Weekly Volcano Watch: 26 March 2009

Volcanic Activity Report: 18 March – 24 March 2009

Source: SI / USGS Weekly Volcanic Activity Report

New activity/unrest:

• Galeras, Colombia
• Hunga Tonga-Hunga Ha’apai, Tonga
• Koryaksky, Eastern Kamchatka
• Redoubt, Southwestern Alaska (search FEWW for previous entries)

VoW: Fonualei, Tonga Islands (SW Pacific)

• Country: Tonga
• Subregion Name: Tonga Islands
• Volcano Type: Stratovolcano
• Volcano Status: Historical
• Last Known Eruption: 1957
• Summit Elevation: 180 m (591 feet)
• Latitude: 18.02°S  (18°1’0″S)
• Longitude: 174.325°W  (174°19’30″W)
• Source: USGS

Fonualei:  Seen from the NE, Fonualei volcano has an upturned saucer profile. The small, less than 2-km-wide island of Fonualei contains a fumarolically active crater, which is breached to the SW with a fresh lava flow extending to the sea and forming a rugged shoreline. Blocky lava flows from a central pyroclastic cone have reached the sea through notches in the rim of a small caldera. Eruptions at Fonualei have been recorded since 1791, with the two largest taking place in October 1846 and July 1847. [In 1847,] explosive eruptions produced large pumice rafts, and ashfall damaged crops on the island of Vavua (56 km away) and fell on vessels up to 950 km distant. In 1939 explosive and effusive activity occurred from summit and flank vents, and water spouts were reported 1.6 km SE of the island. Photo by Paul Taylor (published in Taylor and Ewart, 1997). Caption: GVP

FEWW Comment: Fonualei may be one of the next volcanoes in the Tonga region to erupt in the next 30-90 days.

Ongoing Volcanic Activity:

• Batu Tara, Komba Island (Indonesia)
• Chaitén, Southern Chile
• Dempo, Sumatra (Indonesia)
• Etna, Sicily (Italy)
• Gamkonora, Halmahera
• Karymsky, Eastern Kamchatka
• Kilauea, Hawaii (USA)
• Kuchinoerabu-jima, Ryukyu Islands (Japan)
• Lewotobi, Flores Island (Indonesia)
• Okmok, Fox Islands
• Popocatépetl, México
• Rabaul, New Britain (PNG)
• Sakura-jima, Kyushu (Japan)
• Shiveluch, Central Kamchatka (Russia)
• Soufrière Hills, Montserrat (Caribbean sea)
• Tungurahua, Ecuador
• Ubinas, Perú

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.

Elevated Volcanic Activity in the US [Source: USGS]

Mar 25, 2009 at 21:08:47 PDT [PDT is 7 hours behind of Coordinated Universal Time,UTC]

The following U.S. volcanoes are known to be above normal background (elevated unrest or eruptions) or have shown activity that warranted an Information Release (for example, an earthquake swarm).

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

Volcano Hazards

Redoubt: Alert Level=WATCH. Aviation Color Code=ORANGE. As of Mar 25, 2009, 13:35 ADT

• No explosions in last 36 hours and seismicity has declined. Possible lava dome growth at the summit. Explosions could resume without much warning.
  (Change to current status occurred on Mar 25, 2009 13:35 ADT from Alert Level WARNING and Aviation Color Code RED )For more information see http://www.avo.alaska.edu/activity/Redoubt.php

Kilauea: Alert Level=WATCH. Aviation Color Code=ORANGE. As of Mar 25, 2009, 07:53 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

Cleveland: Alert Level=ADVISORY. Aviation Color Code=YELLOW. As of Mar 24, 2009, 12:46 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

Mauna Loa: Alert Level=ADVISORY. Aviation Color Code=YELLOW. As of Mar 2, 2009, 15:05 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

Program Webcams page links to webcams at 19 of the 169 active volcanoes in the U-S.