Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 7 February - 13 February 2018

Agung | Bali (Indonesia) : On 10 February PVMBG reported that activity at Agung had declined during the previous month or two leading the observatory to lower the Alert Level to 3 (on a scale of 1-4) and adjusted the exclusion zone to a 4-km radius. The report noted that the tallest eruption plume in January was 2.5 km above the crater rim, occurring on 19 January, and the last event on 24 January generated a plume that rose 1 km. The volume of erupted lava was an estimated 20 million cubic meters in December 2017, and had not significantly changed. Seismicity continued to fluctuate, though the number and magnitude of events had declined. Satellite data showed a decrease in thermal output reflective of a reduced lava flow rate. PVMBG warned that activity at Agung is still high and unstable; tiltmeter data showed low rates of inflation (GPS patterns were stable) and gas-emission data indicated magma movement at depth, though at a lower intensity compared to values measured at the end of November 2017. An event at 1149 on 13 February generated as ash plume that rose 1.5 km above the crater rim.

Aira | Kyushu (Japan) : JMA reported that very small events occurred at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 7-9 February. Crater incandescence from the summit crater was visible during 8-10 February. An event at 2201 on 11 February generated a plume that rose 1 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Ambae | Vanuatu : Based on satellite, pilot, and webcam observations, the Wellington VAAC reported that during 8-9 February ash plumes from Aoba rose to altitudes of 2.7-3 km (9,000-10,000 ft) a.s.l. and drifted N and E.

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 7-8 February ash plumes from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NE.

Cleveland | Chuginadak Island (USA) : AVO reported that there was no evidence of significant activity at Cleveland since the last explosion was detected on 18 December 2017. The Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory. AVO noted that low-level unrest continued.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 7-13 February ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE, E, and SE.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 5-8 February generated ash plumes that rose as high as 2.4 km (7,900 ft) a.s.l. Ash fell in Severo-Kurilsk on 8 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 3 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 7-13 February HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali, and on the coastal plain.

Pacaya | Guatemala : INSIVUMEH reported that during 7-13 February Strombolian explosions at Pacaya’s Mackenney Crater ejected material 30 m above the main cone. Lava flows were at most 150 m long on the SW and W flanks.

Popocatepetl | Mexico : Each day during 7-13 February CENAPRED reported 25-101 emissions from Popocatépetl, with emissions during 11-13 February containing slight amounts of ash. Explosions were detected at 0130 and 2213 on 7 February, at 0457 on 8 February, at 1729 on 12 February, and at 0631 on 13 February. Minor crater incandescence was visible on the morning of 9 February, and at night during 11-12 February. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; there was an average of 18 explosions recorded per day during 5-11 February. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 3.9 km above the crater rim and drifted 50 km NW, SW, S, and SE. The MIROVA system detected three thermal anomalies. The sulfur dioxide flux was high, at 2,062 tons per day on 10 February. The report noted that the public should not to approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that explosions at Santa María's Santiaguito lava-dome complex, detected by the seismic network during 7-13 February, generated ash plumes that rose as high as 700 m and drifted SW. Avalanches of material descended the E and SE flanks of the lava dome. Ash fell on La Florida ranch (5 km S) on 10 February.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 1-4 and 7 February. The Aviation colour Code remained at Orange.

Shishaldin | Fox Islands (USA) : On 7 February AVO reported that seismic and infrasound activity from Shishaldin declined to background levels during the previous month, prompting the observatory to lower the Aviation colour Code to Green and the Volcano Alert Level to Normal.