Shockwaves from Tonga volcano and tsunami picked up by Lancaster University weather station

The incident on Saturday - called an "unprecedented disaster" by the Tongan government - caused catastrophic damage, with homes destroyed and many communities covered in a thick layer of ash.

Communications with Tonga have been severely disrupted, with the single undersea cable connecting it to the outside world severed in the eruption.

The Red Cross said 80,000 people could have been affected, with a british person among those reported missing.

The scale of the disaster can be seen by recordings taken at the university's weather station at Hazelrigg.

The station's barograph, which continuously measures atmospheric pressure, picked up on the two shockwaves following the Tonga eruption, which arrived over the UK about 14 hours later, and can be seen in the image at around 7.30pm Saturday and 2am on Sunday.