Wednesday, March 28, 2018

Runaway Arctic Ice Menaces Oil Rigs and Shipping as the Planet Warms

As Arctic sea ice breaks up, it’s starting to move southward faster, creating new and unexpected hazards.  More icebergs calving off Greenland add to the threat.

A massive iceberg floated off the coast of Newfoundland on April 26, 2017. The North Atlantic has seen four years of extreme iceberg seasons, and appears to be facing another. (Credit: Drew Angerer/Getty) Click to Enlarge.
As the planet warms, giant icebergs and sea ice that once would have remained trapped in the frozen Arctic are moving southward faster and more frequently, menacing shipping and oil and gas drilling operations.

In the North Atlantic, scientists say the number of icebergs spotted south of 48 degrees latitude—where they start to get into more shipping lanes—is up again this year, following a series of extreme iceberg seasons.

"So far, iceberg numbers crossing south of 48 degrees look to be higher this year than last, and last year saw a relatively high iceberg flux year—about 1,000 icebergs crossing 48 North, compared to the long-term mean of 450," said University of Sheffield geographer Grant Bigg, who studies icebergs and climate.

That ice can pose serious risks to ships and offshore oil and gas rigs.  Last year, strong storms sent a swarm of icebergs surging into the oil and gas drilling field at the Grand Banks off Newfoundland, marking the fourth extreme iceberg season in a row, according to International Ice Patrol Commander Gabrielle McGrath.
Another Warm Winter Raises the Risks
This past winter, persistent heat waves returned to the Arctic.  Scientists tracked a huge area of open water north of Greenland where the thickest ice typically would be.  Around the same time, there was open water north of Svalbard, in the European Arctic, and off the North Coast of Alaska—extreme conditions caused by climate change across the Arctic.  When the spread of Arctic sea ice reached its peak for the winter on March 17, it was at its second-lowest maximum extent on record.

Increased ice mobility is a sign that the Arctic climate system is likely to change in big increments in the next few decades, said University of Manitoba ice researcher Dave Babb, one of scientists who tested the sea ice off Newfoundland last year.

The sea ice pack is becoming mechanically weaker, Babb and his colleagues wrote in a new study describing their findings in the scientific journal Geophysical Research Letters.  Solid ice structures that once blocked the narrow Arctic Ocean channels and kept the ice pack bottled up are forming later in the winter as global temperatures rise, letting massive slabs of sea ice, some up to 20-feet thick, move south faster than ever before, they said.

Read more at Runaway Arctic Ice Menaces Oil Rigs and Shipping as the Planet Warms

No comments:

Post a Comment