Smithsonian / USGS Weekly Volcanic Activity Report 17-23 August 2022

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5-5-5-5-5-5-5-5-5-5-5-5-5-5


From: "Kuhn, Sally" <KUHNS@xxxxxx>


Smithsonian / USGS Weekly Volcanic Activity Report

17-23 August 2022



Sally Kuhn Sennert - Weekly Report Editor (kuhns@xxxxxx)

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhiNpy-pk$  
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppszN_1dM$>





New Activity/Unrest: Bagana, Bougainville (Papua New Guinea)  |
Chikurachki, Paramushir Island (Russia)  | Krysuvik-Trolladyngja, Reykjanes
Peninsula  | Mayon, Luzon (Philippines)  | Nevados de Chillan, Central
Chile  | Ofu-Olosega, American Samoa (SW Pacific)  | Semisopochnoi,
Aleutian Islands (USA)  | Ta'u, American Samoa (SW Pacific)



Ongoing Activity: Aira, Kyushu (Japan)  | Bezymianny, Central Kamchatka
(Russia)  | Bulusan, Luzon (Philippines)  | Ebeko, Paramushir Island
(Russia)  | Great Sitkin, Andreanof Islands (USA)  | Kaitoku Seamount,
Volcano Islands (Japan)  | Karymsky, Eastern Kamchatka (Russia)  | Kilauea,
Hawaiian Islands (USA)  | Lewotolok, Lembata Island  | Merapi, Central
Java  | Nevado del Ruiz, Colombia  | Pavlof, Alaska Peninsula, Alaska  |
Semeru, Eastern Java  | Sheveluch, Central Kamchatka (Russia)  |
Suwanosejima, Ryukyu Islands (Japan)





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, these reports
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 about recent activity are published in
issues of the Bulletin of the Global Volcanism Network.



Note that 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





Bagana  | Bougainville (Papua New Guinea)  | 6.137°S, 155.196°E  | Summit
elev. 1855 m



The Darwin VAAC reported that on 22 August an ash plume from Bagana rose to
3 km (10,000 ft) a.s.l. and drifted SW based on satellite and wind model
data.



Geologic Summary. Bagana volcano, occupying a remote portion of central
Bougainville Island, is one of Melanesia's youngest and most active
volcanoes. This massive symmetrical cone was largely constructed by an
accumulation of viscous andesitic lava flows. The entire edifice could have
been constructed in about 300 years at its present rate of lava production.
Eruptive activity is frequent and 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 flanks on all sides.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhpgLqi0o$  
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppKT4LToQ$>





Chikurachki  | Paramushir Island (Russia)  | 50.324°N, 155.461°E  | Summit
elev. 1781 m



Observers reported that on 22 August an ash emission from Chikurachki rose
to 2 km (6,600 ft) a.s.l. and drifted E, prompting KVERT to raise the
Aviation Color Code to Orange (the second highest level on a four-color
scale).



Geologic Summary. Chikurachki, the highest volcano on Paramushir Island in
the northern Kuriles, is a relatively small cone constructed on a high
Pleistocene edifice. Oxidized basaltic-to-andesitic scoria deposits
covering the upper part of the young cone give it a distinctive red color.
Frequent basaltic Plinian eruptions have occurred during the Holocene. Lava
flows have reached the sea and formed capes on the NW coast; several young
lava flows are also present on the E flank beneath a scoria deposit. The
Tatarinov group of six volcanic centers is located immediately to the
south, and the Lomonosov cinder cone group, the source of an early Holocene
lava flow that reached the saddle between it and Fuss Peak to the west,
lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex.
In contrast to the frequently active Chikurachki, the Tatarinov centers are
extensively modified by erosion and have a more complex structure.
Tephrochronology gives evidence of an eruption around 1690 CE from
Tatarinov, although its southern cone contains a sulfur-encrusted crater
with fumaroles that were active along the margin of a crater lake until
1959.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhkfFn0Nv$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp4e_N978$>





Krysuvik-Trolladyngja  | Reykjanes Peninsula  | 63.917°N, 22.067°W  |
Summit elev. 360 m



