Smithsonian / USGS Weekly Volcanic Activity Report 24-30 August 2022

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2-2-2-2-2-2-2-2-2-2-2-2-2


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


Smithsonian / USGS Weekly Volcanic Activity Report

24-30 August 2022



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

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJoy-KBOc7$  
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprU83djTEw$>





New Activity/Unrest: Chikurachki, Paramushir Island (Russia)  | 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)  | Dukono, Halmahera  | Ebeko,
Paramushir Island (Russia)  | Erta Ale, Ethiopia  | Great Sitkin, Andreanof
Islands (USA)  | Karymsky, Eastern Kamchatka (Russia)  | Kilauea, Hawaiian
Islands (USA)  | Klyuchevskoy, Central Kamchatka (Russia)  | Lewotolok,
Lembata Island  | Merapi, Central Java  | Pavlof, Alaska Peninsula, Alaska
| Popocatepetl, Mexico  | Reventador, Ecuador  | 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





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



KVERT reported that during 23-25 August occasional ash plumes from
Chikurachki rose as high as 2 km (6,600 ft) a.s.l. and drifted about 20 km
E. A thermal anomaly was identified in satellite images on 25 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. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozX-Dir4$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUmCHQLPA$>





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



SERNAGEOMIN reported that on 29 August an explosion at Dome 4 in Nevados de
Chillánâ??s Nicanor Crater produced a plume with a high tephra content that
rose 2 km above the crater rim and drifted S. The explosion also generated
a pyroclastic flow that descended less than 500 m on the E and SE flanks.
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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo19lTwhv$  
<https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprU1B-EXUw$>
;

Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJoxP7mdpH$  
<https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUf6Y8zEA$>





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



Data from seismometers recently installed on Tutuila, Taâ??u, and Ofu-Olosega
islands of American Samoa to monitor an ongoing seismic swarm indicated
that the events were related to Taâ??u Island and not Ofu-Olosega. HVO
lowered the Volcano Alert Level to Normal and the Aviation Color Code to
Green on 26 August. The report warned residents of Ofu-Olosega that they
could still be significantly affected by events that may take place on or
around Taâ??u Island.



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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo83EiSrR$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUOC2jVW4$>





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



AVO reported ongoing low-level seismicity and steam emissions at
Semisopochnoi during 23-30 August. Satellite images were mostly cloudy;
steam emissions were seen almost daily in webcam images. The Aviation Color
Code remained at Orange and the Volcano Alert Level remained at 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo6iPbAsH$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUdpwiT1g$>





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



HVO reported that an earthquake swarm in the Manu'a Islands of American
Samoa continued to be felt by residents of Ta'u Island and Ofu-Olosega
islands during 24-30 August. Three advanced seismometers were installed
beginning the second week of August, one on Ofu Island and two on Ta'u, and
by 26 August the data indicated that the source of the activity was related
to Ta'u Island. Around 30 earthquakes per hour were recorded each day. At
2033 on 23 August an earthquake widely felt by residents of the Manu'a
islands and Tutuila Island was characterized as producing light-to-moderate
shaking (a maximum Intensity of V on the Modified Mercalli Intensity
Scale); the estimated M 3-3.5 event was the largest recorded since the new
instruments were installed. The largest earthquakes recorded during 25-26
August had estimated magnitudes between 3 and 4 and were felt by residents
of Manu'a. An estimated M 2.8 event was strongly felt at 0932 on 27 August.
Numerous events were felt during 27-28 August, but none were reported
during 28-30 August. Booming noises had been reported and investigated for
weeks; scientists confirmed that they were related to the earthquakes,
noting that the sound waves generated by some earthquakes could produce
sounds audible to humans. No signs of ground cracking, landslides,
rockfalls, or other activity that could have caused the sounds were seen.
The Volcano Alert Level remained at Advisory and the Aviation Color Code
remained at Yellow.



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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo83EiSrR$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUOC2jVW4$>





Ongoing Activity





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



JMA reported low but continuing activity from Minamidake Crater (at Aira
Calderaâ??s Sakurajima volcano) during 22-29 August. Small eruptive events
were recorded throughout the week, and nighttime incandescence was visible
from the crater was visible during 26-29 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo_4EilCV$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUCSctr7o$>





Dukono  | Halmahera  | 1.693°N, 127.894°E  | Summit elev. 1229 m



PVMBG reported that almost daily white plumes from Dukono rose as high as
200 m above the summit and drifted SW, W, and NW. During 27-18 August dense
white, gray, and brown ash plumes rose as high as 1 km above the summit and
drifted SW and W. The Alert Level remained at 2 (on a scale of 1-4), and
the public was warned to remain outside of the 2-km exclusion zone.



