PAWhat lies beneath the surface of the Antarctic ice isn’t exactly a party conversation, but it’s still interesting.
Especially after NASA revealed a ‘mantle plume’ is the source of the extraordinary heat which is leading the ice to crack and eventually melt.
The idea was first posed by a scientist at the University of Colorado, Denver, some 30 years ago.
They said the reason for random volcanic-like activity above the region of the continent – known as Marie Byrd Land – may be down to a mantle plume.
PANow not all of us are scientists so let’s go over what a mantle plume precisely is.
As per ScienceDaily:
A mantle plume is an upwelling of abnormally hot rock within the Earth’s mantle.
As the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcanic centers known as hotspots and probably also to have caused flood basalts.
It is a secondary way that Earth loses heat, much less important in this regard than is heat loss at plate margins.
Some scientists think that plate tectonics cools the mantle, and mantle plumes cool the core.
Two of the most well known locations that fit the mantle plume theory are Hawaii and Iceland as both have volcanic activity.
PAHélène Seroussi of NASA’s Jet Propulsion Laboratory, who helped in the research, said:
I thought it was crazy. I didn’t see how we could have that amount of heat and still have ice on top of it.
On their website, NASA explained:
They found the flux of energy from the mantle plume must be no more than 150 milliwatts per square meter. For comparison, in U.S. regions with no volcanic activity, the heat flux from Earth’s mantle is 40 to 60 milliwatts.
Under Yellowstone National Park – a well-known geothermal hot spot – the heat from below is about 200 milliwatts per square meter averaged over the entire park, though individual geothermal features such as geysers are much hotter.
GettyThe Marie Byrd Land mantle plume formed 50 to 110 million years ago, a good deal before the West Antarctic ice sheet even came about.
At the end of the last ice age, around 11,000 years ago, the ice sheet went through ‘a period of rapid, sustained ice loss when changes in global weather patterns and rising sea levels pushed warm water closer to the ice sheet’ – similar activity is happening today.
The paper, ‘Influence of a West Antarctic mantle plume on ice sheet basal conditions’, was published in the Journal of Geophysical Research and if you fancy reading the thing in full, you can do so right here.