The Institute of Earth Sciences reported that lava effusion at the fissure
eruption in the Krýsuvík-Trölladyngja volcanic system continued during
16-19 August. Lava erupted mainly from a central cone, containing a lava
pond, and flowed SE. Measurements taken during an overflight on 16 August
indicated that the flow rate had decreased to 2 cubic meters per second. An
estimated 12 million cubic meters of lava had erupted. The lava near the
vent was 20-40 m thick, but flows were 5-15 m thick in the Meradalir
valley, outside the crater area. Seismic tremor began to decrease on 19
August. Incandescence from the northern vent and from the lava flows was
reflected by the gas plume that rose from the crater, but through the night
of 20-21 August incandescence from the flow diminished. Incandescence from
the vent was visible until about 0400 on 21 August. Beginning at around
0500 several explosions ejected spatter from the vent over a period of
about 15 minutes. Just before 0600 a dense, bluish-gray plume rose from the
crater, and simultaneously seismic tremor signals stopped. On 22 August IMO
lowered the Aviation Color Code to Yellow.



Geologic Summary. The Krýsuvík-Trölladyngja volcanic system is described by
the Catalogue of Icelandic Volcanoes as an approximately 50-km-long
composite fissure swarm trending about N38°E, including a 30-km-long swarm
of fissures, with no central volcano. It is one of the volcanic systems
arranged en-echelon along the Reykjanes Peninsula west of Kleifarvatn lake.
The Fagradalsfjall and Krýsuvík fissure swarms are considered splits or
secondary swarms of the Krýsuvíkâ??Trölladyngja volcanic system. Small shield
volcanoes have produced a large portion of the erupted volume within the
system. Several eruptions have taken place since the settlement of Iceland,
including the eruption of a large basaltic lava flow from the Ogmundargigar
crater row around the 12th century. The latest eruption, identified through
tephrochronology, took place during the 14th century.



Sources: Icelandic Meteorological Office (IMO) https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhsaVdFl2$  
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpprfGlKXw$>
;

Institute of Earth Sciences https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhl51Gpn1$  
<https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppFziYq6g$>





Mayon  | Luzon (Philippines)  | 13.257°N, 123.685°E  | Summit elev. 2462 m



On 21 August PHIVOLCS raised the Alert Level for Mayon to 1 (on a 0-5
scale) noting changes at the summit lava dome that was emplaced in 2018.
Changes in morphology of the dome and minor extrusion estimated at about
40,000 cubic meters was detected during 6 June-20 August based on daily
visual and camera monitoring data. Minor inflation, particularly on the NW
and SE flanks, had been recorded since April. Sulfur dioxide emissions
averaged 688 tonnes/day on 12 August, near baseline levels. Seismic
activity was at baseline levels for most of 2022, though short-lived spikes
in the number of low-frequency volcanic earthquakes were recorded on 26 May
and 20 June. Based on the data PHIVOLCS stated that the dome growth was
likely the result of gas pressurization at shallow depths.



Geologic Summary. Symmetrical Mayon, which rises above the Albay Gulf NW of
Legazpi City, is the most active volcano of the Philippines. The steep
upper slopes are capped by a small summit crater. Recorded eruptions since
1616 CE range from Strombolian to basaltic Plinian, with cyclical activity
beginning with basaltic eruptions, followed by longer term andesitic lava
flows. Eruptions occur predominately from the central conduit and have also
produced lava flows that travel far down the flanks. Pyroclastic flows and
mudflows have commonly swept down many of the approximately 40 ravines that
radiate from the summit and have often damaged populated lowland areas. A
violent eruption in 1814 killed more than 1,200 people and devastated
several towns.



Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhsoR_TVG$  
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppksoPSWI$>





Nevados de Chillan  | Central Chile  | 36.868°S, 71.378°W  | Summit elev.
3180 m



On 11 August SERNAGEOMIN reported that the lava dome on the floor of
Nevados de Chillánâ??s Nicanor Crater had grown taller in the previous few
days based on webcam views. The portion of the dome that was visible with
the webcam was reddish and rocky. The report noted that an increase in
sulfur dioxide emissions and more intense explosions had been detected
since 18 July. Similarly, an increase in the intensity and occurrence of
thermal anomalies in the crater had been noted since 18 July, though
anomalies had further intensified during the recent period of dome
extrusion. An explosion at 1041 on 10 August was followed by the most
intense thermal anomaly recorded during the last month. The Alert Level
remained at Yellow, the second lowest level on a four-color scale. ONEMI
stated that Alert Level Yellow (the middle level on a three-color scale)
remained in place for the communities of Pinto and Coihueco, noting that
the public should stay at least 2 km away from the crater.



