From: leonard78sp on

                     SI / USGS Weekly Volcanic Activity Report

                                           30 June- 6 July 20 2010
4 New+ 12 Ongoing = 16 active

New Activity/Unrest:

| Ebeko, Paramushir Island
| Gorely, Southern Kamchatka (Russia)
| Tiatia, Kunashir Island
| Ulawun, New Britain

Ongoing Activity:

| Arenal, Costa Rica
| Bagana, Bougainville
| Dukono, Halmahera
| Karymsky, Eastern Kamchatka (Russia)
| Kilauea, Hawaii (USA)
| Kliuchevskoi, Central Kamchatka (Russia)
| Miyake-jima, Izu Islands (Japan)
| Pagan, Mariana Islands (Central Pacific)
| Sakura-jima, Kyushu
| Shiveluch, Central Kamchatka (Russia)
| Soufrière Hills, Montserrat
| Tungurahua, Ecuador

                         Weekly Report Editor Sally Kuhn Sennert -



                    This page is updated on Wednesdays, please
                    see the GVP Home Page for news of the
                    latest significantactivity.

                    The Weekly VolcanicActivityReport is a
                    cooperative project between the Smithsonian's
                    Global Volcanism Program and the US
                    Geological Survey'sVolcanoHazards Program.

                   Updated by 2300 UTC every Wednesday,
                    notices of volcanicactivityposted 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
                    volcanos 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 volcanos 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

EBEKO Paramushir Island 50.68°N, 156.02°E; summit elev. 1156 m

KVERT reported that, according to observers in Severo-Kurilsk about 7
km E, activity from Ebeko increased on 2 July. Explosions produced ash
plumes that rose to an altitude of 1.8 km (5,900 ft) a.s.l. and
drifted SSE. The Level of Aviation Color Code was raised to Yellow.

Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the
northern end of Paramushir Island. Three summit craters located along
a SSW-NNE line form Ebeko volcano proper, at the northern end of a
complex of five volcanic cones. The eastern part of the southern
crater of Ebeko contains strong solfataras and a large boiling spring.
The central crater of Ebeko is filled by a lake about 20 m deep whose
shores are lined with steaming solfataras; the northern crater lies
across a narrow, low barrier from the central crater and contains a
small, cold crescentic lake. Historical activity, recorded since the
late-18th century, has been restricted to small-to-moderate explosive
eruptions from the summit craters. Intense fumarolic activity occurs
in the summit craters of Ebeko, on the outer flanks of the cone, and
in lateral explosion craters.


Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Ebeko Information from the Global Volcanism Program

GORELY Southern Kamchatka (Russia) 52.558°N, 158.03°E; summit elev.
1829 m

KVERT reported that during 24 June-2 July seismic activity from Gorely
was above background levels, further increasing on 28 and 29 June.
Analysis of satellite imagery showed a thermal anomaly over Gorely
during 24-28 June; cloud cover prevented observations on other days. A
gas-and-steam plume drifted 35 km S on 28 June. The Level of Aviation
Color Code was raised to Yellow.

Geologic Summary. Gorely volcano, one of the most active in southern
Kamchatka, consists of five small overlapping stratovolcanoes
constructed along a WNW-ESE line within a large 9 x 13.5 km late-
Pleistocene caldera. The massive Gorely complex contains 11 summit and
30 flank craters. During the early Holocene, activity was
characterized by frequent mild eruptions with occasional larger
explosions and lava flows that filled in the caldera. Quiescent
periods became longer between 6,000 and 2,000 years ago, after which
the activity was mainly explosive. About 600-650 years ago
intermittent strong explosions and lava flow effusion accompanied
frequent mild eruptions. Historical eruptions have consisted of
vulcanian and phreatic explosions of moderate volume.


Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Gorely Information from the Global Volcanism Program

TIATIA Kunashir Island 44.351°N, 146.256°E; summit elev. 1819 m

SVERT reported that a thermal anomaly from Tiatia volcano was detected
by satellite on 25 June.

Geologic Summary. Tiatia volcano, one of the most impressive of the
Kuril Islands, consists of a beautifully symmetrical cone that rises
above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide
caldera. The 1819-m-high Tiatia (also known as Chacha-dake) occupies
the NE tip of Kunashir Island and morphologically resembles Mount
Vesuvius. The pristine-looking conical central cone, mostly formed by
basaltic to basaltic-andesite strombolian eruptions, rises 400 m above
the floor of the caldera and contains a 400 x 250 m wide crater with
two explosion vents separated by a linear septum. Fresh lava flows
cover much of the SW caldera floor and have overflowed the rim,
extending to the foot of the older somma, which formed during the late
Pleistocene or early Holocene. A lava flow from a flank cone on the
northern caldera rim reached the Sea of Okhotsk. A major explosive
eruption in 1973 was the first since Tiatia's initial historical
eruption in 1812.


