A massive lake discovered in South America, could answer how volcanoes erupt
Scientists have discovered a massive lake, 15 kilometres below a huge volcano in South America, a discovery that could answer why and how volcanoes erupt.
The water body which is dissolved into partially molten rock at a temperature of around 1,000 degrees Celsius is equivalent to what can be found in some of the world’s biggest freshwater lakes, like Lake Superior.
What Discovery describes
The discovery by researchers from University of Bristol in the United Kingdom and colleagues led scientists to consider if the similar water bodies just like in South America may be ‘hidden’ under the other volcanoes and could help explain why and how volcanoes erupt.
“Bolivian Altiplano has been a site of extensive volcanism over the past 10 million years, although currently it has no active volcanoes,” stated Professor Jon Blundy, who was a part of the project at Cerro Uturuncu volcano in the Bolivian Altiplano.
“The Altiplano is bridled by a large geophysical anomaly at depths of 15 km below the Earth surface.
In and out of the Discovery
“This abnormally has a volume of one-and-a-half million cubic kilometres or sometimes even more and is described by reduced seismic wave speeds and increased electric conductivity. This indicates the existence of molten rock,” said Blundy.
“The rocks are not fully molten, but partially molten. Only about 10 to 20 per cent of the rock is in actuality liquid; the rest is finely solid. The rocks at these depths in South America are at a temperature of around 970 degrees Celsius,” he said.
In order to describe the partially molten region the team executed high temperature and pressure experiments at the University of Orleans in France.
This experiment measured the electrical conductivity of the molten rock in the ‘anomalous’ region and resulted that there might be about eight to ten per cent of water dissolved in the silicate melt.
“Silicate melting can only dissolve water at a high pressure; at low pressure this water pops out of the solution and forms bubbles. Crucially, these bubbles can lead to volcanic eruptions.
“Around eight to ten per cent of water dissolves in the massive anomaly region amounts to a total mass of water equal to what is found in some of the biggest freshwater lakes of North America,” Blundy added.
“This is a large fraction of water, helping in explaining why these silicate liquids are so electrically conductive,” said Gaillard.