High in a narrow, seawater-filled crevasse in the base of Antarctica’s largest ice shelf, cameras on the remotely operated Icefin underwater vehicle relayed a sudden change in scenery.
Walls of smooth, cloudy meteoric ice abruptly turned green and rougher in texture, transitioning to salty marine ice.
Nearly 1,900 feet above, near where the surface of the Ross Ice Shelf meets Kamb Ice Stream, a U.S.-New Zealand research team recognized the shift as evidence of “ice pumping” – a process never before directly observed in an ice shelf crevasse, important to its stability.
“We were looking at ice that had just melted less than 100 feet below, flowed up into the crevasse and then refrozen,” said Justin Lawrence, visiting scholar at the Cornell Center for Astrophysics and Planetary Science in the College of Arts and Sciences (A&S). “And then it just got weirder as we went higher up.”
Read more at Cornell University
Image: The remotely operated underwater vehicle Icefin, developed by a team led by Britney Schmidt, is visible as it is lowered via a 4.3-mm fiber-optic tether through a borehole to start one of three dives beneath the Ross Ice Shelf near Kamb Ice Stream in December 2019. A tent shelter’s color is reflected in the ice. (Credit: Icefin/NASA PSTAR RISE UP/Schmidt/Quartini via Cornell University)