Source: Sakhalin Volcanic Eruption Response Team (SVERT)

Tiatia Information from the Global Volcanism Program

ULAWUN New Britain 5.05°S, 151.33°E; summit elev. 2334 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 1 and 2-5 July ash plumes from Ulawun drifted 55-195 km at an
altitude of 3 km (10,000 ft) a.s.l.

Geologic Summary. The symmetrical basaltic to andesitic Ulawun
stratovolcano is the highest volcano of the Bismarck arc, and one of
Papua New Guinea's most frequently active. Ulawun rises above the N
coast of New Britain opposite Bamus volcano. The upper 1,000 m of the
2,334-m-high volcano is unvegetated. A steep-walled valley cuts the NW
side of the volcano, and a flank lava-flow complex lies to the S of
this valley. Historical eruptions date back to the beginning of the
18th century. Twentieth-century eruptions were mildly explosive until
1967, but after 1970 several larger eruptions produced lava flows and
basaltic pyroclastic flows, greatly modifying the summit crater.


Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Ulawun Information from the Global Volcanism Program

Ongoing Activity

ARENAL Costa Rica 10.463°N, 84.703°W; summit elev. 1670 m

OVSICORI-UNA reported that during June activity originating from
Arenal's Crater C consisted of gas emissions, sporadic Strombolian
eruptions, and occasional avalanches. Some of the Strombolian
eruptions caused glass to vibrate in buildings located 4 km N. A lava
flow that began in mid-January remained active on the S flank.
Avalanches from edges of the lava flow and from the N and NE crater
rim descended multiple flanks. Acid rain and small amounts of ejected
pyroclastic material affected the NE, E, and SE flanks. Small
explosions of gas and occasionally ash originated from a vent N of
Crater C, while Crater D produced only fumarolic activity.

Geologic Summary. Conical Volcan Arenal is the youngest stratovolcano
in Costa Rica and one of its most active. The 1,657-m-high andesitic
volcano towers above the eastern shores of Lake Arenal, which has been
enlarged by a hydroelectric project. The earliest known eruptions of
Arenal took place about 7,000 years ago. Growth of Arenal has been
characterized by periodic major explosive eruptions at several-hundred-
year intervals and periods of lava effusion that armor the cone.
Arenal's most recent eruptive period began with a major explosive
eruption in 1968. Continuous explosive activity accompanied by slow
lava effusion and the occasional emission of pyroclastic flows has
occurred since then from vents at the summit and on the upper western


Source: Observatorio Vulcanologico y Sismologico de Costa Rica-
Universidad Nacional (OVSICORI-UNA)

Arenal Information from the Global Volcanism Program

BAGANA Bougainville 6.140°S, 155.195°E; summit elev. 1750 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft)
a.s.l. on 4 July and drifted 75 km W.

Geologic Summary. Bagana volcano, occupying a remote portion of
central Bougainville Island, is one of Melanesia's youngest and most
active volcanoes. Bagana is a massive symmetrical lava cone largely
constructed by an accumulation of viscous andesitic lava flows. The
entire lava cone could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity at Bagana is
characterized by non-explosive effusion of viscous lava that maintains
a small lava dome in the summit crater, although explosive activity
occasionally producing pyroclastic flows also occurs. Lava flows form
dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with
prominent levees that descend the volcano's flanks on all sides.


Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Bagana Information from the Global Volcanism Program

DUKONO Halmahera 1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery, the Darwin VAAC reported that
during 30 June-2 July and on 6 July ash plumes from Dukono rose to an
altitude of 2.4 km (8,000 ft) a.s.l. and drifted 90-225 km W and NW.

