Erin Pettit

Erin Pettit explores glaciers to better understand and predict changing climate and rising seas. She is an assistant professor of geophysics and glaciology at the University of Alaska Fairbanks and creator of Girls on Ice, a wilderness science experience for high school girls.

Erin Pettit has conversations with glaciers. Mainly, she listens. As she translates their language, shell tell the rest of us what theyre saying about sea level rise, climate change, and how critical processes like ocean circulation may be transformed.

Pettit came up with the idea of using underwater listening instruments to record the noisy boundary of ice and sea. Acoustic research has already contributed much of what we know about the ocean, she observes. But no one had applied the technique to studying glaciers.

Glaciologists love to examine the ice-ocean boundary because its dynamic nature may reveal what triggers glacial changewarmer water, the atmosphere above, or as yet unknown forces. Its also a very dangerous place. Scientists have long looked for ways to safely make measurements amid disintegrating ice shelves and iceberg-jammed waters. Pettits carefully placed hydrophones in Alaska and the Antarctic Peninsula could be one ingenious way.

Glaciers meet oceans in an explosion of sound. Calving ice slams into waves, water gushes out from below, and air bubbles pop as icebergs melt upon impact with sea. This symphony comes from different sources within the glacier, says Pettit. Im dissecting our recordings to figure out whats generating flute sounds versus deep tuba notes versus midrange trumpets, so we can infer glacial changes from the sounds themselves. Im especially interested in freshwater rushing out from underneath the glacier, because it directly contributes to sea level rise and signals major changes caused by ice-ocean-air interaction. The more water that spews out, the faster the glacier slides. These huge flushes of freshwater could alter circulation in a bay, then a gulf, and even further out.