Twenty years of tracking Sperry Glacier retreat

Measuring glacier ice loss at high altitude

USGS glaciologists drill and survey snow depth across elevation stakes on Sperry Glacier, discovering winter snow gone and bare glacial ice exposed.

How Glaciologists Measure Mountain Ice Loss

36 feet of water lost from Sperry Glacier

Two decades of USGS data show Sperry Glacier lost over 36 feet of water equivalent, sending massive torrents of meltwater down the peak.

[00:22] How Glaciologists Measure Mountain Ice Loss
[00:56] A 3-Story Wall of Water Lost From Sperry Glacier