earthquakes isn’t too earth shattering, they said.This image from NASA Terra spacecraft shows Mount Erebus, the world southernmost historically active volcano, overlooking the McMurdo research station on Ross Island. “They’re like little earthquakes,” he said. Kyle emphasized that there was no danger of the explosives creating any sort of reaction in the volcano.
Snelson said the velocity of the waves also says something about the types of rocks and liquids buried below. The seismic waves recorded by the instruments after the explosions help the scientists infer where areas of heat and magma are located. Following detonation, non-explosive residues are collected and transported to McMurdo Station for disposal as waste.)
(Environmental effects from the installation, operation and removal of the seismic instruments - in addition to the use of explosive charges on Mount Erebus - should be less than minor or transitory, according to an environmental review of the project prior to the beginning of the season. “The emphasis this year is to develop the technique.” “We’re going down about 21 kilometers,” Snelson said. She and blasters from McMurdo Station had managed to set off seven blasts to start building an image in the upper 2 kilometers of the volcano, in what they hope will set the stage for a possible larger campaign in a coming field season. In addition, the team set up 14 temporary sensors just to record the explosions, and later recovered those instruments.Ĭatherine Snelson, assistant professor of geophysics at New Mexico Institute of Mining and Technology, is in charge of the active-source seismic work.
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Still, as the season came to a close at the end of January, the scientists had managed to install 23 of 25 planned broadband seismic stations around the flanks and summit that will stay out to record sound waves from distant earthquakes and the volcano’s own rumblings over the next year. Atrocious weather often pinned down the people working on the 3,796-meter-high volcano and left helicopters on standby at McMurdo Station for days at a time. This year’s goal to establish the seismic network and test the concept hasn’t been an easy one to reach.
He makes the point with a zigzag of his fingers.
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Instead, Kyle said, what probably exists is a conduit that leads down to a series of irregularly shaped chambers. “What you see in the textbooks - the long, straight conduit leading down to a round chamber - probably isn’t at all what it looks like.” “There have been very few direct studies of a volcano’s magma chamber,” Kyle said. But so far, he only has suspicions of what lies below the magma lake, a pool of molten rock, visible from the crater rim.
Kyle, a volcanologist with the New Mexico Institute of Mining and Technology, has learned much about Erebus in the last 35 years. Seismometers measure and record the size and force of underground energy, or seismic, waves.īy studying the refracted and reflected seismic waves, the scientists can map the interior of the volcano, much as a CT scan images the inside of an object using X-rays. Researchers spent more than three months installing an array of seismometers around Mount Erebus to listen to waves of energy generated by small, controlled blasts from explosives they buried along its flanks and perimeter. Antarctic Sun story: Mount Erebus Throws Fit
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