The melting rate of glaciers in the Juneau Icefield, spanning the border between Alaska and British Columbia, Canada, has significantly accelerated since 2010, potentially surpassing previous estimates. This concerning discovery comes from a study by scientists at Newcastle University, published in the journal Nature Communications. The research team, led by Bethan Davies, examined data dating back to 1770, utilizing historical documents, aerial photographs, satellite images, and geomorphological mapping.

The study identified three distinct periods of ice volume change. From 1770 to 1979, ice loss was relatively constant, ranging from 0.65 to 1.01 cubic kilometers per year. Between 1979 and 2010, the average annual loss increased to 3.08 to 3.72 cubic kilometers. From 2010 to 2020, the loss rate doubled, reaching 5.91 cubic kilometers per year. In total, about a quarter of the original ice mass in the Juneau Icefield has been lost between 1770 and 2020.

Alongside the increased rate of glacier thinning, the researchers observed greater glacier fragmentation. They documented a dramatic rise in disconnections, where lower glacier sections separate from upper sections. By 2019, all studied glaciers had retreated from their 1770 positions, and 108 glaciers had completely disappeared.

“The rapid acceleration in melting we’ve found is incredibly alarming,” Davies commented. “Alaskan glaciers, being predominantly flat, are especially vulnerable to accelerated melting due to climate warming, as ice loss affects the entire surface area. The processes we’ve observed in Juneau could also occur in other similar regions.”

“Our study,” added Robert McNabb from the University of Ulster, “indicates that current projections might underestimate the risk of ice loss. Long-term records are an invaluable resource, providing unprecedented detail on landscape changes.”

Lascia un commento

Il tuo indirizzo email non sarà pubblicato. I campi obbligatori sono contrassegnati *