The Size and Frequency of the Largest Explosive Volcanic Eruptions on Earth
Abstract
An analysis of the size and frequency of the largest known explosive eruptions on Earth reveals 42 known eruptions with erupted masses in excess of 1015 kg (magnitude 8 or larger) in the past 40 million years. This places the minimum frequency of eruptions of magnitude 8 and larger at ~1.4 Ma-1, in two pulses over the past 40 Ma. On the basis of the activity of the past 13.5 Ma, there is at least a 75% probability of an eruption of this scale occurring within the next 1 Ma. There is a 1% chance of an eruption of this scale in the next 460 - 7200 years. While the impact of any individual large magnitude eruption would be considerable, the time-averaged impact (i.e. erupted mass × frequency) of the very largest eruptions is small, due to their rarity. The long-term time-averaged erupted mass flux from magnitude 8 and 9 eruptions is one to two orders of magnitude less than for magnitude 7 eruptions, involving between 1014 and 1015 kg of magma. Comparison of the energy release by volcanic eruptions with that due to asteroid impacts suggests that on timescales of < 100,000 years, energetic volcanic eruptions are considerably more frequent than impacts of a similar energy yield and destructiveness. This has important implications for our understanding of risk from extreme events.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2005
- Bibcode:
- 2005AGUSM.V33A..02M
- Keywords:
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- 0370 Volcanic effects (8409);
- 8400 VOLCANOLOGY;
- 8414 Eruption mechanisms