Tonga Volcano Eruption Recorded in Hastings

Incredibly the impact of the Tonga volcano eruption was recorded in Hastings, East Sussex, almost as far as you can get from the small Polynesian kingdom of more than 170 South Pacific islands.

Hastings weather kiosk, on the seafront just to the west of the pier, houses a barograph, which records air pressure. It is clockwork - probably the only piece of clockwork equipment still in regular use by Hastings Borough Council  - and as the attached chart shows, recorded pronounced 'blips' in air pressure late Saturday afternoon and again around six hours later. These are the impact the volcanic eruption, literally half as world away, had on the air pressure here in Hastings.

Changes in air pressure like this travel at the speed of sound. Tonga is just over 10 000 miles away and, at the speed of sound, that's around 14 hours away.

As the eruption was at 0410 GMT on Saturday the shock wave pulses should start to be recorded at approximately 1800 to 1900 in the UK. As the attached photo of the barograph chart for last week shows, the first blip in Hastings occurred at 1700 which, allowing for our barograph running up to two hours slow at the end of a week (as the clockwork mechanism runs slightly slow!) means we actually recorded the eruption, as expected, at around 1830.

The second downward blip recorded approximately six hours later is also part of the volcanic eruption pressure wave recording.

It is quite amazing to realise that here in Hastings we are able to measure - and see - the impact of a volcano in the South Pacific, and recorded on clockwork equipment.

This data was provided by Hastings Borough Council's volunteer meteorologists, who record the weather in the town every single day of the year.