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 north-flank cone
of Gunung Mamuya. This complex volcano presents a broad, low profile with
multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of
the summit crater complex, contains a 700 x 570 m crater that has also been
active during historical time.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo7DSXBUy$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUyeFbYx8$>





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 during 18-19,
22, and 25 August. According to volcanologists in Severo-Kurilsk
(Paramushir Island, about 7 km E) explosions generated ash plumes that rose
up to 3 km (10,000 ft) a.s.l. during 19 and 22-25 August and drifted N and
E. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozX-Dir4$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUmCHQLPA$>





Erta Ale  | Ethiopia  | 13.6°N, 40.67°E  | Summit elev. 613 m



Thermal anomalies of variable intensities at Erta Aleâ??s N and S pit craters
were periodically identified in satellite images during August. On 1 August
there were two anomalies in the S pit crater and none in the N pit crater.
Images were cloudy on 6 and 11 August. On 16 August two anomalies were
again visible in the S pit crater while one large anomaly occupied the N
crater. Translucent weather clouds obscured views on 21 August, though two
anomalies were visible in the S pit crater. Dense weather clouds covered
the N pit crater on 26 August and obscured the S pit crater, though one
anomaly was visible.



Geologic Summary. The Erta Ale basaltic shield volcano is the most active
in Ethiopia, with a 50-km-wide edifice that rises more than 600 m from
below sea level in the barren Danakil depression. It is the namesake and
most prominent feature of the Erta Ale Range. The volcano includes a 0.7 x
1.6 km elliptical summit crater hosting steep-sided pit craters. Another
larger 1.8 x 3.1 km wide depression elongated parallel to the trend of the
Erta Ale range is located SE of the summit and is bounded by curvilinear
fault scarps on the SE side. Fresh-looking basaltic lava flows from these
fissures have poured into the caldera and locally overflowed its rim. The
summit caldera usually also holds at least one long-term lava lake that has
been active since at least 1967, or possibly since 1906. Recent fissure
eruptions have occurred on the N flank.



Source: Sentinel Hub https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo9wVPyfY$  
<https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUsnj8pUQ$>





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



AVO reported that slow lava effusion at Great Sitkin probably continued
during 24-30 August with lava around the vent likely thickening. Weather
clouds often obscured satellite and webcam views during most of the week;
elevated surface temperatures were occasionally visible. Seismicity was
very low. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo6iPbAsH$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUdpwiT1g$>





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



KVERT reported that the eruption at Karymsky continued during 18-25 August.
A thermal anomaly over the volcano was identified in satellite images
during 18-19, 22, and 24-25 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozX-Dir4$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUmCHQLPA$>





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



HVO reported that lava continued to effuse from a vent in the lower W wall
of Kilaueaâ??s Halema`uma`u Crater during 24-30 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo83EiSrR$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUOC2jVW4$>





Klyuchevskoy  | Central Kamchatka (Russia)  | 56.056°N, 160.642°E  | Summit
elev. 4754 m



Strong winds re-suspended ash from the E flank of Klyuchevskoy and created
plumes that were visible in satellite images drifting more than 205 km E
during 25-26 August. KVERT raised the Aviation Color Code to Orange on 26
August; plumes were not visible the next day so the Aviation Color Code was
lowered back to Green.



Geologic Summary. Klyuchevskoy (also spelled Kliuchevskoi) is Kamchatka's
highest and most active volcano. Since its origin about 6000 years ago, the
beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced
frequent moderate-volume explosive and effusive eruptions without major
periods of inactivity. It rises above a saddle NE of sharp-peaked Kamen
volcano and lies SE of the broad Ushkovsky massif. More than 100 flank
eruptions have occurred during the past roughly 3000 years, with most
lateral craters and cones occurring along radial fissures between the
unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m
elevation. The morphology of the 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 numerous major explosive and
effusive eruptions from flank craters.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozX-Dir4$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUmCHQLPA$>





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



PVMBG reported that the Strombolian eruption at Lewotolok continued during
23-30 August. Daily white emissions rose as high as 700 m above the summit
and drifted in multiple directions. Photos posted with daily reports showed
crater incandescence and occasional 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo7DSXBUy$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUyeFbYx8$>





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



BPPTKG reported that the eruption at Merapi continued during 19-25 August.
Seismicity intensified compared to the previous week; in particular the
number of deep volcanic earthquakes increased and indicated magmatic
activity at depths less than 1.5 km. As many as 19 lava avalanches traveled
down the Bebeng drainage on the SW flank, reaching a maximum distance of
1.8 km. Photo analyses showed no height changes at the SW and central lava
domes, though some changes at the SW dome were observed due to avalanche
activity. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJowfPLUpQ$  
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprU6UBMqtU$>





