Roundup of Global Volcanic Activity – Ongoing Activity for the week of 25 January-31 January 2017
Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 25 January an ash plume from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.
Bogoslof | Fox Islands (USA) : AVO reported that no further emissions were detected at Bogoslof after an explosion at 0453 on 24 January; the Aviation Color Code (ACC) was lowered to Orange and the Volcano Alert Level (VAL) was lowered to Watch the next day. An hour-long seismic increase began at 0134 on 25 January though no evidence of eruptive activity was evident. Based on lightning and seismic data an explosive event began at 0650 on 26 January, and another burst of seismicity was recorded at 0706. The ACC was raised to Red and the VAL was raised to Warning. An ice-rich cloud, first identified in satellite data at 0700, likely contained ash, and rose as high as 9.8 km (32,000 ft) a.s.l. and drifted SE at lower altitudes, and NE at altitudes above about 6.1 km (20,000 ft) a.s.l. The ACC was lowered to Orange and the VAL was lowered to Watch later that day. Lightning and seismic data again indicated an explosive event at 0824 on 27 January, prompting AVO to raise the Aviation Colour Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. An ice-rich cloud that likely contained ash rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted E; seismicity related to ash emissions remained elevated for 48 minutes. The ACC was lowered to Orange and the VAL was lowered to Watch later that day.
Several short bursts of seismic activity were detected at 0520 and 0608 on 30 January. An infrasound signal accompanied the first event indicating an explosion; an eruption cloud was identified in satellite data at 0530, rising to an altitude of 6.1 km (20,000 ft) a.s.l. later that day AVO noted that bursts of explosive activity continued and intensified; more than 10 short-duration explosions were detected in seismic, infrasound, and lightning data. The Aviation Colour Code (ACC) was raised to Red and the Volcano Alert Level (VAL) was raised to Warning. Ash plumes rose as high as 7.6 km (25,000 ft) a.s.l. and drifted 125 km SE. Trace amounts of ashfall and a sulphur odour were reported in Unalaska/Dutch Harbour (98 km E). By the next day the explosions had subsided or ended. Satellite images acquired on 31 January showed significant changes to the island. AVO stated that freshly erupted volcanic rock and ash had formed a barrier that separated the vent from the sea, suggesting that the change had resulted in the more ash-rich emissions occurring during 30-31 January.
Colima | Mexico : Based on webcam and satellite images, the Mexico City MWO, and model data, the Washington VAAC reported that during 25-29 January ash plumes from Colima rose to altitudes of 4.7-7 km (17,000-26,000 ft) a.s.l. and drifted NE. Ash plumes were identified in satellite images at least 370 and 650 km NE of Colima on 25 and 27 January, respectively.
Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 25-26 and 29-31 January ash plumes from Dukono rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted NE, E, ESE, and SW.
Ebeko | Paramushir Island (Russia) : KVERT reported that moderate gas-and-steam emissions possibly containing small amounts of ash may have continued at Ebeko during 20-27 January. The Aviation Colour Code remained at Orange (the second highest level on a four-colour scale).
Fuego | Guatemala : Based on INSIVUMEH notices, CONRED reported that at 1345 on 25 January a Strombolian phase began at Fuego. Weak-to-moderate explosions generated ash plumes that rose 750 m above the crater rim and drifted 10 km W and SW. Lava fountains rose 200 m above the crater rim and fed lava flows that traveled 1 km SSW down the Ceniza drainage. Avalanches of material advanced more than 300 m down the Ceniza and Trinidad (S) drainages into vegetated areas. Ash fell on the SW and W flanks. The report also noted that a previous Strombolian phase had begun on 3 January.
INSIVUMEH reported that during 27-31 January explosions generated ash plumes that rose 500-900 m and drifted 5-10 km W, SW, S, and SE. Avalanches of material descended the Ceniza, Trinidad, and Santa Teresa (W) drainages.
Kilauea | Hawaiian Islands (USA) : During 25-31 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu’u ‘O’o.
HVO noted that thermal images showed a high-temperature area about 5-10 m from the edge of the sea cliff, with hot cracks running parallel to the cliff around the entry point, suggesting sea cliff instability. HVO scientists did not observe significant delta development from ground vantage points on 29 January. A stream of lava continued to pour into the ocean from an opening in a lava tube about 20 m above the water.
Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 25-27 January ash plumes from Langila rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and drifted NW and N.