The paper[1] says there were three blasts, the largest of which was 15 megatons. Another paper[2] estimates 61 megatons. USGS gives 24 megatons for St Helens 1

The paper[1] says there were three blasts, the largest of which was 15 megatons. Another paper[2] estimates 61 megatons. USGS gives 24 megatons for St Helens 1980 and 70 megatons for Pinatubo 1991.[3][4] The time period over which energy is integrated is an important distinction here, and sources are not always clear about it. It's also relevant in comparisons with nuclear explosives, which detonate extremely rapidly and achieve far higher peak power than any natural phenomenon on Earth. My guess is that possibly St Helens and probably Pinatubo achieved higher peak power in the last century. [1] https://doi.org/10.1126/sciadv.adf5493 https://doi.org/10.1126/sciadv.adf5493 [2] https://doi.org/10.1007/s00193-022-01092-4 https://doi.org/10.1007/s00193-022-01092-4 [3] https://pubs.usgs.gov/fs/2000/fs036-00/ https://pubs.usgs.gov/fs/2000/fs036-00/ [4] https://pubs.usgs.gov/pinatubo/tahira/ https://pubs.usgs.gov/pinatubo/tahira/