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Abstract Axial Seamount is a basaltic hot spot volcano with a summit caldera at a depth of ∼1,500 m below sea level, superimposed on the Juan de Fuca spreading ridge, giving it a robust and continuous magma supply. Axial erupted in 1998, 2011, and 2015, and is monitored by a cabled network of instruments including bottom pressure recorders and seismometers. Since its last eruption, Axial has re‐inflated to 85%–90% of its pre‐eruption level. During that time, we have identified eight discrete, short‐term deflation events of 1–4 cm over 1–3 weeks that occurred quasi‐periodically, about every 4–6 months between August 2016 and May 2019. During each short‐term deflation event, the rate of earthquakes dropped abruptly to low levels, and then did not return to higher levels until reinflation had resumed and returned near its previous high. The long‐term geodetic monitoring record suggests that the rate of magma supply has varied by an order of magnitude over decadal time scales. There was a surge in magma supply between 2011 and 2015, causing those two eruptions to be closely spaced in time and the supply rate has been waning since then. This waning supply has implications for eruption forecasting and the next eruption at Axial still appears to be 4–9 years away. We also show that the number of earthquakes per unit of uplift has increased exponentially with total uplift since the 2015 eruption, a pattern consistent with a mechanical model of cumulative rock damage leading to bulk failure during magma accumulation between eruptions.
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The tangled tale of Kīlauea’s 2018 eruption as told by geochemical monitoring
Changes in magma chemistry that affect eruptive behavior occur during many volcanic eruptions, but typical analytical techniques are too slow to contribute to hazard monitoring. We used rapid energy-dispersive x-ray fluorescence analysis to measure diagnostic elements in lava samples within a few hours of collection during the 2018 Kīlauea eruption. The geochemical data provided important information for field crews and civil authorities in advance of changing hazards during the eruption. The appearance of hotter magma was recognized several days before the onset of voluminous eruptions of fast-moving flows that destroyed hundreds of homes. We identified, in near real-time, interactions between older, colder, stored magma—including the unexpected eruption of andesite—and hotter magma delivered during dike emplacement.
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- Award ID(s):
- 1838502
- PAR ID:
- 10126472
- Publisher / Repository:
- American Association for the Advancement of Science (AAAS)
- Date Published:
- Journal Name:
- Science
- Volume:
- 366
- Issue:
- 6470
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- Article No. eaaz0147
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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