Researchers have found that collapsing ice blocks in Antarctica not only trigger a tsunami at the water’s surface, but also a second tsunami deep below. This event has a significant impact on water temperature and underwater biodiversity.
At the poles, theto collapseto collapse sea ice obviously causes strong turbulenceturbulence in the water, in the form of massive waves that are similar to a real tsunami. However, scientists have made an additional discovery: in addition to the tsunami at the surface of the water, falling ice causes a second tsunami in the depths.
From a distant point of view like ours, this “detail” does not seem to matter. However, this double tsunami has consequences on the composition of the ocean by having the effect of mixing several massesmasses of water. According to’European Space AgencyEuropean Space Agency that published the abstract of a study, a British research team was on board a ship in the peninsula AntarcticAntarctic in January 2020 when a piece of the glacierglacier William collapsed in front of them.
At the same time, a Copernicus Sentinel-1 satellite took an image of the event. This showed the difference in the distribution of ice and water between January 8 (before the collapse) and January 20 (the day of the collapse). This subsidence caused the detachment of a 78,000m blocktwothe equivalent of 10 football fields, knowing that the William Glacier has already lost 3 km of ice since 1955.
The collapse of part of the William Glacier in Antarctica filmed in 2020. © European Space Agency
Submarine tsunami alters the temperature of the water
The research team later witnessed the tsunami occurring at the ocean surface, but was also able to record, using sensorssensors, the second tsunami to occur underwater. A very important phenomenon in climate prediction models, and that until now had not been discovered.
The chaos caused by the tsunami submarinesubmarine has several consequences: by mixing masses of water that should not meet, underwater waves, which can reach more than 10 meters, have an impact on animal and plant life, underwater temperatures at different depths and on the meltingmelting hence ice cream. Once separated from its main block, the pieces of ice often give rise to icebergs. But some of them sink into the ocean and melt.
Before the glacier collapsed, the ocean water was cold at a depth of 50 to 100 m, with a layer of warmer water below. After the underwater tsunami, the mixing of the waters created a much more uniform temperature between these different masses of water. the nutrientsnutrients available in the ocean, and that feed the biodiversitybiodiversity, are distributed according to the different temperatures present in the water layers. By mixing these layers and standardizing temperatures, ice collapse impacts the entire planet.ecosystemecosystem of the ocean, and therefore of biodiversity.
A parameter that can be used to specify the results of weather forecasts.
In general, these water mixtures occur mainly on the surface, with the action of the wind and tidestides. But the ice collapse linked to the global warmingglobal warming causes a sudden mixing of water in depth, of the same type that occurs during an earthquake or a landslide, specifies the European Space Agency.
So far, these sudden mixings caused by melting ice have only been observed in Antarctica, but scientists believe they may also occur in Greenland and Antarctica. ArcticArctic. An important parameter to take into account in the evolution of future climate and the consequences of global warming that, at present, is not yet integrated into climate prediction models.
Therefore, this discovery will have to be added in the calculations of new climate modelsclimate models, whose objective is to stimulate the climate of the coming years. The integration of this parameter will thus make it possible to obtain more precise results on the evolution of sea level rise, on the future composition of marine ecosystems and on global warming of the Planet.
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