Category Archives: 2013 (11/18) The Pressure Ridges

The Pressure Ridges

November 18, 2013

Yesterday I did a midnight hike to the pressure ridges on the frozen ocean near Scott base (the New Zealand station on the coast near McMurdo).



These ridges form out on the frozen ocean where floating sea ice gets lodged into the fast ice shelf that protrudes from Ross Island. In this way it’s quite similar to tectonic plates that create mountain ranges, but with ice– the sea ice floating around the ocean during summer gets scraped into the ‘island ice’ that spreads out to the sea from the shoreline, then it all freezes together in a long stretch of ridgelines on top of the ocean.



Although it’s still sunny at midnight, the sun is lower in the sky and casts really long, beautiful shadows on the ridges.


In the future, more sea ice will push into new boundaries in the fast ice shelf and both build up the pre-existing ridges and create new ones farther away from the shore.


IMG_7677bLayers of dense ice create a bluish hue

IMG_7705bStanding next to the pressure ridges

While I’ve been in McMurdo for nine days cleaning sample bottles and organizing equipment, tomorrow I’ll finally head out to the Dry Valleys of the Transantarctic mountains. I may not have internet for a few days but I’ll try to check in again soon. In the mean time, we also saw a weddell seal on our pressure ridges hike, and I’ll try to write a post about the seal with some photos when I’ve finished sorting through them all. It was a beautiful hike on the sea ice!