Activity for the week of 4 July-10 July 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
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
A decrease in volcanic activity began on 3 July that led PHIVOLCS to reduce the Alert Level on 4 July from 5 (hazardous eruption in progress) to 4 (hazardous eruption imminent). In comparison to the previous week SO2 emissions decreased, seismic activity was lower, the rate of inflation of the volcano's edifice decreased, and there was no ash in the steam clouds that emanated from the crater. Alert Level 4 was maintained due to the possibility of minor ash puffs and secondary explosions caused by the contact of water with the voluminous hot lava. The extended danger zone was reduced from 8 km to 7 km in radius. On 4 July ~20,000 people who were evacuated from the most distal parts of the evacuation zone were permitted to return to their homes.
Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Associated Press
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3295 m
After 4.5 days of low-level activity at Etna, an eruption occurred at Southeast Crater on 4 July that lasted for approximately 5 hours. The episode began with lava flowing from the NNE vent towards the NE and SSE and was followed by modest Strombolian activity. At the summit vent powerful explosions sent an incandescent fountain up to 400-500 m high and several large magma bubbles burst sending fragments to the base of the Southeast Crater cone. A dense tephra column rose from the summit vent and deposited ash on Etna's SE flank. Fine ash and 3- to 5-mm-long Pele's hair fell as far as the town of Acireale, ~20 km SE of the volcano. On 7 July another eruptive episode lasted for approximately 1 hour at Southeast Crater. The episode consisted of lava flows and the eruption of black ash and small volcanic blocks that reached a height of ~1 km above the volcano and drifted to the E.
Sources: Italy's Volcanoes, Etna Volcan Sicilien (Charles Rivière)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
Small surface flows of pahoehoe lava were located in the W and E branches of the lava flow field. Like the previous week, lava poured into the sea at the E Kupapa`u ocean entry. Generally, weak, steady tremor and related long-period earthquakes continued beneath Kilauea's caldera. Tremor remained weak to moderate near Pu`u `O`o and seismicity was at normal levels elsewhere. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Piton de la Fournaise
| Reunion Island (France)
| 21.244°S, 55.708°E
| Elevation 2632 m
The eruption that started on 11 June stopped on 7 July after 1 week of increased tremor. On 3 July tremor and the intensity of local earthquakes increased. The earthquakes had magnitudes less than 3 and were located under Dolomieu crater at a depth near sea level. On 6 and 7 July two aa lava flows in the Grand Brûlé area crossed the national highway. On 7 July the end of the eruption was marked by the disappearance of the tremor and a dramatic decrease in the intensity of local earthquakes.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
| 19.023°N, 98.622°W
| Elevation 5393 m
On 3 July at 0410 and 0648 moderate-sized explosions occurred. The latter explosion lasted about 10 minutes and produced an ash cloud that rose ~4 km above the volcano. Initially the cloud drifted to the SE and later the highest portion of the cloud drifted to the NW. Based on information from pilot reports and ground observations, the Washington VAAC reported that the ash cloud was 9.3 km SE of Mexico City Airport at 0930. Ashfall occurred in several towns including Chalco, ~35 km NW of the volcano, and there were reports of light ashfall on the airport's runways.
Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC), Associated Press, CNN
| Eastern Java (Indonesia)
| 8.108°S, 112.922°E
| Elevation 3657 m
Based on information from pilot reports and the Meteorological and Geophysical Agency of Indonesia, the Darwin VAAC reported that on 8 July at 1503 a SE-drifting ash plume rose to ~2.5 km above the volcano. Ground based reports prior to the eruption revealed that each day during 18-24 June Semeru emitted ash to ~0.6 km above the volcano.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
During 29 June to 6 July seismic activity remained above background levels, but the level of explosive volcanic activity decreased in comparison to the previous week. On 2 and 3 July a thermal anomaly was visible on satellite imagery. On 3, 4, and 5 July voluminous gas-and-steam plumes rose 2-2.5 km above the volcano. Due to the decrease in volcanic activity the Concern Color Code at Shiveluch was reduced from Orange to Yellow.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 16.72°N, 62.18°W
| Elevation 915 m
During 29 June to 6 July volcanic activity at Soufrière Hills remained similar to the previous week. Lava dome growth appeared to still be concentrated on the S side of the dome above the White River. On 30 June a large number of rockfalls traveled down the N side of the talus apron in the Tar River. On 4 July two small pyroclastic flows traveled down the volcano's W flank in the Amersham area. The Washington VAAC reported that on 4 July an ash cloud rose ~3 km a.s.l. and drifted to the WNW. Also, on 10 July numerous rockfalls produced W-drifting ash plumes that did not exceed ~3 km a.s.l. in height.
Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 3-8 July several small-to-moderate eruptions produced ash clouds. One of the larger eruptions occurred on 5 July at 1310, producing an ash cloud that a pilot reported rose to ~7.6 km a.s.l. However, satellite imagery and additional information suggested that the dense SE-drifting ash cloud rose to ~9 km a.s.l.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
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.