Volcanologists in the D.R. Congo reported that the intensity of the lava flows decreased in March, but there was a large amount of smoke and relatively high seismic activity. While the intensity of the lava flows lessened, registered seismic activity was at similar levels to December, before the eruption began.
On 30 March the IGNS reported that a moderate-sized hydrothermal explosion occurred in the Alum Lakes area, Wairakei, knocking over trees and destroying vegetation near the crater. Water levels at several of the Alum Lakes had dropped several weeks before the explosion.
On 29 March OVSICORI-UNA personnel visited the area affected by pyroclastic flows that traveled down the flanks of Arenal on 24, 25, and 26 March. The pyroclastic-flow deposits were located on the N and NE flanks of the volcano. The ash clouds produced from the pyroclastic flows drifted towards the W and SW, depositing ash on an area up to 10 km2 including two towns.
The MVO reported that during 23-30 March volcanic activity at Soufriere Hills volcano was extremely low. Seismic and rockfall activity were low and there was a small amount of growth in the S of the lava dome. The MVO warned that though activity is low, dangerous conditions can develop quickly and in the event of heavy rain the Belham Valley to the NE of the volcano should be avoided due to the possibility of mudflows.
The KVERT reported that at 0555 on 24 March a 2-minute-long shallow earthquake was followed by weak spasmodic volcanic tremor that lasted ~10 minutes. This burst of activity may have corresponded to weak ash-and-gas explosions that reached a height of ~2 km above the crater. On 27 March a powerful gas-and-steam plume rose 800 m above the volcano.
The IGNS reported that on 27 March a very small eruption of mud and water occurred from a vent in Kuirau Park, Rotorua. The park was the site of a large eruption in late January 2001.
CENAPRED reported that volcanic activity continued at Popocatépetl, with several small exhalations and moderate seismic activity. The volcano remained at Alert Level Yellow Phase III, with a restricted 12-km-radius area.
PHIVOLCS reported that during the week ending on 1 April there had been a total of 23 low-frequency earthquakes. The SO2 flux during the same period averaged 2,174 metric tons/day, which is still significantly above the baseline value of 500 tons/day. Deformation monitoring showed that the volcano was inflated, but the present trend revealed insignificant change.
Wed, 28 Mar 2001, 06:00
The KVERT reported that during the beginning of the report period (23-30 March), seismic activity was above background levels with spasmodic tremor and shallow earthquakes registered, but gradually decreased towards the end of the week. The KVERT lowered the Level of Concern Color Code from Yellow to Green.
Read allWed, 28 Mar 2001, 06:00
The HVO reported on 2 April that surface lava flows confined to a single flow in the E branch of the flow field continued to travel down the Pulama Pali. In addition, lava flows were still visible on the coastal plain and were 400-450 m from the coast. Overall, volcanic tremor near Pu`u `O`o cone was at low-to-moderate levels and at Kilauea's caldera tremor was low.
Read allWed, 28 Mar 2001, 06:00
Based on information from the IG, the Washington VAAC reported that an ash cloud was observed at 0137 on 31 March. No ash was visible on GOES-8 imagery. The volcano remained at Alert Level Yellow.
Read allWed, 28 Mar 2001, 06:00
According to the Italy's Volcanoes website, volcanic activity continued at Etna through the end of March. Continuous Strombolian activity was observed at a pit in Bocca Nuova Crater. Lava continued to slowly flow from the NNE flank of the Southeast Crater.
Read allWed, 28 Mar 2001, 06:00
The AVO reported that after 24 March, satellite imagery has not shown the thermal anomaly that had been visible since the 19 March eruption of Cleveland. No further explosive activity has been reported. Occasional avalanching of material from the steep flanks of Cleveland may produce small, localized plumes.
Read allWed, 21 Mar 2001, 06:00
During the week of 18-24 March seismicity and fumarolic activity at Tungurahua continued. The IG reported that at 1915 on 22 March an eruption column with an incandescent point rose to a height of 2 km and lasted 10 minutes. Another eruption on 23 March at 1014 lasted for 30 minutes, sending a column 2 km high that moved NW.
Read allWed, 21 Mar 2001, 06:00
The OVPDLF reported that an eruption began in Dolomieu Crater at 1130 on 27 March. Additional details are not yet available, but inspection of photographs (http://www.ipreunion.com/) shows a fissure eruption, fountaining, and lava flows.
