Volcanos

Global Volcanic Activity - New Activity for the week of 26 June - 2 July 2019

Manam | Papua New Guinea : RVO reported that RSAM values at Manam began increasing on 27 June and then spiked from 540 to over 1,400 within a short period of time (~30 min). According to news articles, residents reported hearing thundering noises around 0100 on 28 June. An eruption plume was visible in satellite images around 0620 drifting SW, around the time residents reported the start of the eruption. The Darwin VAAC issued a notice stating that by 0910 the ash plume had risen to 15.2 km (50,000 ft) a.s.l. and was drifting SW. Pyroclastic flows descended the W and NE flanks. About 3,775 people evacuated their homes. Additional ash plumes rose to 4.6 km (15,000 ft) a.s.l. and drifted W, and by 1700 the higher-altitude plume had detached from the volcano and continued to drift SW. A thermal anomaly persisted on 29 June, and the next day an ash plume rose to 2.4 km (8,000 ft) a.s.l. and drifted W. Air Niugini stopped all aircraft overnighting in Madang due to the eruption. On 30 June they resumed operations at Hoskins airport, after rerouting all flights out of nearby airports during 29-30 June.

Mauna Loa | Hawaiian Islands (USA) : HVO reported that during the previous several months earthquake and ground deformation rates at Mauna Loa were elevated above background levels. During the first half of 2018 the seismic network recorded fewer than 20 shallow, small-magnitude earthquakes per week. Following a significant earthquake swarm in October, the rate increased to at least 50 events per week beneath the summit, upper Southwest Rift Zone, and upper west flank. These locations were similar to those that preceded eruptions in 1975 and 1984. GPS and satellite RADAR data detected deformation consistent with recharge of the shallow magma storage system. The increased seismicity and deformation indicated that Mauna Loa is no longer at background levels, prompting HVO to raise the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory. HVO noted that an eruption was not imminent.

Raikoke | Kuril Islands (Russia) : SVERT and KVERT reported that during 25 June-1 July steam-and-gas plumes with ash rose 1.5-2 km above Raikoke and drifted WNW based on satellite images. The Aviation colour Code was lowered to Yellow on 25 June and then to Green on 27 June.

Ubinas | Peru : Instituto Geofísico del Perú (IGP) and INGEMMET reported that seismic activity at Ubinas remained elevated during 24-30 June; volcano-tectonic events averaged 200 per day and signals indicating fluid movement averaged 38 events per day. Emissions of gas, water vapor, and ash rose from the crater and drifted N and NE based on webcam views and corroborated with satellite data. According to a news article an eruption plume rose 400 m above the crater rim and drifted 10 km NE. The Alert Level was raised to Yellow (on a 4-level scale) on 27 June.

Ulawun | New Britain (Papua New Guinea) : RVO reported that on 27 June diffuse white plumes rose from Ulawun’s summit crater and incandescence was visible from pyroclastic or lava flow deposits on the N flank from the significant eruption the day before. The seismic station located 11 km NW of the volcano recorded low RSAM values between 2 and 50. According to the Darwin VAAC a strong thermal anomaly was visible in satellite images, though not after 1200. Ash from 26 June explosions continued to move away from the volcano and became difficult to discern in satellite images by 1300, though a sulfur dioxide signal persisted; ash at 13.7 km (45,000 ft) a.s.l. drifted SW to SE and dissipated by 1620, and ash at 16.8 km (55,000 ft) a.s.l. drifted NW to NE and dissipated by 1857. RVO noted that at 1300 on 27 June satellite images captured an ash explosion not reported by ground-based observers likely due to cloudy weather conditions. The Alert Level was lowered to Stage 1. RSAM values slightly increased at 0600 on 28 June and fluctuated between 80 to 150 units afterwards. During 28-29 June diffuse white plumes continued to rise from the crater and from the North Valley vent. On 29 June a news article stated that around 11,000 people remained evacuated to shelters.