Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 21 March - 27 March 2018

Ambae | Vanuatu : Based on satellite data, webcam observations, and wind model data, the Wellington VAAC reported that during 21-27 March ash plumes from the vent at Ambae’s Lake Voui rose to altitudes of 3-4.6 km (10,000-15,000 ft) a.s.l. and drifted mainly S and SW, but towards the end of the week to the N and W. News articles noted that ashfall had significantly impacted the S and W parts of the island, damaging crops, contaminating water, and collapsing homes, leading to the evacuation of three villages. On 25 March a flight was cancelled. Residents of Santo reportedly witnessed incandescent material being ejected as high as 1 km around 1800 and 2200; residents also noted four more events during the next morning that were also heard in Pentecost and Maewo.

Copahue | Central Chile-Argentina border : According to ONEMI, OVDAS-SERNAGEOMIN reported that a hydrothermal explosion at Copahue was recorded on 24 March, along with increased tremor. The Alert Level was raised to Yellow (second highest level on a four-colour scale); SERNAGEOMIN recommended no entry into a restricted area within 1 km of the crater. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the municipality of Alto Biobío.

Ijen | Eastern Java (Indonesia) : Based on information from residents of Sempol (8 km W), PVMBG reported that 27 people in Watu Capil village (7 km NW) required medical treatment after exposure to sulfur dioxide gas from Ijen at 2100 on 21 March. The path from Paltuding (SW base) to the top of the crater was closed as a result. During 21-22 March white plumes rose 100-200 m above the summit area; there were no visible changes in the emissions after the incident. PVMBG noted that there had been three occurrences of anomalous gas concentrations during January-March. The Alert Level remained at 1 (on a scale of 1-4), and residents and visitors were advised to not approach the crater rim or crater floor.

Kick 'em Jenny | North of Grenada : On 22 March the University of the West Indies (UWI) Seismic Research Centre (SRC) and the National Disaster Management Agency (NaDMA) reported that seismicity at Kick 'em Jenny continued to decline. The Alert Level was lowered to Yellow (the second lowest level on a four-colour scale) and the maritime exclusion zone was adjusted to a radius of 1.5 km.

Kirishimayama | Kyushu (Japan) : JMA reported that the eruption at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, continued during 19-27 March. Lava effusion possibly stopped on 9 March, though the lava flow on the NW flank continued to advance. A high number of volcanic earthquakes continued to be recorded, in addition to many low-frequency earthquakes with shallow hypocenters. Short-duration volcanic tremor was occasionally recorded. During a field survey on 22 March scientists measured 600 tons/day of sulfur dioxide gas, and noted that the crack on the W flank had grown slightly larger. On 25 March an explosion at 0735 was followed by an ash plume that rose 3.2 km above the crater rim and ejected material as far as 800 m. An event at 0845 generated an ash plume that rose 2.1 km above the crater rim, and a very small pyroclastic flow that traveled 800 m W. Sulfur dioxide emissions were 300 tons/day on 24 March. The Alert Level remained at 3 (on a scale of 1-5).

Myojinsho | Japan : JMA issued a warning on 24 March for the waters surrounding Myojinsho after reports from the Japan Coast Guard indicated discoloured water from a possible eruptive event.