This is the Guardian. Last Friday as volcanologist Helga Tor Radotir was working in her office in the Icelandic capital

Reykjavik, she started hearing something strange.

It's a bit of a creepy sound and also fascinating.

In the afternoon things got really shaky.

The rumble was just the latest in a series of more

than 20,000 earthquakes that have hit the southwest of the country since late

October.

I have my cabinet here up in my living room with like wine glasses and I put the glasses very close to each other so I could have like a bit of a seismic meter in my home and they start to jingle a little bit.

So I was like, okay, this is either getting closer to us or more severe.

The same day, 4,000 residents of the small fishing town of Grindavik, were evacuated from their homes.

Huge cracks and sinkholes have now appeared in roads, and sulphur dioxide has been detected in the air.

For now, the country is waiting and preparing.

A devastating eruption could come any day.

Perhaps by the time you're listening to this it's already hit.

But volcanologists are also predicting this could be the start of a centuries long volcanic era. So today we're asking what's going on

beneath the ground in Iceland and how do scientists predict when and where a volcano is going to blow?

From the Guardian I'm Madeline Finley and this is Science Weekly.

Helga Tortir, you're a volcanologist in Iceland and we're chatting on Wednesday and actually there have been some more signs today that an eruption

could be imminent but of course you've been following this develop over the past

week so what's been happening?

So if we just start from the beginning in the big picture

we have two tectonic plates that are opening up here or splictic.

...