Thursday 14 January 2016

Volcanos

Roundup of Global Volcanic Activity

Egon (Flores): Following a further increase in seismic activity, an eruption warning for the volcano was issued this morning. Residents living at the feet of the volcano were asked to evacuate for safety reasons. The Volcanology and Disaster Mitigation Center PVMBG raised the alert status for the volcano to level 3 on a scale of 1-4. An exclusion zone was extended to 3 km radius around the crater which now includes the village of Egon Gahar.

Nishino-shima (Volcano Islands, Japan): The eruption seems to have ended in mid December. During the past two visits of the Japanese Coast Guard on 27 Dec and 3 Jan 2016, no more eruptive activity has been noted. The two years of eruption since late November 2013 increased the size of the island from its tiny 0.26 to approx. to 2.63 square km. Now, it is up to the waves to slowly eat away at the young shores and gradually decrease it again, until a next eruption occurs...

Karangetang (Siau Island, Sangihe Islands, Indonesia): Ash from the volcano has been observed on satellite imagery during 11-12 Jan, Darwin VAAC reported. Likely, this came from a larger rockfall triggering a small pyroclastic flow, but this needs to be confirmed. The latest VSI report from this morning only mentions continuing glow from the active summit lava dome and small to moderate rockfalls. In case of heavy rains, larger rockfalls and lahars could occur, in particular towards the valleys radiating to the SE from the volcano. Seismic activity remains elevated with an increase in shallow volcanic quakes.

Sinabung (Sumatra, Indonesia): The volcano's eruption continues with little changes into its third year. Slow lava extrusion at the summit results in occasional small to moderate pyroclastic flows as well as sporadic explosions. This activity occurs in weeks-to-month long alternating phases of more and less intense frequency, as lobes of the overspilling dome grow too large and then break off to generate a series of collapses within a shorter time. Both the pyroclastic flows and explosions produce ash plumes that regularly rise a few km above the volcano and are often reported by Darwin VAAC.

Bromo (East Java, Indonesia): Ash emissions of varying intensity have been near continuous during the past weeks. The frequent ash falls have been causing significant damage to farmland, vegetation and lightly built structures in surrounding villages.

Dukono (Halmahera): The volcano continues to be very active with near-continuous ash emissions from the crater. Darwin VAAC reported an ash plume extending 70 km to the south of the volcano this morning.

Lokon-Empung (North Sulawesi, Indonesia): The volcano remains at significant unrest and moderate to large explosions could occur any time, the latest evaluation report of the volcano observatory states and alert level is being maintained at 3 ("siaga") on a scale of 1-4. During the past weeks, visual activity consisted in degassing creating a plume of 25-150 m above the Tumpalun crater. Seismic activity has been dominated by frequent shallow volcanic earthquakes (up to 21 per day), sometimes felt nearby. No clear trend has been visible over the past two weeks.

Santiaguito (Guatemala): INSIVUMEH reports strong degassing, a few weaker explosions and small to moderate rockfalls on the eastern side of the active Caliente lava dome.

Pacaya (Guatemala): The active intra-crater cone continues to grow (and slowly fill the crater). During clear nights, incandescence can be seen from the Mackenney crater.

Fuego (Guatemala): Since its last (relatively weak) paroxysm during the first days of 2016, the volcano has now been unusually calm. According to this morning's status report of the observatory, no explosions have been seen (or heard) since 5 days… (This will surely change.)

San Miguel (El Salvador): A new phase of eruptive activity began at the volcano on Monday. Accompanied by a spike in volcanic tremor, weak to moderate ash emissions have been occurring from the main crater. This activity, the 22nd eruptive phase since Dec 2013 according to MARN, has been decreasing since yesterday.

Copahue (Chile/Argentina): Near-continuous, but generally weak ash emissions and intense degassing continue at the volcano. Sernageomin maintains alert level yellow.

Nevados de Chillán (Central Chile): A short pulse of ash emissions occurred in the evening of 8 Jan 2016 around 18:49 local time. No further emissions have occurred since and it is believed that the event was caused by phreatic activity of the shallow hydrothermal system of the volcano (not by fresh magma). Sernageomin raised the alert status of the volcano to yellow.

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