Smithsonian / USGS Weekly Volcanic Activity Report 10-16 August 2022

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7-7-7-7-7-7-7-7-7-7-7-7-7-7


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


Smithsonian / USGS Weekly Volcanic Activity Report

10-16 August 2022



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

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLOZHiLvp$  
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFIBjeyog$>





New Activity/Unrest: Krysuvik-Trolladyngja, Reykjanes Peninsula  | Ta'u,
American Samoa (SW Pacific)



Ongoing Activity: Aira, Kyushu (Japan)  | Ebeko, Paramushir Island
(Russia)  | Great Sitkin, Andreanof Islands (USA)  | Ibu, Halmahera  |
Kadovar, Northeast of New Guinea  | Karymsky, Eastern Kamchatka (Russia)  |
Kilauea, Hawaiian Islands (USA)  | Krakatau, Sunda Strait  | Merapi,
Central Java  | Pavlof, Alaska Peninsula, Alaska  | Popocatepetl, Mexico  |
Sangay, Ecuador  | Semeru, Eastern Java  | Sheveluch, Central Kamchatka
(Russia)  | Suwanosejima, Ryukyu Islands (Japan)  | Taal, Luzon
(Philippines)





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





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



The fissure eruption in the Krýsuvík-Trölladyngja volcanic system that
began on 3 August continued in the Meradalir valley during 10-16 August.
Lava erupted mainly from a central cone and flowed ESE. According to the
Institute of Earth Sciences the effusion rate had notably decreased, from
an average of 11 cubic meters per second during 4-13 August to 3-4 cubic
meters per second during 13-15 August. A news article stated that the
effusion rate significantly decreased during 0530-0630 on 13 August based
on information from IMO staff who were investigating the eruption site for
new changes. The Institute of Earth Sciences estimated that 10.6 million
cubic meters of lava had covered an area of 1.25 square kilometers by 15
August. Data collected during an overflight on 16 August indicated that the
effusion rate had further reduced to 2 cubic meters per second during the
previous day, though the uncertainty in that estimate was high. On 16
August residents reported seeing a purple-tinged sulfur dioxide gas cloud
over the eruption area slowly drifting SW during sunrise.



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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLBlSha-B$  
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFUCxrRNM$>
;

Institute of Earth Sciences https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLG4azsF-$  
<https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFYQ4xwMU$>
;

Icelandic National Broadcasting Service (RUV)
https://urldefense.com/v3/__https://www.ruv.is/frett/2022/08/13/drop-in-unrest-means-new-fissure-could-open__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLKJ88q0I$  
<https://urldefense.com/v3/__https://www.ruv.is/frett/2022/08/13/drop-in-unrest-means-new-fissure-could-open__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHF_pUXhQE$>
;

Icelandic National Broadcasting Service (RUV)
https://urldefense.com/v3/__https://www.ruv.is/frett/2022/08/16/wyplyw-lawy-o-polowe-mniejszy-niz-na-poczatku__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLKvZ5G5A$  
<https://urldefense.com/v3/__https://www.ruv.is/frett/2022/08/16/wyplyw-lawy-o-polowe-mniejszy-niz-na-poczatku__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFVbXpGcU$>





