PHIVOLCS reported that during 28 February to 6 March, 15 to 50 low-frequency earthquakes were recorded daily. An average of 1,855 metric tons per day (t/d) of SO2 was recorded during the previous week, which was significantly above the baseline value of 500 t/d. A slight inflationary trend was detected at the volcano's edifice, no incandescence was observed at the crater, and weak-to-moderate steaming was occasionally seen.
The VSI reported that following the 28 January eruption, activity decreased at Lokon-Empung with only small steam emissions occurring. A small tectonic earthquake (M 1) was reported in the area. The volcano remained at Alert Level 3 (on a scale of 1-4).
Based on satellite imagery and pilot reports, the Tokyo VAAC reported that an eruption may have occurred at Kliuchevskoi. The ash cloud produced from the eruption rose to a height of ~9.5 km and was visible on GMS-5 imagery at 1532 on 4 March. By 1832 the same day the ash cloud was no longer visible on satellite imagery.
The AVO reported that no further eruptive activity was observed or detected at Cleveland since the 19 February eruption. During 19 February to 2 March, GOES-10 imagery showed a weak thermal anomaly that was probably related to hot material deposited on the flanks of the volcano on the 19th. Photographs taken a few days after the eruption showed significant accumulation of spatter and lava blocks high on the steep flanks of the volcano; occasional avalanching of this debris may produce small, localized ash plumes.
The KVERT reported that during 25-27 February there was an increase in seismic activity. Two- and three-minute-long series of shallow earthquakes were registered and followed by weak volcanic tremor. These outbursts may have corresponded to weak ash-and-gas explosions that reached a height of ~2 km above the crater.
The VSI reported that a small steam plume rose ~100 m above Semeru's summit and that seismicity was dominated by 702 explosion earthquakes. In addition to the explosion earthquakes, three deep volcanic, 58 avalanche, and five tectonic earthquakes occurred. The volcano remained at Alert Level 2 (on a scale of 1 to 4).
CENAPRED reported that activity remained relatively low at Popocatépetl during the week, with small exhalations accompanied by steam emissions. The volcano remained at Alert Level Yellow Phase III, with a restricted area of 12-km-radius.
Lava continued to flow down Pulama pali without reaching the sea. Overall, volcanic tremor near Pu`u `O`o was low-to-moderate and tremor at Kilauea's caldera was low. Tiltmeters in the summit area and along the E rift zone showed flat signals.
Wed, 28 Feb 2001, 06:00
During 20-26 February, the number of earthquakes recorded was relatively high; 42 shallow volcanic earthquakes and five tectonic earthquakes were detected. The volcano remained at Alert Level 2 (on a scale of 1-4).
Read allWed, 28 Feb 2001, 06:00
According to the Italy's Volcanoes website, during late February fluctuating eruptive activity continued at Etna's summit craters. Strombolian activity continued at two vents in Bocca Nuova Crater and within the central pit of Northeast Crater. In addition, lava continued to slowly flow from the NNE flank of the Southeast Crater.
Read allWed, 21 Feb 2001, 06:00
The IG reported that at 1056 on 21 February an eruption sent an ash cloud to ~8.8 km a.s.l. that drifted to the NW. The ash cloud was not visible on the Washington VAAC's GOES-8 imagery. The IG reminded residents near the volcano that strong rains in the area may remobilize ash and generate lahars.
Read allWed, 21 Feb 2001, 06:00
Based on reports from White Island tour operators, the IGNS stated that on 19 February minor ash eruptions began at White Island. A light gray plume of fine ash rose ~2 km above the MH vent and drifted towards the mainland. Fine ash was deposited on and near White Island, but only an acid aerosol cloud reached the mainland near the town of Matata.
Read allWed, 21 Feb 2001, 06:00
The IGNS reported that an episode of strong volcanic tremor was recorded at Ruapehu. The tremor episode peaked on 16 February and was the strongest tremor recorded since the 1996 eruptions, but direct observations of the crater revealed a lack of unusual activity. By approximately 23 February the tremor had declined to background levels.
Read allWed, 21 Feb 2001, 06:00
The agency responsible for monitoring active volcanoes in Guatemala, INSIVUMEH, observed several indications of renewed eruptive vigor at Pacaya. A local seismometer recorded over 700 earthquakes per day in comparison to 100 earthquakes per day recorded approximately 2 weeks earlier. SO2 gas emissions increased from 253 tons/day to 550 tons/day.
Read allWed, 21 Feb 2001, 06:00
Based on reports from the VSI, the Darwin VAAC stated that during 15-21 February volcanic activity decreased at Merapi. According to the Meteorological and Geophysical Agency of Indonesia, during 11-18 February daily ash emissions rose up to ~150 m above the summit. The volcano remained at Alert Level 4, the highest level.
