During 19-26 April, there were several emissions of gas, steam, and ash. The highest rising ash cloud reached 800 m above the volcano and visual observations suggested that rockfalls probably accompanied the eruption. Seismicity decreased slightly during the report period; there were earthquakes with magnitudes less than or equal to 2.0 at depths of 0-5 km, many local shallow seismic signals (from possible avalanches or weak gas-and-ash explosions), and intermittent episodes of weak volcanic tremor.
Volcanic activity remained higher than normal at Semeru during 15-21 April. A small plume rose ~400 m above the summit and a "red reflection" was occasionally visible 25 m above the crater rim. Lava avalanches traveled 750 m to the E down Besuk Kembar River. The volcano remained at Alert Level 2.
During 24-30 April, Popocatépetl emitted small clouds of steam, gas, and generally minor amounts of ash. In addition, episodes of harmonic tremor were recorded. On 29 April at 2232 an eruption produced an ash cloud to a height of 1.5 km and sent incandescent fragments 500 m from the crater.
During 15-21 April, several incandescent lava avalanches were observed traveling down Merapi's flanks, predominately SW to the upstream portions of the Lamat, Sat, and Senowo rivers, reaching a maximum run-out distance of ~2.5 km. Two minor pyroclastic flows traveled up to 1.8 km on 14 April. Seismicity decreased in comparison to the previous week, SO2 emission rates were average, and the lava dome showed no signs of deformation.
Activity at Lokon remained higher than normal during 15-21 April. Volcanic tremor was high, gas explosions occurred at the bottom of the crater, and a low-level steam plume was visible. The volcano remained at Alert Level 3 (on a scale of 1-4).
Scientists from the Rabaul Volcano Observatory carried out a 4-day investigation at Lamington and concluded that there was no new volcanic activity. For the previous 3-4 weeks rumors had been circulating that Lamington was active, with reports of "fire" and "smoke" emanating from the volcano, felt earthquakes, and volcanic noises.
On 23 April inflation occurred at Pu`u `O`o, with no change in seismicity at Kilauea. Observations on the 24th revealed that the January 2002 cone continued to emit lava onto the Pu`u `O`o crater floor. During 24-29 April, no surface lava was visible on Pulama pali.
During 19-26 April, Karymsky's seismicity was above background levels and its character suggested that weak ash-and-gas explosions, gas blow-outs, and debris avalanches occurred. Thermal anomalies were visible on AVHRR satellite imagery. Traces of ashfall were visible on MODIS imagery on 17 April.
Wed, 24 Apr 2002, 06:00
Ash emissions that had been occurring at Bocca Nuova crater for several weeks seemed to diminish during 23-25 April. During the 24th-25th, only ash-free gas emissions were observed, mostly from Bocca Nuova and Northeast craters. On the 28th a brief emission of brown ash was seen coming from the W side of Bocca Nuova.
Read allWed, 24 Apr 2002, 06:00
During 19-24 April, there was an increase in the number of deep and shallow volcanic earthquakes at Dieng in comparison to previous weeks. A small steam cloud rose 20-25 m above Sileri crater and temperatures taken at several crater lakes on the 20th and 21st had not increased. The volcano was at Alert Level 2 (on a scale of 1-4).
Read allWed, 24 Apr 2002, 06:00
As of 29 April volcanism continued at Colima with incandescent lava avalanches travelling down the volcano's flanks and seismicity occurring that was indicative of small explosive events and landslides. Incandescent lava avalanches, generated from the fronts of block-lava flows, continued to travel 2-3 km down Colima's S, E, and W flanks and 700 m down the SW flank.
Read allWed, 17 Apr 2002, 06:00
During 17-23 April, emissions of gas, steam, and ash continued at Tungurahua. A small ash cloud was visible on satellite imagery on 19 April.
Read allWed, 17 Apr 2002, 06:00
Increases in volcanic and seismic activity at Lokon-Empung led VSI to raise the Alert Level from 2 to 3 (on a scale of 1-4) on 12 April. Eruptions occurred on 10 April at 2302 and on the 12th at 1816. On 13 April eight gas-and-ash explosions occurred and on the 14th five occurred.
Read allWed, 17 Apr 2002, 06:00
The Darwin VAAC stated on 24 April that reports of an eruption at Lamington on 22 April were false. Based on information from Geoscience Australia and satellite imagery, the Darwin VAAC originally reported that an E-drifting ash cloud from Lamington seemed to be evident on satellite imagery on 22 April at 1741. Thunderstorms near the volcano made it difficult to locate possible ash on satellite imagery.
