Iceland 'is on edge' waiting for volcanic eruption amid fears river of lava could hit power plant after giant crack tears through town, thousands are evacuated and hundreds more earthquakes hit, with 'unholy sounds' coming up from the earth

The whole of Iceland 'is on edge' as experts say earthquakes which have been rumbling beneath the surface for days and have torn through a town are a precursor to a volcanic eruption.

More than 500 quakes were recorded in the southwestern Reykjanes Peninsula yesterday, and despite them being slightly weaker than in previous days the Fagradalsfjall volcano is still expected to erupt.

Iceland has been shaken by thousands of tremors over the past few days, with a state of emergency declared on Friday and around 4,000 people ordered to leave the town of Grindavik. 

Evacuated residents have reported being left feeling 'seasick' by the tremors and hearing 'unholy sounds' emanating from beneath the ground as they fled their homes.

Huge sinkholes have opened up around the town, and now dramatic aerial footage captured by the Coast Guard shows a chasm running through the centre, with smoke pouring out of the gaping splits as magma rises. 

Meanwhile, authorities are urgently preparing to build defence walls around a nearby geothermal power plant which they desperately hope will protect it from lava flows - amid concerns that a volcanic eruption could be imminent.

'We believe that this intrusion is literally hovering, sitting in equilibrium now just below the earth's surface,' said Matthew James Roberts, director of the service and research division at the meteorological office.

'We have this tremendous uncertainty now. Will there be an eruption and if so, what sort of damage will occur?' he said.

Magma has been accumulating under the town and experts said yesterday that a 'corridor' around nine miles (14km) long has developed beneath it, with an eruption possible anywhere along the intrusion. 

Local media reports that seismic activity overnight was similar to the day before, with 'about a hundred tremors per hour'. 

Most were small, but the largest measured 3.1 and 2.8 in size, according to Visir.is.

Hans Vera, a Belgian-born 56-year-old who has lived in Iceland since 1999, said there had been a constant shaking of his family's house.

'You would never be steady, it was always shaking, so there was no way to get sleep,' said Vera, who is now staying at his sister-in-law's home in a Reykjavik suburb.

'It's not only the people in Grindavik who are shocked about this situation it's the whole of Iceland.'

'We are really concerned about all the houses and the infrastructure in the area,' head of Iceland's Civil Protection and Emergency Management, Vidir Reynisson said earlier this week.

'The magma is now at a very shallow depth, so we're expecting an eruption within a couple of hours at the shortest, but at least within a couple of days.'

Icelanders are 'essentially just waiting', local journalist Holmfridur Gisladottir told Sky News on Monday.

A looming eruption has revived the trauma of the 2010 explosion at another of Iceland's volcanoes, Eyjafjallajokull, for many locals.

It produced a huge cloud of ash which prompted the biggest shutdown of global aviation since the Second World War, with 50,000 flights cancelled and eight million passengers affected.

Discussing the differences between a potential eruption of Fagradalsfjall and Eyjafjallajokull, Mr Roberts said an eruption could see lava spew over the town, but was less likely to cause the same ash blast. 

He told BBC R4's Today programme on Monday: 'First of all there isn't an ice cap on top and it's not a stratovolcano so wouldn't be an explosive blast of volcanic ash into the atmosphere.

'This would be a lava-producing volcanic eruption along a series of fissures and that would be the main hazard.'

He added that an eruption 'that persists for weeks' is possible, meaning roads and other infrastructure could be 'in harm's way'.

Located between the Eurasian and the North American tectonic plates, among the largest on the planet, Iceland is a seismic and volcanic hot spot as the two plates move in opposite directions.

In March 2021, lava fountains erupted spectacularly from a fissure in the ground measuring between 500-750 metres long in the region's Fagradalsfjall volcanic system. 

Volcanic activity in the area continued for six months that year, prompting thousands of Icelanders and tourists to visit the scene. 

In August 2022, a three-week eruption happened in the same area, followed by another in July of this year.