Showing posts with label Ice Calving. Show all posts
Showing posts with label Ice Calving. Show all posts

Sunday, February 28, 2010

Another Giant Antarctic Iceberg Crash

Satellite images reveal that a giant crash earlier this month between Antarctica's Mertz glacier's giant floating tongue of ice and another iceberg has resulted in a new iceberg (the size of Luxembourg) to break off the continental shelf.



Yet another instance of "ice calving" that may be related to climate change (refer to previous blog post on January 14), the occurrence is feared by scientists to ultimately affect ocean circulation patterns.

Exactly how would that happen? Well the collision halved the size of the tongue that drains ice from the vast East Antarctic ice sheet into the Southern Ocean. The removal of this tongue of floating ice would reduce the size of that area of open water, which would slow down the rate of salinity input into the ocean, which would also slow down the rate of Antarctic bottom water formation.

Oceans act like a giant flywheel for the planet's climate by shifting heat around the globe via myriad currents above and below the surface. When such instances disrupt this process the end result could prove quite significant as it relates to our evolving climate.

Thursday, January 14, 2010

Now that's an Iceberg!



Within the past couple days a massive piece of ice broke off of Antarctica's Filchner Ice Shelf. The images above taken on January 12 and January 13 by NASA’s Terra and Aqua satellites captured the huge piece of ice as it was breaking away. At about 150 kilometers long by 25 kilometers wide, the piece of the ice shelf that broke away was larger than the state of Rhode Island.

The ice shelf is a portion of Antarctica’s expansive ice sheets that extend over the ocean. As fresh snow falls on the ice sheet, the weight compresses it out like pancake batter spreading on a pan. The ice shelf grows out until waves and ocean currents break off the edge, forming a new iceberg.

This process is known as "ice calving" --
a sudden release and breaking away of a mass of ice from an iceberg, ice shelf or glacier. Although calving can be caused by tidal and seismic events, periodic calving and disintegration of ice masses are considered normal geological processes.