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



HVO reported that earthquakes were felt by residents of the Manu?a group of
islands in American Samoa beginning on 26 July. Residents of Ofu and
Olosega islands began reporting earthquakes on 10 August. Experts from HVO,
Pago Pago National Weather Service Office (NWS), National Oceanic and
Atmospheric Administration (NOAA) Pacific Tsunami Warning Center, NOAA-IOC
(NOAA-Intergovernmental Oceanographic Commission), International Tsunami
Information Center, and USGS National Earthquake Information Center have
been working together to respond to the unrest. USGS scientists arrived on
the islands and installed two microseismometers, one in Fiti?uta village on
Ta?u island on 13 August and the other in Olosega village on 14 August. The
instruments began recording about 20 earthquakes per hour. The largest
earthquakes, including the felt events, were estimated to be between
magnitudes 2 and 3; most of the events were too small to be felt. The exact
location and depth of these earthquakes was unknown, due to limited
earthquake monitoring equipment, though the data suggested that the events
were beneath the Manu?a Islands, likely closer to Ta?u island rather than
Ofu-Olosega, and were probably not related to the recently active Vailulu?u
seamount. HVO noted that American Samoaâ??s volcanoes were monitored remotely
by satellites and a distant seismic station in Apia, Samoa; the lack of
ground-based monitoring stations does not allow for advanced warning of new
activity. Both the Volcano Alert Level and Aviation Color Code were
categorized as Unassigned due to the lack of a volcano-monitoring
network.HVO reported that earthquakes were felt by residents of the Manu?a
group of islands in American Samoa beginning on 26 July. Residents of Ofu
and Olosega islands began reporting earthquakes on 10 August. Experts from
HVO, Pago Pago National Weather Service Office (NWS), National Oceanic and
Atmospheric Administration (NOAA) Pacific Tsunami Warning Center, NOAA-IOC
(NOAA-Intergovernmental Oceanographic Commission), International Tsunami
Information Center, and USGS National Earthquake Information Center have
been working together to respond to the unrest. USGS scientists arrived on
the islands and installed two microseismometers, one in Fiti?uta village on
Ta?u island on 13 August and the other in Olosega village on 14 August. The
instruments began recording about 20 earthquakes per hour. The largest
earthquakes, including the felt events, were estimated to be between
magnitudes 2 and 3; most of the events were too small to be felt. The exact
location and depth of these earthquakes was unknown, due to limited
earthquake monitoring equipment, though the data suggested that the events
were beneath the Manu?a Islands, likely closer to Ta?u island rather than
Ofu-Olosega, and were probably not related to the recently active Vailulu?u
seamount. HVO noted that American Samoaâ??s volcanoes were monitored remotely
by satellites and a distant seismic station in Apia, Samoa; the lack of
ground-based monitoring stations does not allow for advanced warning of new
activity. Both the Volcano Alert Level and Aviation Color Code were
categorized as Unassigned due to the lack of a volcano-monitoring network.



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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLCN-XQMO$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFwh5pfSY$>





Ongoing Activity





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



JMA reported that nighttime incandescence at Minamidake Crater (at Aira
Calderaâ??s Sakurajima volcano) was visible during 8-15 August. The seismic
network recorded 33 eruptive events and 12 explosions. Volcanic plumes rose
as high as 2.5 km above the crater rim and material was ejected large
ballistics as high as 1.7 km above the summit. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLK5Ya1I3$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFo4fANuo$>





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



KVERT reported that moderate activity at Ebeko was ongoing. 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.
and drifted in multiple directions during 4-5 and 7-8 August. A thermal
anomaly over the volcano was identified in satellite images during those
same days. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLCsNl5oq$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFs2WGQUE$>





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 9-16
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. Elevated surface temperatures were
identified in satellite images on most days. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLExMU4Xz$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHF_0wwsqY$>





Ibu  | Halmahera  | 1.488°N, 127.63°E  | Summit elev. 1325 m



PVMBG reported that the eruption at Ibu continued during 9-16 August.
Gray-and-white ash plumes of variable densities generally rose as high as
1.5 km above the summit and drifted in multiple directions. The Alert Level
remained at a 2 (on a scale of 1-4), and the public was warned to stay at
least 2 km away from the active crater and 3.5 km away on the N side



Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along
the NW coast of Halmahera Island has large nested summit craters. The inner
crater, 1 km wide and 400 m deep, has contained several small crater lakes.
The 1.2-km-wide outer crater is breached on the N, creating a steep-walled
valley. A large cone grew ENE of the summit, and a smaller one to the WSW
has fed a lava flow down the W flank. A group of maars is located below the
N and W flanks. The first observed and recorded eruption was a small
explosion from the summit crater in 1911. Eruptive activity began again in
December 1998, producing a lava dome that eventually covered much of the
floor of the inner summit crater along with ongoing explosive ash emissions.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLDpzvXpt$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFQfQhxVo$>





Kadovar  | Northeast of New Guinea  | 3.608°S, 144.588°E  | Summit elev.
365 m



Based on satellite and wind model data, the Darwin VAAC reported that on 14
August an ash plume from Kadovar rose to an altitude of 2.1 km (7,000 ft)
a.s.l. and drifted NW.



