Fortunately, the 15 January climactic eruption of the underwater volcano at Hunga Tonga-Hunga Ha'apai (HTHH) in the south Pacific resulted in very few deaths, even though it too produced large tsunamis.
Scientists now have access to an extraordinary array of ground-based and spaceborne instruments, including atmospheric pressure sensors, seismometers, hydro-phones, and a fleet of satellites that monitor the Earth across the entire light spectrum.The colossal Tonga explosion, which came at the end of of several weeks of activity at the seamount, produced several types of atmospheric pressure waves that propagated vast distances.The network's data indicated the Tonga volcano blast produced an atmospheric pressure wave comparable with that from the biggest ever nuclear explosion - the Tsar bomb detonated by the Soviets in 1961 - but lasted four times longer.The papers discuss at length the perturbations driven by so called Lamb waves, named after the early 20th Century mathematician Horace Lamb.The Lamb wave pulses produced by the Tonga eruption were seen to circle the Earth at least four times.In the UK, which is some 16,500km from Tonga, these pulses began arriving on the evening of the 15th, about 14 hours after the climactic eruption on the other side of the planet.Some were undoubtedly crafted by pressure waves from the volcano pushing down on the water surface, but investigations are on-going to determine whether collapse of part of the volcano also made a significant contribution.
1 day ago
1 day ago
1 day ago
1 day ago