FYI
The U.S. National/Naval Ice Center has identified a new iceberg that has broken away from the heavily crevassed Ninnis Ice Shelf in eastern Antarctica. The newly formed iceberg has been named Iceberg C-34 because it is the 34th substantial iceberg to have broken off the Antarctic ice shelf, in the quadrant that faces Australia, since 1976.
Ninnis glacier is a large and heavily knolled area of ice and crevassedglacier descending steeply from the high interior to the sea in a broad valley, on George V Coast in Antarctica. The Ninnis glacial tongue is one of two prominent floating glacier tongues that extend into the Southern Ocean from the coast of King George V Land. The Ninnis and Mertz glaciers are situated along the eastern coast of the Antarctic Ice Sheet. The King George V Land coast is characterized by embayments and large floating ice sheets that jut out from the coast. A floating glacier tongue acts as an obstacle to sea ice drift. They provide anchor points for fast ice, and contribute to the formation of open-water areas surrounded by sea ice.
From USNIC Iceberg C-34 Calves off the Ninnis ice shelf in the eastern Wilkesland Sea
April 27, 2017 SUITLAND, MD —The U.S. National Ice Center (USNIC) identified a new iceberg that calved from the Ninnis Ice Shelf in Antarctica. Analysts at the USNIC have been monitoring the iceberg since January 2017. Using RADARSAT imagery from 26 Apr 2017, USNIC analysts were able to identify the iceberg drifting west towards the Mertz Glacier. C-34 is located at 67°54’ South, 147°06’ East, in the eastern Wilkesland Sea. The iceberg measures 11 nautical miles on its longest axis and 5 nautical miles on its widest axis.
An interesting tidbit on this region in E Antarctica is that it was the site of one of the largest impact craters that ever hit earth. Phys.org reports:
The 300-mile-wide crater lies hidden more than a mile beneath the East Antarctic Ice Sheet. And the gravity measurements that reveal its existence suggest that it could date back about 250 million years -- the time of the Permian-Triassic extinction, when almost all animal life on Earth died out.
Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward.
Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider.
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The scientists used gravity fluctuations measured by NASA's GRACE satellites to peer beneath Antarctica’s icy surface, and found a 200-mile-wide plug of mantle material -- a mass concentration, or "mascon" in geological parlance -- that had risen up into the Earth's crust.
Mascons are the planetary equivalent of a bump on the head. They form where large objects slam into a planet's surface. Upon impact, the denser mantle layer bounces up into the overlying crust, which holds it in place beneath the crater.
It is unclear on what, if any, ramifications from this newly calved iceberg might mean.