The Western United States is losing its glaciers.

A new inventory from Portland State University researchers show that some glaciers have disappeared entirely, some no longer show movement, some are too small to meet the 0.01 square kilometer minimum and some are actually rock glaciers — rocky debris with ice in the pore spaces.

Andrew Fountain, a geology professor emeritus at PSU, and research assistant Bryce Glenn, inventoried glaciers and perennial snowfields in the western continental U.S. using aerial and satellite imagery between 2013 and 2020. The inventory, published in the journal Earth System Science Data, identified 1,331 glaciers and 1,176 perennial snowfields.

It updates a mid-20th century inventory, derived from U.S. Geological Survey topographic maps made over a 40-year span, and provides a baseline for estimating future changes amid a warming climate.

“Glaciers are disappearing and this is a quantification of how many around us have disappeared and will probably continue to disappear,” Fountain said.

Read more at Portland State University

Photo Credit: Walter Siegmund via Wikimedia Commons