Activity for the week of 14 January-20 January 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
| Kyushu (Japan)
| 32.884°N, 131.104°E
| Elevation 1592 m
According to the Japanese Meteorological Agency, a "mud eruption" occurred at Aso's Crater 1 on 14 January at 1541. The eruption was accompanied by volcanic tremor and ash emissions that rose to low levels above the crater. Small amounts of very fine ash fell in Takamori Town about 10 km ESE of the crater. The level of thermal activity at Aso had risen during the previous year, with the last "mud eruption" occurring in July 2003. The Alert Level at Aso was raised from 2 to 3, and no tourists were permitted entrance within 1 km of the crater.
Sources: Volcano Research Center-Earthquake Research Institute (University of Tokyo), Reuters
| Central Kamchatka (Russia)
| 55.972°N, 160.595°E
| Elevation 2882 m
Video footage showed a strong explosion at Bezymianny on 14 January at 1053 producing an ash plume that rose to 6-8 km a.s.l. and extended ENE. A large pyroclastic flow probably traveled SSE down the volcano's flank. This abrupt increase in activity at Bezymianny led KVERT to raise the Concern Color Code from Green (the lowest level) to Red (the highest level), but later the same day they reduced it to Orange. By 1134 on 14 January the ash plume extended ~55 km and was at a height around 6 km a.s.l, and by 1421 it extended ~190 km and was at 4-6 km a.s.l. No ash was deposited in the nearby settlement of Ust'-Kamchatsk. On 16 January the Concern Color Code was further reduced to Yellow. On that day a lava dome was growing and viscous lava was probably flowing slowly from it. Precise seismic monitoring at Bezymianny was hampered due to high-level volcanic tremor at nearby Kliuchevskoi volcano. Visual observations at Bezymianny revealed that gas-and-steam plumes rose to ~100 m above the lava dome.
Prior to the 14 January eruption, a weak thermal anomaly has been registered at Bezymianny since an eruption on 26 July 2003. On 9 January one shallow M 2.2 earthquake was recorded at the volcano. During 10-13 January, a 1-2 pixel thermal anomaly was noted at the volcano and during 10-12 January gas-and-steam plumes rose to low levels above the volcano.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC), Anchorage Volcanic Ash Advisory Center (VAAC), Pravda News
| 12.506°N, 86.702°W
| Elevation 728 m
According to INETER, an unusually large amount of seismic tremor occurred at Cerro Negro from December 2003 to at least mid January. The tremor had variable intensity, but was too small to be felt by the population near the volcano. During visits to Cerro Negro on 6 and 10 January, scientists did not observe any surficial changes or measure a temperature increase at fumaroles in comparison to previous months. INETER reported that the alert level may be increased from no alert to Green (the lowest alert level) if the amplitude of the tremor increases, or if there is an increase in other precursory activity.
Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), La Prensa (Nicaragua)
| Kyushu (Japan)
| 31.934°N, 130.862°E
| Elevation 1700 m
Seismicity increased from "normal" levels at Kirishima on 13 December, and the same day Dr. Kobayashi of Kagoshima University found new fumarole pits at the volcano's Ohachi Crater. A video camera at the volcano showed steam rising above the crater rim. Observers saw two new pits that formed in the middle of the crater's southern inner wall and steam rising to ~100 m. Also, pebbles (that were 2-3 cm across) and mud were scattered within about 10 m of these pits. JMA issued a volcanic advisory on 16 December, as the possibility of a small eruption had increased, judging from the high level of seismic and thermal activity. On 17 December authorities announced that tourists were not permitted to visit Ohachi Crater. The level of seismicity peaked in mid December, then declined somewhat, continuing at a relatively high level through at least mid January.
Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)
| 2.005°S, 78.341°W
| Elevation 5286 m
According to the Washington VAAC, satellite imagery showed a plume emitted from Sangay on 14 January around 0500 extendeding ~45 km E. The plume most likely contained ash. During this time a hotspot was also visible on satellite imagery.
