October 20, 2011 – BOLIVIA – Should anyone ever decide to make a show called “CSI: Geology,” a group of scientists studying a mysterious and rapidly inflating South American volcano have got the perfect storyline. Uturuncu is a nearly 20,000-foot-high (6,000 meters) volcano in southwest Bolivia. Scientists recently discovered the volcano is inflating with astonishing speed. “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 — blowing up like a giant balloon under a wide disc of land some 43 miles (70 kilometers) 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.” The peak is perched like a party hat at the center of the inflating area. “It’s very circular. It’s like a big bull’s-eye,” said Jonathan Perkins, a graduate student at the University of California, Santa Cruz, who recently presented work on the mountain at this year’s Geological Society of America meeting in Minneapolis. Scientists figured out from the inflation rate that the pocket of magma beneath the volcano was growing by about 27 cubic feet (1 cubic meter) per second. “That’s about 10 times faster than the standard rate of magma chamber growth you see for large volcanic systems,” Perkins told OurAmazingPlanet. “It’s not a volcano that we think is going to erupt at any moment, but it certainly is interesting, because the area was thought to be essentially dead,” de Silva said. Uturuncu is surrounded by one of the most dense concentrations of super-volcanoes on the planet, all of which fell silent some 1 million years ago.
Super-volcanoes get their name because they erupt with such power that they typically spew out 1,000 times more material, in sheer volume, than a volcano like Mount St. Helens. Modern human civilization has never witnessed such an event. The planet’s most recent super-volcanic eruption happened about 74,000 years ago in Indonesia. These eruptions are thought to have not only a local and regional impact, but potentially a global impact,” de Silva said. Uturuncu itself is in the same class as Mount St. Helens in Washington State, but its aggressive rise could indicate that a new super-volcano is on the way, or not? De Silva said it appears that local volcanoes hoard magma for about 300,000 years before they blow — and Uturuncu last erupted about 300,000 years ago. “So that’s why it’s important to know how long this has been going on,” he said. If this is a super-volcano, it could be one of the largest on the planet. –Our Amazing Planet