Massive ice crack on Antarctica Peninsula points to faster sea level rise [1]
Friday, March 3, 2017 - 13:35
A huge crack on the Antarctic Peninsula, across the Larsen C ice shelf, is set to break free an enormous iceberg in the next few months, six times larger than Tonga’s combined landmass, and a quarter the size of Wales.
The crack is more than 100 miles in length and 1,500 feet across (wider than the height of Auckland’s Sky Tower which stands at around 1,076 feet), and is being monitored by scientists at Project MIDAS, an Antarctic research group, who say they "are watching with bated breath".
The group reported recently that the crack increased suddenly by a further 18 km during the second half of December 2016, and a further 10km since 1 January, with only 20 km of the iceberg remaining connected to the ice shelf. This means it could break free within the next few months because the leverage of 175 km of iceberg is too overwhelming for the last 20 km to hold.
Scientists estimate when the iceberg splits it could be around 1,930 square miles (5,000 square kilometers) in size. In comparison Tonga’s combined land size is 748 square kilometers or around 289 square miles.
The Project MIDAS group says the calved iceberg will change the landscape of the Antarctic Peninsula and the ice shelf will be left in a less stable condition.
The Larsen C ice shelf will follow its neighbours the Larsen A and B ice shelves lost in 1995 and 2002 respectively.
Although the calving of icebergs is normal as part of the glacier life cycle, scientists say when this berg calves, the Larsen C ice shelf could retreat.
The group says they don’t have enough information to confirm the expected Larsen C ice shelf calving is caused by climate change, however there is good scientific evidence confirming climate change is causing the thinning of the ice shelf.
The area has attracted a number of high-level visitors such as the US former Secretary of State, John Kerry, and Buzz Aldrin, the second man to walk on the moon. John Kerry is reported to be the highest-ranking visitor from the US government in the area last November. The visit raises questions of the gravity of the situation in the Antarctic and the effect it has worldwide.
Coastal cities around the world and Small Island States such as Tonga are the most vulnerable and the first to suffer the effects of rising sea levels.
Sea level rise.
The loss of the ice shelf, which acts as a barrier to the flow of land ice, can cause ice to move faster into the ocean contributing to a rise of global sea levels. The collapse of Larsen B ice shelf in 2002 accelerated ice flow into the ocean six times faster, even 15 years later after the event.
Since the start of the 20th century, global sea levels have risen by around 8 inches.
Climate Central [2] report similar situations are occurring on other parts of the Antarctic such as West Antarctic showing signs of slow melting because of warming oceans and air. Past research shows continuous melting would drive oceans to rise by at least 10 feet and this could already be underway although it could take centuries for the process to play out.
East Antarctica is also showing a massive melt water lake inside the Roi Baudouin ice shelf caused by warm winds blowing down from the ice sheet. The Totten ice shelf is also melting away from below caused by warm ocean waters.