Geologic Summary. The compound volcano of Nevados de Chillán is one of the
most active of the Central Andes. Three late-Pleistocene to Holocene
stratovolcanoes were constructed along a NNW-SSE line within three nested
Pleistocene calderas, which produced ignimbrite sheets extending more than
100 km into the Central Depression of Chile. The dominantly andesitic Cerro
Blanco (Volcán Nevado) stratovolcano is located at the NW end of the
massif. Volcán Viejo (Volcán Chillán), which was the main active vent
during the 17th-19th centuries, occupies the SE end. The Volcán Nuevo
lava-dome complex formed during 1906-1945 on the NW flank of Viejo. The
Volcán Arrau dome complex was then constructed on the SE side of Volcán
Nuevo between 1973 and 1986, and eventually exceeded its height. Smaller
domes or cones are present in the 5-km valley between the two major
edifices.



Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhhOHPzDA$  
<https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppVjH0KaE$>
;

Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhsUx274s$  
<https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppfD2euzA$>





Ofu-Olosega  | American Samoa (SW Pacific)  | 14.175°S, 169.618°W  | Summit
elev. 639 m



HVO reported that an earthquake swarm in the Manuâ??a Islands of American
Samoa continued to be recorded and felt by residents of Taâ??u Island and
Ofu-Olosega. About 20 earthquakes per hour were recorded by four
microseismometers distributed on Tutuila, Taâ??u, and Ofu-Olosega Islands.
The largest events were estimated to be between magnitudes 2 and 3; most
events are too small to be felt. Analysis of the seismic data indicated
that the earthquakes were occurring beneath or around the Manuâ??a Islands,
likely closer to Taâ??u rather than Ofu-Olosega, though the exact locations,
depths, and magnitudes were unknown. The number, size, and frequency of
earthquakes recorded by instruments and being felt by people and on both
islands indicated that seismicity was above background levels; HVO changed
the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow
for both volcanoes. Earthquakes continued to be recorded at around the same
rate during 20-22 August. Two additional seismometers were installed on
Taâ??u during 22-23 August.



Geologic Summary. The two triangle-shaped islands of Ofu and Olosega in
eastern Samoa, with a combined length of 6 km, are separated by a narrow
strait. The islands are formed by two eroded, coalescing basaltic shield
volcanoes whose slopes dip to the east and west. Steep cliffs up to 600-m
high truncate the northern and southern sides of the islands. The narrow,
steep-sided ridge forming the eastern tip of Ofu Island consists of a dike
complex. The shield volcano on Ofu is cut on the north by the A'ofa
caldera; bathymetry suggests that a caldera may also exist on the Sili
shield volcano of Olosega. The Nu'utele tuff cone, forming a small
crescent-shaped island immediately off the west end of Ofu Island, is
Holocene in age. A submarine eruption took place in 1866 at the opposite
end of the two islands, 3 km SE of Olosega, along the ridge connecting
Olosega with Ta'u Island.



Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhl0aDPAv$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppHio7gv8$>





Semisopochnoi  | Aleutian Islands (USA)  | 51.93°N, 179.58°E  | Summit
elev. 1221 m



AVO reported that at 1347 on 21 August a short-lived explosion at
Semisopochnoi's North Cerberus cone produced an ash emission that was
visible in webcam images. The ash emission was not visible in satellite
images due to weather clouds, indicating that they did not rise above 6 km
(20,000 ft) a.s.l. This was the first explosion detected since 12 June. The
Aviation Color Code was raised to Orange and the Volcano Alert Level was
raised to Watch.



Geologic Summary. Semisopochnoi, the largest subaerial volcano of the
western Aleutians, is 20 km wide at sea level and contains an 8-km-wide
caldera. It formed as a result of collapse of a low-angle, dominantly
basaltic volcano following the eruption of a large volume of dacitic
pumice. The high point of the island is Anvil Peak, a double-peaked
late-Pleistocene cone that forms much of the island's northern part. The
three-peaked Mount Cerberus was constructed within the caldera during the
Holocene. Each of the peaks contains a summit crater; lava flows on the N
flank of Cerberus appear younger than those on the south side. Other
post-caldera volcanoes include the symmetrical Sugarloaf Peak SSE of the
caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake
in the NE part of the caldera. Most documented eruptions have originated
from Cerberus, although Coats (1950) considered that both Sugarloaf and
Lakeshore Cone could have been recently active.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhi67CUtd$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpppbNpIA4$>





