At 2017 minimum, scientists ask: Is Arctic entering the Thin Ice Age?

At 2017 minimum, scientists ask: Is Arctic entering the Thin Ice Age?

SOURCE: Mongabay DATE: September 25, 2017 SNIP: After 16 months of consecutive record and near-record lows in late 2016 and early 2017, sea ice extent in the Arctic held fast over the summer thanks to more moderate weather and cooler temperatures. As of September 13, sea ice covered some 4.64 million square kilometers (1.79 million square miles) at its minimum, roughly 1.25 million square kilometers (482,000 square miles) more than record-setting year 2012. Still, while 2017’s summer melt season didn’t break the record, it falls far below the 1981 to 2010 median extent by over 1.58 million square kilometers (610,000 square miles). Moreover, surface cover isn’t everything when it comes to the state of the Arctic — what experts say matters most is the total volume of ice — a combination of thickness and extent, and 2017 saw summer volumes among the lowest ever recorded. Some scientists are now saying colloquially that the Arctic Ocean has in recent decades entered the “Thin Ice Age.” Since 1980, the average ice thickness come July has decreased by an estimated 120 centimeters (47...
How did that get there? Plastic chunks on Arctic ice show how far pollution has spread

How did that get there? Plastic chunks on Arctic ice show how far pollution has spread

SOURCE: The Guardian DATE: September 23, 2017 SNIP: A British-led expedition has discovered sizeable chunks of polystyrene lying on remote frozen ice floes in the middle of the Arctic Ocean. The depressing find, only 1,000 miles from the north pole, is the first made in an area that was previously inaccessible to scientists because of sea ice. It is one of the most northerly sightings of such detritus in the world’s oceans, which are increasingly polluted by plastics. It has prompted fears that plastic waste is flowing into the Arctic as the ice melts because of climate change. The thaw is simultaneously releasing plastic that has long been trapped in the ice. “For the 25 years I have been exploring the Arctic I have never seen such large and very visible items of rubbish,” said Hadow, the only person to have trekked solo, without resupply, from Canada to the geographic north pole. “Finding pieces of rubbish like this is a worrying sign that melting ice may be allowing high levels of pollution to drift into these areas,” Gordon said. “This is potentially very dangerous for the Arctic’s...
As ice thaws, rock avalanches on Southeast Alaska mountains are getting bigger

As ice thaws, rock avalanches on Southeast Alaska mountains are getting bigger

SOURCE: Alaska Dispatch News DATE: September 19, 2017 SNIP: A study of rock avalanches in the western part of Glacier Bay National Park and Preserve found that the likelihood of large slides covering about 2 square miles has at least doubled in the last five years. As the climate has warmed, characteristics of the region’s rock avalanches have changed, says the study, published in Landslides, the journal of the International Consortium on Landslides. “They’re bigger, and they’re traveling farther,” said lead author Jeffrey Coe, a U.S. Geological Survey landslide expert based in Colorado. The likely reason, says the study, is thaw of the ice that fills the mountains’ rock cracks, crevices and fractures, referred to as “rock-permafrost,” abetted by melt of the region’s glaciers and the particular structures of the slopes. The rock-permafrost helps hold steep slopes intact, so thaw or even softening of that ice destabilizes the rock, Coe said. “You can get ice degradation below freezing,” he said. Glacial thinning is likely a secondary factor, he said. Thinned glaciers are less effective at propping up mountain faces, he said. “In many places, you have a de-buttressing effect of the ice loss,” he said. The study correlates the increasing size of Glacier Bay rock avalanches to a long-term warming trend. The large avalanches began about two years after the area’s annual maximum temperature shifted above freezing, the study points...
Walruses on packed Alaska beach may have died in a stampede

Walruses on packed Alaska beach may have died in a stampede

SOURCE: CBC News DATE: September 14, 2017 SNIP: Thousands of Pacific walrus are coming to Alaska’s northwest shore again in the absence of summer sea ice and not all are surviving. A survey Monday of a mile of coastline near the Inupiaq Eskimo village of Point Lay found 64 dead walruses, the U.S. Fish and Wildlife Service told The Associated Press. Most of the animals were younger than a year old. The cause of death is not known, said agency spokeswoman Andrea Medeiros, but stampedes — set off when startled walruses rush to the sea, crushing smaller animals — are a likely suspect. Walrus dive hundreds of feet to eat clams on the ocean bottom, but unlike seals, they cannot swim indefinitely. Historically, sea ice has provided a platform for rest and safety far from predators for mothers and calves north of the Bering Strait. However, sea ice has receded much farther north in recent years because of global warming, beyond the shallow continental shelf, over water more than 3,050 metres deep. That’s far too deep for walruses to reach the ocean bottom. Instead of staying on sea ice over the deep water, walruses have gathered on shore to rest. The ultimate threat to walruses is the rapid loss of sea ice due to climate disruption, [Shaye Wolf, climate science director for the Center for Biological Diversity] said, adding that rollbacks of climate change protections by the Trump administration will further endanger the...
Narwhals Are Helping NASA Understand Melting Ice and Rising Seas

Narwhals Are Helping NASA Understand Melting Ice and Rising Seas

SOURCE: Bloomberg DATE: August 24, 2017 SNIP: Greenland’s ice cap holds beneath it 10 percent of the earth’s freshwater, enough to raise global sea levels by 20 feet. While there’s no doubt it is melting, scientists have little certainty about exactly what’s happening inside this 10,000-year-old ice roughly three times the size of Texas. Last winter was the warmest on record in the Arctic, and as Greenland heats up, understanding this glaciate has become essential to navigating our future. That’s why scientists need narwhals, whales with 9 foot long unicorn-like tusks, which are some of the only mammals benefiting from all that melting ice. “The narwhals like it,” said Josh Willis, the project lead for NASA’s Oceans Melting Greenland. When melting ice falls into the sea, it churns up the water, bringing such food as plankton and krill to the surface. The whales tend to feed at the bottom of melting glaciers and can dive to depths of 1,800 meters, precisely the areas that OMG needs to survey. It’s a perfect match. So far, OMG has measured Greenland’s seafloor and mapped the continental shelf, a crucial piece in the melt puzzle. “Ancient glaciers carved these troughs through the continental shelf,” Willis said. The channels allow warm water to flow between the glaciers, eating away at the ice. Unfortunately, “a lot more of these glaciers sit in deeper water than we expected,” he...