Volcano World

Volcanic tremor amplitude increased at Asoson at around 2100 on 2 May, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) at 2255. The public was warned to stay at least 1 km away from the crater. Sulfur dioxide emissions were low, at 200 tons per day on 3 May, and white steam plumes rose as high as 300 m above the crater rim.

Source: Japan Meteorological Agency (JMA)

PVMBG reported that a phreatic eruption at the Sileri Crater lake (Dieng Volcanic Complex) occurred at 1825 on 29 April, ejecting rocks 200 m S and E and mud 400 m S and 300 m E. According to a news article a local road was temporarily closed because rocks (about 10 cm in diameter) from the eruption were scattered along the road and the mud made conditions slippery. The closest residents are 1 km away. The Alert Level remained at 1 (on a scale of 1-4), and the public was warned to stay 500 m away from the crater rim.

Sources: Detik News,Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images during 22-23 and 29 April. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

OVPF reported that the eruption at Piton de la Fournaise continued during 28 April-4 May, though inclement weather obscured visual observations during most of the week. Both craters were active, producing lava flows that mainly traveled though lava tubes. Lava emerged from the end of the flow field, advancing E and setting fire to local vegetation. Minor inflation of the summit area was recorded. Lava fountaining was weak at the smaller vent to the SE during 3-4 May and a small lava pond occupied the crater of the larger cone, just NW at the higher elevation. On 4 May weak fountaining at the smaller cone occasionally ejected material just above the crater rim and the pond was active in the larger crater. The lava flow advanced another 180 m, reaching 1,500 m elevation. According to a news article two students in their 20s were found dead in the caldera on 22 April, near the active cones. The cause of death was not immediately known. The Alert Level remained at 2-2.

Sources: Agence France-Presse (AFP),Observatoire Volcanologique du Piton de la Fournaise (OVPF)

JMA reported that during 26 April-3 May incandescence from Minamidake Crater (at Aira Caldera?s Sakurajima volcano) was visible nightly. There was a total of 10 explosions, producing ash plumes that rose as high has 2.4 km above the summit and ejected bombs 1.3-1.7 km away from the crater. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 22-24 April that sent ash plumes to 3 km (10,000 ft) a.s.l. and drifted NE and SW. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 28 April-4 May through a submerged inlet. The depth of the lake was about 227 m and lava continued to circulate in the W part, though the active area continued to shrink. The E half of the lake remained solidified and comprised about 93 percent of the total area, based on thermal measurements acquired on 16 April. The sulfur dioxide emission rate was 250 and 475 tons/day on 30 April and 2 May, respectively, continuing a downward trend that began in mid-April; the recent rates suggested that the effusion rate had also decreased. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

IMO reported that the fissure eruption in the W part of the Krsuvk-Trlladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 28 April-4 May. According to a news source, activity at the S vent of the fifth cone, which had opened on 13 April with N and S vents, intensified at around 2030 on 26 April. Fountaining became more explosive and lava was jetted 40-50 m high. The lava-flow rate significantly increased; lava flowed S then E and descended a valley into Meradalir. By 29 April activity had intensified at the fifth cone where lava ejections reached 250 m high, but had ceased at the others. By 1 May lava flows had traveled N in Meradalir and connected to the flows that had previously descended into the valley from a fissure that opened on 5 April. IMO noted that fountaining at the vent was steady until around 0000-0100 on 2 May when it became more pulsating. Resting periods of 1-2 minutes were punctuated by intense fountaining reaching 100-150 m high for periods of 8-12 minutes. Gas plumes with minor amounts of ash rose 800-900 m a.s.l. A news source noted that on 2 May lava fountains rose over 300 m, the highest to date, and were seen from Reykjavik. Ejecta set fire to vegetation on the hill to the S of the vent, causing a smoke plume. The Aviation Color Code remained at Orange due to the lack of ash and tephra emissions.

Sources: Icelandic Meteorological Office (IMO),Icelandic National Broadcasting Service (RUV)

PVMBG reported that white plumes from Lewotolok rose as high as 500 m and drifted SE, SW, and W on most days during 27 April-3 May. Gray-and-white plumes rose 500 m and drifted W on 30 April and 2 May. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

BPPTKG reported that the lava dome just below Merapi?s SW rim and the lava dome in the summit crater both continued to extrude lava during 23-29 April. The SW rim lava dome had an estimated volume of 1,141,850 cubic meters on 28 April, with a growth rate of about 11,900 cubic meters per day, and continued to shed material down the flank. A total of 12 pyroclastic flows traveled a maximum of 2 km down the SW flank. Incandescent avalanches, recorded 113 times, traveled as far as 2 km down the SW flank. The volume of the summit lava dome was 1,794,000 cubic meters on 28 April, unchanged from the previous week. Electronic Distance Measurement (EDM) data showed a distance shortening between points in the NW at a rate of 0.5 cm per day, indicating inflation. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the summit.

Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)