Geologic Summary. The 2-km-wide island of Kadovar is the emergent summit of
a Bismarck Sea stratovolcano of Holocene age. It is part of the Schouten
Islands, and lies off the coast of New Guinea, about 25 km N of the mouth
of the Sepik River. Prior to an eruption that began in 2018, a lava dome
formed the high point of the andesitic volcano, filling an arcuate
landslide scarp open to the south; submarine debris-avalanche deposits
occur in that direction. Thick lava flows with columnar jointing forms low
cliffs along the coast. The youthful island lacks fringing or offshore
reefs. A period of heightened thermal phenomena took place in 1976. An
eruption began in January 2018 that included lava effusion from vents at
the summit and at the E coast.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLKA3ploY$  
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFqfmHOAc$>





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



KVERT reported that the eruption at Karymsky continued during 4-11 August.
A daily thermal anomaly over the volcano was identified in satellite
images. Explosions during 5-9 August produced ash plumes that rose as high
as 5 km (16,400 ft) a.s.l. and drifted 550 km in multiple directions. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLCsNl5oq$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFs2WGQUE$>





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 9-16 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLCN-XQMO$  
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFwh5pfSY$>





Krakatau  | Sunda Strait  | 6.102°S, 105.423°E  | Summit elev. 155 m



PVMBG reported that cloudy weather often prevented visual confirmation of
the ongoing eruption at Anak Krakatau during 9-16 August. Incandescence at
or near the vent was seen in nighttime photos on most days. The Alert Level
remained at 3 (on a scale of 1-4), and the public was warned to stay at
least 5 km away from the crater.



Geologic Summary. The renowned volcano Krakatau (frequently misstated as
Krakatoa) lies in the Sunda Strait between Java and Sumatra. Collapse of
the ancestral edifice, perhaps in 416 or 535 CE, formed a 7-km-wide
caldera. Remnants of that volcano are preserved in Verlaten and Lang
Islands; subsequently Rakata, Danan, and Perbuwatan volcanoes were formed,
coalescing to create the pre-1883 Krakatau Island. Caldera collapse during
the catastrophic 1883 eruption destroyed Danan and Perbuwatan, and left
only a remnant of Rakata. This eruption caused more than 36,000 fatalities,
most as a result of tsunamis that swept the adjacent coastlines of Sumatra
and Java. Pyroclastic surges traveled 40 km across the Sunda Strait and
reached the Sumatra coast. After a quiescence of less than a half century,
the post-collapse cone of Anak Krakatau (Child of Krakatau) was constructed
within the 1883 caldera at a point between the former cones of Danan and
Perbuwatan. Anak Krakatau has been the site of frequent eruptions since
1927.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLDpzvXpt$  
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFQfQhxVo$>





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



BPPTKG reported that the eruption at Merapi continued during 5-11 August
and seismicity remained at high levels. As many as 43 lava avalanches
traveled down the Bebeng drainage on the SW flank, reaching a maximum
distance of 1.5 km. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLPIHc1DQ$  
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFxzFX5nI$>





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 9-16 August, though cloud cover often prevented visual
confirmation. Seismic tremor persisted and multiple small daily explosions
were detected in local and regional seismic and infrasound data. The
explosions may have produced minor ash emissions that rose no higher than 3
km (10,000 ft) a.s.l. and dissipated quickly, though on a few of the clear
views none were seen. Elevated surface temperatures were identified in
satellite images on most of the days. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLExMU4Xz$  
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHF_0wwsqY$>





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



CENAPRED reported that there were 19-204 steam-and-gas emissions, sometimes
containing minor amounts of ash, rising from Popocatépetl each day during
9-16 August. A minor explosion was recorded at 0839 on 10 August and a
moderate explosion was detected at 1528 on 11 August. Minor ashfall was
reported in the municipality of Ecatzingo, State of Mexico. An explosion at
1952 on 13 August was followed at 2125 by minor amounts of ashfall in
Tetela del Volcán. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLGnpg44X$  
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFF9ZLnGU$>





Sangay  | Ecuador  | 2.005°S, 78.341°W  | Summit elev. 5286 m



IG reported that a notable increase in seismicity at Sangay began at around
1000 on 12 August and was followed by the effusion of a lava flow that
descended more than 1 km on the SE flank. Strombolian activity was visible
at the summit. Ash plumes rose as high as 3.5 km above the summit and
drifted 500 km W and SW, past the coastline, and caused daily ashfall in
the provinces of Chimborazo and Guayas during 12-16 August. The Guayaquil
International Airport canceled several commercial flights on 13 August due
to the presence of ash in the atmosphere. Seismicity decreased to previous
levels by 16 August.