Read allWed, 17 Apr 2002, 06:00
During 12-19 April, the level of volcanism at Soufrière Hills slightly decreased in comparison to the previous week. Lava-dome growth was concentrated on the SE area of the dome complex, although small rockfalls occurred in other areas. The lava dome evolved from a large striated lobe at the beginning of the week, to a series of small spines by week's end.
Read allWed, 17 Apr 2002, 06:00
During 12-19 April, gas-and-steam and ash-and-gas emissions occurred at Shiveluch and seismicity remained above background levels. A short-lived explosive eruption on 15 April at 1906 produced an ash-and-gas plume that rose 1 km above the volcano. Seismicity during the report period included earthquakes with magnitudes less than or equal to 2.3 at depths of 0-5 km, many local shallow seismic signals (from possible avalanches or weak gas-and-ash explosions), and episodes of weak intermittent volcanic tremor.
Read allWed, 17 Apr 2002, 06:00
During 17-23 April, Popocatépetl emitted small clouds of steam, gas, and generally minor amounts of ash. In addition, episodes of harmonic tremor were recorded.
Read allWed, 17 Apr 2002, 06:00
During 18-22 April, surface activity was visible at a minimum of two vent areas of Pu`u` O`o's crater and at the rootless shields. No surface lava flows were visible on Pulama pali. Generally, tremor at Pu`u` O`o was low and only a few small earthquakes and low-level tremor occurred at Kilauea's caldera.
Read allWed, 17 Apr 2002, 06:00
A pilot reported observing an ash cloud from an explosion at Karymsky on 15 April at 1115 that rose 3 km above the volcano. During 12-19 April, seismicity was above background levels and its character indicated that weak ash-and-gas explosions, gas blow-outs, and debris avalanches possibly occurred. Thermal anomalies were visible on AVHRR satellite imagery.
Read allWed, 17 Apr 2002, 06:00
During 14-18 April, a dense ash plume persisted at the SE vent of Etna's Bocca Nuova crater. Dense ash-free plumes rose above Voragine and Northeast craters. Earthquakes continued on Etna's SE flank, and there were reports of seismicity on the NE flank.
Read allWed, 10 Apr 2002, 06:00
Observations of Villarrica on 9 April revealed that no incandescence or explosive noises occurred in the volcano's crater. A lava lake, whose surface was 200 m below the crater rim, was last seen at the volcano on 19 January. At that time explosions at Villarrica occurred every 5-10 minutes.
Read allWed, 10 Apr 2002, 06:00
During 10-13 April, small emissions of gas, steam, and ash rose 500 m above Tungurahua. On the 11th a small amount of ash fell in the N-flank resort town of Baños.
Read allWed, 10 Apr 2002, 06:00
During 5-12 April, volcanism slightly decreased at Soufrière Hills in comparison to the previous week. Lava-dome growth over the entire summit region produced rockfalls that traveled predominately to the SE, E, and NE. Several pyroclastic flows traveled E for ~2 km down the Tar River Valley, reaching the sea.
Read allWed, 10 Apr 2002, 06:00
During 29 March-5 April, gas-and-steam and ash-and-gas emissions occurred at Shiveluch and seismicity remained above background levels. A short-lived explosive eruption on 10 April at 0900 produced an ash-and-gas plume that rose 1 km above the volcano. Seismicity during the report period included earthquakes with magnitudes less than or equal to 2.1 at depths of 0-9 km, many local shallow seismic signals (from possible avalanches or weak gas-and-ash explosions), and episodes of weak intermittent volcanic tremor.
Read allWed, 10 Apr 2002, 06:00
During 10-15 April, Popocatépetl emitted small clouds of steam, gas, and generally minor amounts of ash. In addition, episodes of harmonic tremor were recorded.
Read allWed, 10 Apr 2002, 06:00
VSI reported that an eruption occurred at Lokon-Empung's Tompaluan crater on 10 April at 1104. The dark plume rose about 1 km above the volcano and tephra fell around the crater. Based on a pilot report, the Darwin VAAC first erroneously attributed the ash cloud to an eruption from Mahawu.
Read allWed, 10 Apr 2002, 06:00
During 10-15 April, observers saw small surface lava flows descending along the path of the lava-tube system that drains the rootless shield area. These flows were sometimes visible above and on the Pulama pali scarp. Activity occurred at the rootless shields, and lava was visible in parts of Pu`u `O`o crater.
Read allWed, 10 Apr 2002, 06:00
After about 6 days of instrument downtime, the seismic station near Karymsky began to operate again. As was the case before the seismic station malfunction, seismicity was above background levels at 10 earthquakes per hour. The character of the seismicity indicated that weak ash-and-gas explosions and avalanches possibly occurred.
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