The scientists on the research vessel watched the front of the glacier fall apart. They recorded internal underwater waves as tall as a house, a phenomenon that has been missed in the understanding of ocean mixing and in computer models.
In the journal Science Advances, a team of researchers report their observations.
Life in the ocean, temperatures at different depths, and how much ice the ocean can melt are some of the factors that affect ocean mixing. There is ice on the coast along the glaciers. Much of the ice that falls into the ocean is broken into smaller pieces, which can be as big as a country.
The front of the William Glacier was destroyed into thousands of small pieces as a team on board the RRS James Clark Ross took ocean measurements.
The William Glacier usually has one or two large calving events per year, and the team estimated this one broke off around 78,000 square meters of ice, around the area of 10 football pitches.
The water temperature was cooler than 100 meters in depth before it broke. The temperature went up even more across different depths after the baby was born.
The lead author of the study said that they were lucky to be in the right place. A lot of glaciers end in the sea. This can cause waves at the surface, but it can also cause waves in the ocean. Life in the sea is affected by how warm the sea is at different depths and how much ice it can melt. This is something we need to understand better.
Ocean mixing is important for the health of the fish and the environment. In the summer, we thought it was mostly wind and tides, but it never occurred to us that the mixing was caused by internal tsunamis caused by the ice breaking.
The Principal Scientific Officer on the RRS James Clark Ross was Professor James Scourse, Head of the Department of Earth and Environmental Sciences at the University of Exeter.
The Centre for Geography and Environmental Science on the Penryn campus has two scientists who are central to the interpretation of the data captured.
The most important and exciting discoveries in science can be made at the right time with the right instruments and the right people. The first data on a process that has implications for how fast the ocean is able to melt the ice sheets was produced after we did that in Brgen Bay. This has consequences for everyone.
The waves caused by wind and tides are different from the waves caused by earthquakes or floods.
There have been internal tsunamis in a few places. They are happening all the time because of the thousands of glaciers in the area. The glaciers in other places are likely to be affected as well.
As global warming continues glaciers are going to retreat and calve more. It's possible that this will increase the number of internal tsunamis.
Current computer models don't take this process into account. This discovery will change our understanding of how the ocean aroundAntarctica is mixed and will improve knowledge about what it means for climate and sea level rise.
The timing shows how much more we need to know about these remote environments.
More information can be found in Science Advances. There is a book titled "Sci Adv.add0720."
Journal information: Science Advances
All Rights Reserved © 2024
