Geologists say they are close to creating the hottest borehole in the world.
They are drilling into the heart of a volcano in the south-west of Iceland.
They have told the BBC that they should reach 5km down, where temperatures are expected to exceed 500C, in the next couple of weeks.
The researchers want to bring steam from the deep well back up to the surface to provide an important source of energy.
"We hope that this will open new doors for the geothermal industry globally to step into an era of more production," said Asgeir Margeirsson, CEO of the
Iceland Deep Drilling Project (IDDP), a collaboration between scientists, industry and the Icelandic government.
"That’s the aim - that’s the hope. We have never been this deep before, we have never been into rock this hot before, but we are optimistic."
The project is located on the Reykjanes peninsula, where a volcano last erupted 700 years ago.
<snip>
"In this area at Reykjanes, we typically drill to 2km or 3km depth to harness the steam, to run power plants and produce clean, renewable electricity," explained Asgeir Margeirsson.
"We want to see if the resources go deeper than that.
"
When the drill gets to 5km, the team expects to find molten rock mixed with water. But with the extreme heat and immense pressure found at this depth, the water becomes what is known as "supercritical steam".
It is neither a liquid nor a gas, but it holds far more energy than either. And it is this supercritical steam that the team wants to bring back up to the surface to convert into electricity.
<snip>
