Laguna del Maule Volcano: Ground under ancient Chilean volcano is rising fast

Laguna del Maule in the Chilean Andes Mountains. Researchers have found uplift in part of the volcanic field.

Credit: Sarah Strierch / Wikimedia Commons

The Laguna del Maule volcanic field in the Chilean Andes Mountains lies in the heart of volcano country.

The region is a well-known subduction zone, where the friction of one crustal plate sliding under another heats rock to form magma.

But for the last 2,000 years, Laguna del Maule has been a quiet water-filled caldera.

Now, scientists are recording rapid deformation of the land around the caldera, suggesting that a magma reservoir is inflating below the surface.

Helene Le Mével of the University of Wisconsin – Madison, GeoScience dept, presented a poster at the American Geophysical Union’s Fall Meeting in San Francisco Wednesday to share the findings.

Researchers at the Southern Andean Volcano Observatory (OVDAS) monitor and archive volcanic activity throughout the region, but Le Mével said that until now, the observatory had no reason to focus on the Laguna del Maule field. “It’s such an old caldera that there’s nobody there,” she said.

Using a radar technique to measure changes in the level of the ground, Le Mével and her colleagues observed that several areas around and under the lake were rising.

When they set up three GPS stations to confirm this data, the results were startling: The ground is uplifting at a rate of almost 30 centimeters per year, and is now 1.4 meters higher than it was in 2007.

Using this information, the team found that the area is organized as a ring fault – a circular pattern of vents formed as land collapsed inward during the eruptions that created the volcano’s cauldron-like shape.

The area is of particular concern, Le Mével said, because the rock in this region contains a high concentration of silicon dioxide, the tough crystalline material used to make glass.

Unlike magma consisting mostly of basalt, found in the more “flowy” volcanoes of Hawaii, silicic magma very thick. It tends to build up in gluey domes under the surface, and then push upward in a violent explosion.

The scientists estimate that the horizontal reservoir of magma, called a sill, measures 7.5 by 5.5 km, and sits about 5 km underground. Not only is the sill growing, pushing up the earth above it, but its growth is also accelerating.

“At some point, a magma reservoir is always going to erupt when it’s ready, we just don’t know when,” said Le Mével.

She expects to see increasing seismicity right before the eruption, which she said could still be 1,000 years away. But she hopes this new evidence will be enough to fuel further research on the processes driving the deformation.

“We rarely observe large silicic systems that are likely to erupt, even if it’s not next week or next year. And so it’s going to be exciting to follow it. To see how it continues.”

Americans mark 10th anniversary of September 11 attacks

Americans Sunday remembered the horror of September 11, 2001, and the nearly 3,000 people who died in the hijacked plane attacks as authorities worked to ensure the emotional 10th anniversary was peaceful.

Law enforcement authorities in New York and Washington were on high alert against what was described as a "credible but unconfirmed" threat of an al Qaeda plot to attack the United States again a decade after the toppling of the World Trade Center's twin towers by hijacked airliners.

Security was especially tight in Manhattan, where police set up vehicle checks on city streets as well as bridges and tunnels coming into the city.

President Barack Obama and former President George W. Bush, who was president at the time of the attacks, were scheduled to be among the dignitaries at the Ground Zero site in New York.

They were set to join victims' families to hear the reading of the names of those who died on September 11. Bells will toll across the city.

In the attacks, 19 men from the Islamic militant group al Qaeda hijacked airliners and crashed them into the World Trade Center, the Pentagon outside Washington and a field in Shanksville, Pennsylvania.

EDRS: high-speed data from LEO to ground

At its core, the EDRS system will enable satellites in low-Earth orbits (LEO), which are usually only able to communicate directly with a ground station for just a few minutes per orbit, to send their data almost continuously via laser link up to receivers mounted on spacecraft in geostationary orbit.

These are in permanent view of ground stations, so the data can be sent down at high speed and distributed to end-users.

This architecture vastly improves existing space applications and enables new services. For example, when a forest fire is first spotted, a satellite could be tasked to acquire images and send the data via EDRS quickly to the ground, where maps could be generated within just a few hours. This is very difficult with current systems.

The EDRS system will also provide graduated levels of commercial service by offering lower-speed data transfer via traditional Ka-band radio links, at lower cost, in addition to the high-speed optical links.