Activity for the week of 12 May-18 May 2004
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
| 4.487°N, 75.389°W
| Elevation 2749 m
According to news articles, the Observatory Vulcanológico and Sismológico de Manizales reported that there was an increase in seismicity at Machín in April. About 60 earthquakes were recorded daily, in comparison to the 1-10 earthquakes normally recorded. No surficial changes were seen at the volcano.
Sources: El Tiempo, El Tiempo
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
According to a news article, PHIVOLCS reported that three volcanic earthquakes were recorded at Mayon during the week of 9 May, suggesting a renewed period of unrest. In addition, incandescence was visible in the crater and moderate steaming was seen. On 12 May, the sulfur-dioxide flux increased from the normal level of ~500 tons per day to ~1,170 tons. People were reminded not to enter the 6-km-diameter Permanent Danger Zone around Mayon.
Source: ABS-CBN News
| Pantar Island (Indonesia)
| 8.508°S, 124.13°E
| Elevation 862 m
According to a news article, Sirung began erupting "smoke and dust" around 13 May. A local government official reportedly said that hundreds of residents were evacuated from within 1 or 2 kilometers of the volcano. There were no reports of injuries or damage.
Source: ABC News - Australian Broadcasting Corporation
| 28.271°N, 16.641°W
| Elevation 3715 m
Local volcanologists reported that there was increased seismicity at Tenerife in mid-May, according to a news article. The article stated that during several days before 18 May there were "five successive low-intensity earthquakes in the island's most volcanically active zone in the area between Mont Teide and Santiago del Teide." The director of the Estación Vulcanológica de Canarias stated that the earthquakes, which were less than M 2, could be an early sign that something unusual was happening at the volcano.
Source: Yorkshire Post Today News
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that explosions at Sakura-jima occurred on 15 May at 1107 and on 17 May at 1946, sending ash plumes to heights of ~1.8 km and 2.1 km a.s.l., respectively. A pilot reported ash on 18 May, at a height of ~1.2 km a.s.l., ~23 km S of the Amori region.
Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Associated Press, Itar-Tass News
| Mariana Islands (USA)
| 16.35°N, 145.67°E
| Elevation 790 m
During 13-17 May, volcanic activity continued at Anatahan. Explosions occasionally threw volcanic material hundreds of meters out of the crater, and steam-and-ash emissions probably rose several hundred meters above the volcano. On 17 May the seismic energy release nearly doubled in comparison to the previous several days, but remained well below the peak level reached on 24 April.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
| 19.514°N, 103.62°W
| Elevation 3850 m
Universidad de Colima reported on 15 May that low-intensity activity continued at Colima, with an average of three ash-containing explosions daily during the previous few days. The plumes rose to less than 2 km above the volcano and drifted W, N, and E. Some explosions produced pyroclastic flows to distances less than 2 km. On 14 May at 1028 an explosion produced a plume to ~2 km above the volcano that drifted E. In addition, three small pyroclastic flows traveled down the volcano's W, N, and E flanks.
Sources: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima, Washington Volcanic Ash Advisory Center (VAAC)
| 14.473°N, 90.88°W
| Elevation 3763 m
During 10-17 May, moderate volcanic activity continued at Fuego. Several explosions produced ash plumes, with the highest one reaching ~1.8 km above the volcano on 13 May. Explosions on 13 May at 0411 and 0618 emitted incandescent volcanic material ~150 m. In addition, a lahar traveled W toward Seca Ravine.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
During 7-14 May, seismicity was above background levels at Karymsky, with 330-450 shallow earthquakes occurring daily. Based on interpretations of seismic data, possible ash-and-gas explosions rose to 2.5-3 km a.s.l. daily. On 8 May an ash plume was visible extending more than 16 km NE of the volcano. Karymsky remained at Concern Color Code Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
On 12 May, the Banana lava flow at Kilauea stopped moving toward the sea. There were several incandescent areas along the route of the flow from Paliuli to the top of Pulama pali. During the report period, tremor was at low levels at Kilauea's summit and at moderate levels at Pu`u `O`o. A deflation-inflation-deflation event occurred at Kilauea's summit on 15 May.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| DR Congo
| 1.408°S, 29.2°E
| Elevation 3058 m
During a flight over Nyamuragira on 12 May scientists noted that volcanic activity remained strong, but stable. The lava lake at the volcano's summit was in a ~15-m-deep pit and its activity had greatly decreased in comparison to observations on 9 May. The lake's surface had crusted over, with three vents exhibiting Strombolian activity (lava spattering and overflows producing short lava flows). In addition, the eruptive fracture on the volcano's NNW flank had four main cones with very active lava fountains reaching heights of 30-50 m. Small lava flows from the cones coalesced into one wide lava flow, covering a large area to a distance of ~12 km. The TOMS (Total Ozone Mapping Spectrometer) Volcanic Emissions Group reported that sulfur-dioxide clouds were visible on TOMS satellite imagery since the eruption began on 8 May, although some of the gas may be attributed to emissions from neighboring Nyiragongo (~13 km SE from Nyamuragira).