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 from 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 Volcanic Ash Advisory Centre (VAAC)

Dukono Information from the Global Volcanism Program

KARYMSKY Eastern Kamchatka (Russia) 54.05°N, 159.45°E; summit elev.
1536 m

KVERT reported that during 25 June-2 July seismic activity from
Karymsky was above background levels and suggested that possible ash
plumes rose to an altitude of 7 km (23,000 ft) a.s.l. A strong thermal
anomaly was detected in satellite imagery on 27 June; cloud cover
prevented views of the volcano on other days. The Aviation Color Code
level remained at 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 (KVERT)

Karymsky Information from the Global Volcanism Program

KILAUEA Hawaii (USA) 19.421°N, 155.287°W; summit elev. 1222 m

During 30 June-6 July HVO reported that activity at Kilauea continued
from the summit and the east rift zone. At the summit, the level of a
lava-pool surface in the deep pit inset within the floor of
Halema'uma'u crater remained mostly stable; glow from the vent was
also visible at night. A plume from the vent mainly drifted SW,
dropping small amounts of tephra, and occasionally fresh spatter,

At the east rift zone, lava flows that broke out of the TEB lava-tube
system built up a number of rootless shields between 580 and 395 m
elevation. Thermal anomalies detected in satellite images and visual
observations showed that minor lava flows originating from the shields
traveled as far down as 365 m elevation on 1 July. A gas vent on the E
wall of Pu'u 'O'o crater was incandescent during most of the reporting

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 of lava flows less than about 1,100 years old; 70% of the
volcano's surface is younger than 600 years. A long-term eruption from
the East rift zone that began in 1983 has produced lava flows covering
more than 100 sq km, destroying nearly 200 houses and adding new
coastline to the island.


Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kilauea Information from the Global Volcanism Program

KLIUCHEVSKOI Central Kamchatka (Russia) 56.057°N, 160.638°E; summit
elev. 4835 m

KVERT reported that during 25 June-2 July seismic activity from
Kliuchevskoi was above background levels and Strombolian activity was
observed on 24 and 29 June. Ash plumes occasionally rose to an
altitude of 5.3 km (17,400 ft) a.s.l. Satellite imagery analysis
revealed a large daily thermal anomaly from the volcano and an ash
plume that drifted 32 km S on 1 July. The Aviation Color Code level
remained at Orange.

Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active
volcano. Since its origin about 7,000 years ago, the beautifully
symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent
moderate-volume explosive and effusive eruptions without major periods
of inactivity. More than 100 flank eruptions, mostly on the NE and SE
flanks of the conical volcano between 500 m and 3,600 m elevation,
have occurred during the past 3,000 years. The morphology of its 700-m-
wide summit crater has been frequently modified by historical
eruptions, which have been recorded since the late-17th century.
Historical eruptions have originated primarily from the summit crater,
but have also included major explosive and effusive events from flank


Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kliuchevskoi Information from the Global Volcanism Program

MIYAKE-JIMA Izu Islands (Japan) 34.079°N, 139.529°E; summit elev. 815

Based on information from JMA, the Tokyo VAAC reported a possible
eruption from Miyake-jima on 4 July. Details of possible resulting
plumes were unreported.

Geologic Summary. The circular, 8-km-wide island of Miyake-jima forms
a low-angle stratovolcano that rises about 1100 m from the sea floor
in the northern Izu Islands about 200 km SSW of Tokyo. Parasitic
craters and vents, including maars near the coast and radially
oriented fissure vents, dot the flanks of the volcano. Frequent
historical eruptions have occurred since 1085 AD at vents ranging from
the summit to below sea level, causing much damage on this small
populated island. After a three-century-long hiatus ending in 1469,
activity has been dominated by flank fissure eruptions sometimes
accompanied by minor summit eruptions. A 1.6-km-wide summit caldera
was slowly formed by subsidence during an eruption in 2000; by October
of that year the crater floor had dropped to only 230 m above sea


Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Miyake-jima Information from the Global Volcanism Program

PAGAN Mariana Islands (Central Pacific) 18.13°N, 145.80°E; summit
elev. 570 m

Minor gas-and-steam plumes from Pagan continued to be observed in
satellite imagery during breaks in cloud cover from 25 June to 2 July.
The Washington VAAC reported that on 5 July a small cloud of ash mixed
with a gas plume was observed in satellite imagery. The Aviation Color
Code remained at Yellow and the Volcano Alert Level remained at

Geologic Summary. Pagan Island, the largest and one of the most active
of the Marianas Islands volcanoes, consists of two stratovolcanoes
connected by a narrow isthmus. Both North and South Pagan
stratovolcanoes were constructed within calderas, 7 and 4 km in
diameter, respectively. The 570-m-high Mount Pagan at the NE end of
the island rises above the flat floor of the caldera, which probably
formed during the early Holocene. South Pagan is a 548-m-high
stratovolcano with an elongated summit containing four distinct
craters. Almost all of the historical eruptions of Pagan, which date
back to the 17th century, have originated from North Pagan volcano.
The largest eruption of Pagan during historical time took place in
1981 and prompted the evacuation of the sparsely populated island.


