Thursday, September 27, 2018

Global Warming Is Destabilizing Mountains, Creating Landslide Risks

As more permafrost thaws and water seeps deeper into mountains crags, extreme storms can trigger dangerous landslides and rockfalls.

Storms have triggered landslides in the Alps that have sent mud and debris pouring into villages. Bondo, in the Swiss Alps, has been hit more than once in recent years. The video below shows the destruction from 2017. (Credit: Miguel Medina/AFP/Getty Images) Click to Enlarge.
It's not just the atmosphere and the oceans that are heating up.  An ever-denser blanket of greenhouse gases is also sending warmer air and water deeper into the planet's rocky bones.

In the mountains of Switzerland, scientists have measured startling temperature increases, with jumps of as much as half a degree Celsius in just a decade 20 feet deep into the rocks.  On Svalbard, an Arctic island north of Norway, similar warming has been measured more than 100 feet deep in the permafrost.

Tracking these changes is critical to assessing growing threats to people, said Bjørn Samset, research director at the CICERO climate research center in Oslo.

The warming, combined with other climate effects like extreme rainfall, is speeding up some basic geological processes.  Softer rocks and soils that used to stay frozen most of the year, like permafrost, are thawing and eroding faster.  Seemingly monolithic slabs of solid granite are peeling off mountainsides like the layers of an onion.  And powerful rock glaciers—wide swaths of slow-moving ice and rock rubble that can pulverize granite—are speeding up, in one case from 40 feet per year to 226 feet per year.

Read more at Global Warming Is Destabilizing Mountains, Creating Landslide Risks

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