Volcanos

Roundup of New Global Volcanic Activity:

Dukono | Halmahera | 1.68°N, 127.88°E | Elevation 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 29 August and during 31 August-3 September ash plumes from Dukono rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted 80-240 km W and NW

Guntur | Western Java (Indonesia) | 7.143°S, 107.84°E | Elevation 2249 m

CVGHM reported that the number of deep and shallow volcanic earthquakes at Guntur increased during 15-21 August; seismicity declined after that period. On 30 August at 0820 seismicity again increased, characterized by continuous tremor that lasted until 1450. At 1600 CVGHM raised the Alert Level to 2 (on a scale of 1-4) and reminded residents and visitors not to approach the active crater within a 2-km radius.

Iliwerung | Lomblen Island (Indonesia) | 8.53°S, 123.57°E | Elevation 1018 m

CVGHM reported that observers at a post 6 km away from Iliwerung reported that diffuse fumarolic emissions from the crater were visible during the mornings from 19 August to 1 September. Seismicity decreased on 19 August and remained at normal levels. On 2 September the Alert Level was lowered to 1 (on a scale of 0-4).

Karangetang [Api Siau] | Siau I | 2.78°N, 125.4°E | Elevation 2700 m

Based on observations from the post in Salili, CVGHM reported that, although Karangetang was sometimes covered in fog during 1 August-2 September, white plumes were seen rising as high as 500 m above the main crater and as high as 300 m above Crater II. Incandescence from the crater was often observed at night. Avalanches began traveling down the Batuawang drainage on 2 September and then intensified the next day. The Alert Level was raised to 3 (on a scale of 1-4) on 3 September.

Kliuchevskoi | Central Kamchatka (Russia) | 56.057°N, 160.638°E | Elevation 4850 m

KVERT reported that moderate seismic activity at Kliuchevskoi was detected during 23-30 August. A video camera recorded incandescence from the summit at night and gas-and-steam plumes containing minor amounts of ash. A large thermal anomaly from the lava dome was detected in satellite images. Strombolian activity that began on 15 August continued; a new lava flow effused onto the SW flank on 26 August, producing a thermal anomaly detected in satellite images. The Aviation Color Code remained at Yellow.

Sakura-jima | Kyushu | 31.585°N, 130.657°E | Elevation 1117 m

JMA reported that 34 explosions from Sakura-jima's Showa Crater ejected tephra as far as 1,300 m during 26-30 August. Incandescence from the crater was visible at night on 26 August. An explosion on 29 August at 0927 generated an ash plume that rose 3 km and caused ashfall in areas from Miyazaki (80 km NW) to Kagoshima (12 km W). Tephra 1 cm in diameter was confirmed in an area 4 km E.

Based on information from JMA, the Tokyo VAAC reported that during 28 August-3 September explosions generated plumes most days that rose to altitudes of 1.5-4 km (5,000-13,000 ft) a.s.l. and drifted E, NE, and NW. On 31 August a pilot observed an ash plume that rose to an altitude of 2.7 km (9,000 ft) a.s.l. and traveled NE.

Santa María | Guatemala | 14.756°N, 91.552°W | Elevation 3772 m

INSIVUMEH reported that during 28-29 August abundant degassing at Santa María's Santiaguito lava-dome complex generated gas plumes that rose 2.7 km. During 29-31 August explosions produced ash plumes that rose 700-900 m and sometimes drifted SW. Block avalanches descended the S and E flanks. On 31 August a lahar traveled down the Nima I drainage on the S flank carrying 2-m-diameter blocks, tree branches, and tree trunks. Cloud cover prevented views on 2 September. Overnight during 2-3 September explosions generated ash plumes that rose 700 m and drifted SW. Block avalanches descended the S flank.

Suwanose-jima | Japan | 29.635°N, 129.716°E | Elevation 799 m

According to the Tokyo VAAC, the JMA reported that on 28 August pilots observed ash plumes from Suwanose-jima that rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted E and NW. Explosions during 28-29 August generated ash plumes that rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE. Ash was detected in satellite images on 29 August, and explosions were detected on 30 August and 1 September.

Ubinas | Peru | 16.355°S, 70.903°W | Elevation 5672 m

IGP reported six phreatic explosions from Ubinas during 1-3 September. The series of explosions decreased in both energy and length of the tremor signal associated with each explosion; tremor lasted 75 minutes for the first explosion and 5-10 minutes for the last one. Most of the explosions generated ash plumes that rose 1.5-2 km above the crater.

The first explosion occurred at 2246 on 1 September, lasted 110 seconds, ejected ballistics up to 2 m in diameter, and caused ashfall 2 km ENE. The second explosion, at 1552 on 2 September, lasted 292 seconds and ejected fewer ballistics. Details for the 3rd through the 6th explosions are as follows: the 3rd occurred at 2350 on 2 September and lasted 279 seconds; the 4th occurred at 0809 on 3 September and lasted 296 seconds; the 5th occurred at 1021 on 3 September and lasted 288 seconds; the 6th occurred at 1029 on 3 September and lasted 74 seconds.