Scientists have discovered shades of jade in sea ice anchored on the coast of East Antarctica.
Jan Rieser analyzed countless satellite images of frozen ocean water clinging to the coast of East Antarctica. This ice is known as land ice, or simply land ice. first ice cream-Regulates the seaward flow of land ice and provides habitat for animals. The texture of ice varies, but its color is mostly grayscale. But in October 2023, something green caught his eye.
discovery of green iceberg
“I came across this jade iceberg among other icebergs trapped in pack ice,” said Leeser, a meteorologist and sea ice scientist with the Australian Bureau of Meteorology and the University of Tasmania. “Large scenes may not look very noticeable, but if you zoom in to the right, you’ll find scenes that are hundreds of times smaller.”
The outlier iceberg can be seen in these images acquired by Landsat 9’s OLI-2 (Operational Land Imager-2) on October 18, 2023.
The wide field (top) shows part of the iceberg trapped in fast ice that day, east of the Western Ice Shelf (not visible in the photo). Dark, linear areas on the leeward side of mountains are where the wind has blown away the snow, exposing the bare ice below. This is a process called wind washing. The detailed image (below) shows a close-up of the possibly green iceberg. Even in this view, the size of the iceberg is relatively small, so you have to look closely to see the green pixels.
Iceberg colors and meanings
Icebergs range in color from blue (in their pure form) to green. One reason for the green color may be the presence of iron oxides obtained from mainland rock dust. scientists suggested These iron-rich mountains may be transporting nutrients important for marine life from land to sea. Rieser points out that a second satellite image is needed to confirm the green color of the iceberg seen here. So far, that image has been elusive. East Antarctica is notorious for being cloudy in the spring.
Research and operational applications
Green icebergs aside, Reaser has both a scientific and operational purpose of studying satellite images of fast ice. For example, he uses images to help ecologists study and locate seabirds. In this image, similarly smaller but less colored spots (brown) on the ice are due to penguin guano buildup.
He also applies his insights about ice extent to help those working in East Antarctica. Large amounts of fast ice can prevent ships from reaching their destinations. Conversely, large amounts of fast ice can support ice-based transportation such as trucking and various replenishment activities.
Monitor changes in fast ice
Finally, scientists want to know where the fast ice is and how it is changing. recent research The year 2022 has shown a significant loss of ice floes that have existed for more than 20 years.
NASA Earth Observatory image by Wanmei Liang using Landsat data from the U.S. Geological Survey.