The 2018 rift eruption at Kīlauea Volcano: eruption triggering through mechanical failure and the role of extreme rainfall.
Abstract
The May 2018 rift intrusion-eruption of Kīlauea Volcano (Hawai'i, USA) represented one of its most extraordinary eruptive sequences in at least 200 years, yet the trigger mechanism of this remarkable eruption has remained elusive. The event was preceded by 4 months of anomalously high precipitation, a factor that has been previously proposed to modulate volcanic activity, and is known to influence numerous geological phenomena including silent slip events, shallow landslide generation, and remote triggering of earthquakes . By incorporating gauge- and satellite-derived rainfall estimates into numerical hydraulic diffusion models, we examine whether the anomalous rainfall leading up to the rift eruption could have brought about mechanical failure within the rift zone, prompting opportunistic dyke intrusion and ultimately facilitating the eruption. Infiltration of rainfall into the volcano's subsurface caused increases in pore pressure of at least 0.1-1 kPa at 1-3 km depth. Just prior to the rifting activity pore pressures were at their highest in almost 50 years, suggesting that the anomalously high rainfall observed across the island contributed to the onset of the volcanic crisis. This is consistent with the lack of precursory summit inflation, showing that this intrusion, in contrast to others, was not caused by the forceful intrusion of new magma into the rift zone. Moreover, statistical analysis of historic eruption occurrence suggests that rainfall patterns may contribute significantly to the timing and frequency of Kīlauea's eruptions and intrusions not just in 2018, but throughout its eruptive history. Volcanic activity can be modulated by extreme rainfall encouraging edifice rock failure: a factor that should be considered when assessing volcanic hazards in an era of changing climate patterns. We highlight that increasingly extreme weather patterns associated with ongoing anthropogenic climate change could globally increase the potential for rainfall-triggered volcanic phenomena.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.V51C..02F
- Keywords:
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- 8408 Volcano/climate interactions;
- VOLCANOLOGY;
- 8414 Eruption mechanisms and flow emplacement;
- VOLCANOLOGY;
- 8424 Hydrothermal systems;
- VOLCANOLOGY;
- 8427 Subaqueous volcanism;
- VOLCANOLOGY