Volcano Listserv Messages (2005)
- Subject: GVP / USGS Weekly Volcanic Activity Report 21-27 Dec. 2005
- From: Kristi Diller <Kristi.Diller@xxxxxxx>
- Date: Wed, 28 Dec 2005 15:48:36 -0700
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GVP / USGS Weekly Volcanic Activity Report
21-27 December 2005
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From: Gari Mayberry <mayberry@xxxxxxxxxxxxxx>
New Activity: | Fuego, Guatemala | Piton de la Fournaise, Reunion Island |
Soputan, Indonesia
Ongoing Activity: | Augustine, USA | Barren Island, Andaman Islands | Colima,
Mexico | Galeras, Colombia | Karymsky, Russia | Kilauea, USA | Popocatépetl,
Mexico | Santa Ana, El Salvador | Soufriére Hills, Montserrat | St. Helens, USA
New Activity/Unrest
FUEGO Guatemala 14.47°N, 90.88°W; summit elev. 3,763 m
On 27 December an eruption at Fuego produced an ash plume to a height of ~7.6
km (25,000 ft) a.s.l. that extended SSW and SSE of the volcano. The higher
level ash (~7.6 km a.s.l.) drifted W to Honduras, while ash below ~6.1 km
(20,000 ft) a.s.l. drifted E to the Pacific coast. According to news articles,
two lava flows that were both ~2 km long traveled down the volcano's flanks,
but posed no threat to inhabited areas. Articles also reported that about
25,000 local residents were put on alert, and emergency teams said that there
was no immediate need for evacuations.
Background. Volcán Fuego, one of Central America's most active volcanoes, is
one of three large stratovolcanoes overlooking Guatemala's former capital,
Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high
Fuego and its twin volcano to the north, Acatenango. Construction of Meseta
volcano continued until the late Pleistocene or early Holocene, after which
growth of the modern Fuego volcano continued the southward migration of
volcanism that began at Acatenango. Frequent vigorous historical eruptions
have been recorded at Fuego since the onset of the Spanish era in 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.
Sources: Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html, Reuters
http://news.yahoo.com/s/nm/20051227/sc_nm/guatemala_volcano_dc_1
Fuego Information from the Global Volcanism Program
/world/volcano.cfm?vnum=1402-09=
PITON DE LA FOURNAISE Réunion Island, Indian Ocean 21.23°S, 55.71°E; summit
elev. 2,631 m; All times are local (= UTC + 4 hours)
Following summit inflation that had been measured at Piton de la Fournaise
since the last eruption on 29 November, a seismic crisis began beneath
Dolomieu Crater on 26 December at 1444. During the next 2 hours, seismicity
shifted to the NE in the direction of "Nez Coupé de Sainte Rose." A first
fissure opened at 1715 at the NE base of Piton de la Fournaise. At 2200
eruptive fissures opened in the caldera wall ~500 m E of "Nez Coupé de Sainte
Rose," and a lava flow traveled into the "Plaine des Osmondes." By the 28th,
eruptive activity was almost constant and an aa lava flow slowly traveled in
the "Grandes Brûlé" and had reached to within ~3 km of the national road.
Background. The massive Piton de la Fournaise shield volcano on the island of
Réunion is one of the world's most active volcanoes. Most historical eruptions
have originated from the summit and flanks of Dolomieu, a 400-m-high lava
shield that has grown within the youngest of three large calderas. This latter
caldera is 8 km wide and is breached to below sea level on the eastern side.
More than 150 eruptions, most of which have produced fluid basaltic lava flows
within the caldera, have been documented since the 17th century.
Source: Observatoire Volcanologique du Piton de la Fournaise via the Volcano Listserv
Piton de la Fournaise Information from the Global Volcanism Program
/world/volcano.cfm?vnum=0303-02=
SOPUTAN Sulawesi, Indonesia 1.11°N, 124.73°E; summit elev. 1,784 m; All times
are local (= UTC + 8 hours)
A phreatic eruption began at Soputan on 26 December around 1230 following
heavy rain that contacted lava at the volcano's summit. On 27 December at
0400, a Strombolian eruption began that lasted ~50 minutes. Incandescent
volcanic material was ejected ~35 m, and avalanches of volcanic material
traveled as far as 750 m E. Around 0640 the avalanches became larger, as
pyroclastic avalanches occurred from the edge of the lava. The avalanches
extended 200 m E, and booming noises were heard as far as 5 km from the
summit. The Darwin VAAC reported that an ash plume reached a height of ~5.8 km
(~19,000 ft) a.s.l. and drifted SE.
As of 28 December, eruptive activity continued at Soputan, producing ash
plumes to a height of ~1 km above the volcano (or 9,100 ft a.s.l.).
