Sunday, 15 September 2013

Volcanos

Roundup of Global Volcanic Activity:

New Activity:

Arenal | Costa Rica | 10.463°N, 84.703°W | Elevation 1670 m

OVSICORI-UNA reported that plumes composed mainly of water vapor rose from the NE and SE edges of Arenal's Crater C on 8 and 9 September. Tremors indicative of hydrothermal and magmatic activity were detected on 8 September. The report noted that seismic and fumarolic activity had been very low in the past three years; however steam plumes associated with heavy rains had been frequent.

Etna | Sicily (Italy) | 37.734°N, 15.004°E | Elevation 3350 m

Sezione di Catania - Osservatorio Etneo reported that a series of small and sporadic ash emissions from Etna's New Southeast Crater (NSEC) began during the morning of 3 September, marking the end of four months of complete quiescence. Weak Strombolian activity from NSEC was observed during the early morning of 6 September. At daybreak small ash puffs were emitted once or twice per hour. The same morning intense incandescence emanated from Bocca Nuova. The report stated that since early May only degassing from the summit craters was noted, along with usual bangs and rumblings from deep within the conduit of the Northeast Crater (NEC), which during the past few weeks had become more continuous and louder.

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

KVERT reported that moderate seismic activity at Kliuchevskoi was detected during 30 August-6 September. A video camera recorded incandescence from the summit and WSW flank at night, and gas-and-steam plumes containing minor amounts of ash. Strombolian activity continued and a lava flow effused onto the SW flank. A large thermal anomaly from the lava dome was detected in satellite images.

Lokon-Empung | Sulawesi | 1.358°N, 124.792°E | Elevation 1580 m

Based on ground reports from CVGHM, the Darwin VAAC reported that on 9 September an ash plume from Lokon-Empung rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted N. Ash was not detected in satellite images due to meteorological clouds. According to a news article an explosion at 0630 generated an ash plume that rose 1.5 km; the explosion was heard 10 km away. The VAAC noted that the next day ash plumes rose to an altitude of 2.4 km (8,000 ft) a.s.l. although ash was again not identified in satellite images.

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

JMA reported that 15 explosions from Sakura-jima's Showa Crater ejected tephra as far as 1,300 m during 2-6 September. Incandescence from the crater was visible some nights. An explosion at 1100 on 4 September generated an ash plume that rose 2.8 km and drifted S, causing ashfall in areas downwind including Arimuracho (4 km SSE). Tephra 4 cm in diameter was confirmed in an area 3 km S, and tephra 1 cm in diameter was reported 10 km SSE.

Based on information from JMA, the Tokyo VAAC reported that during 4-10 September explosions generated plumes that rose to altitudes of 2.4-4.3 km (8,000-14,000 ft) a.s.l., and most days drifted N, NE, E, S, and SW. On 6 and 8 September pilots observed ash plumes that rose to altitudes of 3-4.6 km (15,000 ft) a.s.l.; plumes drifted NE on 8 September.

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

INSIVUMEH reported that at 1405 on 5 September a lahar descended Santa María's Nima I drainage on the S flank carrying mostly fine sediment and 50-cm-diameter blocks, but also a small percentage of blocks 1-2 m in diameter. During 5-10 September white plumes rose 200-500 m and drifted W, SW, E, and NE. A few weak avalanches descended the S part of the active crater of the Santiaguito lava-dome complex. On 10 September another lahar traveled down the Nima I drainage, carrying blocks up to 3 m in diameter. The lahar was 15 m wide, 6 m deep, and had a sulfur odour.

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

According to the Tokyo VAAC, the JMA reported that during 5-6 September explosions from Suwanose-jima generated ash plumes that rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NW and N.

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

According to a news source, IGP reported that a seventh phreatic explosion from Ubinas occurred just after 1800 on 4 September; six explosions were recorded between 1 and 3 September. The explosion caused alarmed residents of Querapi, 4 km S, to temporarily leave their homes and congregate in the town square.

Ongoing Activity

Fuego | Guatemala | 14.473°N, 90.88°W | Elevation 3835 m

INSIVUMEH reported that during 4-6 September explosions from Fuego generated ash plumes that rose 800-850 m and drifted 10-12 km W and SW. Block avalanches descended the Ceniza (SSW) drainage. During 5-6 September explosions produced shock waves that rattled structures in villages 10 km away.

On 6 September the number and magnitude of explosions increased; rumbling and shock waves were reported 12 km away. Ash plumes rose 750 m and drifted 10 km W and SW. During 7-10 September explosions generated ash plumes that rose 250-400 m; plumes drifted 7 km W and NW on 7 September. Incandescent material was ejected 100 m high and then formed small avalanches. On 9 September heavy rain was followed by lahars in the Las Lajas and El Jute drainages which carried blocks 2 m in diameter. During 9-10 September ash plumes drifted 6 km E and SE.

