New Activity:
| Epi, Vanuatu
|
Ongoing Activity:
| Ambrym, Vanuatu
| Anatahan, Mariana Islands
| Dukono, Indonesia
| Fuego, Guatemala
| Karymsky, Russia
| Kilauea, USA
| Santa María, Guatemala
| Shiveluch, Russia
| Soufrière Hills, Montserrat
| Tungurahua, Ecuador
| Yasur, Vanuatu
|
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.
Note: Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.
New Activity/Unrest
EPI Vanuatu 16.68°S, 168.37°E; summit elev. 833 m
According to a report from John Seach, an eruption at East Epi caldera in early March marked the first reported activity at the largely undersea caldera since 1988.
Geologic Summary. Epi Island, located slightly W of the main New Hebrides volcanic arc, largely consists of two Quaternary volcanoes, Mount Allombei on the W and Pomare (Tavani Kutali) on the E. Tavani Ruro, which forms an elongated eastern extension of Epi Island across a narrow isthmus, is related to Kuwae caldera to the E. Pomare volcano is the highest point on the island and has three well-preserved subsidiary cones to the E with youthful summit craters. Pomare volcano is truncated on its eastern side by the largely submarine East Epi caldera, which has been the source of all historical eruptions. Three small submarine basaltic and dacitic cones are located along the northern rim of the breached caldera. Ephemeral islands were formed during eruptions in 1920 and 1953.
Source: Volcanolive.com
Epi Information from the Global Volcanism Program
Ongoing Activity
AMBRYM Ambrym Island, Vanuatu 16.25°S, 168.12°E; summit elev. 1,334 m
According to a report from John Seach, during March an active lava lake was present in Ambrym's Mbwelesu crater.
Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides arc. A thick, almost exclusively pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major Plinian eruption with dacitic pyroclastic flows about 1900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.Source: Volcanolive.com
Ambrym Information from the Global Volcanism Program
ANATAHAN Mariana Islands, central Pacific Ocean 16.35°N, 145.67°E; summit elev. 788 m
A seismic swarm began beneath Anatahan on 31 March. During 31 March to at least 4 April, volcanic seismicity was at its highest level since the eruption of May-June 2003, with events as large as M 2.5. The earthquakes were usually followed by tremor-like signals that scientists believed indicated steam and/or ash emissions to altitudes well below 1 km. As of 6 April, the seismic swarm continued to intensify slowly.
Geologic Summary. The elongated, 9-km-long island of Anatahan in the central Mariana Islands consists of two coalescing volcanoes with a 2.3 x 5 km, E-W-trending summit depression formed by overlapping summit calderas. The larger western caldera is 2.3 x 3 km wide and extends eastward from the summit of the western volcano, the island's 788 m high point. Ponded lava flows overlain by pyroclastic deposits fill the caldera floor, whose SW side is cut by a fresh-looking smaller crater. The summit of the lower eastern cone is cut by a 2-km-wide caldera with a steep-walled inner crater whose floor is only 68 m above sea level. Sparseness of vegetation on the most recent lava flows on Anatahan indicated that they were of Holocene age, but the first historical eruption of Anatahan did not occur until May 2003, when a large explosive eruption took place forming a new crater inside the eastern caldera.
Source: Emergency Management Office of the Commonwealth of the Northern Mariana Islands and the US Geological Survey Hawaiian Volcano Observatory
Anatahan Information from the Global Volcanism Program
DUKONO Halmahera, Indonesia 1.70°N, 127.87°E; summit elev. 1,185 m
During 31 March to 6 April, ash clouds emitted from Dukono were sometimes visible on satellite imagery at a height of ~3 km a.s.l.
Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred since 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.
Source: Darwin VAAC
Dukono Information from the Global Volcanism Program
FUEGO Guatemala 14.47°N, 90.88°W; summit elev. 3,763 m
During 31 March to 6 April, weak-to-moderate explosions continued at Fuego. The highest rising ash plume produced from the explosions reached ~1.2 km above the volcano on 5 April and drifted SSE. Lahars flowed down Seca Ravine on 30 March, and near the village of Sangre de Cristo on 3 April. During the report period, incandescent avalanches of volcanic material traveled down several ravines, including Santa Teresa, Ceniza, and Taniluyá.
Geologic Summary. Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. Collapse of the ancestral Meseta volcano about 8,500 years ago produced a massive debris avalanche that traveled about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango, the northern twin volcano of Fuego. Frequent vigorous historical eruptions have been recorded since 1524 and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. The last major explosive eruption from Fuego took place in 1974, producing spectacular pyroclastic flows visible from Antigua.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia
Fuego Information from the Global Volcanism Program
KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m
Seismicity remained above background levels at Karymsky during 26 March to 2 April, with 240-380 shallow earthquakes occurring per day. Based on interpretations of seismic data, plumes from ash-and-gas explosions may have reached 3.5 km a.s.l. every day. On 30 March ash deposits were seen extending SE and SW from the volcano. Karymsky remained at Concern Color Code Orange.
Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.
