The Bottom of the Ocean Is Sinking

The Bottom of the Ocean Is Sinking

SOURCE: LiveScience DATE: January 4, 2018 SNIP: The bottom of the ocean is more of a “sunken place” than it used to be. In recent decades, melting ice sheets and glaciers driven by climate change are swelling Earth’s oceans. And along with all that water comes an unexpected consequence — the weight of the additional liquid is pressing down on the seafloor, causing it to sink. Consequently, measurements and predictions of sea-level rise may have been incorrect since 1993, underestimating the growing volume of water in the oceans due to the receding bottom, according to a new study. [Scientists] found that around the world for two decades, ocean basins deformed an average of 0.004 inches (0.1 millimeter) per year, with a total deformation of 0.08 inches (2 mm). However, there were distinct regional patterns to the seafloor’s bending and stretching, and the amount of sag in certain parts of the ocean bottom could be significantly higher — as much as 0.04 inches (1 mm) per year in the Arctic Ocean, for a total of 0.8 inches (20 mm), the study authors reported. As a result, satellite assessments of sea-level change — which don’t account for a sinking ocean bottom — could be underestimating the amount that seas are rising by 8 percent, according to the...
Melting Ice Could Mess Up Deep-Sea Chemistry

Melting Ice Could Mess Up Deep-Sea Chemistry

SOURCE: Scientific American DATE: November 28, 2017 SNIP: Melting glaciers might be making ocean water more acidic, an unexpected finding that’s given scientists new cause for concern. A new study published yesterday in the journal Nature Climate Change suggests surprising ways that climate change is drastically altering the water chemistry in deep seas—a process that may happen faster than researchers anticipated. The threat of ocean acidification has drawn increasing attention in recent years. The ocean absorbs a substantial amount of the carbon dioxide that humans emit into the atmosphere—and when carbon dioxide goes into the sea, a chemical reaction occurs that causes the water to become more acidic. That’s a big concern for marine biologists, as research suggests that the decreasing pH levels could disrupt the ability of corals, mollusks and other marine organisms to build the hard outer shells they need to survive. As the new research points out, dead plants and animals also release carbon dioxide as they drift to the bottom of the sea and decompose. Deep ocean currents can help to move the carbon dioxide throughout the water so it doesn’t sit in one place. But some scientists believe that certain effects of climate change—including the influx of cold, fresh water from melting glaciers, or an increase in the heat absorption as sea ice disappears and exposes the water to the sun—may eventually disrupt these currents or cause them to slow down. Now, the new study’s authors suggest this process could speed up the acidification of the deep...
In Peru’s Deserts, Melting Glaciers Are a Godsend (Until They’re Gone)

In Peru’s Deserts, Melting Glaciers Are a Godsend (Until They’re Gone)

SOURCE: New York Times DATE: November 26, 2017 SNIP: VIRU, Peru — The desert blooms now. Blueberries grow to the size of Ping-Pong balls in nothing but sand. Asparagus fields cross dunes, disappearing over the horizon. The desert produce is packed and shipped to places like Denmark and Delaware. Electricity and water have come to villages that long had neither. Farmers have moved here from the mountains, seeking new futures on all the irrigated land. It might sound like a perfect development plan, except for one catch: The reason so much water flows through this desert is that an icecap high up in the mountains is melting away. And the bonanza may not last much longer. The flow of water is already declining as the glacier vanishes, and scientists estimate that by 2050 much of the icecap will be gone. Mr. García, the council member in Huancaquito Alto, is not taking any chances. He has refurbished an old well used by his father to hold water in the days before this area was irrigated, and he is building a new one near his asparagus fields. “Because of this water, our children have been able to go to university,” he said. “But if there is no water from the Santa River, that all changes.” He added: “We have to get our wells ready. Sure, it’s like going back in time, but what can we...
Venezuela is losing its last glacier

Venezuela is losing its last glacier

SOURCE: EarthSky Voices DATE: November 19, 2017 SNIP: Venezuela used to have five glaciers. Today, only one remains. The last glacier in Venezuela, the Humboldt glacier, is about to disappear. Once Venezuela loses the Humbolt, it will become the first country in modern history to have lost all of its glaciers. The glacier is expected to completely vanish in ten to twenty years, and scientists have expressed the importance of studying the glacier in its last...
Pakistan’s glaciers face new threat: Highway’s black carbon

Pakistan’s glaciers face new threat: Highway’s black carbon

SOURCE: Reuters DATE: November 3, 2017 SNIP: The Karakoram Highway has been around since 1982, but the Chinese-funded upgrade – which opened in 2015 – has turned a once treacherous track into a 15-foot-wide paved road. A series of tunnels, cut through the mountains, have reduced the driving time to the Khunjerab Pass from Gilgit, the capital of Gilgit-Balistan region, from eight hours to four hours. Now trucks are pouring over the border, laden with Chinese goods and equipment headed to Sost, the first border town on the Pakistani side, and then further down the 1,300-kilometre (800-mile) highway toward the port of Gwadar. The highway upgrade, part of the ambitious China Pakistan Economic Corridor, “has two impacts – one is positive and the other negative,” said Qamar-uz-Zaman Chaudhry, the author of Pakistan’s national climate change policy. “It will bring in much-needed infrastructure. But the carbon emissions and the soot going into the atmosphere will definitely increase – and our mountain glaciers will melt. We need to do a comprehensive study on the impacts and then develop a strategy,” he said. [D]ata gathered over the last 50 years shows that all but around 120 of the glaciers are showing signs of melting, meteorological officials said. Warming temperatures are to blame for much of the melting but so-called “black carbon” – black soot released from diesel vehicle exhaust, factories, open fires and cookstoves – also is to blame, experts say. The highway upgrade is just part a huge Chinese investment push into infrastructure in Pakistan – including a series of new coal-fired power plants – under the China Pakistan Economic Corridor...