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A technician checks the operations of a geothermal power plant in San Vicente Pacaya, Guatemala August 6, 2010. Sitting above shifting tectonic plates in the Pacific basin known to cause earthquakes and volcanic eruptions, the region has huge potential for geothermal power generated by heat stored deep in the earth. Guatemala, Central America's biggest country, aims to produces 60 percent of its energy from geothermal and hydroelectric power by 2022. Picture taken August 6, 2010. REUTERS/Daniel LeClair

The mystery behind the Earth's tectonic plate, a theory that suggests that the outer shell of the planet is divided into several plates that move above the mantle, has been solved by geologists. The geologists made use of half a tonne of dynamite which exploded underground, through which they studied the fine details of the plates with the help of sound waves, reported Live Science.

A geologist from the Victoria University of Wellington, Tim Stern, along with his colleagues, tried to understand the happenings beneath the surface of the Earth on the north Island of New Zealand. A number of powerful earthquakes had taken place in that area in recent years.

According to Stern, the findings by the scientists revealed a hidden channel of molten rock. Stern explained that a process called subduction was taking place because of which the Pacific plate was diving beneath the Australian plate at a shallow angle.

Stern and his colleagues placed half a tonne of dynamite into many steel-encased holes in the subduction zone. The dynamite exploded,, causing powerful sound waves in the zone. The team measured the reflected waves through which they could visualise the top of the plate which was about 20 to 30 kilometres beneath the surface. Stern said that they were surprised about the fact that they got more echoes from much deeper distance. The team came to a conclusion that the echoes came from about 73 kilometres below the top of the plate, which was the bottom plate.

Stern said that the findings could help provide insight about questions regarding the mechanics of plate tectonics. On investigating further, they found that a tiny bit of melt was at the base of the plate and that the movement of the plate was blocking the melt, which resulted in the creating of a soft spot. This helped in the easy gliding of the plate above the mantle. He also said that the discovery gave them a more detailed view of the base of a tectonic plate in comparison to past methods that have been implemented like the measurement of the seismic waves from the earthquakes.

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