Source: Kamchatkan Volcanic Eruption Response Team via the Alaska Volcano Observatory
Karymsky Information from the Global Volcanism Program
KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m
During 31 March to 5 April, surface lava flows were visible at the southern part of Kilauea's rootless-shield complex, which is along the Mother's Day lava tube several hundred meters S of Pu`u `O`o cone. Incandescence was also visible from several vents in the crater of Pu`u `O`o. Seismicity was at low levels at Kilauea's summit, and tremor at Pu`u `O`o remained moderate. During the report period, there were episodes of inflation and deflation at Uwekahuna and Pu`u `O`o.
Geologic Summary. Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed by lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. The latest Kilauea eruption began in January 1983 along the E rift zone. This long-term ongoing eruption from Pu`u `O`o-Kupaianaha has produced lava flows that have traveled 11-12 km from the vents to the sea, paving about 104 km2 of land on the S flank of Kilauea and building 207 hectares of new land.
Source: US Geological Survey Hawaiian Volcano Observatory
Kilauea Information from the Global Volcanism Program
SANTA MARÍA Guatemala 14.756°N 91.552°W; summit elev. 3,772 m; All times are local (= UTC - 6 hours)
During 31 March to 6 April, weak-to-moderate explosions continued at Santa Maria's Santiaguito lava-dome complex, producing plumes to 1.3 km above the volcano. Several partial lava-dome collapses produced avalanches down the volcano's S flank. A strong explosion on 1 April at 1706 caused a partial lava-dome collapse and produced a pyroclastic flow that traveled ~4 km SW toward the Nimá II river.
Geologic Summary. Symmetrical, forest-covered Santa María volcano is one of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1-km-wide crater, which formed during a catastrophic eruption in 1902 and extends from just below the summit to the lower flank. The renowned Plinian eruption of 1902 followed a long repose period and devastated much of SW Guatemala. The large dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four westward-younging vents, accompanied by almost continuous minor explosions and periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia
Santa María Information from the Global Volcanism Program
SHIVELUCH Kamchatka Peninsula, Russia 56.653°N, 161.360°E; summit elev. 2,283 m
According to KVERT, during 26 March to 2 April seismicity was above background levels at Shiveluch. About 14 shallow earthquakes up to M 2 occurred during 25 and 28-31 March. Based on interpretations of seismic data, 15 ash-and-gas explosions may have produced plumes to 5 km a.s.l. during 25 and 28-31 March. Shiveluch remained at Concern Color Code Orange.
Geologic Summary. The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large horseshoe-shaped caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. During the 1990s, intermittent explosive eruptions took place from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.
Sources: Kamchatkan Volcanic Eruption Response Team via the Alaska Volcano Observatory, RIA Novosti News, Itar-Tass News
Shiveluch Information from the Global Volcanism Program
SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev. 1,052 m
Seismic and volcanic activity were at moderate levels at Soufrière Hills during 26 March to 2 April. Seismicity was dominated by near-continuous low-to-moderate tremor. Vigorous steam venting was visible from several areas of the crater, but no new lava-dome growth occurred. The sulfur-dioxide flux remained at moderate levels.
Geologic Summary. The complex andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but the first well-documented historical eruption on Montserrat did not take place until 1995. Long-term small-to-moderate ash eruptions were accompanied by lava dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing severe social and economic disruption.
Sources: Montserrat Volcano Observatory, Washington VAAC
Soufrière Hills Information from the Global Volcanism Program
TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m; All times are local (= UTC - 5 hours)
During 30 March to 3 April, volcanic activity at Tungurahua was at relatively low levels, but emissions of steam and ash occurred and incandescence was visible in the crater. On 4 April at 1902 an explosion produced a plume containing a moderate amount of ash that rose to 800 m above the crater.
Geologic Summary. The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have been restricted to the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and initially prompted temporary evacuation of the entire town of Baños on the N side of the volcano.
Sources: Instituto Geofísico-Escuela Politécnica Nacional, Washington VAAC
Tungurahua Information from the Global Volcanism Program
YASUR Tanna Island, Vanuatu 19.52°S, 169.43°E; summit elev. 361 m
According to a report from John Seach, eruptive activity at Yasur continued at "normal" levels during March, with an average of 500 explosions occurring per day.
Geologic Summary. Yasur, the best-known and most frequently visited of the Vanuatu volcanoes, has been in more-or-less continuous Strombolian and vulcanian activity since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Yasur is a mostly unvegetated pyroclastic cone with a nearly circular, 400-m-wide summit crater. Yasur is largely contained within the small Yenkahe caldera in SE Tanna Island. It is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. Active tectonism along the Yenkahe horst accompanying eruptions of Yasur has raised Port Resolution harbor more than 20 m during the past century.
Source: Volcanolive.com
Yasur Information from the Global Volcanism Program
Additional Reports of Volcanic Activity by Country
The following websites have frequently updated activity reports on volcanoes in addition to those that meet the criteria for inclusion in the Weekly Volcanic Activity Report. The websites are organized by country and are maintained by various agencies.
Ecuador, Indonesia, Japan, New Zealand, United States and Russia
URL: http://www.volcano.si.edu/reports/usgs/