Ta'u  | American Samoa (SW Pacific)  | 14.23°S, 169.454°W  | Summit elev.
931 m



HVO reported that an earthquake swarm in the Manuâ??a Islands of American
Samoa continued to be recorded and felt by residents of Taâ??u Island and
Ofu-Olosega. About 20 earthquakes per hour were recorded by four
microseismometers distributed on Tutuila, Taâ??u, and Ofu-Olosega Islands.
The largest events were estimated to be between magnitudes 2 and 3; most
events are too small to be felt. Analysis of the seismic data indicated
that the earthquakes were occurring beneath or around the Manuâ??a Islands,
likely closer to Taâ??u rather than Ofu-Olosega, though the exact locations,
depths, and magnitudes were unknown. The number, size, and frequency of
earthquakes recorded by instruments and being felt by people and on both
islands indicated that seismicity was above background levels; HVO changed
the Volcano Alert Level to Advisory and the Aviation Color Code to Yellow
for both volcanoes. Earthquakes continued to be recorded at around the same
rate during 20-22 August. Two additional seismometers were installed on
Taâ??u during 22-23 August.



Geologic Summary. The 10-km-wide Ta'u Island, located at the E end of the
Samoan islands, is ringed by sea cliffs. It is the emergent portion of the
large Lata shield volcano. A major flank collapse event around 22 ka
resulted in the steep scarps on the southern side of the island. Two
smaller shields were constructed along rift zones at the NW and NE tips of
the island. The NW corner of the island has a tuff-cone complex that
ejected large dunite xenoliths and coral blocks. Numerous Holocene
post-caldera cones occur at the summit and on the flanks.



Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhl0aDPAv$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppHio7gv8$>





Ongoing Activity





Aira  | Kyushu (Japan)  | 31.593°N, 130.657°E  | Summit elev. 1117 m



JMA reported that 0009 on 15 August an explosion at Minamidake Crater (at
Aira Calderaâ??s Sakurajima volcano) generated an ash plume that rose 2 km
above the crater rim. Sulfur dioxide emissions were slightly high at 1,500
tons per day, measured during a field visit on 16 August. Two eruptive
events were recorded during 19-22 August. The Alert Level remained at 3 (on
a 5-level scale), and residents were warned to stay 2 km away from the
crater.



Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay
contains the post-caldera Sakurajima volcano, one of Japan's most active.
Eruption of the voluminous Ito pyroclastic flow accompanied formation of
the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera
was formed during the early Holocene in the NE corner of the Aira caldera,
along with several post-caldera cones. The construction of Sakurajima began
about 13,000 years ago on the southern rim of Aira caldera and built an
island that was finally joined to the Osumi Peninsula during the major
explosive and effusive eruption of 1914. Activity at the Kitadake summit
cone ended about 4850 years ago, after which eruptions took place at
Minamidake. 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: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhlpuphs7$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppyip7l0g$>





Bezymianny  | Central Kamchatka (Russia)  | 55.972°N, 160.595°E  | Summit
elev. 2882 m



The Tokyo VAAC reported that on 22 August an ash plume from Bezymianny was
identified in a satellite image rising to 3.7 km (12,000 ft) a.s.l. and
drifting NE.



Geologic Summary. The modern Bezymianny, much smaller than its massive
neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed
about 4,700 years ago over a late-Pleistocene lava-dome complex and an
ancestral edifice built about 11,000-7,000 years ago. Three periods of
intensified activity have occurred during the past 3,000 years. The latest
period, which was preceded by a 1,000-year quiescence, began with the
dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in
1980, produced a large open crater that was formed by collapse of the
summit and an associated lateral blast. Subsequent episodic but ongoing
lava-dome growth, accompanied by intermittent explosive activity and
pyroclastic flows, has largely filled the 1956 crater.