Sources: Observatoire Volcanologique de Goma (OVG), OMI Sulfur Dioxide Group
Piton de la Fournaise
| Reunion Island (France)
| 21.244°S, 55.708°E
| Elevation 2632 m
The eruption that began at Piton de la Fournaise on 2 May continued through 15 May. After 2 days of low activity, eruption tremor increased by about a factor of 3 on the morning of 15 May. Lava flows followed the S border of Enclos Fouqué caldera and flowed down the Grandes Pentes area.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
| 0.077°S, 77.656°W
| Elevation 3562 m
During 3-9 May, the level of seismicity at Reventador did not change significantly. During 7-8 May, lahars traveled down Reventador's flanks, disrupting travel on the Chaco-Lumbaquí road for about a day.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
| 14.757°N, 91.552°W
| Elevation 3745 m
During 10-17 May, weak-to-moderate explosions at Santa María's Santiaguito lava-dome complex produced gas-and-ash plumes that rose to ~1 km above the crater. Small partial collapses at the edge of the Caliente lava dome produced avalanches of incandescent volcanic material to the SW. On 17 May a lahar traveled S down Nimá River I.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
During 7-14 May seismic activity was above background levels at Shiveluch, with a large number of shallow earthquakes occurring. Based on interpretations of seismic data, during 6-7 May there may have been three ash-and-gas explosions that produced plumes to ~ 7 km a.s.l. On 9 May a strong explosion deposited ash in Ust-Kamchatsk, closing the airport. The road and the dam in the area of the Bekesh river were destroyed by mud flows.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| Fox Islands (USA)
| 54.756°N, 163.97°W
| Elevation 2857 m
During 7-14 May seismic unrest continued at Shishaldin, characterized by sequences of volcanic earthquakes, small explosions, and seismic tremor. A weak thermal anomaly observed at Shishaldin's summit on 11 May was similar to those detected occasionally since January 2004. Shishaldin remained at Concern Color Code Yellow.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| 16.72°N, 62.18°W
| Elevation 915 m
Volcanic and seismic activity at Soufrière Hills remained at low levels during 7-14 May. Spasmodic tremor ceased on 7 May, ending a protracted period of low-to-moderate amplitude tremor that began on 15 March. The sulfur-dioxide flux was at low-to-moderate levels, reaching the lowest recorded value on 13 May (146 metric tons per day) since the major explosions and collapse event during 12-15 July 2003.
Source: Montserrat Volcano Observatory (MVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 12-17 May, moderate emissions of steam, gas, and ash continued at Tungurahua. On 12 May, an explosion produced an ash cloud to ~3 km above the volcano that drifted SW. On 13 May seismicity increased moderately, related to the increased numbers of emissions. Incandescence was visible at the lava dome during some nights.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
| United States
| 56.17°N, 159.38°W
| Elevation 2507 m
During 7-14 May unrest continued at Veniaminof, characterized by intermittent low-level volcanic tremor and small volcanic earthquakes. No emissions were seen. In comparison to the previous week, seismicity was more intermittent and lower in amplitude. However, seismicity suggested that ash bursts occasionally occurred. Veniaminof remained at Concern Color Code Yellow.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
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.
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