This blog will expose readers to many facets of scientific investigation and discovery. Recent news in science will be shown and expanded on to teach far more. Biographies of scientists will give a deeper insight than what you may have read in textbooks. I hope that the posts will help improve scientific literacy, expand your interest in many fields of science, and inform you about some important scientists.
Sunday, March 3, 2024
A weird upside-down world lurks beneath Antarctica’s ice
Antarctica is about as large as Alaska and is home to penguins and over 29 countries with 70 permanent scientific research stations. They conduct non-military investigations into glaciology, astronomy, meteorology, marine biology, engineering, and medicine. Researchers study the air, snow and ice as well as resident and migratory animal populations, plus the surrounding waters. Its largest plants are mosses, and the largest non-migratory animals are a few species of insects such as midges. The soil contains various microscopic life, too. Recently, one group of researchers looked under the ice with a new exploration tool and discovered new life.
Dr. Britney Schmidt is the lead investigator of Cornell University's Planetary Habitability and Technology Lab. She is an associate professor of astronomy, but her interests take her underwater, and specifically under the ice, because she is curious about studying Jupiter's moon Europa. Europa is surrounded by a layer of hard and soft ice 10-30 km (6-20 miles) thick. Under that, however, it is believed to have liquid salty water 100 km (60 miles) deep. It is considered one of the likely places in the solar system where life may be found, other than on Earth. Schmidt's interests in that environment have led her to study beneath the ice in Antarctica.
In 2019, Schmidt and her team joined forces with the UK on the International Thwaites Glacier Collaboration to study the Thwaites Glacier on the western side of Antarctica. Almost all glaciers on the
continent spill into the ocean and form icebergs. They can stop where the land underneath ends and be "grounded", or they an stick out beyond the land as "tongues" or ice shelves before they calve into bergs. The point where they begin to jut our across the water past their contact with land is called the grounding line. That is where warmer ocean waters (relatively speaking) meet glaciers, and Schmidt said the effect has never really been investigated before. So, she did.
To investigate under the ice is a serious challenge. First of all, it is 2,000 kilometers (1,200 miles) away from the U.S. McMurdo Station research facility. Seond, aside from the temperature of the water being around 2ºC (35.6ºF), the glacial ice above it is a quarter of a mile thick (587 meters, or 1,926 feet). Once you are there, a lot of measurements need to be taken at many locations, so a remotely operated vehicle (ROV) was designed and built in Schmidt's earlier lab at the Georgia Institute of Technology (Atlanta). It was tested at McMurdo Station before being shipped to the Thwaites Glacier. The ROV was named Icefin. Finally, the glacial camp consisted of mere tents. So, this was not just a simple field trip. (There is a 6-min video at the end of this article showing an observation capsule a mere 9 feet under the ice.)
Icefin is a 7-module tube 26 cm (10 inches) in diameter, 3 m (9.8 ft) long and 109 kg (240 pounds) in weight. It has five thrusters (two vertical, two horizontal and one rear) for flexible movement, and it is attached to the surface by a 4.3-mm fiber-optic tether to allow for real-time viewing from its cameras and sensors.
Icefin operating under the ice at McMurdo Station (YouTube)
Then, the unexpected discovery occurred. As Dr. Schmidt was watching the views from Icefin's camera under the ice, she saw star-like lights coming from the under-surface of the ice. But they weren't rigid ice structures. They waved tiny tentacles. These were a species of sea anemones clinging to the ice and then scurrying into cracks when approached.
Anemones are commonly found on the ocean floor, even around Antarctica. Schmidt wasn't the first to discover these attached to ice, though. Researchers at the University of Nebraska-Lincoln found them in 2013 under the ice of Ross Ice Shelf, not far from McMurdo Station. They even stunned them with hot water and returned them to the surface for study. The new species was called Edwardsiella andrillae, after the international ANDRILL (Antarctica Drilling Project) that they were part of.
Other types of Edwardsiella species have been found in coastal waters elsewhere, where the water may be highly salty or highly diluted from rivers feeding into the ocean.
2013 anemone specimen from under the Ross Ice Shelf
Schmidt wasn't even the first to use an ROV. The University of Nebraska team had a much smaller version called SCINI (Submersible Capable of under Ice Navigation and Imaging) ROV, which was 1.4 m long and 15 cm in diameter.
One difference, other than size, between SCINI and Icefin is that the former was made to survey the ocean floor, while the latter was intended for floor, water, and ice measurements. In both cases, the investigators just happened to look up and saw the unexpected life on the ice.
Dr. Schmidt remarked about the view from Icefin:
"In the background is like all these sparkling stars that are like rocks and sediment and things that were picked up from the glacier, And then the anemones. It's really kind of a wild experience."
So, perhaps looking up even further, all the way to Jupiter, may find even more wondrous things. Right now, Icefin is run partially under manual control and partially autonomously through programmed routes. But Schmidt is developing a prototype cell counter so that any floating debris can be ignored and life can be identified.
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