A Mantle Plume Melts Antarctica From Bellow
A new study developed by NASA scientists indicates that a mantle plume melts Antarctica from bellow, delivering almost as much heat as the Yellowstone supervolcano. Researchers have recently discovered the source of the massive meltdown in West Antarctica. The massive layers of ice are melting from below due to the heat produced by a mantle plume.
The hot rock is located under Marie Byrd Land, situated between the Ross Sea and the Ross Ice Shelf. Hence, the melting process creates numerous rivers and lakes under the sheet of ice. Researchers argue that only the existence of this mantle plume could actually account for such a big change. Hence, this time we cannot blame climate change and greenhouse gas emissions by melting down the ice sheets.
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This area is extremely unstable today, and it has also collapsed at the end of the last Ice Age, approximately 11,000 years ago. Experts explain that mantle plumes are part of the plumbing systems which bring hot air and materials up from Earth’s interior. When all this hot material penetrates the mantle, it spreads under that crust, and it fuels volcanoes with magma. Then, volcanic eruptions can appear. Specialists argue that the area above a mantle plume is known as hotspot.
The mantle plume melts Antarctica from beneath
NASA scientists have been studying this area for about three decades, and they have been suggesting that the existence of a mantle plume is possible. However, now they are able to state their beliefs turn to be true since only this could explain the regional volcanic activity under Marie Byrd Land. Furthermore, there is also a dome feature in the area. Scientists had no evidence back then regarding the existence of the plume.
Nevertheless, now, scientists from NASA’s Jet Propulsion Laboratory have developed advanced numerical models to establish the level of heat needed to account for their beliefs. They used the models to try and determine how much heat should come from underneath in order to melt massive ice sheets. Furthermore, they have also considered the formation of the dome and the massive subsurface lakes and rivers to account for their study.
The lakes which formed due to the meltdown will periodically fill and drain, while the ice layers situated thousands of feet above rise and fall. Their movement can vary, sometimes reaching even as much as 20 feet. Helen Seroussi, the study author from JPL, indicates that she believed that the existence of a mantle plume in the area is a crazy idea. She refused to believe this, at first.
Seroussi argues that she could not account for the existence of both a huge amount of heat and the formation of ice sheets on top of it. Helen Seroussi and her colleagues’ study was recently published in the Journal of Geophysical Research: Solid Earth . Seroussi claims that they have analyzed the most well-examined magma plume on our planet, namely the Yellowstone hotspot.
Yellowstone supervolcano and the plume in Antarctica emit similar amounts of heat
To develop their research, the team first created a mantle plume model. They used it to see how much geothermal heat would account for what happens at Marie Byrd Land. Then, researchers decided to use the Ice Sheet System Model (ISSM). This model reveals the physics of ice sheets, helping experts look at the natural sources of heat transport and heating.
Due to the use of this model, researchers were able to establish a constraint on the possible melt rate that could exist there. Hence, they have tested different scenarios, indicating how much heat the plume produced underneath the ice shelves.
Hence, their findings indicate that the energy generated by the mantle plume id of 150 milliwatts per square meter. That is what their calculations and models proved. If the energy of the plume were bigger, then the meltdown would have been even more severe than it is now. Then, scientists compared these results with the heat generated under the Yellowstone National Park.
The results indicated that the Yellowstone plume triggers massive heat of 200 milliwatts per square meter, the value being only with 50 milliwatts bigger than the one in the Marie Byrd Land. NASA scientists indicated that they had found an area in Antarctica where the heat reached even higher levels, touching 150-180 milliwatts per square meter. However, at the new location, the heat appears to come from a rift.
The heat coming from below is incredibly high
A rift represents a fracture in the crust of our planet through which a massive amount of heat can rise towards the surface. The team of researchers indicates that the mantle plume at the Marie Byrd Land location might have formed about 50-110 million years ago. Hence, this was long before the whole land was even covered in ice. Scientists claim that the heat coming from the plume has a crucial local impact on the ice shelve.
By developing further studies and understanding more about these processes, scientists would be able to find out what will happen to the ice shelves in the area in the future. If the mantle plume continues to melt the area from West Antarctica, then a lot of ecosystems will be in danger.
Scientists explain that the stability of an ice sheet relies on the quantity of water that lubricates it from below. Hence, it will easily damage glaciers, causing them to slide even more. This plume situated under the ice triggered Antarctica’s bedrock to become laced with massive lakes and rivers.
To make sure their model is as realistic as possible, specialists developed observation of changes in the altitude of the ice shelve surface. They used the airborne Operation IceBridge campaign and NASA’s IceSat satellite. Erik Ivins, one of the researchers in Seroussi’s team, argues that these observations pose a great constraint on the possible melt rates that could exist there.
The new study developed by NASA scientists sheds light on how mantle plumes influence severe meltdown. We should no longer think that climate change is the only culprit for massive meltdown events in Antarctica. The subsurface plumes have even a much stronger effect on ice shelves than climate change does.