VolcanoWatch Weekly [7 October 2009]

VOW:  Ambrym

Destructive acid rain caused by eruption

According to press reports, an eruption from Benbow Crater occurred on 10 February [1979.]  Gases from the eruption caused acid rainfall on the SW portion of Ambrym Island, destroying most vegetation within 24 hours, contaminating water supplies, and burning some inhabitants. Jean-Luc Saos, Director of Mineral Resources for the New Hebrides government, reported a high concentration of HCl and sulfur compounds in the volcanic gases. Although heavy ashfalls have occurred in the area in the past, this is the first report of acid rains. More …

View of the Marum cone at Ambrym looking SW, 7 June 2007. Incandescence from the active lava lakes can be seen reflected in the clouds (left). Courtesy of Steven Clegg.

Lava lake inside Mbwelesu crater within Marum cone at Ambrym, 7 June 2007. Courtesy of Steven Clegg.

A hazy layer of vog—volcanic fog—overlies Malekula and a few other islands of the Vanuatu archipelago in this natural-color satellite image. The source of the vog is Ambrym, a volcano in the southeast (lower right) corner of this scene. The haze extends over the Coral Sea several hundred kilometers to the northwest. Ambrym emits sulfur dioxide—the gas responsible for the formation of vog— intermittently. (Kilauea Volcano has recently affected the residents of Hawaii with similar vog emissions.)  The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite acquired this natural-color image on October 6, 2009. [Large earthquake measuring up to 8.2 Mw struck Vanuatu region  on October 7, 2009 at 22:03 UTC. FEWW] NASA image by Jeff Schmaltz, MODIS Rapid Response, NASA Goddard Space Flight Center. The Rapid Response Team provides twice-daily images of this region. Caption by Robert Simmon.

Ash plume from Ambrym Volcano, Vanuatu October 4, 2004, 23:00 UTC.  Source: NASA/MODIS Rapid Response System.

View into the Mbwelesu crater on the Marum cone at Ambrym, captured 7 September 2008. Lava can be seen through two gaps in the crusted-over lava lake (enlarged insets). Courtesy of Arnold Binas.

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. Caption: GVP

Ambtym
Country: Vanuatu
Subregion Name: Vanuatu
Volcano Number: 0507-04=
Volcano Type: Pyroclastic shield
Volcano Status: Historical
Last Known Eruption: 2009
Summit Elevation: 1334 m 4,377 feet
Latitude: 16.25°S 16°15’0″S
Longitude: 168.12°E 168°7’0″E

SI /USGS Weekly Volcanic Activity Report
(30 September – 6 October 2009)

New activity/Unrest:

• Chaitén, Southern Chile
• Cleveland, Chuginadak Island
• Galeras, Colombia
• Gaua, Banks Islands (SW Pacific)
• Karymsky, Eastern Kamchatka (Russia)
• Kliuchevskoi, Central Kamchatka (Russia)
• Sakura-jima, Kyushu
• Shiveluch, Central Kamchatka (Russia)
• Soufrière Hills, Montserrat

News From GVP:

On 29 September, people living in Chaitén town, 10 km SW of Chaitén’s Domo Nuevo 1 (Phase I) and Domo Nuevo 2 (Phase II) lava-dome complex, noticed that the eruption column was larger. Scientists conducted an overflight and saw a third lava dome (Phase III) in the SW area of the complex, which had filled up a depression left by a collapse on 19 February.

According to news articles from 2 October, increased seismicity at Gaua was detected during the previous two weeks. Villagers living nearby reported ashfall and sulfur odors.

An explosive eruption from Galeras on 30 September prompted INGEOMINAS to raise the Alert Level. An ash plume rose to an approximate altitude of 12.3 km (40,400 ft) a.s.l. and drifted E, then N. —GVP

Ongoing Activity:

• Batu Tara, Komba Island (Indonesia)
• Dukono, Halmahera
• Kilauea, Hawaii
• Langila, New Britain
• Popocatépetl, México
• Rabaul, New Britain
• Reventador, Ecuador
• Sangay, Ecuador
• Suwanose-jima, Ryukyu Islands (Japan)

Related Links:

• Messages From Earth’s Powerhouse
• Weekly Volcano Watch: 19 March 2009

• A New Era of Intense Volcanic Unrest May Have Begun
• Tonga’s Metis Shoal may be erupting
• Rumble III Volcano “blew its top!”
• Volcanoes
• Earthquakes

FEWW Volcanic Activity Forecast

• Sumatra’s Mt Kerinci Erupts

• Sumatra’s Mt Kerinci Erupts
• Volcano Watch Weekly: 23 April 2009

• Weekly Volcano Watch: 16 April 2009
• Weekly Volcano Watch: 2 April 2009

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Other Related Links:

• U.S. Volcano Status Map
• Elevated Activity Page
• U.S. Volcano Webcams

Recent Posts on Chaitén:

• Chaitén: A New Phase of Activity?
• Chaitén Still Awake!
• Chaitén: Volcano with a Mission?
• Chaitén: Volcano that Doesn’t Sleep

Weekly Volcano Watch: 2 April 2009

Volcanic Activity Report: 25 March – 31 March 2009

Source: SI / USGS Weekly Volcanic Activity Report

New activity/unrest:

• Ambrym, Vanuatu (SW Pacific)
• Gorely, Southern Kamchatka
• Redoubt, Southwestern Alaska
• Reventador, Ecuador

VoW: Bandai

Country: Japan
Region: Honshu Is (Japan)
Volcano Type:  Stratovolcano
Last Known Eruption: 1888
Summit Elevation: 1819 m  (5,968 feet)
Latitude: 37.598°N  (37°35’53″N)
Longitude: 140.076°E  (140°4’32″E)

