Day: November 21, 2019

Global Volcanic Activity – New Activity for the week of 13 November – 19 November 2019

Cleveland | Chuginadak Island (USA) : AVO lowered the Volcano Alert Level for Cleveland to Advisory and the Aviation colour Code to Yellow on 15 November, noting that new satellite data and reanalysis of previous data over the past week showed that lava effusion likely had not begun on 8 November. Regional seismic and infrasound data showed no evidence of eruptive activity during 8-19 November; weakly-to-moderately elevated surface temperatures were sometimes identified in satellite images and steam plumes were sometimes visible in webcam images.

Kirishimayama | Kyushu (Japan) : The number of volcanic earthquakes with hypocenters just below Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, increased around 1900 on 17 November and continued to increase through the next day. JMA raised the Alert Level to 2 (on a scale of 1-5) on 18 November. Bad weather conditions prevented visual webcam observations.

Lateiki | Tonga Islands : Satellite images showed that the mid-October eruption at Lateiki (Metis Shoal) had formed a new and larger island, but by 14 November it had eroded to a size similar to the pre-eruptive size.

Shishaldin | Fox Islands (USA) : AVO reported that the eruption at Shishaldin continued at variable levels during 13-19 November. Seismicity increased during 13-14 November, and elevated surface temperatures were visible in satellite and webcam data. Minor ash emissions were visible and likely resulting from spatter cone collapses. Lava and debris flows had not advanced since 8 November; lava flows had traveled as far as 1.2 km and a large branched network of debris flows extended at least 5.5 km NE. Strongly elevated surface temperatures and a steam plume drifting more than 100 km SE were visible on 15 November. An incandescent lava flow on the NE flank was recorded in webcam images. Activity during 17-18 November was characterized by low seismic tremor and weakly-to-moderately elevated surface temperatures, consistent with cooling lava flows. Seismicity and surface temperatures again increased during 18-19 November. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

White Island | North Island (New Zealand) : GeoNet reported that minor increases in sulfur dioxide emission had been detected at White Island over the past several weeks, and the level of volcanic tremor increased from weak to moderate levels during the previous few weeks. The report noted that the changes are not uncommon and could be related to a variety of processes, though the elevated activity was above the expected range for minor volcanic unrest and associated hazards; GeoNet raised the Volcanic Alert Level for White Island to 2 and the Aviation colour Code to Yellow on 15 November.