Activity for the week of 15 August-21 August 2001
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 by 2300 UTC every 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 at 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
| Halmahera (Indonesia)
| 0.32°N, 127.4°E
| Elevation 1357 m
An eruption began at Makian on 16 August at 1930. During the eruption, chunks of incandescent lava were ejected 75 m through the air. Residents were evacuated to the S side of the island. The volcano is at Alert Level Red.
NOTE: VSI has since reported that this eruption is likely to have been a bush fire. We are seeking more information.
Source: Société Volcanologique Européenne
| 12.702°N, 87.004°W
| Elevation 1745 m
There was renewed volcanic and seismic activity at San Cristóbal during the week. During mid-August a gradual increase in seismic tremor and long-period earthquakes began and the amount of tremor peaked during the night of 11 August. The same night INETER personnel heard rumbling emanate from the volcano. Seismicity began to decrease on 12 August and increased again the night of 14 August, reaching the same level detected on 11 August. On 14 August incandescence was visible in the crater for the first time during the current episode. INETER stated that the lava lake in the crater illuminated gas and clouds above the summit crater. Seismic tremor gradually decreased until approximately 1400 on 17 August when strong seismic activity began again. Fumarolic activity increased during the current episode and small lagoons within the crater had dried.
Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
| 1.467°S, 78.442°W
| Elevation 5023 m
The series of eruptions that began at Tungurahua on 6 August continued during the week. Seismic activity was characterized by many long-period earthquakes and seismic signals that represented ash emissions. Several sporadic explosions occurred, with the largest explosion beginning on 15 August at 2231. The eruption produced an ash cloud that rose to 12.2 km a.s.l. IG reported that on 17 August volcanic activity increased slightly and incandescent material was ejected up to 1 km W of the crater. According to news reports, as of 15 August ash affected more than 23,000 people, blanketed approximately 89,000 acres of crops, and killed an undetermined number of livestock. The Alert Level remained at Yellow in the town of Baños and at Orange for the rest of the population in the high-risk zone, as it has since 5 September 2000.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC), Associated Press, Reuters
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3295 m
During the week volcanic activity was relatively low at Etna, with no explosions or lava flows. There were several small earthquakes, and slight degassing at fissures on the volcano's flanks. Vapor was emitted from the summit craters, and was accompanied by occasional plumes of brown ash at Bocca Nuova crater.
Source: Etna Volcan Sicilien (Charles Rivière)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
Lava continued to enter the sea at the E Kupapa`u entry. Surface lava flows were visible on the coastal plain in both the E and W branches of the current flow field. A short, stubby surface flow was visible halfway down the Pulama pali scarp. On 15 August volcanic tremor abruptly increased at Kilauea's summit and at Pu`u `O`o, but it reached only moderate-to-low levels. Generally, weak, rather steady tremor and a few small earthquakes continued beneath Kilauea's caldera. Tiltmeters across the volcano showed no significant deformation.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
Volcanic activity remained relatively low at Mayon during the week. Few rockfalls were observed, seismicity was relatively low, incandescence was not visible in the crater, and no inflation was detected at the volcano's summit. SO2 emission rates reflected continuous degassing of residual magma. Because volcanic and seismic activity had been declining for the previous 2 weeks, on 21 August PHIVOLCS decreased the Alert Level at the volcano from 4 (hazardous eruption imminent) to 3 (increased tendency towards eruption). As a consequence, the Extended Danger Zone (EDZ) in the SE returned to the original 6-kilometer radius Permanent Danger Zone (PDZ).
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
| 19.023°N, 98.622°W
| Elevation 5393 m
Small emissions of steam, gas, and small amounts of ash continued at Popocatépetl. The Mexico City MWO reported that on 17 August at 1514 an ash emission produced a cloud that rose to 7.3 km a.s.l. The Washington VAAC reported that GOES-8 satellite imagery did not show an ash plume, but did show an occasional hotspot. CENAPRED reported that recent activity was related to the growth of a new lava dome inside the crater. The volcano remained at Alert Level Yellow Phase II.
Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
Seismic activity remained above background levels during the week and included several small earthquakes. On 15 August volcanic tremor decreased gradually to background levels. Observers in Klyuchi reported that on 11 August gas-and-steam plumes rose 1.2-1.5 km above the dome. Several thermal anomalies were recorded on satellite imagery, as well as a gas-and-steam plume extending 75 km SE. The volcano remained at Concern Color Code Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 16.72°N, 62.18°W
| Elevation 915 m
Volcanic activity remained low during 10-17 August. Weak banded tremor began on 14 August and continued throughout the week. The new lava dome continued to grow within the scar produced from the 29 July partial dome collapse. Deposits in the upper reaches of the Tar River Valley indicated that the new dome had produced several small pyroclastic flows.
Source: Montserrat Volcano Observatory (MVO)
Weekly Reports Archive
||Huila, Nevado del
||Hunga Tonga-Hunga Ha'apai
||Soufriere St. Vincent
||South Sarigan Seamount
|Campi Flegrei del Mar di Sicilia
||Tair, Jebel at
|Chillan, Nevados de
||Palena Volcanic Group
||Kick 'em Jenny
|Dieng Volcanic Complex
||Rincon de la Vieja
|Etorofu-Yakeyama [Grozny Group]
||Lengai, Ol Doinyo
||Ruiz, Nevado del
|Fournaise, Piton de la
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Criteria & Disclaimers
The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
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An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.
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