Active volcanoes in the world from 13/07/2011 to 19/07/2011

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program.
Updated every Week (mostly Wednesday), notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity of volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.

New Activity, Unrest or activity change

Tofua island and volcano - Panoramio image from Magic Dragon 55 - http://www.panoramio.com/photo/17193074

TOFUA Tonga Islands 19.75°S, 175.07°W; summit elev. 515 m
Based on information from Tonga Meteorological Services and pilot observations, the Wellington VAAC reported that a cloud from Tofua rose to an altitude of 1.2 km (4,000 ft) a.s.l.
Volcano description : The low, forested Tofua Island in the central part of the Tonga Islands group is theemergent summit of a large stratovolcano that was seen in eruption by Captain Cook in 1774. The first Caucasian to set foot on the 515-m-high island was Capt. William Bligh in 1789, just after the renowned mutiny on the "Bounty." The volcano's summit contains a 5-km-wide caldera whose walls drop steeply about 500 m. Three post-caldera cones were constructed at the northern end of a cold fresh-water caldera lake, whose surface lies only 30 m above sea level. The easternmost cone has three craters and produced young basaltic-andesite lava flows, some of which traveled into the caldera lake. The largest and northernmost of the cones, Lofia, has a steep-sided crater that is 70 m wide and 120 m deep and has been the source of historical eruptions, first reported in the 18th century. The fumarolically active crater of Lofia has a flat floor formed by a ponded lava flow.

KABA Sumatra (Indonesia) 3.52°S, 102.62°E; summit elev. 1952 m
On 14 July CVGHM reported that, since the Alert Level for Kaba was raised on 20 October 2009, seismicity had fluctuated but decreased overall. During September 2009-May 2011, when weather permitted, white plumes were seen rising 25-300 m above the crater rim, and during June-July 2011 diffuse white plumes rose 50 m above the crater rim. The Alert Level was lowered to 1 (on a scale of 1-4) on 12 July.
Volcano description : Kaba, a twin volcano with Mount Hitam, has an elongated summit crater complex dominated by three large historically active craters trending ENE from the summit to the upper NE flank. The SW-most crater of 1952-m-high Gunung Kaba, Kawah Lama, is the largest. Most historical eruptions have affected only the summit region of the volcano. They mostly originated from the central summit craters, although the upper-NE flank crater Kawah Vogelsang also produced explosions during the 19th and 20th centuries.

ETNA Sicily (Italy) 37.734°N, 15.004°E; summit elev. 3330 m
Sezione di Catania - Osservatorio Etneo reported that on 13 July volcanologists visited Bocca Nuova and observed a single large vent on the crater floor that was the source of the Strombolian activity. The strongest explosions ejected incandescent bombs several tens of meters above the crater rim. Most bombs fell back into the crater but some went over the rocky partition that divided Bocca Nuova from Voragine, and fell into the S portion of the latter.
In the evening of 15 July, volcanologists again visited Bocca Nuova and noted that the Strombolian activity had decreased slightly but within less than two hours had increased to levels greater than those observed on 13 July. Immediately to the W of the explosive vent, a lava flow was issuing from underneath a sheet of pyroclastic material deposited by the nearby Strombolian activity. The flow cascaded into a deeper depression in the W central portion of the crater floor.
On 16 July, a series of ash emissions from the pit crater located on the E flank of the SE Crater cone marked the resumption of explosive activity within the crater, and produced loud booming sounds that were widely heard in populated areas on Etna's flanks. On the evening on 18 July Strombolian activity increased and culminated into a new paroxysmal eruptive episode on 19 July. Lava flows traveled down the steep W slope of the Valle del Bove, following the same path as the lavas emitted during the preceding eruptive episodes, and stagnated at the base near Monte Centenari. Lava fountains rose 200-250 m and produced heavy fallout of fluid spatter, forming several lava flows. The largest lava flow descended the S flank of the cone reaching the base. A dense plume of gas and ash drifted E.
Volcano description : Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BC. Historical lava flows cover much of the surface of this massive basaltic stratovolcano, the highest and most voluminous in Italy. Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater. Flank eruptions, typically with higher effusion rates, occur less frequently and originate from fissures that open progressively downward from near the summit. A period of more intense intermittent explosive eruptions from Etna's summit craters began in 1995. The active volcano is monitored by the Instituto Nazionale di Geofisica e Volcanologia (INGV) in Catania.
See also our in-depth report including the eruption video recorded on July 9.