Strombolian eruptions continued, ejecting incandescent volcanic material up to
200 m above the summit (or 6,500 ft a.s.l.). Pyroclastic avalanches traveled
~500 m E and SW. This was the fourth event at Soputan in 2005, with previous
activity on 14 and 20 April, and on 12 September. The Alert Level remained at
2, since the volcano is about 11 km from the nearest settlement. Visitors are
prohibited from climbing Soputan's summit and camping around Kawah Masem.
Background. The small conical volcano of Soputan on the southern rim of the
Quaternary Tondano caldera is one of Sulawesi's most active volcanoes. During
historical time the locus of eruptions has included both the summit crater and
Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of
intermittent major lava flows until 1924.
Sources: Directorate of Volcanology and Geological Hazard Mitigation
http://www.vsi.esdm.go.id/news/, Darwin Volcanic Ash Advisory Center
http://www.bom.gov.au/info/vaac/advisories.shtml
Soputan Information from the Global Volcanism Program
/world/volcano.cfm?vnum=0606-03=
Ongoing Activity
AUGUSTINE SW Alaska, USA 59.363°N, 153.43°W; summit elev. 1,252 m
During 16-23 December, unrest continued at Augustine, with elevated seismicity
and several small steam explosions occurring. Thermal imaging of the summit
area on 22 December using a helicopter-mounted FLIR (Forward Looking Infrared
Radiometer) confirmed the presence of a new, high-temperature fumarole or gas
vent high on the S flank of the volcano. A gas-measurement flight on 20
December detected sulfur dioxide for the first time at Augustine since routine
airborne measurements began in the early 1990s. Aerial observations and
analysis of photography and video of the summit area indicated that some
deformation occurred within the summit crater area. A crack or fissure was
noted cutting the 1986 lava dome and extending to the SE. Heavy steam from
this feature, along with patches of bare ground, indicated that heat output at
the summit had increased. Augustine remained at Concern Color Code Yellow
<http://www.avo.alaska.edu/color_codes.php>.
Background. Augustine volcano, rising above Kamishak Bay in the southern Cook
Inlet about 290 km SW of Anchorage, is the most active volcano of the eastern
Aleutian arc. It consists of a complex of overlapping summit lava domes
surrounded by an apron of volcaniclastic debris that descends to the sea on
all sides. Few lava flows are exposed; the flanks consist mainly of debris-
avalanche and pyroclastic-flow deposits formed by repeated collapse and
regrowth of the volcano's summit. The latest episode of edifice collapse
occurred during Augustine's largest historical eruption in 1883; subsequent
dome growth has restored the volcano to a height comparable to that prior to
1883. The oldest dated volcanic rocks on Augustine are more than 40,000 years
old. At least 11 large debris avalanches have reached the sea during the past
1800-2000 years, and five major pumiceous tephras have been erupted during
this interval. Historical eruptions have typically consisted of explosive
activity with emplacement of pumiceous pyroclastic-flow deposits followed by
lava dome extrusion with associated block-and-ash flows.
Source: Alaska Volcano Observatory
http://www.avo.alaska.edu/activity/avoreport.php?view=update
Augustine Information from the Global Volcanism Program
/world/volcano.cfm?vnum=1103-01-
BARREN ISLAND Andaman Islands, Indian Ocean, India 12.29°N, 93.88°E; summit
elev. 354 m
During 21-23 December, ash plumes from Barren Island were visible on satellite
imagery at a maximum height of 4.6 km (15,000 ft) a.s.l. on the 21st.
Background. Barren Island, a possession of India in the Andaman Sea about 135
km NE of Port Blair in the Andaman Islands, is the only historically active
volcano along the N-S-trending volcanic arc extending between Sumatra and
Burma (Myanmar). The 354-m-high island is the emergent summit of a volcano
that rises from a depth of about 2,250 m. The small, uninhabited 3-km-wide
island contains a roughly 2-km-wide caldera with walls 250-350 m high. The
caldera, which is open to the sea on the W, was created during a major
explosive eruption in the late Pleistocene that produced pyroclastic-flow and -
surge deposits. The morphology of a fresh pyroclastic cone that was
constructed in the center of the caldera has varied during the course of
historical eruptions. Lava flows fill much of the caldera floor and have
reached the sea along the western coast during eruptions in the 19th century
and more recently in 1991 and 1995.
Source: Darwin Volcanic Ash Advisory Center
http://www.bom.gov.au/info/vaac/advisories.shtml
Barren Island Information from the Global Volcanism Program
/world/volcano.cfm?vnum=0600-01=
COLIMA Western México 19.514°N, 103.62°W; summit elev. ~3,850 m
During 21-27 December, several small explosions occurred at Colima, producing
ash plumes that reached ~6.7 km (22,000 ft) a.s.l. on 26 December.
