New Zealand's National Institute for Water and Atmospheric Research (NIWA) press release about January Hunga-Tonga #volcano eruption. https://niwa.co.nz/news/tonga-eruption-confirmed-as-largest-ever-recorded
"Hunga-Tonga Hunga-Ha'apai (HT-HH) emitted the biggest atmospheric explosion recorded on Earth in more than 100 years (…) almost 10km3 of seafloor was displaced (…) the caldera, or crater, is now 700m deeper than before the eruption."
"NIWA scientists have also unravelled one of the biggest unknowns of the eruption – the pyroclastic flows (…) Samples showed [underwater] pyroclastic deposits [at least] 80km away from the volcano."
In a recent Science paper, Proud et al. estimated that the Hunga Tonga-Hunga Ha’apai volcanic plume reached an altitude of 57km "well past the stratosphere and into the mesosphere and higher than any volcanic plume previously recorded".
They used geostationary weather satellite imagery. The different satellites recorded the #volcano eruption with multiple viewing geometries. This allowed the researchers to compute plume altitude based on the parallax effect.