On 26 September at least two phreatic eruptions occurred at Poás. One during the night of 25 September reached a height of at least 350 m above the warm acid lake, depositing rock fragments, mud, and water in the southern part of the inner crater and outside the western part of the crater. Material ejected that night reached Trojas de Sarchí, almost 10 km SW. A smaller eruption on the morning of 26 September was limited to the area of the lake, and formed green-yellow semicircular zones of mud and sulfur up to 75 m in diameter.

Increased seismicity at Dempo resulted in an elevation of the hazard status to Alert Level 2.
 

On the morning of 23 Sept, an ash plume emitted by a strong explosion of Tungurahua volcano reached an altitude of 9 km a.s.l. (VAAC Washington). The geophysical institute of Ecuador reports increased levels of tremor and sulphur dioxide emission.

The summit eruption of Etna volcano starting in August 2006 is terminated. The weak strombolian explosions from the south-east crater stopped and emission of lava flows stopped.

Seismic activity and lava extrusion from Mayon decreased during 6-12 September. Ground-deformation measurements showed an overall deflation. On 11 September, the Alert Level was lowered from 4 to 3 and around 30,000 people who had been evacuated early in August were allowed to return to their homes.

Lava flows on the coastal flat and on the pali (11 Sept. 06, Photo: Phil)


A small new skylight near the ocean entry (Photo: Phil)

Phil went to the flows last night and reports the following: "...the lava is going off at the moment: Two entries still. E Ka`ili`ili has 6+ points of entry along the bench fed by at least 3 tube branches, with explosions and flying lava a common sight nowadays. Surface flows fairly extensive just a short distance inland and east, with lots of small breakouts over a tube branch that last week was feeding a flow onto the bench and into the ocean. There is a small, accessible skylight near the coast with clear views of fast-moving flowing lava and that amazing gurgling sound.
Two rivers of lava originate from a single point near the visible top of the pail, one flowing downhill to the east along the forest's edge, causing lots of smoke and visible flare-ups when trees would dry up enough to ignite, and the other flowing down to the west for the entire length of the pali, I perhaps up to a 1000 ft drop in elevation. Cheers, Phil"

Strombolian activity at the SE crater and lava emission from vents inside the crater continue at Etna volcano. Parts of the cone are collapsing, permitting viscous lava to flow out from the center.

Visual observations show that the dome has grown substantially during the past week, with the main focus of growth being on the western part of the edifice. The two vigorous vents that opened on 31 August are still active. The one above the Gage’s wall is emitting a plume of hot gases, the more northerly vent, near the summit of the dome, is producing mostly ash and steam.

Seismic tremor and emission of sulphur dioxide at Bromo is increasing and VSI set the alert level to 3 ("caution"). An eruption could be imminent. The last vulcanian eruption at Bromo occurred on 8 June 2004, killing two tourists who got surprised while on the stairs leading up to the crater rim.

Based on satellite imagery, the Darwin VAAC reported that ash-and-steam plumes
from Ulawun drifted SW and S on 30 August and 2 September, respectively.

Based on pilot reports and satellite imagery, the Buenos Aires VAAC reported
continuous emissions of ash plumes from Ubinas during 30 August-1 September and
on 4 September. The plumes reached altitudes of ~4.9-5.5 km (~16,000-18,000 ft)
a.s.l. and drifted NE, E, and SE.
 

During 30 August-5 September, seismicity at Tungurahua remained low. Steam and
gas plumes with low to no ash content rose to 300-600 m above the summit
(17,500-18,400 ft a.s.l.) and drifted NNW and W. On 1 September, lava flows on
the NW flank were confirmed to have ceased. On 2 September, incandescence at the
summit was observed.

During 30 August-5 September, the lava dome at Mount St. Helens continued to
grow. A moderate seismic event and associated rockfall occurred on 3 September.
The hazard status remained at Volcano Advisory (Alert Level 2); aviation color
code Orange.

Based on information from JMA, the Tokyo VAAC reported that eruptions at
Sakura-jima on 3 and 4 September generated plumes that rose to ~2.7 km (~9,000
ft) a.s.l. and drifted mainly NW and N, respectively.

According to the Washington VAAC, emissions of gas, steam, and possibly ash from
Popocatépetl were visible from the camera operated by CENEPRED during 4-5
September. The resulting eruption cloud drifted W and did not rise high above
the summit. Incandescence was periodically observed at the summit.
 

A small "seismic crisis" at Piton de la Fournaise began at 1000 on 30 August. A
summit eruption started from the SSE edge of Dolomieu Crater at 1135 and
scientists witnessed the opening of a fissure on the crater floor. A large
portion of the crater floor was covered with lava by the afternoon. A second
fissure opened just outside of the crater and produced a lava flow on the E
flank. On 31 August, seismicity remained high and a new cone had formed in
Dolomieu Crater.

Based on satellite imagery, the Darwin VAAC reported that ash-and-steam plumes
from Manam reached altitudes of 4.6 km (15,000 ft) a.s.l. and drifted W on 1 and
2 September. Steam plumes with possible ash were visible on satellite imagery
below 3 km (10,000 ft) a.s.l. and drifted NE.
 

During 23-29 August, lava from Kilauea continued to flow off of a lava delta
into the ocean at the East Lae'apuki and East Ka'ili'ili entries. On 1
September, the area of the East Lae'apuki lava bench was an estimated 22
hectares (54 acres) and East Ka'ili'ili was an estimated 2.3 hectares (5.7
acres). Incandescence was visible from the East Pond and January vents, South
Wall complex, and Drainhole vent in Pu'u 'O'o's crater during the reporting
period. Summit inflation S of Halema'uma'u caldera continued. Tremor at Pu'u
'O'o remained at a very typical moderate level.
 

Activity at Karymsky continued during 26 August-1 September, with 30-70 shallow
earthquakes occurring daily. Based on interpretations of seismic data, ash
plumes reached altitudes of 3 km (10,000 ft) a.s.l. A thermal anomaly in the
crater was detected on 26 and 28 August. Karymsky remained at Concern Color Code
 

PHIVOLCS reported that steam plumes from Bulusan reached up to 350 m above the
summit (6,300 ft a.s.l.) on 30 August and 1 September. The plumes drifted NW and
SE, respectively.