Geologic Summary. The isolated Sangay volcano, located east of the Andean
crest, is the southernmost of Ecuador's volcanoes and its most active. The
steep-sided, glacier-covered, dominantly andesitic volcano grew within
horseshoe-shaped calderas of two previous edifices, which were destroyed by
collapse to the east, producing large debris avalanches that reached the
Amazonian lowlands. The modern edifice dates back to at least 14,000 years
ago. It towers above the tropical jungle on the east side; on the other
sides flat plains of ash have been sculpted by heavy rains into
steep-walled canyons up to 600 m deep. The earliest report of a historical
eruption was in 1628. More or less continuous eruptions were reported from
1728 until 1916, and again from 1934 to the present. The almost constant
activity has caused frequent changes to the morphology of the summit crater
complex.



Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLO3kkoHe$  
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFdVVnPqc$>





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



The eruption at Semeru continued during 10-16 August. The Darwin VAAC
reported that during 13-16 August ash plumes rose to altitudes of 4.3-4.6
km (14,000-15,000 ft) a.s.l. and drifted SW and W based on satellite images
and wind models. 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: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLKA3ploY$  
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFqfmHOAc$>





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 4-11 August. A
daily thermal anomaly was identified in satellite images, and gas-and-steam
plumes containing some ash were visible drifting 70 km E and SE during 8-9
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 high, isolated massif of Sheveluch volcano (also
spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most
active volcanic structures. 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 dot its outer flanks. The Molodoy
Shiveluch lava dome complex was constructed during the Holocene within the
large horseshoe-shaped caldera; Holocene lava dome extrusion also took
place on the flanks of Stary Shiveluch. At least 60 large eruptions have
occurred during the Holocene, making it the most vigorous andesitic volcano
of the Kuril-Kamchatka arc. 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLCsNl5oq$  
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFs2WGQUE$>





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



JMA reported that the number of daily explosions at Suwanosejima's Ontake
Crater began increasing on 2 August and remained elevated through 7 August;
their frequency began decreasing on 8 August. About 11 explosions were
recorded during 8-15 August. Eruption plumes rose as high as 2 km above the
crater rim and large ballistics were ejected as far as 800 m from the
crater. Incandescence from the crater was often visible at night. 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, spindle-shaped 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. Suwanosejima, one of Japan's most frequently active
volcanoes, was in a state of intermittent strombolian activity from Otake,
the NE summit crater, that began in 1949 and lasted until 1996, after which
periods of inactivity lengthened. The largest historical 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 horseshoe-shaped 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!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLK5Ya1I3$  
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFo4fANuo$>





Taal  | Luzon (Philippines)  | 14.002°N, 120.993°E  | Summit elev. 311 m



PHIVOLCS reported that sulfur dioxide emissions at Taal averaged
3,802-6,844 tonnes per day during 9-10 and 12-15 August; a high of 13,572
tonnes per day was recorded on 11 August causing significant vog around the
caldera and a sulfur odor reported by residents of Banyaga, (Agoncillo),
Poblacion 5, Boso-boso, and Gulod (Laurel), and Poblacion (Talisay).
Upwelling volcanic gasses and fluids in the lake were visible, along with
voluminous steam-rich plumes that rose as high as 3 km above the lake and
drifted mainly NE, SE, and SW. The Alert Level remained at 1 (on a scale of
0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island
was a Permanent Danger Zone (PDZ).



Geologic Summary. Taal is one of the most active volcanoes in the
Philippines and has produced some of its most powerful historical
eruptions. Though not topographically prominent, its prehistorical
eruptions have greatly changed the landscape of SW Luzon. The 15 x 20 km
Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2
surface lies only 3 m above sea level. The maximum depth of the lake is 160
m, and several eruptive centers lie submerged beneath the lake. The
5-km-wide Volcano Island in north-central Lake Taal is the location of all
observed eruptions. The island is composed of coalescing small
stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows
and surges have caused many fatalities.



Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!YvR2uMfCh1vCZK8DsOEn9laVvxNgaxdI6GCtFSX-gXeZ9v3MRYpznYnSmkZwUifzojppbWeVLKz0oqqY$  
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!fYqxrejwenqrx4L1rCG2axXtqmynMOPuGJn61e8NZEgxEML0wkOGcpHHyBO4nxkwMxHFjgjj8N8$>




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

End of Volcano Digest - 15 Aug 2022 to 17 Aug 2022 (#2022-83)
*************************************************************


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