Larsen-B ice shelf
From Envirowiki
“One of the warning signs that a dangerous warming trend is underway in Antarctica will be the breaking of ice shelves on both coasts of the Arctic Peninsula, starting with the northernmost and extending gradually southward.” -Scientist John Mercer
The Larsen-B was a long ice shelf along the northwestern Antarctic Peninsula. It rose roughly 700 feet above the ocean surface. The shelf was about 150 miles long, and 30 miles wide. It was part of the larger Larsen ice shelf comprised of three smaller shelves, A, B, and C. The significance of the ice shelf is seen in its collapse, as a likely result of global warming.
This massive structure is likely more than 12,000 years old, and has been stable since the last ice age. It was recently believed by scientists that with the threat of global warming, the ice shelf could be stable for about another century. However, these estimates proved to be flawed. The temperatures in the Antarctic have steadily risen by 0.5 degrees Celsius per decade, measured since the 40s[reference needed].The Larsen-B ice shelf took only 35 days starting on January 31, 2002, to completely disintegrate into the ocean. However the majority of its collapse spanned 2 days. Usually ice shelves break apart by melting on the surface, and ice bergs breaking off, but in the case of the Larsen-B, pools of water formed on the top of the shelf, and slowly sank through, causing a Swiss cheese like effect. The part that fell into the water was about the size of the state of Rhode Island.
The events that followed are what are leading scientists to worry. As the ice shelf dissolved into the sea, the land-based ice that had been secured by the ice shelf followed suit, and began to dissolve into the ocean. Ice that sits on water increases the albedo of the ocean, as it melts, but does not raise the sea levels. However, the ice that sits on land (glaciers and ice shelves) raises sea-levels world wide as it melts, and fall into the ocean. This can and will have dramatic and tragic repercussions, if we do not work quickly enough to halt global warming.
The disappearance of the Larsen-B ice shelf is only a microcosm for what is to come, especially in areas like Greenland, and Antarctica, if our current path of destruction, and global warming does not change. Experts say sea level could quickly rise more than 20 feet worldwide, and millions of people would be displaced. Lets stop global warming before we have a chance to see.
[edit] 1 See Also
[edit] 2 Sources
- Gore, Al. An Inconvenient Truth. Emmaus: Rodale, 2006
- Larsen Ice Shelf. Wikipedia.org. Checked 8 Mar 2007, 03:34 UTC. Wikimedia Foundation, Inc.