LOKON-EMPUNG Sulawesi 1.358°N, 124.792°E; summit elev. 1580 m
According to news articles, three eruptions during 14-15 July from Tompaluan crater, in the saddle between the Lokon-Empung peaks, ejected lava and ash, and caused forest fires on the W flank. A local mayor noted that 6,000 people were in shelters and one person had died from a heart attack while evacuating. Other articles stated that 5,200 people had evacuated. Explosions during 17-18 July produced ash plumes that rose 0.6-3.5 km above the crater.
Volcano description : The twin volcanoes Lokon and Empung, rising about 800 m above the plain of Tondano, are among the most active volcanoes of Sulawesi. Lokon, the higher of the two peaks (whose summits are only 2.2 km apart) has a flat, craterless top. The morphologically younger Empung volcano has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century, but all subsequent eruptions have originated from Tompaluan, a 150 x 250 m wide double crater situated in the saddle between the two peaks. Historical eruptions have primarily produced small-to-moderate ash plumes that have occasionally damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred.
http://www.vsi.esdm.go.id/
See also our in-depth report including the eruption video recorded on July 11

NABRO Eritrea 13.37°N, 41.70°E; summit elev. 2218 m
Based on analyses of satellite imagery, the Toulouse VAAC reported that on 16 July an ash plume from Nabro rose to altitudes below 5.5 km (18,000 ft) a.s.l. A weak eruption detected on 17 July decreased through the day then appeared to have stopped.
Volcano description : The 2218-m-high Nabro stratovolcano is the highest volcano in the Danakil depression of northern Ethiopia and Eritrea. Located at the SE end of the Danakil Alps, Nabro lies in the Danakil horst. Nabro is the most prominent and NE-most of three volcanoes with large summit calderas aligned in a NE-SW direction SW of Dubbi volcano. These three volcanoes, along with Sork Ale volcano, collectively comprise the Bidu volcanic complex. The complex Nabro stratovolcano is truncated by nested calderas, 8 and 5 km in diameter. The larger caldera is widely breached to the SW. Nabro was constructed primarily of trachytic lava flows and pyroclastics. Post-caldera rhyolitic obsidian domes and basaltic lava flows were erupted inside the caldera and on its flanks. Some very recent lava flows were erupted from NNW-trending fissures transverse to the trend of the Nabro volcanic range.
See also our extensive reporting in Earthquake-report.com

PUYEHUE-CORDON CAULLE Central Chile 40.590°S, 72.117°W; summit elev. 2236 m
OVDAS-SERNAGEOMIN reported that on 12 and 14 July cameras installed around the Puyehue-Cordón Caulle volcanic complex recorded eruption plumes that rose no higher than 2 km above the Cordón Caulle rift zone and drifted E; weather prevented observations of the plume on 13 July. Seismic activity declined significantly. On 15 July satellite imagery showed a plume drifting 80 km E and seismic signals indicated that lava started to flow again. The effusion rate increased on 16 July, however weather again prevented observations. A light gray plume on 17 July rose 2 km above the crater and was observed in satellite imagery drifting 240 km E. According to a news article, the first plane landed at the airport in Bariloche, about 100 km E, since the airport had closed on 4 June. On 18 July a gray plume rose 5 km above the crater and drifted 150 km NW. Incandescent material observed at night was ejected 500 m above the crater and lava flows continued to be active. The Alert Level remained at Red.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN) http://www.sernageomin.cl/
See also our extensive reporting in Earthquake-report.com

For the list of volcanoes with Ongoing activity, please click here

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Comments

  1. cloud rising from Tofua volcano to 3,000 ft (ca. 1 km) in the Tonga Islands at 04:42 GMT
    http://matangitonga.to/2012/08/14/wild-boar-chase-fires-smoke-over-tofua