Read allWed, 21 Mar 2001, 06:00
Activity continued after the 28 January 2001 explosion. On 26 March 2001 at 1440 another eruption sent a dark ash plume 1,500 m above the crater rim. Ash drifted E and N.
Read allWed, 21 Mar 2001, 06:00
PHIVOLCS noted in a 21 March report that since January 2001 earthquake clusters or occurrences have been recorded by the seismic monitoring network around the volcano. These earthquakes may signify a reactivation of the volcanic system at depth and could be a precursor to more vigorous activity, such as ash explosions. This interpretation is based on similar earthquake clusters manifested prior to the 10 August 1996 phreatic explosion from the active summit crater of the volcano.
Read allWed, 21 Mar 2001, 06:00
OVSICORI-UNA reported on 26 March that at least three pyroclastic-flow episodes occurred on 24 March between 1234 and 1342. Unlike previous pyroclastic flows, these descended the W flank. National Park guards observed the resulting ash clouds moving SW. There were no reports of injuries or damage.
Read allWed, 21 Mar 2001, 06:00
The MVO reported that during 16-23 March activity at Soufrière Hills remained at low levels. Most of the 84 detected rockfalls were small events and occurred on the eastern and southern faces of the lava dome. There has been a small amount of growth in the south part of the dome.
Read allWed, 21 Mar 2001, 06:00
The KVERT reported that seismicity was mainly at background levels. On 18 March a 12-minute-long series of shallow earthquakes registered. On 22 March a 2-minute-long shallow earthquake swarm was followed by 20 minutes of weak spasmodic volcanic tremor.
Read allWed, 21 Mar 2001, 06:00
The summit of the volcano was covered by clouds during 12-18 March, but the seismic record showed increasing activity. Explosion and avalanche earthquakes still dominated seismicity and increased over the past week. There were 349 explosion earthquakes, an increase over the 303 detected during 6-12 March.
Read allWed, 21 Mar 2001, 06:00
According to CENAPRED, volcanic activity remained low and relatively unchanged throughout 22-27 March. Low-intensity steam-and-gas exhalations continued, sometimes with small amounts of ash. Spoardic episodes of harmonic tremor were reported on most days, with the longest episode lasting 1.5 hours on the evening of 24 March.
Read allWed, 21 Mar 2001, 06:00
Visual and instrumental monitoring by VSI personnel through 18 March revealed that volcanic activity continued at Merapi. Hot lava avalanches continued to enter the Sat, Senowo, Bebeng, and Lamat rivers, with a maximum runout distance of 3 km in the Sat River. Pyroclastic flows traveled up to 1 km down the Sat, Senowo, and Bebeng rivers.
Read allWed, 21 Mar 2001, 06:00
PHIVOLCS reported that during the week ending on 25 March there had been a total of 86 low-frequency volcanic earthquakes with relative amplitudes of 45 mm. The SO2 flux during the same period averaged 2,975 metric tons/day, which is still significantly above the baseline value of 500 tons/day. Deformation monitoring showed that the volcano was inflated, but the present trend revealed insignificant change.
Read allWed, 21 Mar 2001, 06:00
Anak Krakatau showed a significant increase in activity during the week of 12-18 March. The number of shallow volcanic earthquakes (type B) rose to 79 from 25 the previous week. Activity decreased again during 19-26 March, with only 34 shallow volcanic events.
Read allWed, 21 Mar 2001, 06:00
The KVERT reported that during 16-22 March seismic activity was above background levels, with interrupted spasmodic tremor and shallow earthquakes registered. On 18-19 March a gas and steam plume rose 50-100 m above the volcano. On 22 March the volcano was quiet.
Read allWed, 21 Mar 2001, 06:00
Lava continued to flow down the Pulama Pali and across the coastal flat, but has not yet entered the ocean. During the past few weeks, the flows have covered about 230 m of the private access road to Royal Gardens and are now farther east than any active flows since 1992. Activity is robust on the coastal flat near the truncated road that formerly accessed Royal Gardens but that has long since been cut off by lava.
Read allWed, 21 Mar 2001, 06:00
The IG reported that during the week of 18-24 March a total of 806 long-period earthquakes were registered. However, 460 of those occurred on the 18th along with a moderate ash emission. Long-period event counts were below 20/day as of 21 March.
Read all
