Yellow and red represent unusually low resistivity below Erebus (10 and 5 ohm meters, respectively). Mount Erebus is fed by a column of hotter rock extending vertically from at least 100 kilometers deep (yellow) and melted magma that extends up through the crust (red).
Solar weather also produces waves that propagate through Earth.Ĭaptured by custom “voltmeters” on the surface and fed into a modeling algorithm, the waves can create a 3D picture of the electrical resistivity of material below, “kind of like a CT scan of the human body,” said Wannamaker.
“A lightning bolt is an impulsive antenna, if you will, and electromagnetic waves ripple out from that into your survey area,” said Wannamaker. “Hats off to Graham for the energy and drive to cover the entire island,” said Wannamaker.Īt each site, they’d recorded the natural electromagnetic waves that travel through Earth from the Sun and distant lightning bolts. They visited 129 sites on Erebus and Ross Island, taking exhaustive measurements. So Hill, Wannamaker, and their colleagues took a different approach: magnetotelluric data.ĭuring summers between 20, the team visited Erebus via helicopter. But Erebus has very few crustal-scale earthquakes, hamstringing the method to shallow depths. Scientists use seismic waves traveling through Earth to ascertain the material below. Past studies into Erebus relied on seismic data to probe its inner workings. Although its name ultimately harkens to Greek mythology’s personification of darkness, Captain James Ross named the volcano after one of his ships, the HMS Erebus, in 1841. Mount Erebus overlooks McMurdo Station, and nearby sits the hut built by legendary polar explorer Ernest Shackleton and his men before they summited Erebus in 1908. The snow-covered Mount Erebus is the southernmost active volcano on Earth and shares Antarctica’s Ross Island with three other volcanoes, all dormant. Credit: Robert Falcon Scott/ Wikimedia, Public Domain Get the most fascinating science news stories of the week in your inbox every Friday.Įrebus has long been familiar to polar explorers-this photo was taken by Robert Falcon Scott on his ill-fated expedition to the South Pole. “This is the first great image of one,” said geophysicist Phil Wannamaker at the University of Utah, who participated in the work. “If we can also get an idea of where the magmatic system is, you can better understand the monitoring data when these systems enter periods of unrest,” said lead scientist and geophysicist Graham Hill at the Institute of Geophysics at the Czech Academy of Sciences. This dryness allows magma to travel much closer to the surface than water (H 2O)-rich volcanoes that stall out at about 5 kilometers below the surface.ĬO 2-rich volcanic systems are less well understood than the more common H 2O-rich arc volcanoes. Instead, it’s rich in carbon dioxide (CO 2). Unlike arc volcanoes such as the Cascades in western North America, Erebus has very little water in its magma. Now, research has revealed the plumbing underneath Mount Erebus that keeps the lake full.ĭata taken by measuring natural electromagnetic waves traveling through Earth revealed the volcano’s magmatic system brings lava much closer to the surface than subduction arc volcanoes. The lake occasionally blasts out lava bombs from the summit crater of Mount Erebus, 3,794 meters high. One of Antarctica’s only active volcanoes is home to one of the few long-lasting lava lakes on Earth.
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