Sources: Emergency Management Office of the Commonwealth of the
Mariana Islands, Office of the Governor, United States Geological
Survey Volcano Hazards Program, Washington Volcanic Ash Advisory
Center (VAAC)

Pagan Information from the Global Volcanism Program

SAKURA-JIMA Kyushu 31.585°N, 130.657°E; summit elev. 1117 m

Based on information from JMA, the Tokyo VAAC reported that during 30
June-1 July and 4-6 July explosions from Sakura-jima sometimes
produced plumes. Those plumes, along with ash plumes occasionally seen
by pilots, rose to altitudes of 1.5-4.6 km (5,000-15,000 ft) a.s.l.
and drifted E and SE.

Geologic Summary. Sakura-jima, one of Japan's most active volcanoes,
is a post-caldera cone of the Aira caldera at the northern half of
Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was
associated with the formation of the 17 x 23-km-wide Aira caldera
about 22,000 years ago. The construction of Sakura-jima began about
13,000 years ago and built an island that was finally joined to the
Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kita-dake summit cone ended about 4,850 years
ago, after which eruptions took place at Minami-dake. Frequent
historical eruptions, recorded since the 8th century, have deposited
ash on Kagoshima, one of Kyushu's largest cities, located across
Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.


Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sakura-jima Information from the Global Volcanism Program

SHIVELUCH Central Kamchatka (Russia) 56.653°N, 161.360°E; summit elev.
3283 m

KVERT reported that during 24 June-2 July seismic activity from
Shiveluch was above background levels and suggested that possible ash
plumes occasionally rose to an altitude of 6.6 km (21,600 ft) a.s.l.
On 24 and 29 June ash plumes from hot avalanches rose to an altitude
of 4.5 km (14,800 ft) a.s.l. Strong fumarolic activity was also noted
on these days. On 1 July, seismicity increased and may have indicated
ash plumes rose to an altitude of 8 km (26,200 ft) a.s.l. Ashfall was
reported in Klyuchi village, 50 km SW. Satellite imagery showed a
large daily thermal anomaly over the lava dome. Based on analysis of
satellite imagery and information from Yelizovo Airport (UHPP), the
Tokyo VAAC reported that on 3 July an ash plume rose to an altitude of
6.1 km (20,000 ft) a.s.l. and drifted N. Satellite imagery showed a
possible eruption the next day. The Aviation Color Code level remained
at 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 breached 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. Intermittent
explosive eruptions began in the 1990s 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 (KVERT), Tokyo
Volcanic Ash Advisory Center (VAAC)

Shiveluch Information from the Global Volcanism Program

SOUFRIERE HILLS Montserrat 16.72°N, 62.18°W; summit elev. 915 m

On 28 June, MVO reported that for the first time since February 2010
ash venting from the Soufrière Hills lava dome was observed and caused
light ashfall in several areas across Montserrat. Ash venting began on
25 June and was coincident with small swarms of volcano-tectonic
earthquakes on 23 and 25 June, although with no other discernable
associated seismicity. Observations initially from MVO staff and
during a later overflight indicated that the ash venting occurred from
inside the collapse scar (near the N rim of English's crater) and from
the S part of the summit crater that had formed on 11 February. On the
nights of 25 and 26 June audible roaring was heard from several
locations on the island. Ash venting diminished on 28 June. The Hazard
Level remained at 3.

Geologic Summary. The complex dominantly 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. English's Crater, a 1-km-wide crater
breached widely to the E, was formed during an eruption about 4,000
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 Soufrière 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 (MVO)

Soufrière Hills Information from the Global Volcanism Program

TUNGURAHUA Ecuador 1.467°S, 78.442°W; summit elev. 5023 m

Observations of Tungurahua's summit area during 30 June-6 July were
mostly not possible due to inclement weather. On 2 July, gas plumes
were seen drifting WSW during breaks in the cloud cover. Ashfall was
reported in areas 8-9 km W and SW, and as far away as 40 km WSW in San
Juan. Incandescence from the crater was seen at night and slight
roaring was heard. Ashfall was again reported in areas 8-9 km W and SW
during 3-4 July. Steam-and-ash plumes were seen on 5 July and rose to
an altitude of 7 km (23,000 ft) a.s.l. Ash fell in areas 8 km to the
SW. Steam-and-ash plumes were again seen on 6 July; ashfall was
reported in areas 8 km W, NW, and N.

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 all originated from 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 prompted temporary evacuation of the town of
Baños on the N side of the volcano.


Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)

Tungurahua 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

Sally Kuhn Sennert - Weekly Report Editor

Global Volcanism Program — Department of Mineral Sciences
National Museum of Natural History — Smithsonian Institution