Source: Tokyo Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhlCkxxYg$  
<https://urldefense.com/v3/__http://ds.data.jma.go.jp/svd/vaac/data/vaac_list.html__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpplUqsDRw$>





Bulusan  | Luzon (Philippines)  | 12.769°N, 124.056°E  | Summit elev. 1535 m



PHIVOLCS lowered the Alert Level for Bulusan to 0 (on a scale of 0-5) on 21
August, noting that unrest had further declined to background levels. The
frequency of volcanic earthquakes declined to baseline levels during the
third week of July. Deformation data showed short-term inflation at the SE
flank, though long-term data showed no deformation associated with the
volcano. Sulfur dioxide emissions averaged 1,900 tonnes/day during 5-12
June and declined to about 230 tonnes/day during 25 July-6 August.
Steam-laden emissions from the active vents declined to low-to-moderate
levels. PHIVOLCS reminded the public not to enter the 4-km-radius Permanent
Danger Zone (PDZ) nor the 2 km Extended Danger Zone (EDZ) on the SE flank.



Geologic Summary. Luzon's southernmost volcano, Bulusan, was constructed
along the rim of the 11-km-diameter dacitic-to-rhyolitic Irosin caldera,
which was formed about 36,000 years ago. It lies at the SE end of the Bicol
volcanic arc occupying the peninsula of the same name that forms the
elongated SE tip of Luzon. A broad, flat moat is located below the
topographically prominent SW rim of Irosin caldera; the NE rim is buried by
the andesitic complex. Bulusan is flanked by several other large
intracaldera lava domes and cones, including the prominent Mount Jormajan
lava dome on the SW flank and Sharp Peak to the NE. The summit is
unvegetated and contains a 300-m-wide, 50-m-deep crater. Three small
craters are located on the SE flank. Many moderate explosive eruptions have
been recorded since the mid-19th century.



Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhsoR_TVG$  
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppksoPSWI$>





Ebeko  | Paramushir Island (Russia)  | 50.686°N, 156.014°E  | Summit elev.
1103 m



KVERT reported that moderate activity at Ebeko was ongoing. A thermal
anomaly over the volcano was identified in satellite images on 13 and 18
August. According to volcanologists in Severo-Kurilsk (Paramushir Island,
about 7 km E) explosions generated ash plumes that rose up to 3.5 km
(11,500 ft) a.s.l. during 15-18 August; ash plumes drifted more than 65 km
SE during 17-18 August. The Aviation Color Code remained at Orange (the
second highest level on a four-color scale). Dates are based on UTC times;
specific events are in local time where noted.



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. Blocky lava flows extend west from Ebeko and SE from the
neighboring Nezametnyi cone. The eastern part of the southern crater
contains strong solfataras and a large boiling spring. The central crater
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, on the outer flanks of the
cone, and in lateral explosion craters.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhkfFn0Nv$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp4e_N978$>





Great Sitkin  | Andreanof Islands (USA)  | 52.076°N, 176.13°W  | Summit
elev. 1740 m



AVO reported that slow lava effusion at Great Sitkin continued during 16-23
August; no changes to the flow margins were visible but the lava had
deepened around the vent. Weather clouds often obscured satellite and
webcam views during most of the week. Seismicity was low and occasional
local earthquakes were recorded. The Aviation Color Code and the Volcano
Alert Level remained at Orange and Watch, respectively.



Geologic Summary. The Great Sitkin volcano forms much of the northern side
of Great Sitkin Island. A younger parasitic volcano capped by a small, 0.8
x 1.2 km ice-filled summit caldera was constructed within a large
late-Pleistocene or early Holocene scarp formed by massive edifice failure
that truncated an ancestral volcano and produced a submarine debris
avalanche. Deposits from this and an older debris avalanche from a source
to the south cover a broad area of the ocean floor north of the volcano.
The summit lies along the eastern rim of the younger collapse scarp.
Deposits from an earlier caldera-forming eruption of unknown age cover the
flanks of the island to a depth up to 6 m. The small younger caldera was
partially filled by lava domes emplaced in 1945 and 1974, and five small
older flank lava domes, two of which lie on the coastline, were constructed
along northwest- and NNW-trending lines. Hot springs, mud pots, and
fumaroles occur near the head of Big Fox Creek, south of the volcano.
Historical eruptions have been recorded since the late-19th century.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhi67CUtd$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpppbNpIA4$>





Kaitoku Seamount  | Volcano Islands (Japan)  | 26.127°N, 141.102°E  |
Summit elev. -95 m



JMA reported that discolored water around the Kaitoku Seamount was visible
during 18-19 August.



Geologic Summary. A submarine eruption was observed in 1984 from Kaitoku
Seamount (Kaitoku Kaizan), a three-peaked submarine volcano 130 km NNW of
Kita-Iojima. A submarine eruption had previously been reported in 1543 from
a point about 40 km to the SW, which the Japan Meteorological Agency
attributes to Kaitoku.



