Activity for the week of 20 February-26 February 2002
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
| 12.506°N, 86.702°W
| Elevation 728 m
A temporary increase in tremor and very small earthquakes occurred at Cerro Negro during 19 February at 2300 to 20 February at 1100. During a visit to the volcano on the 20th, INETER and Civil Defense personnel noted no important changes in activity in comparison to their previous visit on 16 February. They found a small 80- to100-m-long and 45-m-wide landslide, a new fumarole, fumarole temperatures that were slightly higher than normal, and a large amount of sulfur deposited on many fumaroles. According to INETER, the increase in tremor was possibly due to a temporary increase in volcanic gas emission related to the formation of the new fumarole. They stated that the population near Cerro Negro was not in direct danger, although people should be aware of the possibility of unexpected events.
Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), La Prensa (Nicaragua), La Prensa (Nicaragua)
| DR Congo
| 1.408°S, 29.2°E
| Elevation 3058 m
According to news articles, a team of volcanologists from the UN Office for the Coordination of Humanitarian Affairs and the Goma Volcanological Observatory stated that seismicity dramatically increased at Nyamuragira about 25 February. In a statement released to UN headquarters the team of volcanologists said they expect Nyamuragira to erupt within the next several days or weeks. They added that the population near the volcano should not be worried by the warning. Dario Tedesco, a UN volcanology consultant, expressed concerns that seismic activity near Lake Kivu could upset the balanced layers of carbon dioxide and methane in the bottom of the lake, leading to the release of toxic gases. Nyamuragira is ~13 km NW of Nyiragongo and ~30 km NW of the city of Goma, which was devastated by lava flows from Nyiragongo in January 2002. Nyamuragira last erupted in February 2001.
Sources: Reuters, Associated Press
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
Volcanic unrest continued at Shiveluch during 15-22 February, with several ash-and-gas explosions occurring and seismicity remaining above background levels. An eruption on 15 February at 1501 produced an ash cloud accompanied by pyroclastic flows that traveled 2.5 km down the SE slope of the dome. The highest rising observed ash cloud was produced by an eruption on 19 February at 0800; it reached a height of 3.5-4 km above the lava dome. Seismicity included earthquakes with magnitudes less than 2.4 at depths of 0-5 km, many local shallow seismic signals (from possible avalanches or weak gas-ash explosions), and episodes of weak intermittent volcanic tremor. Thermal anomalies and ash clouds were visible on satellite imagery. The volcano remained at Color Concern Code Orange ("volcano is in eruption or eruption may occur at any time").
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Anchorage Volcanic Ash Advisory Center (VAAC)
| Paramushir Island (Russia)
| 50.324°N, 155.461°E
| Elevation 1781 m
According to reports KVERT received from the town of Severo-Kurilsk (~70 km NE of the volcano), volcanism that began at Chikurachki on 25 January had decreased by 20 February. Visual observations from a helicopter on 18 February revealed that a small new crater had formed in the SSE part of the volcano's summit crater. A gas-and-steam plume was visible rising 150 m above the crater and extending to the ESE. A stripe of fresh ash was visible on the volcano's E slope. No thermal anomaly or ash plume was visible on satellite imagery. KVERT reported that the possibility of ash explosions occurring remained. According to the Tokyo VAAC, possible eruptions on 21 February at 0325 and 24 February at 1232 may have produced ash clouds that rose to ~6 and 5.8 km, respectively.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| 19.514°N, 103.62°W
| Elevation 3850 m
During 19-24 February, avalanches of incandescent material continued to travel down the S, SW, and W flanks of Colima. They extended 2-3 km from the volcano's summit and were recorded in seismic data. Lava continued to flow down the SW flank of the volcano, extending as far as 200 m from the summit. Lava was also visible flowing down the volcano's W flank as far as 2 km from the summit. Avalanches are expected to occur from the lava-flow front travelling down the volcano's E flank. About 300 metric tons of SO2 were measured per day, which was lower than values measured in 1998 when the current eruptive episode began.
Source: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
The level of seismicity at Karymsky during 15-22 February was similar to the previous week, with about 10 events occurring per hour. Thermal anomalies and small gas-and-steam plumes were visible on satellite imagery. The volcano remained at Color Concern Code Yellow ("volcano is restless").