Karymsky | Eastern Kamchatka (Russia) | 54.05°N, 159.45°E | Elevation 1536 m

KVERT reported that moderate seismic activity at Karymsky was detected during 30 August-6 September. Weak ash explosions likely occurred. Satellite images detected no activity or were obscured by clouds. The Aviation Colour Code remained at Orange.

Kilauea | Hawaii (USA) | 19.421°N, 155.287°W | Elevation 6800 m

During 4-10 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater; the lake level was 47-56 m below the Halema'uma'u crater floor. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor. Short lava flows issued from one or more of the NE spatter cones four times during 8-9 September.

The 3.2-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, was active with scattered break-out flows and burned the forest N of Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakouts on the pali and coastal plain.

Kizimen | Eastern Kamchatka (Russia) | 55.13°N, 160.32°E | Elevation 2485 m

KVERT reported that during 30 August-6 September moderate seismic activity continued at Kizimen. Video and satellite data showed that lava continued to extrude from the summit, producing incandescence, strong gas-and-steam activity, and hot avalanches on the W and E flanks. A thermal anomaly was detected in satellite images on 2 and 5 September; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.

Manam | Papua New Guinea | 4.08°S, 145.037°E | Elevation 3100 m

RVO reported that after a small eruption from Manam's Southern Crater during 27-28 August, activity subsided. Diffuse gray-brown ash plumes, emitted at short intervals, rose from the crater during 29-30 August, and crater incandescence was noted. Seismicity declined and was at a low level by the end of the day on 31 August.

Popocatépetl | Mexico | 19.023°N, 98.622°W | Elevation 5465 m

CENAPRED reported that during 4-10 September seismicity at Popocatépetl indicated continuing emissions of water vapor, gas, and small amounts of ash; cloud cover sometimes prevented observations of the crater. Incandescence from the crater was observed on most nights. Steam, gas, and ash plumes drifted SE on 8 September and NW on 9 September. The Alert Level remained at to Yellow, Phase Two.

Rabaul | New Britain | 4.271°S, 152.203°E | Elevation 1200 m

RVO reported that during 1-31 August low-level activity at Rabaul caldera's Tavurvur cone consisted of pale gray plumes with variable but mostly minor ash content. Intervals between emissions ranged from tens of seconds to hours. Ash plumes rose as high as 1 km and drifted NW, causing ashfall mainly in a narrow band between the E part of old Rabaul town (3-5 km NW) and Namanula Hill, and further downwind towards Nonga area. Malaguna No. 1 and other parts of Rabaul town were also affected. Most noises were associated with forceful emissions and were short in duration. Seismicity was high and dominated by ash-emission events.

Ash plume characteristics were similar during 1-5 September, although the interval time between emissions ranged from tens of seconds to tens of minutes. Plumes rose 50 m and were immediately blown NW by strong winds which re-suspended older ash deposits in widespread areas including Rabaul town. Residents of Rabaul town reported a chlorine odor; RVO noted that the odor, although uncommon, did not represent an increase in activity.

Reventador | Ecuador | 0.077°S, 77.656°W | Elevation 3562 m

IG reported that seismicity remained elevated at Reventador during 4-10 September. Although cloud cover often prevented observations, ash plumes were occasionally observed rising from the lava dome. On 6 September IG staff observed 1-km-long deposits from a pyroclastic flow that had descended the S flank after an explosion. Ash plumes rose 1-2 km above the lava dome during 6-7 September, and minor ash emissions were noted on 9 September.

Shiveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Elevation 3395 m

Based on visual observations and analyses of satellite data, KVERT reported that during 30 August-6 September a viscous lava flow effused onto the N and NW flanks of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. A thermal anomaly was detected daily in satellite images. The Aviation Color Code remained at Orange.

Tara, Batu | Komba Island (Indonesia) | 7.792°S, 123.579°E | Elevation 3750 m

Based on analyses of satellite imagery and wind data, the Darwin Volcanic Ash Advisory Centre (VAAC) reported that on 5 September an ash plume from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 75 km W.

Ulawun | New Britain | 5.05°S, 151.33°E | Elevation 3000 m

RVO reported that activity at Ulawun was low during 4-31 August; emissions from the summit crater consisted of white vapor until 16 August, and were gray during 17-31 August. Emissions were more energetic on 24 August, rising 200 m. A single booming noise and weak incandescence was also reported that day. RSAM values fluctuated but decreased overall.

Veniaminof | United States | 56.17°N, 159.38°W | Elevation 2560 m

AVO reported continuous seismic tremor at Veniaminof during 4-10 September, and elevated surface temperatures detected in satellite images consistent with lava effusion and fountaining. Cloud cover sometimes prevented web cam views (from Perryville, 32 km SSE) of the intracaldera cone, although on 4 September a diffuse ash plume was observed rising several hundred feet above the cone and drifting E. On 7 September the web cam recorded a plume more steam-rich than in recent days. No ash emissions were visible in web cam images on 10 September. The Volcano Alert Level remained at Watch and the Aviation Colour code remained at Orange.

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