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 3320 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)
News Feeds and Google Placemarks
The RSS (Really Simple Syndication) 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.
The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.
A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.
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:
- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.
Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.
It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.
1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.
2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.
3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.
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RSS and CAP Feeds
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.
At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.
CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management.
Google Earth Placemarks
A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.