Activity for the week of 30 May-5 June 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
| Honshu (Japan)
| 37.735°N, 140.244°E
| Elevation 1949 m
On 29 May the Fukushima Local Meteorological Observatory reported that seismic activity increased slightly beneath Azuma during May. The Coordinating Committee for the Prediction of Volcanic Eruptions' seismic network detected 51 small-magnitude volcanic earthquakes during 21 and 22 May and 39 on 21 May (the most recorded in one day since November 1998). During March four low-frequency tremor events were recorded, while 40 were detected in April.
Source: The Japan Times
| 19.514°N, 103.62°W
| Elevation 3850 m
During an excursion to Colima on 17 March by personnel from the Universidad de Colima a new crater was observed that was assumed to have been formed during the 22 February 2001 eruption. The crater was ~190,000 m3 in volume, making it the largest crater to form at Colima since the 1960s. On 26 May scientists discovered that a new lava dome that was ~150,000 m3 in volume had formed in the crater. They also noted that fumarolic activity was stronger in May than in March and fumaroles were active around the new dome mainly to the N, NE, and E. The new lava dome was the first evidence of effusive volcanic activity since the November 1998-February 1999 effusive episode.
Source: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima
| Fox Islands (USA)
| 53.891°N, 166.923°W
| Elevation 1800 m
Since July 2000 AVO has detected a slight increase in the number of small earthquakes beneath Makushin. The earthquakes generally ranged in depth between 0 and 8 km and were too small to be felt by humans (M0-1.5). The seismic activity was not considered to be an immediate precursor to eruptive activity. Similar fluctuations in earthquake activity have been observed at a number of Aleutian volcanoes that did not result in an eruption. The Concern Color Code remained at Green.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3295 m
According to the Italy's Volcanoes website, volcanic activity was at similar levels as it has been during the previous few weeks. Lava continued to travel from a vent on the NNE flank of the Southeast Crater cone, and mild, discontinuous Strombolian activity continued at the Southeast Crater's summit vent. Scientists determined that the lava effusion rate was approximately 5-10 cubic meters per second, which is high for Etna. On 31 May mountain guides reported that pressure waves, which were caused by explosions, were observed approximately every 10 minutes and that volcanic bombs were thrown ~100 m above the crater rim. Degassing was observed at Southeast Crater and occurred to a lesser extent at Bocca Nuova crater, but increased at Northeast Crater.
Source: Italy's Volcanoes
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During the beginning of the week lava flowed down Pulama pali and entered the ocean at two areas. By 3 June there were few surface flows with most of the lava traveling in lava tubes and entering the ocean sporadically. On 3 June a pause in volcanic activity may have begun at about 0900 with slow deflation (~2.6 microradians) occurring at the tiltmeter closest to HVO. The inflation ended around 2400 and on 4 June at 0125 rapid inflation (~2.7 microradians) began, most occurred in about 55 minutes. On 3 June at 1015 slow deflation (0.9 microradians) began at Pu`u `O`o and ended at about 2200. Slow inflation occurred at least until 4 June. Background volcanic tremor at Kilauea's summit gradually increased on 3 June starting at mid-morning, after the deflation had begun. There was no significant change in the tremor at Pu`u `O`o.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
During the week a large amount of high-frequency short-duration harmonic tremor occurred at Mayon. The tremor was associated with the intermittent descent of small lava avalanches and incandescent volcanic material down the Bonga Gully on the SE flank of the volcano. Moderate amounts of steam were observed rising from the summit crater where incandescence was occasionally observed. SO2 emission (up to 2,900 metric tons/day) was above the baseline value of 500 tons/day. Alert Level 3 remained in effect, prohibiting entry within the 6-km-radius permanent danger zone. PHIVOLCS warned that residents around the volcano, especially those staying in areas facing the Bonga Gully and the SE sector, should be vigilant and prepared to evacuate at any time.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
| 19.023°N, 98.622°W
| Elevation 5393 m
CENAPRED reported that on 31 May at 2136 a moderate-sized eruption began with the most intense phase lasting ~1 minute. Incandescent material traveled 2-3 km down the NE flank of the volcano. According to the Mexico City MWO a steam-and-ash cloud was observed rising up to 7.6 km a.s.l. and drifting to the W. A smaller eruption occurred on 1 June at 0804 that sent a steam-and-ash cloud up to 7 km a.s.l.
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
Volcanic activity decreased following the 22 May eruption, therefore, on 30 May the Concern Color Code was further reduced from Orange to Yellow. During the week several small eruptions produced gas-and-steam plumes that rose up to 1.2 km above the old lava dome. Seismic activity decreased in comparison to the previous week, but remained above background levels.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 16.72°N, 62.18°W
| Elevation 915 m
MVO reported that during 25 May-1 June volcanic activity remained at high levels. There was a significant increase in long-period earthquakes, although most were small. MVO personnel observed an area of new growth in the S sector of the lava dome. Sulfur dioxide flux varied, but was generally lower than the previous week. The daytime entry zone remained closed.
Source: Montserrat Volcano Observatory (MVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
Volcanic activity increased at Tungurahua. A large number of long-period earthquakes accompanied several small eruptions and near-continuous gas-and-ash emission. The IG reported that an eruption on 31 May at 2120 produced an ash cloud that rose up to ~7.9 km a.s.l. and drifted to the W. Incandescent blocks were ejected during the eruption, and an acoustic wave that sounded like a cannon shot was heard several km away from the volcano. Eruptions also occurred on 29 May at 2012 that sent ash to a height of ~8.2 km a.s.l., on 30 May at 1211 (ash plume to an unknown height), and on 2 June at 1709 with an ash plume to ~7.9 km. Incandescent material was visible in the crater, and IG warned that heavy rain could remobilize ash and generate lahars.
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.