Activity for the week of 14 May-20 May 2014
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
| Mariana Islands (USA)
| 20.42°N, 145.03°E
| Elevation -75 m
On 16 May the USGS reported that during the previous week seismic signals from the source at or near Ahyi seamount had greatly diminished, indicating that the eruption had possibly paused or ended. Scientists aboard the research ship Hi'ialakai conducted water column tests in the vicinity of Ahyi on 15 May and reported no sign of activity, suggesting that the eruption occurred from a nearby volcanic vent and not the summit. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
| Central Java (Indonesia)
| 7.54°S, 110.446°E
| Elevation 2910 m
PVMBG reported that seismicity at Merapi decreased during 9-15 May, as compared to the previous week. Thumping noises continued to be reported from multiple observation posts, and on 12 May fumarolic plumes rose 350 m. The Alert Level remained at 2 (on a scale of 1-4) on 29 April.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
| El Salvador
| 13.434°N, 88.269°W
| Elevation 2130 m
According to SNET, the Ministerio de Medio Ambiente y Recursos Naturales (MARN) reported on 19 May that activity at San Miguel had increased significantly in the previous few days. The activity was characterized by an increase in the frequency and magnitude of gas emissions, rumbling in the crater, and small explosions followed by juvenile ashfall. On 18 May between 2230 and 2300 less than 1 mm of ash fell to the WNW in San Jorge. On 19 May the webcam recorded periodic pulses of gray gas plumes that rose 300 m and drifted W. On 20 May seismicity remained high and gray emissions rose 300 m.
Source: Servicio Nacional de Estudios Territoriales (SNET)
| 14.757°N, 91.552°W
| Elevation 3745 m
INSIVUMEH reported that on 14 May a lahar, the first since the 9 May eruption at Santa María's Santiaguito lava-dome complex, carried blocks up to 2 m in diameter as well as tree trunks. During 15-16 May explosions generated ash plumes that rose 700 m and drifted W and SW. During an overflight on 16 May, experts from both CONRED and INSIVUMEH observed affected areas from the 9 May eruption including deposits in the Nima I river drainage. They also noted that explosions and rumbling from the complex were at normal levels. On 18 May a lahar that was 15 m wide and 2 m deep in the Nima I drainage carried tree trunks and branches and had a strong sulfur odor. A secondary explosion in the drainage was caused by the interaction of water with the hot deposits. Lahars in the San Isidro rivers and Tambor also carried blocks. During 19-20 May explosions produced ash plumes that rose 700 m and drifted SW, causing ashfall in Monte Claro.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| Central Java (Indonesia)
| 7.242°S, 109.208°E
| Elevation 3428 m
BNPB reported that the Alert Level for Slamet was lowered to 2 (on a scale of 1-4) on 12 May because activity had decreased. Visitors and tourists were prohibited from approaching the crater within a radius of 2 km.
Source: Badan Nacional Penanggulangan Bencana (BNPB)
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
JMA reported that an explosion from Showa Crater at Aira Caldera’s Sakurajima volcano at 2229 on 12 May ejected tephra as far as 1.8 km from the crater and produced a plume that rose 1.6 km above the crater rim. Incandescence from the crater was detected at night during 13-14 May.
Source: Japan Meteorological Agency (JMA)
| Komba Island (Indonesia)
| 7.791°S, 123.585°E
| Elevation 633 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 16-18 May ash plumes from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55-75 km NW and W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| 19.514°N, 103.62°W
| Elevation 3850 m
Based on statements from the Mexico City Meteorological Watch Office, the Washington VAAC reported that on 15 May an ash emission from Colima rose to an altitude of 6.1 km (20,000 ft) a.s.l. Ash was not detected in satellite images. On 18 May a possible ash plume was observed in satellite images drifting almost 30 km W.
Source: Washington Volcanic Ash Advisory Center (VAAC)
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 14-15 May ash plumes from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 45 km NW and S.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that Strombolian and weak Vulcanian activity continued at Karymsky during 9-16 May. Satellite images detected a thermal anomaly on the volcano on 14 May. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 14-20 May HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away.
At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor, and from the lava pond in the NE spatter cone. Lava flows from the N spatter cone traveled short distances during 14-15 May. The Kahauale’a 2 lava flow continued to advance, with breakouts from the main stalled lobe, and burn adjoining forest. A satellite image acquired on 14 May showed that the farthest point of activity was 8.8 km NE of Pu’u 'O'o.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that during 9-16 May lava-dome extrusion onto Shiveluch’s SE flank was accompanied by ash explosions, incandescence, hot avalanches, and fumarolic activity. Satellite images showed a bright thermal anomaly daily. Satellite images detected daily thermal anomalies. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Fox Islands (USA)
| 54.756°N, 163.97°W
| Elevation 2857 m
AVO reported that during 14-20 May elevated surface temperatures at Shishaldin's summit were detected in satellite images, and minor steam emissions were observed in webcam images. A report from 16 May noted that dark ash-covered snow near the summit was visible on an unspecified day during the past week. Seismometers near the volcano detected brief explosion signals during 17-20 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| 16.355°S, 70.903°W
| Elevation 5672 m
IGP's Observatorio Volcanologico de Arequipa (IGP-OVA) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 14-16 May emissions at Ubinas continued. On 14 May emissions with minor amounts of ash rose 0.6-1.8 km above the crater. An explosion at 1902 on 14 May ejected fragments around the crater and caused thick ashfall in Chojata and Escacha. Water vapor and ash plumes rose 0.7-3.5 km on 15 May, and gas, steam, and ash plumes rose 500-800 m on 16 May. A moderate explosion at 1915 on 18 May was followed by nine hours of continuous emissions. Later that day gas-and-ash plumes rose 0.4-1.1 km. During 14-16 and 18 May ash fell in various towns downwind of the plumes, including Querapi (4 km S), Ubinas (6.5 km SSE), Escacha, Lloque, Chojata, and Tonohaya.
A news article from 15 May noted that the mayor of the district of San Juan de Tarucani in Arequipa continued the effort to relocate families.
Sources: Instituto Geofísico del Perú (IGP), Instituto Geológico Minero y Metalúrgico (INGEMMET)
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.
3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.
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