Turney’s Iceberg Calved In 1987
By Paul Homewood
Reader ES has tracked down this article about the giant B9B iceberg that has been parked off Commonwealth Bay for the last three years, and consequently led to a build up of sea ice in the bay, where the Akademik Shokalskiy is trapped.
It appears that the iceberg originally broke loose in 1987, and has since been nudging its way west, towards the Mertz Glacier, eventually colliding in 2010.
The report makes clear that this sort of iceberg calving is not unusual, and neither is its size.
A massive iceberg struck Antarctica, dislodging another giant block of ice from a glacier, Australian and French scientists said Friday.
The two icebergs are drifting together about 62 to 93 miles (100 to 150 kilometers) off eastern Antarctica following the collision on Feb. 12 or 13, said Australian Antarctic Division glaciologist Neal Young.
"It gave it a pretty big nudge," Young said of the 60-mile (97-kilometer) -long iceberg, about the size of Luxembourg, that collided with the giant floating Mertz Glacier and shaved off a new iceberg. "They are now floating right next to each other."
The new iceberg is 48 miles (78 kilometers) long and about 24 miles (39 kilometers) wide and holds roughly the equivalent of a fifth of the world’s annual total water usage, Young told The Associated Press.
The iceberg that hit the Mertz Glacier is called B9B and had broken free from another part of Antarctica in 1987. It has been nuzzling and shifting alongside the Mertz for about 18 years before this month’s dislodging, said Benoit Legresy, a researcher with the LEGOS laboratory for geophysical studies in Toulouse, France.
"It was a slow process," Legresy said. He said B9B was "sitting there, it must have been pushed and pulled by the current every day and used as a hammer to bang on the other one by the ocean currents."
The dislodging occurred because of the iceberg’s latest location and water that had warmed during Antarctica’s summer, leaving less sea ice, Legresy said.
Some experts are concerned about the effect of the massive displacement of ice on the ice-free water next to the glacier, which is important for ocean currents, while others are less concerned.
Experts say this type of iceberg calving happens from time to time and these are not record large icebergs.
This area of water had been kept clear because of the glacier, said Steve Rintoul, a leading climate expert. With part of the glacier gone, the area could fill with sea ice, which would disrupt the sinking ability of the dense and cold water.
The impression has been given that the Akademik’s problems have been due to recent warming, but clearly this is not the case. They have resulted from events set in motion decades ago, probably well before 1987, ones that are normal, natural occurrences.
BTW – there is an image of the iceberg and Mertz glacier, taken by NSIDC, back in 2001, before the collision.