Sources: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhlpuphs7$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppyip7l0g$>
;

Japan Coast Guard https://urldefense.com/v3/__http://www.kaiho.mlit.go.jp/index.html__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhn7chmBx$  
<https://urldefense.com/v3/__http://www.kaiho.mlit.go.jp/index.html__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp404P2QU$>





Karymsky  | Eastern Kamchatka (Russia)  | 54.049°N, 159.443°E  | Summit
elev. 1513 m



KVERT reported that the eruption at Karymsky continued during 11-18 August.
A thermal anomaly over the volcano was identified in satellite images
during 12-13, 16, and 18 August. The Aviation Color Code remained at Orange
(the second highest level on a four-color scale). Dates are based on UTC
times; specific events are in local time where noted.



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 during the early Holocene. The caldera cuts
the south side of the Pleistocene Dvor volcano and is located outside the
north margin of the large mid-Pleistocene Polovinka caldera, which contains
the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding
Karymsky eruptions originated beneath Akademia Nauk caldera, located
immediately south. The caldera enclosing Karymsky formed about 7600-7700
radiocarbon years ago; construction of the stratovolcano began about 2000
years later. The latest eruptive period began about 500 years ago,
following a 2300-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.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhkfFn0Nv$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp4e_N978$>





Kilauea  | Hawaiian Islands (USA)  | 19.421°N, 155.287°W  | Summit elev.
1222 m



HVO stated that by 16 August about 104 million cubic meters of lava had
been erupted from a vent in the lower W wall of at Kilaueaâ??s Halema`uma`u
Crater since the current eruption began on 29 September 2021, raising the
crater floor by 137 m. Lava continued to effuse from the vent during 17-22
August, entering the lava lake and flowing onto the crater floor. Part of
the lake was continuously active. The lake level mostly remained within the
bounding levees, though daily breakouts were visible along the margins. The
Aviation Color Code and the Volcano Alert Level remained at Orange and
Watch, respectively.



Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa
shield volcano in the island of Hawaii. Eruptions are prominent in
Polynesian legends; written documentation since 1820 records frequent
summit and flank lava flow eruptions interspersed with periods of long-term
lava lake activity at Halemaumau crater in the summit caldera until 1924.
The 3 x 5 km caldera was formed in several stages about 1,500 years ago and
during the 18th century; eruptions have also originated from the lengthy
East and Southwest rift zones, which extend to the ocean in both
directions. About 90% of the surface of the basaltic shield volcano is
formed of lava flows less than about 1,100 years old; 70% of the surface is
younger than 600 years. The long-term eruption from the East rift zone
between 1983 and 2018 produced lava flows covering more than 100 km2,
destroyed hundreds of houses, and added new coastline.



Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhl0aDPAv$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppHio7gv8$>





Lewotolok  | Lembata Island  | 8.274°S, 123.508°E  | Summit elev. 1431 m



PVMBG reported that the Strombolian eruption at Lewotolok continued during
17-23 August. Daily white emissions rose as high as 500 m above the summit
and drifted in multiple directions. White-and-gray plumes rose as high as
300 m on 19 August. Photos in some daily reports showed Strombolian
activity. The Alert Level remained at 3 (on a scale of 1-4) and the public
was warned to stay 3 km away from the summit crater and 4 km away from the
crater on the SE flank.



Geologic Summary. The Lewotolok (or Lewotolo) stratovolcano occupies the
eastern end of an elongated peninsula extending north into the Flores Sea,
connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is
symmetrical when viewed from the north and east. A small cone with a
130-m-wide crater constructed at the SE side of a larger crater forms the
volcano's high point. Many lava flows have reached the coastline. Eruptions
recorded since 1660 have consisted of explosive activity from the summit
crater.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhvYz5tLu$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppHUWKN5s$>





Merapi  | Central Java  | 7.54°S, 110.446°E  | Summit elev. 2910 m



BPPTKG reported that the eruption at Merapi continued during 12-18 August
and seismicity remained at high levels. As many as 23 lava avalanches
traveled down the Bebeng drainage on the SW flank, reaching a maximum
distance of 1.8 km. Photo analyses showed no changes at the SW and central
lava domes. The Alert Level remained at 3 (on a scale of 1-4), and the
public was warned to stay 3-7 km away from the summit based on location.



Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in
one of the world's most densely populated areas and dominates the landscape
immediately north of the major city of Yogyakarta. It is the youngest and
southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth
of Old Merapi during the Pleistocene ended with major edifice collapse
perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the
eroded older Batulawang volcano. Subsequent growth of the steep-sided Young
Merapi edifice, its upper part unvegetated due to frequent activity, began
SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying
growth and collapse of the steep-sided active summit lava dome have
devastated cultivated lands on the western-to-southern flanks and caused
many fatalities.



Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi
(BPPTKG) https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhpaAh8xq$  
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp0fQoe48$>





Nevado del Ruiz  | Colombia  | 4.892°N, 75.324°W  | Summit elev. 5279 m



Servicio Geológico Colombianoâ??s (SGC) reported that at 1751 on 18 August an
ash emission at Nevado del Ruiz rose 3.2 km and drifted WNW and was
associated with a seismic signal indicating fluid movement. The plume was
visible on webcams and from Manizales. The Alert Level remained at 3
(Yellow; the second lowest level on a four-color scale).



Geologic Summary. Nevado del Ruiz is a broad, glacier-covered volcano in
central Colombia that covers more than 200 km2. Three major edifices,
composed of andesitic and dacitic lavas and andesitic pyroclastics, have
been constructed since the beginning of the Pleistocene. The modern cone
consists of a broad cluster of lava domes built within the caldera of an
older edifice. The 1-km-wide, 240-m-deep Arenas crater occupies the summit.
The prominent La Olleta pyroclastic cone located on the SW flank may also
have been active in historical time. Steep headwalls of massive landslides
cut the flanks. Melting of its summit icecap during historical eruptions,
which date back to the 16th century, has resulted in devastating lahars,
including one in 1985 that was South America's deadliest eruption.



Source: Servicio Geológico Colombiano (SGC)
https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhmYJ58Hu$  
<https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppYsJTmUM$>





Pavlof  | Alaska Peninsula, Alaska  | 55.417°N, 161.894°W  | Summit elev.
2493 m



AVO reported that a minor eruption at a vent on Pavlofâ??s upper E flank was
ongoing during 16-23 August. There was no evidence of lava effusion, but
seismic tremor persisted and multiple small explosions were detected on
most days in local seismic, regional seismic, and infrasound data. During
17-18 August explosions produced minor ash emissions that rose to 3 km
(10,000 ft) a.s.l. and dissipated quickly, as reported by pilots and seen
in webcam images. Daily elevated surface temperatures were identified in
satellite images reflecting a hot vent. The Volcano Alert Level remained at
Watch and the Aviation Color Code remained at Orange.



Geologic Summary. The most active volcano of the Aleutian arc, Pavlof is a
2519-m-high Holocene stratovolcano that was constructed along a line of
vents extending NE from the Emmons Lake caldera. Pavlof and its twin
volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of
symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and
Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW
flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof
Sister, Pavlof has been frequently active in historical time, typically
producing Strombolian to Vulcanian explosive eruptions from the summit
vents and occasional lava flows. The active vents lie near the summit on
the north and east sides. The largest historical eruption took place in
1911, at the end of a 5-year-long eruptive episode, when a fissure opened
on the N flank, ejecting large blocks and issuing lava flows.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhi67CUtd$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpppbNpIA4$>





Semeru  | Eastern Java  | 8.108°S, 112.922°E  | Summit elev. 3657 m



PVMBG reported that the eruption at Semeru continued during 16-23 August.
Eruptive events recorded at 0544 and 0718 on 22 August produced ash plumes
that rose 500 and 300 m above the summit and drifted SW and W,
respectively. The Alert Level remained at 3 (on a scale of 1-4). The public
was warned to stay at least 5 km away from the summit, and 500 m from
Kobokan drainages within 17 km of the summit, along with other drainages
originating on Semeru, including the Bang, Kembar, and Sat, due to lahar,
avalanche, and pyroclastic flow hazards.



