Source: Global Volcanism Program - 10/23/12
17 October-23 October 2012
New Activity/Unrest: | Alaid, Kuril Islands (Russia) | Kliuchevskoi, Central Kamchatka (Russia) | Raung, Eastern Java (Indonesia)
Alaid Volcano
ALAID Kuril Islands (Russia) 50.858°N, 155.55°E; summit elev. 2339 m
According to KVERT, observers on Paramushir Island (SE) reported weak gas-and-steam activity from Alaid during 11 and 16-17 October. A thermal anomaly on the volcano was detected in satellite imagery during 12 and 14-17 October. Cloud cover prevented observations during 19-22 October. Observers on Shumshu Island (50 km E) reported that an ash plume rose 700 m above the crater on 23 October and a thermal anomaly was detected in satellite imagery. The Aviation Color Code remained at Yellow.
Geologic Summary. The highest and northernmost volcano of the Kurile Islands, 2,339-m-high Alaid is a symmetrical stratovolcano when viewed from the N, but has a 1.5-km-wide summit crater that is breached widely to the S. Alaid is the northernmost of a chain of volcanoes constructed W of the main Kuril archipelago and rises 3,000 m from the floor of the Sea of Okhotsk. Numerous pyroclastic cones dot the lower flanks of Alaid, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption. Strong explosive eruptions have occurred from the summit crater beginning in the 18th century. Reports of eruptions in 1770, 1789, 1821, 1829, 1843, 1848, and 1858 were considered incorrect by Gorshkov (1970). Explosive eruptions in 1790 and 1981 were among the largest in the Kurile Islands.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Alaid Information from the Global Volcanism Program
KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit elev. 4835 m
KVERT reported moderate seismic activity at Kliuchevskoi during 12-19 October. Strombolian activity was observed during 13-15 October; clouds prevented views on the other days. A weak thermal anomaly was detected in satellite imagery during 14-15 October. The Aviation Color Code remained at Yellow.
Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation, have occurred during the past 3,000 years. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive events from flank craters.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Kliuchevskoi Information from the Global Volcanism Program
RAUNG Eastern Java (Indonesia) 8.125°S, 114.042°E; summit elev. 3332 m
Seismicity at Raung increased on 17 October and remained elevated, prompting CVGHM to raise the Alert Level to 2 (on a scale of 1-4) on 18 October. During 18-22 October white plumes rose 50-75 m above the crater. Seismic activity increased significantly on 22 October. That same day the Alert Level was raised to 3. Visitors and residents were warned not to approach the crater within a 3-km radius.
Geologic Summary. Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The 3,332-m-high, unvegetated summit of Gunung Raung is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km from the volcano, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)
Raung Information from the Global Volcanism Program