Sources: Washington Volcanic Ash Advisory Center (VAAC), New Zealand Herald
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
During 11-12 January, explosions at Shiveluch produced ash plumes to 4 km a.s.l. that drifted W. The explosions were accompanied by pyroclastic flows with run-out distances around 1 km. On 16 January at 1125 an eruption produced an ash plume that rose ~5.5 km a.s.l. and drifted W. The same day KVERT raised the Concern Color Code to Orange from Yellow. During 9-16 January, seismicity was above background levels at Shiveluch, with the recording of ~70 shallow earthquakes greater than M 1.75 and a large number of weaker earthquakes beneath the active lava dome. In addition, intermittent spasmodic tremor was recorded during 11-16 January.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Itar-Tass News
| 0.171°S, 78.598°W
| Elevation 4784 m
During the afternoon of 7 January, strong rains occurred at Guagua Pichincha and a series of seismic signals attributed to rockfalls and lahars were recorded. A visit to the area by IG scientists on 13 January confirmed that a lahar traveled down the NNE wall of the volcano's crater. In addition, there were small fractures in the SE sector of the volcano and in the crater. IG noted that this activity does not indicate a change in volcanic activity at Guagua Pichincha.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
Seismicity was above background levels at Karymsky during 9-16 January, with 150-300 earthquakes recorded. Ash-and-gas plumes may have risen 1.5-3 km above the volcano. According to the Airport Meteorological Center (AMC) in Yelizovo, during the report period a pilot saw an ash plume rise ~5.5 km above the volcano and extend SSW. On 12 January staff of the Kamchatkan Experimental & Methodical Seismological Department (KEMSD) saw an ash plume rise ~2 km above the volcano and explosions that occured every 5-7 minutes. On 10 January ash deposits were seen on the volcano's snow-covered flanks extending SE. Karymsky remained at Concern Color Code Orange.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
On 18 January during 0550 to 0830 a large period of deflation occurred at Kilauea's Pu`u `O`o cone, amounting in 18.1 microradians of net deflation. During this period a fissure opened at the SE base of Pu`u `O`o, trending approximately radial to the cone. Lava was emitted from the fissure and from three to four vents nearby. The initial flow reached about 1.5 km S of the cone. The S side of Pu`u `O`o was cut by many new fractures. The longest fracture constituted the N boundary of a shallow graben (a linear trough bounded by faults) that was ~75 m long and up to 1 m deep. Surface lava flows were emitted from the E end of the graben, at the base of Pu`u `O`o. The area S of Pu`u `O`o cone appeared to be quite unstable, so HVO scientists warned that no one should venture into the area. Seismicity at Kilauea's summit during 15-20 January was at low levels, while tremor at Pu`u `O`o was continuous and at moderate levels. The tremor picked up during the formation of the graben on 18 January. As of 20 January tilt continued to steadily decline following the 18 January deflation event.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Central Kamchatka (Russia)
| 56.056°N, 160.642°E
| Elevation 4754 m
Seismicity was above background levels at Kliuchevskoi during 9-16 January, with ~175 shallow M 1.9-2.5 earthquakes and a large number of weaker events recorded. Ash explosions rose 0.5-1 km above the volcano during 11-13 January. Strombolian activity was observed at the central crater during 11-12 January. Kliuchevskoi remained at Concern Color Code Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 14.757°N, 91.552°W
| Elevation 3745 m
On the morning of 15 January a moderate explosion at Santa Maria's Santiguito lava-dome complex caused a collapse at the edge of the crater. Volcanic material traveled down the volcano's SW flank, reaching the base. Ash rose ~900 m above the crater and fell on the observatory and property near the volcano. Weak avalanches occurred in the SE portion of the lava dome. On 19 January moderate explosions occurred and avalanches descended the lava dome. The plumes produced from the explosions traveled E, depositing small amounts of fine ash around the volcano, including on the ranches of San Jose, Quina, and San Juan Patzulín.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
| 16.72°N, 62.18°W
| Elevation 915 m
Volcanic activity at Soufrière Hills remained at low levels during 9-16 January. The seismic network recorded 5 rockfalls and 1 long-period and 18 hybrid earthquakes. The sulfur-dioxide flux from the volcano was low at the beginning of the report period (less than 200 tons per day), increasing to around 350 tons per day after a minor ash-venting event on 9 January.
Source: Montserrat Volcano Observatory (MVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 14-19 January, Tungurahua continued to emit gas, steam, and ash. Emissions rose to ~1 km above the crater and drifted predominately N and NE, with variable amounts of ash in the resultant plumes. In addition, low-level seismicity occurred.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
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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