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
Surface lava flows were visible atop the Pulama pali scarp and at its base. Activity occurred at rootless shields (a pile of lava flows built over a lava tube rather than over a conduit feeding magma) located between 680- and 640-m elevations. Generally, volcanic tremor remained at moderate levels at Pu`u `O`o, and long-period earthquakes and weak tremor continued below Kilauea's caldera. Tiltmeters across the volcano showed no evidence of significant deformation.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Papua New Guinea
| 4.08°S, 145.037°E
| Elevation 1807 m
Mild eruptive activity was observed at Manam during January through late February. Beginning on 13 January weak puffs of ash clouds were emitted from Southern Crater at 5-10 minute intervals. On several days in January fine ash fell on the NE side of the island for periods of several hours. During 8-24 February ash fell to the SE and was occasionally deposited in Warisi village. Main Crater released only weak-to-moderate volumes of white vapor during the report period. No instrumental measurements were made.
Source: Rabaul Volcano Observatory (RVO)
| Central Java (Indonesia)
| 7.54°S, 110.446°E
| Elevation 2910 m
During 18-24 February there were 67 incandescent lava avalanches observed traveling down Merapi's flanks, predominately WSW to the upstream portions of the Lamat and Senowo rivers and partly SW toward the Sat and Bebeng rivers. The maximum run-out distance was ~2.2 km. One minor pyroclastic flow was observed; it traveled 2.2 km down the Senowo River. Seismicity was dominated by avalanche earthquakes (607), which slightly increased in comparison to the previous week (600). Merapi remained at Alert Level 2 (on a scale of 1-4).
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
| 19.023°N, 98.622°W
| Elevation 5393 m
On 19 February frequent small-to-moderate emissions of steam, gas, and minor amounts of ash occurred at Popocatépetl. In addition, small explosions occasionally threw incandescent volcanic fragments short distances from the crater. During 0750-0900 small amounts of ash fell in Paso de Cortés. Also, isolated episodes of harmonic tremor were registered. On 23 February at 2156 a small explosion threw incandescent fragments up to 200 m that fell within the crater and a low-volume ash column rose 700 m above the crater and drifted to the W. Later, isolated harmonic tremor was detected. According to CENAPRED, the activity on the 19th and 23rd was related to the partial destruction of the lava dome in the crater and low-level explosive activity was considered possible in the next days or weeks.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
During 11-24 February volcanic and seismic activity were low at Rabaul's post-caldera cone, Tavurvur. Only white vapor was released from Tavurvur; emissions were blown to the SE and E resulting in vegetation being killed in the town of South Daughter (~2 km to the E). The Rabaul Volcanological Observatory stated that this suggests volcanic gases such as SO2 were being emitted.
Source: Rabaul Volcano Observatory (RVO)
| 16.72°N, 62.18°W
| Elevation 915 m
During 15-22 February, volcanism was generally high at Soufrière Hills. Lava-dome growth continued to be focused on the E sector. Activity increased during the second half of the report period; near-continuous rockfalls and minor pyroclastic flows traveled down the volcano's E flank. Minor rockfalls were also observed on the N flank of the active lava dome. Minor episodes of ash venting occurred from the summit of the dome, and on a number of evenings large parts of the summit were incandescent. SO2emission rates decreased during the report period; on 16 February 600-780 metric tons were measured, while on 19 February 90-130 metric tons were measured.
Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 19-24 February relatively low-intensity Strombolian activity continued at Tungurahua. In addition, there were several emissions of steam, gas, and ash. On the afternoon of 19 February a mixture of rain and ash fell in the Puela sector, and a small lahar traveled W to the Chontapamba sector. That evening, low-intensity Strombolian activity was observed. On the 20th at 2127, incandescent blocks were emitted that rolled down the flank to the Refugio de Pondoa. The next day during 0752-0905 ash columns reached 2 km above the volcano and drifted to the SW. Since 5 September 2000 the volcano has been at Alert Level Yellow for the town of Baños and at Orange for the rest of the population in the high-risk zone.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
| New Britain (Papua New Guinea)
| 5.05°S, 151.33°E
| Elevation 2334 m
During 11-24 February, activity at Ulawun's summit vent remained low, and volcanic tremor was recorded. Weak-to-moderate vapor plumes were emitted from the summit vent, and on the 21st weak roaring noises were heard and a weak red glow was briefly visible. During mid-February tremor increased to moderate levels for the first time since December 2001. After 22 February tremor returned to background levels.
Source: Rabaul Volcano Observatory (RVO)
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.
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