Volcanos

Roundup of Global Volcanic Activity - New Activity for the week of 7 June - 13 June 2023

Ahyi - Mariana Islands (USA) : Unrest at Ahyi Seamount continued during 6-12 June. Possible hydroacoustic signal was detected by pressure sensors on Wake Island (2,270 km E) during 6-8 June, and multiple hydroacoustic signals were detected during 9-11 June. No surface activity was visible in partly cloudy and partly clear satellite images.

Kilauea - Hawaiian Islands (USA) : A new eruption at Kilauea began at 0444 on 7 June with the burst of tall lava fountains from a vent on the central part of the Halema’uma’u Crater floor. Soon after, lava fountains were active along multiple fissures on the crater floor, and along one fissure that bisected the SW crater wall. Between 0800-0900 the sulfur dioxide emission rate was about 65,000 tonnes per day. Residents of Pahala, 30 km downwind of the summit, reported minor deposits of fine gritty ash and Pele?s hair. Lava flows inundated the crater floor (about 1.5 square km) and added about 6 m depth of new lava within a few hours. A small spatter cone had formed at the vent on the SW wall by midday, and lava from the cone was flowing into the active lava lake below. Fountain heights had decreased from the onset of the eruption and were 4-9 m high by 1600, with occasional higher bursts. Inflation switched to deflation and summit earthquake activity greatly diminished shortly after the eruption onset. At 0837 on 8 June HVO lowered the Volcano Alert Level to Watch and the Aviation Color Code to Orange because the initial high effusion rates had declined, and no infrastructure was threatened. The lava lake had dropped by about 2 m likely due to gas loss by the morning of 8 June. The drop left a wall of cooled lava around the margins of the crater floor. Multiple lava fountains were active in the central E part of the lake and fountains rose as high as 10 m. The spatter cone continued to build over the SW wall vent; lava flows from the vent fed the SW part of the lava lake. The preliminary average effusion rate for the first 24 hours of the eruption was about 150 cubic meters per second, though the estimate did not account for vesiculated lava and variations in crater floor topography. The effusion rate during the very earliest phases of the eruption appeared to be significantly higher than the previous three summit eruptions based upon the rapid coverage of the entire crater floor. During 8-9 June multiple lava fountains remained active and rose up to 10 m high. The SW wall vent continued to effuse lava into the crater lake which had increased in depth by about 1.5 m. Active lava and vents covered much of the W half of the crater floor, arranged in a broad horseshoe shape around a central uplifted area. This feature in the basin of the 2021-22 lava lake was described as the "western lava lake" from prior eruptions and had reactivated along with a smaller circular pool just SE of the lake. An active lava lake centered within the uplifted area was fed by a vent in its NE corner. A much smaller area of lava was active in the E portion of the crater floor. The sulfur dioxide emission rate was about 11,000 tonnes per day on 9 June and about 8,900 tonnes per day on 10 June. During 10-12 June multiple lava fountains remained active and were up to 9 m high, and the SW wall vent continued to effuse lava into the crater lake. The active features in the E portion of the lake had stagnated during 10-11 June. Sulfur dioxide emissions averaged 7,400 tonnes per day on 11 June. The W part of the lake rose about 1 m during 11-12 June, likely due to the construction of a levee around the pond. Gas plumes rose to 2.4-3 km (8,000-10,000 ft) a.s.l. and were trapped under a weather inversion layer. Activity decreased during 12-13 June and only a few small lava fountains were active. The western lake and the smaller lava pond in the central portion of the crater floor remained active, along with the vent on the SW wall.

