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Deepest volcanic eruption lies in a field of glass at the li

发布时间:2018-11-07 文章编辑:K8
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Researchers found the deepest known 大发volcanic eruption — right on the cusp of the Mariana Trough.

Image credits Oregon State University.

Nestled in a vast field of volcanic glass on the lip of the Mariana Trough at a depth of 4,050-4,450 meters (2.51 to 2.76 miles), researchers from the National Oceanic and Atmospheric Administration (NOAA) and the Oregon State University (OSU) have found the deepest volcano known to man.

The volcano experienced a massive eruption sometime in 2015, they write, creating the 7.3 kilometer-(4.5 mile-)long field of glass.

At the bottom of the sea

The Mariana Trough is a back-arc basin created by the active volcanoes running along the lip of the Mariana Trench. As it sits on the edge of a subduction zone (where one tectonic plate sinks under another), the Trough sees a lot of volcanic activity. However, it’s usually far beyond our sights.

“We know that most of the world’s volcanic activity actually takes place in the ocean, but most of it goes undetected and unseen,” said OSU marine geologist and paper lead author Bill Chadwick.

“Undersea quakes associated with volcanism are usually small, and most of the instrumentation is far away on land. Many of these areas are deep and don’t leave any clues on the surface. That makes submarine eruptions very elusive.”

Such eruptions are so hard to study that we weren’t able to capture one on camera until 2009, less than a decade ago. Only about 40 submarine lava flows have been detected in total.

The eruption in the current paper was first found in December 2015, by the Woods Hole Oceanographic Institute’s autonomous underwater vehicle Sentry. At that time, the glass flows were brand new and pristine — there were no plants growing on them, and no sediments from which any could sprout. Hydrothermal vents were releasing a milky fluid, which indicated that the lava flow was still warm.

本文源自: 环亚娱乐