Saturday, November 17, 2007
Yellowstone super volcano is on the rise!
The current uplift was detected by a global positioning system stations and radar instruments on an orbiting satellite. The reason for the inflation of the park's surface is due to an infusion of magma about six miles (10 kilometres) underground. But that is because Yellowstone is situated on a giant, geologically active feature known as a supervolcano.
"It's hundreds of times bigger than Mount St. Helens," said Robert Smith, a geophysics professor at the University of Utah. Mount St. Helens is an active volcano in Washington State. "The land is rising because magma and hydrothermal fluids are migrating into the volcano's underground chambers," explained Smith. "It's really kind of a sponge, where you have interlaced open spaces with magma and solid rock between. Only 10% [of the chambers are] actually made up of molten rock," he added. Much of the park sits in a caldera, or crater, some 40 miles (70 kilometres) across, which formed when the cone of the massive volcano collapsed in a titanic eruption 640,000 years ago.
According to Kenneth Pierce of the US Geological Survey in Bozeman, Montana, "The newly detected upswell is part of a natural cycle that is common to calderas." "That's because the Yellowstone caldera has inflated and deflated about six to eight times without a volcanic eruption since the last 14,000 years ago," said Montana. "Since calderas go up and down, we use the term 'restless' to describe these systems," said Smith. The super volcano has produced three large blasts in the past two million years, with 30 smaller eruptions since the caldera formed.
The volcano's most recent flare-up was 70,000 years ago, and volcanic heat continues to fuel the park's famous geysers and hot springs. Many scientists believe the volcano is produced by a "hot spot" in the Earth's mantle, a plume of hot rock rising from hundreds of miles below. "Since the hot spot first rose 16 million years ago, it has produced at least 140 eruptions throughout the north-western United States," said Smith.
"But, there's no evidence of an imminent eruption or hydrothermal explosion," he added. "To gauge any future volcanic activity, the park is continuously monitored by instruments associated with the Yellowstone Volcano Observatory," said Smith. "These provide information of public safety, daily and in real time," he added.