Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 24 January - 30 January 2018

Kadovar | Papua New Guinea : RVO reported that the eruption at Kadovar continued during 23-24 January at levels similar to the previous few days. Main Crater produced light-gray to brown ash plumes that rose at most 100 m and drifted a few tens of kilometers W. Weak incandescence from Main Crater was visible at night. The lava dome at the SE Coastal Vent continued to grow and was an estimated 50 m a.s.l. (the water depth in that area was unknown) and extends out from the coast 150-200 m. The dome glowed red at night. Seismicity was low to moderate, with one high-frequency event, and 12 significant numerous small low-frequency events. Strong sulfur dioxide emissions were detected.

Kusatsu-Shiranesan | Honshu (Japan) : JMA reported that after the 23 January eruption near Motoshiranesan (the highest peak belonging to the Kusatsu-Shiranesan complex) seismicity, characterized by volcanic earthquakes and tremor, was elevated; it decreased the next day. Minor but elevated seismicity continued through 30 January, punctuated by periods of tremor. The eruption occurred from a fissure oriented E-W, located just inside the N rim of the northernmost Kagamiike Kitahi craters. JMA noted no juvenile material in the eruption deposits. The Alert Level remained at 3 (on a 5-level scale).

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 23-29 January there were 2-7 daily episodes of intense and sporadic lava fountaining at Mayon, each lasting 7-74 minutes. The lava fountains rose as high as 600 m above the crater rim, and fed flows in the Mi-isi and Bonga drainages and incandescent rockfalls on the summit area. Ash plumes rose 3-5 km above the crater. As many as three pyroclastic flows each day were detected by the seismic network, and had runout distances exceeding 5 km in the Buyuan drainage. Numerous rockfall events were generated by the growing and collapsing summit lava dome and traveled into the Bonga drainage, and from the front and margins of the advancing 3-km-long lava flow on the Mi-isi drainage. The Buyuan lava flow was 1 km long. Sulfur dioxide gas emissions were between 1,252 and 2,466 tonnes/day during 23-25 January. Heavy rain triggered lahars in the Binaan drainage during 28-29 January. A cycle of energetic lava effusion with sporadic lava fountaining, and pyroclastic flows from lava-collapse events, occurred late on 29 January. The events were mostly visually obscured, and indicated by seismic data. The period began with a large-volume lava collapse at 1950 at the summit crater that generated pyroclastic flows in the Mi-isi and Bonga drainages. Lava fountaining was detected at 2016 and lasted eight minutes. This was followed by large-volume lava effusion that lasted 96 minutes, and was interspersed with sporadic lava fountaining and/or pyroclastic flows. Sporadic lava fountaining was visually and seismically detected until 2306, with lava fountains rising as high as 200 m. Ash plumes rose 1.5 km above the crater. Significant ashfall was reported in Camalig and Guinobatan, Albay before 2100, possibly resulting from the lava fountaining and pyroclastic flows.

Zaozan | Honshu (Japan) : JMA reported that tremor was detected at Zaozan on 28 and 30 January, and minor inflation at the S part of the volcano was recorded. There were 12 volcanic earthquakes detected on 31 January. JMA raised the Alert level to 2 (on a 5-level scale), noting the increased potential for a small eruption.

San Miguel | El Salvador : SNET reported that during 25-26 January seismic activity at San Miguel was slightly higher than normal, with RSAM values fluctuating between 75 and 179 units. Small pulses of gas near the crater rim were visible.