Volcanic Activities Puzzle Researchers
October 26, 2011 • 1:39PM

After a hiatus of almost 19 years, Sicily's Mount Etna has once more become extremely active. The tallest and most active volcano in Europe, Etna is spewing lava for the 17th time this year. Before its first eruption this year, Etna had had no major eruption since 1992. The latest eruption has closed off the airport in nearby Catania, Sicily's second-largest city.

Meanwhile, researchers are puzzled by the phenomenal inflation of the 20,000-feet-high Uturunchu volcano in southwest Bolivia. "I call this 'volcano forensics,' because we're using so many different techniques to understand this phenomenon," said Oregon State University professor Shan de Silva, a volcanologist on the research team. Researchers realized about five years ago that the area below and around Uturuncu is steadily rising, inflating like a giant balloon under a wide disc of land some 43 miles across. Satellite data revealed the region was inflating by 1 to 2 centimeters (less than an inch) per year and had been doing so for at least 20 years, when satellite observations began."It's one of the fastest uplifting volcanic areas on Earth," de Silva told OurAmazingPlanet. "What we're trying to do is understand why there is this rapid inflation, and from there we'll try to understand what it's going to lead to."

Now, researchers are analyzing the deepest active submarine eruption that they had filmed in 2009. The volcano in question, West Mata, lies near the islands of Fiji in the southwestern Pacific, in the Lau Basin. Here, the rate of subduction — the process in which one massive tectonic plate dives under another, typically forming chains of volcanoes — is the highest on Earth, and the region hosts ample signs of recent submarine volcanism.

Scientists discovered West Mata in 2008 during a survey of the northeast Lau Basin. Explosive eruptions were seen in the following year there using a remotely operated underwater vehicle. The first eruption was called Hades, the second Prometheus, both occurring at a depth of approximately 3,900 feet (1,200 meters). The nearly continuous eruptions generated spectacular incandescent gas-filled bubbles of lava up to 3 feet (1 m) wide. Gas flowing through the glowing lava could sometimes look flame-like in appearance, scientists said. "It was absolutely stunning and exciting, something we'd never seen on the seafloor before," researcher Joseph Resing, an oceanographer at the University of Washington in Seattle, told OurAmazingPlanet. This submarine eruption is the deepest seen yet and was deeper than scientists had expected to see explosive eruptions.