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 23-30 August, though there was no evidence of lava effusion.
Seismic tremor persisted. A small ash emission rose to about 4 km (12,000
ft) a.s.l. on 24 August and was seen by passing aircraft. Sulfur dioxide
emissions were also detected that same day. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo6iPbAsH$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUdpwiT1g$>





Popocatepetl  | Mexico  | 19.023°N, 98.622°W  | Summit elev. 5393 m



CENAPRED reported that there were 15-75 steam-and-gas emissions, sometimes
containing minor amounts of ash, rising from Popocatépetl each day during
23-30 August. A moderate explosion was detected at 0117 on 30 August. The
Alert Level remained at Yellow, Phase Two (the middle level on a
three-color scale).



Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for
smoking mountain, rises 70 km SE of Mexico City to form North America's
2nd-highest volcano. The glacier-clad stratovolcano contains a
steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is
modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier
volcano. At least three previous major cones were destroyed by
gravitational failure during the Pleistocene, producing massive
debris-avalanche deposits covering broad areas to the south. The modern
volcano was constructed south of the late-Pleistocene to Holocene El Fraile
cone. Three major Plinian eruptions, the most recent of which took place
about 800 CE, have occurred since the mid-Holocene, accompanied by
pyroclastic flows and voluminous lahars that swept basins below the
volcano. Frequent historical eruptions, first recorded in Aztec codices,
have occurred since Pre-Columbian time.



Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozDrDdTs$  
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUVeKe3w4$>





Reventador  | Ecuador  | 0.077°S, 77.656°W  | Summit elev. 3562 m



IG characterized the ongoing eruption at Reventador as moderate during
23-30 August. Gas-and-ash plumes, observed with webcams or reported by the
Washington VAAC, rose as high as 1.6 km above the summit and drifted in
multiple directions. Crater incandescence was visible on most nights and
often during early morning hours. Incandescent blocks were visible rolling
500 m down the NE flank during 24-25 August and 600 m down all flanks
during 28-29 August.



Geologic Summary. Reventador is the most frequently active of a chain of
Ecuadorian volcanoes in the Cordillera Real, well east of the principal
volcanic axis. The forested, dominantly andesitic Volcán El Reventador
stratovolcano rises to 3562 m above the jungles of the western Amazon
basin. A 4-km-wide caldera widely breached to the east was formed by
edifice collapse and is partially filled by a young, unvegetated
stratovolcano that rises about 1300 m above the caldera floor to a height
comparable to the caldera rim. It has been the source of numerous lava
flows as well as explosive eruptions that were visible from Quito in
historical time. Frequent lahars in this region of heavy rainfall have
constructed a debris plain on the eastern floor of the caldera. The largest
historical eruption took place in 2002, producing a 17-km-high eruption
column, pyroclastic flows that traveled up to 8 km, and lava flows from
summit and flank vents.



Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo2ePog8N$  
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUZcyHgsU$>





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



PVMBG reported that the eruption at Semeru continued during 23-30 August.
Eruptive events at 0735 on 26 August, 0606 and 0628 on 27 August, 0623 on
28 August, and 0618 on 29 August produced ash plumes that rose 500-600 m
above the summit and drifted N, W, and SW. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo7DSXBUy$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUyeFbYx8$>





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 18-25 August. A
daily thermal anomaly was identified in satellite images during 18-19, 21,
and 23-25 August. Ash plumes drifted 190 km SE and 150 km E on 19 and 25
August, respectively. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJozX-Dir4$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUmCHQLPA$>





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



At 2151 on 28 August a large eruptive event at Suwanosejima's Ontake Crater
ejected large bombs 800 m above the vent and produced an eruption plume
that rose into overhead weather clouds. Crater incandescence was visible in
webcam images overnight. By 0900 on 29 August three more explosions were
recorded and produced ash plumes that rose as high as 1.3 km above the
vent. 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!fEnmFeN-NipWQRVO40Zi5rQ6gd-UE-mEIPdhoMxDsHUYZMqT1ffP_6hc2J3R-TK698zmiXOJo_4EilCV$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZV1V5RNMqhsme9QVfqNWrpHFwEC5SBIUF42-CBftitb8eyHeFrONMwnAe_A0TAEyHprUCSctr7o$>



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------------------------------

End of Volcano Digest - 29 Aug 2022 to 31 Aug 2022 (#2022-89)
*************************************************************


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