Read allWed, 21 Feb 2001, 06:00
PHIVOLCS reported that during the week the number of earthquakes recorded at Mayon was similar to the previous week, and lower SO2 emission rates were recorded. Between 6 and 30 low-frequency volcanic earthquakes were recorded daily during 21-26 February. SO2 emission rates decreased from a maximum value of ~3,000 metric tons per day (t/d) on 20 February, to 1,700 t/d on 21 February.
Read allWed, 21 Feb 2001, 06:00
Visual observations by VSI personnel during 12-17 February revealed that volcanic activity remained low at Lokon, with steam plumes rising 200-350 m above the crater rim. Seismic data were not available because the seismograph on the volcano was broken. The volcano remained at Alert Level 3 (on a scale of 1-4).
Read allWed, 21 Feb 2001, 06:00
In the wake of earlier concern about renewed volcanic activity at Kelut, the VSI reported that during 12-17 February the temperature of Kelut's crater lake decreased and its pH increased. The temperature decreased to 47.5°C from a range of 50.1 °C to 51 °C, measured during 29 January to 7 February. The pH of the water increased to 5.3 from 5, measured on 7 February.
Read allWed, 21 Feb 2001, 06:00
The Volcanological Observatory of Colima University reported that a moderate explosion occurred at 0532 on 22 February. After reviewing video footage of the eruption, the observatory concluded that the ash cloud produced from the eruption rose ~2 km above the volcano at an average velocity of 200 meters/second (m/s). Incandescent ballistics were hurled up to 3 km away from the volcano at a rate of ~100 m/s and landed on the NE and SW flanks of the volcano, and to a lesser extent on the N flank.
Read allWed, 21 Feb 2001, 06:00
The ash cloud produced from the 19 February eruption of Cleveland volcano was visible on GOES-10 imagery through 1700 on 21 February. The AVO reported that a thermal anomaly was detected on satellite imagery during 21-26 February. On 22 February a pilot reported that steam was observed rising from near the SE shoreline of the volcano where an apparently fresh deposit entered the sea.
Read allWed, 21 Feb 2001, 06:00
The MVO reported that during 16 to 23 February activity at the Soufrière Hills volcano was similar to the previous week, as lava dome growth continued. The level of seismic activity was also comparable to last week. A large stubby spine was visible in the S part of the summit area on 22 February.
Read allWed, 21 Feb 2001, 06:00
The KVERT reported that during 19-20 February there was an increase in seismic activity. Two- and four-minute-long series of shallow earthquakes were registered, possibly corresponding to weak ash-and-gas explosions. On 22 February, a gas-and-steam plume rose 900 m above the volcano.
Read allWed, 21 Feb 2001, 06:00
CENAPRED reported that small exhalations occurred at Popocatépetl during the week. The Washington VAAC did not report that ash was visible in satellite imagery. The volcano remained at Alert Level Yellow Phase III, with a restricted area of 12-km-radius.
Read allWed, 21 Feb 2001, 06:00
Lava continued to flow SE down the Pulama pali and across the coastal plain to within 1 km of the coast. At 1317 on 20 February a M 3.7 earthquake occurred that was centered about 5 km SE of Halemaumau Crater at a very shallow depth. Brief summit deflation occurred on 24 February, but ended the next day with no corresponding period of inflation following it.
Read allWed, 21 Feb 2001, 06:00
According to the Italy's Volcanoes website, on 20 February slow lava extrusion continued from a vent on the NNE flank of the Southeast Crater cone. Mild eruptive activity continued from the Bocca Nuova Crater, with Strombolian bursts from two vents on the NW and E parts of the crater. During 18-20 February, a slight increase in activity was observed at the Bocca Nuova Crater.
Read allWed, 14 Feb 2001, 06:00
The IG reported that at 1050 on 19 February lahars were registered at a seismic station. The lahars traveled down the NW flank of the volcano via the Cusúa Gorge. The same day a steam column rose 1 km above the summit and drifted to the NE.
Read allWed, 14 Feb 2001, 06:00
There were reports of volcanic activity at San Vicente volcano after a M 6.6 earthquake occurred at 1422 on 13 February. The earthquake caused more than 25 landslides on the flanks of the volcano that reportedly killed 39 people. The Centro de Investigaciones Geotécnicas investigated the activity reports and determined that no volcanic activity had occurred.
Read allWed, 14 Feb 2001, 06:00
According to a Reuters article, the eruption at Nyamuragira that was first observed on 6 February continued at least until 18 February. There were reports of lava flowing from three cones, "flames" rising 100 m above the volcano, and ash falling over an area of 20 to 30 km2 around the volcano. Lava flowed down the S flank of the volcano, threatening to reach roads running N from the town of Goma ~30 km away.
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