Mayon - Luzon (Philippines) : PHIVOLCS reported that the rate of lava-dome extrusion at Mayon’s summit crater increased, leading to an Alert Level increase and evacuations. Sulfur dioxide emissions were at or near baseline levels of 500 tonnes per day, averaging 574 and 332 tonnes per day on 6 and 7 June, respectively. The total number of rockfalls increased from 54 during 1-4 June to 267 during 5-8 June. Additionally, the volumes of the individual rockfall events became larger on 3 June. The rockfalls were generated by partial collapses of the growing lava dome and indicated an increasing extrusion rate. Three pyroclastic density currents (PDCs, or pyroclastic flows) were recorded at 0618, 0953, and 1100 on 8 June, each lasting 4-5 minutes based on the seismic signals. The PDCs traveled as far as 2 km down the Mi-Isi (S), Bonga (SE), and Basud (E) drainages and indicated that new, less degassed lava was collapsing from the summit dome. The Alert Level was raised to 3 (on a 0-5 scale) at 1200 on 8 June and recommended the evacuation of the 6-km radius Permanent Danger Zone. Six PDCs generated by collapses at the lava dome and 199 rockfall events were recorded during 8-9 June, based on seismic data and visual observations. Material from the rockfalls and PDCs descended the S flank within 2 km. Steam-and-gas plumes from the dome rose 800 m and drifted S, and light-brown ash plumes from the rockfalls drifted S. Minor crater incandescence from newly extruded lava and incandescent rockfalls were observed through the night. Rockfall events continued during 9-10 June with total of 59. A new dome, contacting a part of the remnant dome on the SE part of the crater floor, was visible during the morning of 10 June. Sulfur dioxide emissions increased to moderate levels, averaging 1,205 tonnes per day that same day. The DROMIC report stated that 9,314 people from 21 neighborhoods (barangays) spanning six municipalities were in evacuation centers by 10 June. A total of 177 rockfalls traveled as far as 700 m down the S and SE flanks during 10-11 June. Plumes of steam and gas from the dome and minor ash plumes from the rockfalls descended the flanks and then drifted E and SE. Incandescence from the dome and rockfalls was visible at night. Sulfur dioxide emissions averaged 642 tonnes per day on 11 June. Lava flows emerged at about 1947 on 11 June and produced two 500-m-long lobes; lava avalanches from the ends of the flows descended the Mi-Isi, Bonga, and Basud drainages within 2 km of the summit. Effusion of the lava flows was preceded by slight inflation at the upper flanks based on tiltmeter data and accompanied by minor seismicity. During 11-12 June the monitoring network recorded 260 rockfall events, and three collapses at the dome that produced PDCs (each lasting 2-4 minutes). The lava flows continued to be active. There were 14,360 people that had evacuated by 12 June; of those, 584 people were staying in places other than evacuation centers. During 12-13 June the monitoring network recorded 221 rockfall events and collapses at the dome that produced PDCs (each lasting 2-4 minutes). Lava continued to slowly effuse at the summit crater and collapsed material traveled 1 km down the Mi-isi and Bonga drainages. One PDC lasting two minutes was observed and detected by the seismic network. Diffuse ash from the rockfalls and steam-and-gas emissions from the dome drifted downslope and then NE. Rockfalls exposed incandescent material at the summit. By 13 June a total of 16,152 people had evacuated; of those, 15,493 people were in evacuation shelters and 659 people were staying with friends and family.

Nyamulagira - DR Congo : The Observatoire Volcanologique de Goma (OVG) reported that the eruption at Nyamulagira continued at low levels during 5-11 June based on satellite images.

Popocatepetl - Mexico : CENAPRED reported that there were 35-101 daily steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl during 6-13 June. Daily minor or moderate explosions were recorded during 6-11 June. Periods of low-to-moderate amplitude, high-frequency tremor lasting from 34 minutes to just over six hours were recorded each day. A few volcano-tectonic earthquakes with magnitudes of 1.2-2 were recorded during 6, 8, and 11-12 June. According to the Washington VAAC daily ash plumes rose 5.8-7 km (19,000-23,000 ft) a.s.l., or around as high as 1.6 km above the summit, and drifted generally drifted SE, SSE, S, and SW. Minor ashfall was reported in Hueyapan (16 km SSW), Zacualpan de Amilpas (30 SSW), Temoac (32 SSW), Jonacatepec de Leandro Valle (43 SSW), and Tetela del Volcán (18 SW), all within the Mexican state of Morelos during 11-12 June, and in Hueyapan, Yecapixtla (30 km SW), Ayala (45 km SW), and Jantetelco during 12-13 June.

Rincon de la Vieja - Costa Rica : OVSICORI-UNA reported that phreatic explosions continued at Rincón de la Vieja during 6-13 June, with multiple phreatic events recorded during 6-8 June. A 14-minute-long event that began at 0142 on 7 June was comprised of two pulses of gas-and-steam that rose 1 km above the crater rim. At 0942 on 8 June a plume of steam and gas rose 2.5 km above the crater rim, followed at 1810 by a moderate phreatic eruption that ejected lake water with sediment to less than 100 m above the crater rim and produced a white steam plume that rose 3 km and drifted W. Two events recorded at 0138 and 2037 on 9 June were similar in energy to the 8 June event at 1810. Gas emissions were visible on 10 June. Small phreatic events at 0357, 0521, and 0546 on 11 June produced white steam-and-gas plumes that drifted W. White steam-and-gas plumes from small phreatic events at 1031 and 1039 on 12 June rose as high as 1 km above the crater rim.