One of Japan’s most noted volcanoes, Bandai-san rises above the north shore of Lake Inawashiro. The Bandai complex is formed of several overlapping andesitic stratovolcanoes, the largest of which is O-Bandai. Ko-Bandai volcano, which collapsed in 1888, was formed about 50,000 years ago. O-Bandai volcano was constructed within a horseshoe-shaped caldera that formed about 40,000 years when an older volcano collapsed, forming the Okinajima debris avalanche, which traveled to the SW and was accompanied by a plinian explosive eruption. The last magmatic eruption at Bandai took place more than 25,000 years ago, but four major phreatic eruptions have occurred during the past 5,000 years, two of them in historical time, in 806 and 1888.  Seen from the south, Bandai presents a conical profile, but much of the north side of the volcano is missing as a result of the collapse of Ko-Bandai volcano during the 1888 eruption, in which a debris avalanche buried several villages and formed several large lakes. Akahani-yama (extreme right) is another Bandai stratovolcano. The forested ridge at the left foreground is part of an earlier Pleistocene debris-avalanche deposit. Photo by Lee Siebert, 1988 (Smithsonian Institution). Caption: GVP

FEWW Comment: Eastern Gemini Seamount or Mathew Island volcano may erupt by about June 2009.

Ongoing Volcanic Activity:

• Asama, Honshu (Jp.)
• Barren Island, Andaman Is.
• Batu Tara, Komba Island (Indonesia)
• Chaitén, Southern Chile
• Colima, México
• Fuego, Guatemala|
• Karymsky, Eastern Kamchatka (Russia)
• Kilauea, Hawaii (USA)
• Koryaksky, Eastern Kamchatka
• Krakatau, Indonesia
• Rabaul, New Britain
• Sakura-jima, Kyushu
• Shiveluch, Central Kamchatka (Russia)
• Suwanose-jima, Ryukyu Islands (Japan)
• Tungurahua, Ecuador

Elevated Volcanic Activity in the US [Source: USGS]

Wednesday, Apr 1, 2009 at 17:23:17 PDT.

• Cleveland Alert Level=ADVISORY. Aviation Color Code=YELLOW. As of Apr 1, 2009, 12:22 ADT – No activity reported. (Change to current status occurred on Jan 2, 2009 12:52 ADT from Alert Level UNASSIGNED and Aviation Color Code UNASSIGNED ).
  For more information see http://www.avo.alaska.edu/activity/Cleveland.php
• Redoubt Alert Level=WARNING. Aviation Color Code=RED. As of Apr 1, 2009, 12:22 ADT – Continuous emissions of steam, volcanic gases, and minor amounts of ash continue at Mt. Redoubt. Altitudes typically below 15,000ft but as high as 25,000ft at times. (Change to current status occurred on Mar 26, 2009 09:43 ADT from Alert Level WATCH and Aviation Color Code ORANGE )
  For more information see http://www.avo.alaska.edu/activity/Redoubt.php
• Kilauea Alert Level=WATCH. Aviation Color Code=ORANGE. As of Apr 1, 2009, 08:29 HST- Elevated SO2 and some tephra from Halema`uma`u vent; elevated SO2 from Pu`u `O`o vent; lava in tubes to ocean. (Change to current status occurred on Jul 2, 2007 20:09 HST from Alert Level ADVISORY and Aviation Color Code YELLOW ).
  For more information see http://volcanoes.usgs.gov/hvo/activity/kilaueastatus.php
• Mauna Loa Alert Level=ADVISORY. Aviation Color Code=YELLOW. As of Mar 27, 2009, 09:08 HST – Low level of unrest continues. (Mauna Loa has been at this Alert Level and Color Code since this system was implemented in 2005)
  For more information see http://volcanoes.usgs.gov/hvo/activity/maunaloastatus.php

Volcano Alert Levels & Aviation Color Codes defined at http://volcanoes.usgs.gov/activity/alertsystem.

Volcanic Activity News

For New Volcanic Activity/Unrest See

SI / USGS Weekly Volcanic Activity Report

23 July-29 July 2008

New Activity/Unrest:

Anatahan, Mariana Islands (Central Pacific) | Chaitén, Southern Chile | Chikurachki, Paramushir Island | Cleveland, Chuginadak Island | Dukono, Halmahera | Karymsky, Eastern Kamchatka | Llaima, Central Chile | Manam, Northeast of New Guinea (SW Pacific) | Okmok, Fox Islands | Reventador, Ecuador | Soufrière Hills, Montserrat

“Garden of the Fugitives.” Plaster casts of some of the victims of Mount Vesuvius eruption [AD79] are still in the ruins of Pompeii. A few hours after Mount Vesuvius exploded Pompeii and its residents were buried under 3 meters of volcanic ash. Photo copyright: Aschwin Prein. See FEWW Fair Use Notice!

Ongoing Activity:

Batu Tara, Komba Island (Indonesia) | Bezymianny, Central Kamchatka (Russia) | Kilauea, Hawaii (USA) | Krakatau, Indonesia | Rabaul, New Britain | Sakura-jima, Kyushu | Santa María, Guatemala | Semeru, Eastern Java (Indonesia) | Shiveluch, Central Kamchatka (Russia) | Suwanose-jima, Ryukyu Islands (Japan) | Tungurahua, Ecuador | Ubinas, Perú

The skeletal remains of a young woman killed by the eruption of Mount Vesuvius in A.D. 79. The skeleton, unearthed from the ruins of Herculaneum in 1982, was named the “Ring Lady” because of the emerald and ruby rings found on the woman’s left hand. Two gold bracelets and gold earrings were also found by the woman’s side. (Source: Wikipedia)