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An iceberg with bands of stones and sediments. / Thomas Ronge
The ocean basins of the planet are interconnected by large scale current systems and, like a global conveyor, currents carry water around the world at different depths. The resulting distribution of hot and cold water mbades is critical for climatic conditions in various regions of the Earth, and now, scientists from the Alfred Wegener Institute, the Helmholtz Center for Polar Research and marine (AWI, Germany) documented A change in currents in an ocean basin can trigger mbadive and unexpected changes in a remote basin, even on the other side of the planet.
The researchers, who publish their findings in Nature state that Last Ice Age, a mbadive flow of freshwater into the polar Atlantic triggered a series of events in the ocean and the atmosphere, which resulted in intense melting of glaciers in the North Pacific, thousands of kilometers away. At the end of the chain of events, hot water entered the Pacific coastal area of the North American continent, which was also covered with a layer of ice, and parts of the water table became disintegrated and were released in the Pacific.
Iceberg off the Antarctic Peninsula / Thomas Ronge
Since the modern ocean is continually warming due to global warming, scientists of AWI warns of similarities with the process observed in the North-East Pacific during the last glacier: Continuous warming of the ocean could disintegrate the Antarctic ice, which would subsequently cause a significant rise in the level of the Wed.
Scientists used sediment sampling during an expedition with the German research vessel Sonne, 600 kilometers off the coast of Alaska. The glacial sediments recovered included stone-sized stone layers from the mainland, and the only possible explanation, according to the researchers, is that the stones must have been transported from the open North Pacific Ocean during periods when the North American coast was covered with a layer of ice. The confirmation came from the dating of the layers, which reveals that the layers of stone were deposited about 16,000 years ago and 38,500 years ago, well during the last ice age.
To test this thesis, they performed an isotopic badysis of oxygen in the remains of the siliceous solid particles of the diatoms preserved in the sediments, with which they were able to identify when the salinity of the surface was higher. intensely affected by melting ice. "Our badyzes showed that there were large amounts of freshwater in the southern region of Alaska about 16,000 and 38,500 years ago," confirms Edith Maier
Sounds in Tomakomai. / Bernhard Diekmann
Currently, hot surface water is transported from the Pacific to the Indian Ocean, then flows around the southern tip of Africa to the Caribbean Kingdom, then extends into the North Atlantic by a so-called Gulf water course. "The driving force of this global flow is the generation of cold and salt water in the polar North Atlantic. water, produced during the formation of ice, is denser than hot water and, therefore, flows into the deep ocean.Therefore, hot surface water is pumped to the north But 16,000 and 38,500 years ago, the global "pumping system" was seriously affected by the decrease in salinity of the North Atlantic, so only a little warm water from the Pacific sank, which caused the warming of the tropical Pacific, and in turn, the warmer water reached the western shores of Canada and Canada. Alaska.The higher water flow has destabilized the ice cover covering the coastal areas, which has caused the continental ice spill in the ocean and a decrease in surface salinity.
Another study by the same organization said that the Arctic Ocean contains up to 12,000 microplastic particles per liter of sea ice. The largest quantities of microplastics, mostly microscopic in size, have was collected in five regions of the Arctic, along the Transpolar Drift and Fram Strait. The different types of plastics have shown a unique footprint in the ice that allows researchers to find their source: the high percentage of paint and nylon particles indicates intense fishing activities and fishing in parts of the ocean Arctic.
This news was originally published in N + 1, a science that adds up.
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