Geologic Summary. Semeru, the highest volcano on Java, and one of its most
active, lies at the southern end of a volcanic massif extending north to
the Tengger caldera. The steep-sided volcano, also referred to as Mahameru
(Great Mountain), rises above coastal plains to the south. Gunung Semeru
was constructed south of the overlapping Ajek-ajek and Jambangan calderas.
A line of lake-filled maars was constructed along a N-S trend cutting
through the summit, and cinder cones and lava domes occupy the eastern and
NE flanks. Summit topography is complicated by the shifting of craters from
NW to SE. Frequent 19th and 20th century eruptions were dominated by
small-to-moderate explosions from the summit crater, with occasional lava
flows and larger explosive eruptions accompanied by pyroclastic flows that
have reached the lower flanks of the volcano.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhvYz5tLu$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppHUWKN5s$>





Sheveluch  | Central Kamchatka (Russia)  | 56.653°N, 161.36°E  | Summit
elev. 3283 m



KVERT reported that the ongoing eruption at Sheveluch was characterized by
explosions, hot avalanches, and lava-dome extrusion during 11-18 August. A
daily thermal anomaly was identified in satellite images. The Aviation
Color Code remained at Orange (the second highest level on a four-color
scale). Dates are based on UTC times; specific events are in local time
where noted.



Geologic Summary. The high, isolated massif of Sheveluch volcano (also
spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's
largest and most active volcanic structures, with at least 60 large
eruptions during the Holocene. The summit of roughly 65,000-year-old Stary
Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera
breached to the south. Many lava domes occur on its outer flanks. The
Molodoy Shiveluch lava dome complex was constructed during the Holocene
within the large open caldera; Holocene lava dome extrusion also took place
on the flanks of Stary Shiveluch. Widespread tephra layers from these
eruptions have provided valuable time markers for dating volcanic events in
Kamchatka. Frequent collapses of dome complexes, most recently in 1964,
have produced debris avalanches whose deposits cover much of the floor of
the breached caldera.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhkfFn0Nv$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPpp4e_N978$>





Suwanosejima  | Ryukyu Islands (Japan)  | 29.638°N, 129.714°E  | Summit
elev. 796 m



JMA reported that the eruption at Suwanosejima's Ontake Crater continued
during 15-22 August. There were six explosions, producing eruption plumes
that rose as high as 900 m above the crater rim and ejecting large blocks
600 m from the vent. Crater incandescence was observed nightly, and
volcanic tremor was occasionally recorded. The Alert Level remained at 2
and the public was warned to stay 1 km away from the crater.



Geologic Summary. The 8-km-long island of Suwanosejima in the northern
Ryukyu Islands consists of an andesitic stratovolcano with two historically
active summit craters. The summit is truncated by a large breached crater
extending to the sea on the east flank that was formed by edifice collapse.
One of Japan's most frequently active volcanoes, it was in a state of
intermittent Strombolian activity from Otake, the NE summit crater, between
1949 and 1996, after which periods of inactivity lengthened. The largest
recorded eruption took place in 1813-14, when thick scoria deposits
blanketed residential areas, and the SW crater produced two lava flows that
reached the western coast. At the end of the eruption the summit of Otake
collapsed, forming a large debris avalanche and creating the open Sakuchi
caldera, which extends to the eastern coast. The island remained
uninhabited for about 70 years after the 1813-1814 eruption. Lava flows
reached the eastern coast of the island in 1884. Only about 50 people live
on the island.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhlpuphs7$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ab--3kISw2ZsqCky0uIEmfHbtkoo93oY_d0trujXKkPwkAeWD9EG0qpQDsEDMK-whPppyip7l0g$>



5-5-5-5-5-5-5-5-5-5-5-5-5-5



==============================================================



Volcano Listserv is a collaborative venture among Arizona State University
(ASU), Portland State University (PSU), the Global Volcanism Program (GVP)
of the Smithsonian Institution's National Museum of Natural History, and
the International Association for Volcanology and Chemistry of the Earth's
Interior (IAVCEI).



ASU - http://www.asu.edu/

PSU - https://urldefense.com/v3/__http://pdx.edu/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhhWsWvp2$  

GVP - https://urldefense.com/v3/__http://www.volcano.si.edu/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhl7UtkDN$  

IAVCEI - https://urldefense.com/v3/__https://www.iavceivolcano.org/__;!!IKRxdwAv5BmarQ!ZgsnYOlJ7KayNplktS-Wblc20KuS6h4Jv5zfrxMaE2JPB8qhEfe_eKsgXA9rUE5DYLBDF7_vhn7WKyiK$  



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End of Volcano Digest - 22 Aug 2022 to 24 Aug 2022 (#2022-86)
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