Multi-disciplinary characterization of the June 2019 eruptions of Raikoke (Kuril Islands) and Ulawun (Papua New Guinea) volcanoes using remote techniques
Abstract
The 2019 program of the Cooperative Institute for Dynamic Earth Research (CIDER) was organized on the notion that multidisciplinary teams can advance understanding of volcanic processes. Fortuitously, two of the largest explosive volcanic eruptions of the past decade occurred during the program, at Raikoke, Kuril Islands and Ulawun, Papua New Guinea, providing an opportunity to apply this notion in the immediate aftermath of these events. As a CIDER workgroup, we integrated data from satellites (including Sentinel-2, TROPOMI, MODIS, Himawari-8), the International Monitoring System infrasound network, and globally-detected lightning (e.g., GLD360, WWLLN) with information from local authorities and social media to improve understanding of the pre-, syn- and post- eruptive behavior of these volcanoes.
At locally unmonitored Raikoke volcano, we observed six infrasound pulses beginning on 21 June 17:49:55 UTC as well as the main Plinian phase. Each pulse was spatiotemporally tracked with lightning and satellite imagery as the plumes drifted eastward. Post-eruption visible satellite imagery shows expansion of the island's surface area, an increase in crater size, and a possibly linked algal bloom south of the island. We use thermal satellite imagery and plume modeling to estimate plume height at 10-12 km asl and mass eruption rate. At Ulawun volcano, the Rabaul Volcano Observatory recorded ~24 hours of seismic precursors and ~16 hours of SO 2 emissions before the start of the Plinian phase. Infrasound detections and local reports confirm the eruption started on 25 June 19:30 UTC with ~6 hours of infrasonic jetting. The first detected lightning occurred on 26 June 00:14 UTC. Emissions were first detected by Himawari-8 at 01:00 UTC and the Plinian phase began on 26 June 04:20 UTC. Satellite imagery indicates new flow deposits to the south and north of the edifice and ash fall to the west and southwest. Remote infrasound data provide insight into syn-eruptive changes in eruption intensity. During both eruptions, we note a decrease in infrasound peak frequency upon transition to the Plinian phase. This may be related to changes in jet and plume dynamics, such as an increase in vent diameter (observed in satellite). Our analysis illustrates the value of interdisciplinary analysis of remote data to illuminate eruptive processes.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.V23F0259M
- Keywords:
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- 4314 Mathematical and computer modeling;
- NATURAL HAZARDS;
- 8414 Eruption mechanisms and flow emplacement;
- VOLCANOLOGY;
- 8428 Explosive volcanism;
- VOLCANOLOGY;
- 8445 Experimental volcanism;
- VOLCANOLOGY