Activity for the week of 16 May-22 May 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
San Cristobal
| Nicaragua
| 12.702°N, 87.004°W
| Elevation 1745 m
Volcanic activity increased at San Cristóbal on 17 May, accompanied by a relatively large amount of seismic tremor. Pulses of gas-and-ash emissions were observed rising up to 100 m above the rim of the volcano's crater. Light ash fell in the town of Santa Barbara, 14 km SW of the volcano.
Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), El Nuevo Diario, ABC News - Australian Broadcasting Corporation
Sheveluch
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
Due to the occurrence of several large explosions at Shiveluch, KVERT increased the Concern Color Code to Red on 21 May. An approximately 40-minute-long eruption began at 1556 on 19 May. An ash cloud rose to an altitude of 10 km a.s.l. and drifted to the NE. Short pyroclastic flows and hot avalanches from the lava dome were restricted to areas near the lava dome. At 1802 and 1814 on 20 May a large thermal anomaly was visible on satellite imagery. At 1925 and 2014 two explosions sent ash columns to heights ranging between 4.7 and 5 km a.s.l. At 0713 on 21 May an explosion sent an ash column to 10-12 km a.s.l. AVO reported that ash was visible on satellite imagery. At 0209 on 22 May an eruption produced a mushroom-shaped ash column to a height of ~20 km a.s.l. that drifted to the SSE. Reflected incandescence was observed above the volcano from the town of Klyuchi, 46 km from the volcano. The Concern Color Code changed several times during the week; on 19 May it was raised from Yellow to Red, on 20 May it was reduced to Yellow, and the following day it was raised again to Red.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Anchorage Volcanic Ash Advisory Center (VAAC), Tokyo Volcanic Ash Advisory Center (VAAC)
Ongoing Activity
Cleveland
| Chuginadak Island (USA)
| 52.825°N, 169.944°W
| Elevation 1730 m
Cleveland was observed on satellite images numerous times during the week and no thermal anomalies were detected. AVO had received no reports of significant volcanic activity from pilots, residents, or satellite remote-sensors since the last eruption on 19 March.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Etna
| Sicily (Italy)
| 37.748°N, 14.999°E
| Elevation 3295 m
According to the Italy's Volcanoes website, mild eruptive activity continued at Southeast Crater, with persistent lava outflow from a vent on the NNE flank of its cone. Very weak Strombolian bursts occurred at the summit vent of the cone that occasionally sent incandescent bombs up to 100 m above the crater rim.
A Spanish tourist who visited the volcano alone has been missing since 14 May and is presumed dead. The remains of her tent were found on 18 May near the rim of Bocca Nuova crater. Local press sources reported that a rescue team found footprints leading from the tent to the rim of one of the two active pits within the crater, but no prints were found leading back from the pit. It is possible that the tourist was standing on the rim of the pit when a portion of it broke loose.
Source: Italy's Volcanoes
Fujisan
| Honshu (Japan)
| 35.361°N, 138.728°E
| Elevation 3776 m
Based on information from JMA, VRC reported that 67 earthquakes occurred at Mt. Fuji on 30 April, which was the highest number since 53 earthquakes occurred on 18 December 2000. Activity had been relatively low since January 2001. During 3-9 May ~130 predominately low-frequency earthquakes occurred that were located ~15 km beneath an area just NE of the volcano's summit. No other anomalous volcanic activity was observed by NIED.
Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)
Kilauea
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
Lava continued to flow down Pulama pali and was observed entering the sea at the SE corner of the lava flow field. On 20 May the largest tilt event to occur at Kilauea in more than 4 years took place. Beginning at 0500 the volcano's summit began to slowly deflate (~2 microradians) until about 1630 when it very abruptly began to inflate (~10 microradians). The inflation peaked at 1735, and deflation began at 1750. The event was accompanied by strong tremor, which ended a prolonged period of small earthquakes that had lasted, with a 9-hour break on the night of 18 May, for several days. At about 1920 a lava pond was observed forming in Pu`u `O`o crater. Observations the next day revealed that the pond had drained, leaving only a few spattering vents.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Lokon-Empung
| Sulawesi (Indonesia)
| 1.358°N, 124.792°E
| Elevation 1580 m
An article in the Jakarta Post stated that an eruption at Lokon that began at 2014 on 20 May deposited ash in a wide area around the volcano, including the provincial capital of Manado, approximately 20 km NE of the volcano. They reported that ash rose up to 900 m above the volcano and that the eruption was accompanied by tremor.
Source: The Jakarta Post
Mayon
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
Elevated levels of volcanic activity continued at Mayon. Rockfalls were produced from fragments that were shed off of the summit lava dome. Seismic activity was relatively low. SO2 emission rates were at a very high level of ~7,400 metric tons per day, which is significantly above the baseline value of 500 tons/day. Moderate steaming occurred and Intensity I (faint) and II (fair, visible with the naked eye) incandescence was occasionally observed at the crater. Weak-to-moderate ash-and-steam venting occurred from the lava dome. Electronic distance meter (EDM) data indicated a general, but minor, inflation of the volcanic edifice. 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.
Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Associated Press
Miyakejima
| Japan
| 34.094°N, 139.526°E
| Elevation 775 m
Based on information from the JMA, VRC reported that no ash clouds had been observed at Miyake-jima since the 19 March eruption. They also reported that steam plumes with abundant SO2 were continuously emitted from the summit caldera to 0.5-2 km above the caldera rim. Continuous SO2 emission released as much as 33,000 to 46,000 tons of SO2 per day. Low-level seismic activity continued and a M 2.8 earthquake occurred on 7 May. Global positioning system (GPS) measurements showed steady, continuous deflation of the volcano though the rate was lower than before September 2000. During air inspections very small collapses of the caldera rims were occasionally seen.
Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)
Okmok
| Fox Islands (USA)
| 53.43°N, 168.13°W
| Elevation 1073 m
AVO reported that the earthquake swarm centered near Okmok that was first detected on 11 May greatly diminished by 15 May.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Popocatepetl
| Mexico
| 19.023°N, 98.622°W
| Elevation 5393 m
Small-to-moderate sized exhalations consisting mostly of gas and steam occurred at Popocatépetl during the week.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Soufriere Hills
| Montserrat
| 16.72°N, 62.18°W
| Elevation 915 m
MVO reported that during 11-18 May volcanic activity increased, with about twice the number of rockfalls than the previous week. Most of the rockfalls were small and were observed to the SW of the summit, N of the town of Galway's. Growth of the lava dome was concentrated in the S sector of the volcano above White River. A new lobe of lava was observed in the area, although the rate of growth appeared to be low. Sulfur dioxide flux remained low. Most of Montserrat received very light ashfall throughout the week as a result of changeable winds.
Source: Montserrat Volcano Observatory (MVO)
Tungurahua
| Ecuador
| 1.467°S, 78.442°W
| Elevation 5023 m
Volcanic activity increased slightly at Tungurahua during the week. On 15 May several small eruptions occurred, with the largest sending ash up to 3 km above the summit. Light ash fell in the towns of Cotaló and Bilbao. The Washington VAAC reported that an eruption that began around 1830 on 17 May sent an ash cloud to ~9 km a.s.l. that drifted to the SW. According to IG on 17 and 18 May Tungurahua was not visible due to cloudy conditions, but intense activity was indicated by the high number of long-period earthquakes and seismic signals that may have been associated with eruptions. At 0615 on 19 May an eruption produced an ash cloud that rose ~6.7 km a.s.l. IG warned that lahars might be generated if rainfall mixed with ash deposited on the upper W flanks of the volcano.
Sources: Instituto GeofÃsico-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
Criteria
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.
Disclaimers
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.