Background. The Colima volcanic complex is the most prominent volcanic center
of the western Mexican Volcanic Belt. It consists of two southward-younging
volcanoes, Nevado de Colima (the 4,320 m high point of the complex) on the N
and the historically active Volcán de Colima on the S. Volcán de Colima (also
known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-
wide caldera, breached to the S, that has been the source of large debris
avalanches. Major slope failures have occurred repeatedly from both the Nevado
and Colima cones, and have produced a thick apron of debris-avalanche deposits
on three sides of the complex. Frequent historical eruptions date back to the
16th century. Occasional major explosive eruptions (most recently in 1913)
have destroyed the summit and left a deep, steep-sided crater that was slowly
refilled and then overtopped by lava dome growth.
Sources: Universidad de Colima http://www.ucol.mx/volcan/, Washington Volcanic
Ash Advisory Center http://www.ssd.noaa.gov/VAAC/messages.html
Colima Information from the Global Volcanism Program
GALERAS Colombia 1.22°N, 77.37°W; summit elev. 4,276 m
Based on information from the US Geological Survey, the Washington VAAC
reported that a pilot observed an ash plume from Galeras on 23 December at a
height of ~7.3 km (24,000 ft) a.s.l. drifting W.
Background. Galeras, a stratovolcano with a large breached caldera located
immediately W of the city of Pasto, is one of Colombia's most frequently
active volcanoes. The dominantly andesitic Galeras volcanic complex has been
active for more than 1 million years, and two major caldera collapse eruptions
took place during the late Pleistocene. Long-term extensive hydrothermal
alteration has affected the volcano. This has contributed to large-scale
edifice collapse that has occurred on at least three occasions, producing
debris avalanches that swept to the W and left a large horseshoe-shaped
caldera inside which the modern cone has been constructed. Major explosive
eruptions since the mid Holocene have produced widespread tephra deposits and
pyroclastic flows that swept all but the southern flanks. A central cone
slightly lower than the caldera rim has been the site of numerous small-to-
moderate historical eruptions since the time of the Spanish conquistadors.
Source: Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Galeras Information from the Global Volcanism Program
KARYMSKY Kamchatka Peninsula, Russia 54.05°N, 159.43°E; summit elev. 1,536 m
Interpretations of seismic data from Karymsky suggested that ten ash plumes
rose to ~3.6 km (11,800 ft) a.s.l. during 16-23 December. KVERT volcanologists
reported that during 17-21 December, ash plumes rose 2.5-3 km (8,200-9,800 ft)
a.s.l. and extended WSW and ENE of the volcano. They warned that such activity
could affect low-flying aircraft in the vicinity of the volcano. Karymsky
remained at Concern Color Code Orange
<http://volcanoes.usgs.gov/activity/alertsystem/>.
Background. 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
http://www.kcs.iks.ru/ivs/kvert/updates.shtml
Karymsky Information from the Global Volcanism Program
KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m
During 22-27 December, lava from Kilauea continued to enter the sea at the
East Lae`apuki area and surface lava flows were visible on the Pulama pali
fault scarp. Background volcanic tremor was near normal levels at Kilauea's
summit. Volcanic tremor reached moderate levels at Pu`u `O`o. Small amounts of
deformation occurred at the volcano.
Background. 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 more than 200 hectares of new land.
Source: US Geological Survey Hawaiian Volcano Observatory
http://volcanoes.usgs.gov/update.html
Kilauea Information from the Global Volcanism Program
POPOCATÉPETL México 19.02°N, 98.62°W; summit elev. 5,426 m
During 21-27 December, several emissions of gas, steam, and small amounts of
ash occurred at Popocatépetl. A moderate explosion on 25 December produced an
ash plume to ~8.5 km (28,000 ft) a.s.l. that drifted ENE.
Background. Popocatépetl, whose name is the Aztec word for smoking mountain,
towers to 5,426 m 70 km SE of Mexico City and is North America's second-
highest volcano. Frequent historical eruptions have been recorded since the
beginning of the Spanish colonial era. A small eruption on 21 December 1994
ended five decades of quiescence. Since 1996 small lava domes have
incrementally been constructed within the summit crater and destroyed by
explosive eruptions. Intermittent small-to-moderate gas-and-ash eruptions have
continued, occasionally producing ashfall in neighboring towns and villages.
Sources: Centro Nacional de Prevencion de Desastres
http://www.cenapred.unam.mx/, Washington Volcanic Ash Advisory Center
http://www.ssd.noaa.gov/VAAC/messages.html
Popocatépetl Information from the Global Volcanism Program
SANTA ANA El Salvador 13.853°N, 89.630°W; summit elev. 2,365 m
During 21-23 December, seismicity at Santa Ana was above background levels.
