A scheme to provide heating for the Eden Project in Cornwall from geothermal sources has been halted after an earthquake during testing at the site.

       Testing at the geothermal wells on the site was stopped after a seismic event of magnitude 1.7 was detected on Wednesday night.

       Geothermal heat from rocks 4.5km below the surface will be used to heat water that will supply heating for the Eden Project’s biomes, greenhouses and offices, if the project proves successful.

       The scheme is currently in the well testing phase, where water is pumped into the rocks to ensure fluids can be safely run through the naturally fractured granite and pumped out again to provide heating.

       Eden Geothermal, the company running the project, apologised for any disturbance but said the event - which occurred at a depth of 3.7km - had not been dangerous.

       It said it had stopped operations temporarily in order to assess any damage and ensure there were no further seismic events. It is expected to “cautiously” restart operations on Friday.

       “This event was many times smaller than anything which could cause damage or pose any danger,” it said.

       “However, we understand that it has caused alarm and disruption, and are very sorry for this.”

       It said that since the start of injection testing in late January, there had been more than 300 low-level seismic events.

       It added that it operates on levels that reflect the thresholds defined by Cornwall Council for quarry blasting and mining in the local area.

       Local residents reported feeling their houses shake on Wednesday night.

       Helen Franks, who thought something had crashed into her house or that her chimney had collapsed, said: "It felt like my house had been dropped, it did not feel good.

       "This does not bode well and does not engender a sense of trust."

       Belinda Waldock, another local resident, said: “Operations should be immediately stopped, not just paused. Eden has caused a frightening and significant seismic event in our local area that has frightened people, pets and damaged property.”

       Kim Cassap Haynes said: “We were told this wouldn’t happen. You have a community right on your doorstep that would like answers and full transparency.”

       Gus Grand, from Eden Geothermal, told the BBC on Thursday that earthquakes of this size were “very common in the UK”.

       He added: “We're not talking about anything that should cause anybody any worry which is why we put out a statement and stopped pumping for the moment."

       Call for return to fracking

       The event came as the Government faces calls to lift restrictions on fracking for shale gas in the UK, which was halted after a 2.9 magnitude quake from a site in Lancashire in 2019.

       The fracking industry has argued that different standards are being applied to geothermal projects than to shale gas extraction.

       Eden Geothermal hopes its project, which is backed by the EU and Cornwall Council, will herald the way for a new renewable and industry sector in Cornwall and the UK.

       Cornwall is considered a particularly attractive location for geothermal energy because of its resources of 300 million year old granite, which brings heat closer to the surface.