William Glacier disintegrates into a thousand small pieces triggering tsunamis at the surface of the ocean

The William Glacier broke apart into a thousand little pieces right before the eyes of the researchers on board the RRS James Clark Ross of the British Antarctic Survey. William Glacier is located on the Antarctic Peninsula.

Although such events have long been known to cause tsunamis at the ocean’s surface, the team’s analysis of the calving event showed that the glacier calving can also cause strong interior waves, a process that has been overlooked in computer models that drive ocean mixing.

The results were released in the magazine Science Advances.

While the results have been released now, the event happened in 2020 when the team aboard the British Antarctic Survey’s RRS James Clark Ross research ship was taking ocean measurements off the Antarctic Peninsula. They watched the William Glacier disintegrate into a thousand small pieces before their very eyes.

There are normally one or two significant calving events every year on the William Glacier. The scientists calculated that this event ripped off about 78,000 square metres of ice, or the area of 10 football fields, with the front of the glacier standing 40 m above sea level.

The ocean water was cool between 50 and 100 metres deep before the glacier front crumbled, but there was a warmer layer below this. This underwent a significant change following calving, with the temperature being much more uniform at all depths.

Researchers said that internal tsunami waves are an important factor in ocean mixing, which affects marine life, temperatures at different depths, and how much ice the ocean can melt. Researchers used the data from Europe’s Copernicus Sentinel-1 satellites passed overhead while the ship was close to the Peninsula and captured a radar image.

‘This was remarkable to see, and we were lucky to be in the right place at the right time. Lots of glaciers end in the sea, and their fronts regularly split off into icebergs. This can cause big surface waves, but we know now that it also creates waves inside the ocean. These internal waves cause the sea to mix, and this affects life in the sea, how warm it is at different depths and how much ice it can melt,’ Michael Meredith, lead author of the paper said.