Bardarbunga (Iceland): The fissure eruption on Holuhraun continues with no signs of weakening. Icelandic press now counts as a relatively large effusive eruption, comparable to the Krafla fissure eruptions in 1980-1984.
The active eruption fissure is now around 2 km long and has erupted an estimated 16-25 million cubic meters of lava, covering approx. 3-5 square kilometers.
Lava flows continue to expand northwards from the vents. The lava effusion rate was re-estimated to 300-500 cubic meters / second for 20:00 h yesterday evening.
It is unclear how the situation will evolve, in particular because intense earthquake and deformation activity continue, suggesting that magma continues to intrude into fissures at depth, a process that could significantly modify the ongoing eruption at any time.
The fissure eruption is continuing at a stable level with little variation. A curtain of lava fountains up to 70 m high is being erupted above the fissure and pahoehohoe type lava flows are expanding to several kilometers around it, forming a growing flat lava flow field.
The effusion rate along the fissure vent has been estimated to be up to an impressive 1000 cubic meters per second.
Update from IMO this morning:
“No explosive activity is observed, the eruption remains an effusive lava eruption. Visual observation by webcam and low level volcanic tremor on seismometers do not show any obvious changes since evening.
According to local news, the lava flows have already reached more than 3 km distance from the fissure vent. The eruption is much stronger than the previous one on Friday, with up to 10 times lava output.
Since the start of the eruption this morning, earthquake activity has been lower (which is normal as pressure is lowered).
Lava analysis from the Friday eruption at the University of Iceland showed that the erupted basalt magma is relatively rich in Aluminum (>7 wt %) which suggests that it likely originates from a deeper source, directly connected to the upper mantle, rather than from an existing shallow magma reservoir under Bardarbunga (or Askja) volcano.
According to IMO, “the new eruption started in Holuhraun shortly after 04 AM, on the same volcanic fissure, which erupted earlier this week. The fissure is estimated to be 1,5 km long.
“…Fewer earthquakes seem to follow the event than in the previous eruption, but more lava is being extruded.
At 07 AM the lava flow was around 1 km wide and 3 km long towards northeast. The thickness was estimated a few meters, the flow about 1000 m3 pr second.
Approximately 500 earthquakes were detected in the area and smaller than before. The strongest earthquake, M3.8 was in the Bárðarbunga caldera. Poor weather conditions prevail in the area, which makes detection of smaller earthquakes difficult.
A new eruptive phase has started at the same fissure that had been briefly active Friday morning.
The new eruption seems to be bigger than the previous one and located slightly north of the Friday fissure vent. The active fissure was estimated to be 1.5 km long and is located approx. 9 km north of the Dyngjujökull glacier in the Holuhraun lava plain.
At the same time, intense seismic activity continues. More than 200 earthquakes have been detected since midnight, both under the active intrusion under and north of the rim of the glacier NE of the volcano as well as under the caldera of Bárdarbunga itself. The stringest were 7 quakes with magnitudes between 3.0 and 3.8.
The Icelandic Met Office has published two maps showing the (ongoing) mostly horizontal deformation, as evidenced by GPS measurements, in the Bardarbunga area during the past 3 days as well as since the beginning of the crisis. In just 2 weeks, the distance between the DYNC station (western side of the rift) and GSIG (eastern side) has increased by almost 50 cm!
Zhupanovsky (Kamchatka, Russia): New eruptions and ash emissions occurred yesterday. An ash plume rising to 17,000 ft (6 km) altitude and drifting SE was observed on satellite imagery.
Aso (Kyushu): A small eruption at the volcano was reported from Tokyo VAAC this morning. An ash plume rose to approx. 6,000 ft (1.8 km) altitude.
Nishino-shima (Volcano Islands, Japan): The island remains active and continues to grow as lava flows add new land to it. The Japanese Coast Guard made another survey flight on 26 August and observed ongoing effusive and explosive activity in the main crater.
A comparison with pictures from July shows that a new 3-400 m wide platform to the northeast of the island has been added as new land during the past weeks.
In addition, what appears to be a small lava dome has appeared inside the crater of the main cone. It unclear when and how exactly it formed, but is the site of at least occasional explosions.
Sakurajima (Kyushu, Japan): The activity has picked up significantly at the volcano. During the past 30 hours, at least 10 vulcanian-type explosions were recorded. Some of them produced ash plumes rising to 13,000 ft (4 km) altitude, i.e. approx. 3 km above the volcano’s Showa crater.