Small earthquakes occurred, which were interpreted as being associated with
gas pulses. Gas emissions rose to low levels. The Alert Level remained at Red,
the highest level, within a 5-km radius around the volcano's summit crater.
Background. Santa Ana, El Salvador's highest volcano, is a massive
stratovolcano immediately W of Coatepeque caldera. Collapse of the volcano
during the late Pleistocene or early Holocene produced a massive debris
avalanche that swept into the Pacific, forming the Acajutla Peninsula.
Reconstruction of the volcano rapidly filled the collapse scarp. The broad
summit of the volcano is cut by several crescentic craters, and a series of
parasitic vents and cones have formed along a 20-km-long fissure system that
extends from near the town of Chalchuapa NNW of the volcano to the San
Marcelino and Cerro Chino cinder cones on the SE flank. Historical activity,
largely consisting of small-to-moderate explosive eruptions from both summit
and flank vents, has been documented since the 16th century. The San Marcelino
cinder cone on the SE flank produced a lava flow in 1722 that traveled 11 km
to the E.
Source: Servicio Nacional de Estudios Territoriales http://www.snet.gob.sv/
Santa Ana Information from the Global Volcanism Program
SOUFRIÈRE HILLS Montserrat, West Indies 16.72°N, 62.18°W; summit elev. 1,052 m
Volcanic and seismic activity at Soufriére Hills remained elevated during 16-
23 December. Images revealed that the lava dome continued to grow during the
report period. Growth occurred over a broad sector extending from the SW
around to the NE. Vertical growth was focused to the S and SW, with lateral
growth in the E and SE sectors. Numerous small rockfalls traveled down the S,
E, and NE flanks of the lava dome, adding to the talus in the upper reaches of
the Tar River Valley to the NE. The sulfur-dioxide flux averaged 415 metric
tons per day.
Background. The complex dominantly andesitic Soufriére 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.
English's Crater, a 1-km-wide crater breached widely to the east, was formed
during an eruption about 4000 years ago in which the summit collapsed,
producing a large submarine debris avalanche. Block-and-ash flow and surge
deposits associated with dome growth predominate in flank deposits at
Soufriére Hills. Non-eruptive seismic swarms occurred at 30-year intervals in
the 20th century, but with the exception of a 17th-century eruption that
produced the Castle Peak lava dome, no historical eruptions were recorded on
Montserrat until 1995. Long-term small-to-moderate ash eruptions beginning in
that year were later 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 major social and economic
disruption.
Source: Montserrat Volcano Observatory http://www.mvo.ms/
Soufriére Hills Information from the Global Volcanism Program
ST. HELENS Washington, USA 46.20°N, 122.18°W; summit elev. 2,549 m
Growth of the new lava dome inside the crater of Mount St. Helens continued
during 21-27 December, accompanied by low rates of seismicity, low emissions
of steam and volcanic gases, and minor production of ash. Small rockfalls
continued from the growing lava dome, with larger ones producing ash plumes
that were visible above the crater rim. There were no significant changes in
seismicity or deformation during the report period. Seismicity was marked by
the repetitive small earthquakes, occurring every 2-3 minutes, that have come
to characterize the past 15 months. Tiltmeters within 500 m of the new lava
dome showed minute ground deformation; whereas the volcano's flanks were
quiet. St Helens remained at Volcano Advisory (Alert Level 2); aviation color
code Orange.
Background. Prior to 1980, Mount St. Helens formed a conical, youthful volcano
sometimes known as the Fuji-san of America. During the 1980 eruption the
upper 400 m of the summit was removed by slope failure, leaving a 2 x 3.5 km
horseshoe-shaped crater now partially filled by a lava dome. Mount St. Helens
was formed during nine eruptive periods beginning about 40-50,000 years ago,
and has been the most active volcano in the Cascade Range during the
Holocene. The modern edifice was constructed during the last 2,200 years,
when the volcano produced basaltic as well as andesitic and dacitic products
from summit and flank vents. Historical eruptions in the 19th century
originated from the Goat Rocks area on the N flank, and were witnessed by
early settlers.
Source: USGS Cascades Volcano Observatory
http://vulcan.wr.usgs.gov/Volcanoes/MSH/CurrentActivity/framework.html
St. Helens Information from the Global Volcanism Program
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Gari Mayberry
US Geological Survey/Global Volcanism Program
Smithsonian Institution
National Museum of Natural History MRC-119
Dept. of Mineral Sciences
Washington, DC 20560-0119
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