On volcanic islands, landslides can trigger giant eruptions

Jan. 19 (UPI) — New analysis of Mount Teide, the volcano on the island of Tenerife, suggests a strong link between submarine landslides and catastrophic eruptions. In fact, scientists hypothesize the collapse of island flanks could trigger massive eruptions.

When researchers at the National Oceanography Center at the University of Southampton in England studied sediment deposits from the island’s multi-stage submarine landslides, they found volcano material only among the top layers of each deposit. The discovery suggests the landslides began prior to each eruption.

By analyzing the thin layers of volcanic clay sandwiched between the landslide and volcanic deposits, scientists determined the end of each underwater landslide and beginning of each eruption was separated by a ten hour gap.

Teide and the island of Tenerife, located in the Canary Islands off the coast of Spain, aren’t unique. The phenomenon may explain the behavior of other island volcanoes.

“Crucially, this new research shows that after the initial submarine landslide there could be between ten hours to several weeks until the eruption is finally triggered — very different from the near-instantaneous landslide triggering of the 1980 Mt St Helens eruption,” NOC scientist James Hunt said in a news release. “This information could help inform hazard mitigation strategies for volcanoes similar to Teide, such as Mt. St Helens or Montserrat.”

Researchers published their findings this week in the journal Scientific Reports.

Under normal conditions, Teide’s shallow magma chamber doesn’t host enough water and other volatiles to inspire a sizable eruption. Scientists suggest the massive submarine landslides help remove volcanic material and cause the magma from deeper volatile-rich magma chambers to rise and mix with magma in the shallow chamber, inspiring massive eruptions.

Such eruptions are some of the most explosive on Earth. The collapse of volcanic island flanks are some of the largest land mass movements on the plants, and the blasts they inspire can pack the power of an atomic bomb. The landslides and eruptions can also trigger devastating tsunamis.

Scientists hope their improved understanding of the unique dynamics of island volcanoes can inspire improved eruption forecasting models.

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