Suwanose-jima (Ryukyu Islands): The volcano has entered a more active phase again. Several (strombolian-type) explosions and phases of constant ash venting have occurred since yesterday, producing ash plumes of 1-2 km height.
Tungurahua (Ecuador): A series of small pyroclastic flows occurred yesterday evening, IGEPN reported in its latest special bulletin.
The eruptions took place between 18:23 and 19:00 local time, and are the first occurrences of pyroclastic flows since the start of the new eruptive phase that started on 27 July.
Fortunately, the flows were small and eruptive activity remains only moderate, as frequent but typically smaller explosions occur and release pressure. It is thought that the volcano is currently in a state of having an open conduit, allowing magma to rise easily to the crater before building up large pressure.
Ambrym (Vanuatu): active lava lakes in several craters (updated 14 Aug 2013)
Bagana (Bougainville Island, Papua New Guinea): ash emissions, lava dome growth (updated 27 Aug 2014)
Bardarbunga (Iceland): Ongoing northward migration of seismic activity (updated 21 Aug 2014)
Barren Island (Indian Ocean): intermittent activity, likely strombolian-type and/or lava flows (updated 4 Feb 2014)
Batu Tara (Sunda Islands, Indonesia): strombolian explosions, ash plumes up to 500 m, extrusion of a small lava dome with rockfalls (updated 27 Aug 2014)
Colima (Western Mexico): extrusion of lava flow from summit, intermittent explosions (updated 10 Apr 2014)
Dukono (Halmahera): thermal anomaly, probably small explosive activity in summit crater (updated 21 Aug 2014)
Erebus (Antarctica): active lava lake in summit crater (updated 21 Jan 2012)
Erta Ale (Ethiopia): active lava lake in northern pit crater, active hornito with intermittend flow in southern crater (updated 11 Jan 2013)
Fuego (Guatemala): strombolian explosions from summit crater, intermittent lava flows (updated 27 Aug 2014)
Ibu (Halmahera, Indonesia): growing lava dome, occasional ash emissions (updated 28 Jul 2014)
Kilauea (Hawai’i): new lava flow from vents on NE flank of Pu’u ‘O’o (updated 13 Aug 2013)
Lokon-Empung (North Sulawesi, Indonesia): small explosions, lava flow? (updated 25 Jul 2013)
Manam (Papua New Guinea): degassing, occasional ash venting (updated 28 Aug 2013)
Marapi (Western Sumatra, Indonesia): sporadic explosions (updated 27 Mar 2014)
Nishino-shima (Volcano Islands, Japan): lava effusion enlarging the new island (updated 31 Aug 2014)
Nyiragongo (DRCongo): active lava lake in summit crater (updated 26 Feb 2014)
Ol Doinyo Lengai (Tanzania): effusion of natrocarbonatite lava inside the crater (updated 8 Jul 2013)
Rabaul (Tavurvur) (New Britain, Papua New Guinea): lava fountains, ash emissions from Tavurvur cone (updated 29 Aug 2014)
Reventador (Ecuador): ash emissions, explosions (updated 19 Aug 2014)
Sakurajima (Kyushu, Japan): ash venting, intermittent explosions (updated 31 Aug 2014)
Sangeang Api (Indonesia): growing lava dome & lava flow (updated 7 Jul 2014)
Santiaguito (Guatemala): generation of hot lahars (updated 4 Aug 2014)
Semeru (East Java, Indonesia): growing lava dome & lava flow, sporadic explosions (updated 23 Jul 2014)
Shishaldin (United States, Aleutian Islands): small lava lake in summit crater (updated 14 Aug 2014)
Shiveluch (Kamchatka): growing lava dome, incandescent avalanches, occasional explosions (updated 7 Jul 2014)
Sinabung (Sumatra, Indonesia): effusion of viscous lava, steaming, ash emissions (updated 15 Jul 2014)
Slamet (Central Java): mild strombolian activity in summit crater (updated 28 Aug 2014)
Stromboli (Eolian Islands, Italy): continuous effusion of lava finds new pathway (updated 30 Aug 2014)
Suwanose-jima (Ryukyu Islands): strombolian activity in summit crater (updated 31 Aug 2014)
Tungurahua (Ecuador): moderate to strong strombolian explosions from central crater (updated 31 Aug 2014)
Ubinas (Peru): degassing, sporadic small explosions and ash venting (updated 22 Aug 2014)
Yasur (Tanna Island, Vanuatu): ash emissions, weak strombolian explosions (updated 14 Aug 2013)
Zhupanovsky (Kamchatka, Russia): intermittent ash emissions (updated 31 Aug 2014)