Smithsonian / USGS Weekly Volcanic Activity Report 23 February-1 March 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

23 February-1 March 2022



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

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-jVZNl8Q$ 
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9tIRS7eo$>





New Activity/Unrest: Asosan, Kyushu (Japan)  | Ontakesan, Honshu (Japan)  |
Telica, Sierra de los Marrabios



Ongoing Activity: Ambae, Vanuatu  | Ambrym, Vanuatu  | Davidof, Aleutian
Islands (USA)  | Etna, Sicily (Italy)  | Great Sitkin, Andreanof Islands
(USA)  | Karymsky, Eastern Kamchatka (Russia)  | Kilauea, Hawaiian Islands
(USA)  | Merapi, Central Java  | Pavlof, Alaska Peninsula, Alaska  |
Sabancaya, Peru  | Sangay, Ecuador  | Semeru, Eastern Java  |
Semisopochnoi, Aleutian Islands (USA)  | Sheveluch, Central Kamchatka
(Russia)  | Stromboli, Aeolian Islands (Italy)  | Suwanosejima, Ryukyu
Islands (Japan)  | Turrialba, Costa Rica  | Wolf, Isla Isabela (Galapagos)
| Yasur, Vanuatu





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





Asosan  | Kyushu (Japan)  | 32.884°N, 131.104°E  | Summit elev. 1592 m



JMA reported that the amplitude of volcanic tremor signals at Asosan
increased at around 0500 on 24 February and then increased again around
0900. About 45 minutes later JMA raised the Alert Level to 3 (on a scale of
1-5) and warned the public to stay at least 2 km away from the crater.
Tremor amplitude decreased at around 1540 on 27 February. White plumes
continued to rise 700-800 m above the crater rim during 24-28 February.



Geologic Summary. The 24-km-wide Asosan caldera was formed during four
major explosive eruptions from 300,000 to 90,000 years ago. These produced
voluminous pyroclastic flows that covered much of Kyushu. The last of
these, the Aso-4 eruption, produced more than 600 km3 of airfall tephra and
pyroclastic-flow deposits. A group of 17 central cones was constructed in
the middle of the caldera, one of which, Nakadake, is one of Japan's most
active volcanoes. It was the location of Japan's first documented
historical eruption in 553 CE. The Nakadake complex has remained active
throughout the Holocene. Several other cones have been active during the
Holocene, including the Kometsuka scoria cone as recently as about 210 CE.
Historical eruptions have largely consisted of basaltic to
basaltic-andesite ash emission with periodic strombolian and
phreatomagmatic activity. The summit crater of Nakadake is accessible by
toll road and cable car, and is one of Kyushu's most popular tourist
destinations.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-Ok3RytE$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9TsQDy40$>





Ontakesan  | Honshu (Japan)  | 35.893°N, 137.48°E  | Summit elev. 3067 m



JMA reported that the number of volcanic earthquakes at Ontakesan began
increasing at 1415 on 23 February. Four minutes later a volcanic tremor
signal was detected along with uplift on the S flank. At 1635 JMA raised
the Alert Level to 2 (on a scale of 1-5). The report warned the public to
stay at least 1 km away from Crater 79-7 on the SW flank of the Kenga-mine
summit. After a peak on 25 February, the number of daily volcanic
earthquakes began to decline; there were two volcanic earthquakes recorded
on 24 February, a total of 17 on 25 February, 4-5 per day during 26-28
February, and 3 on 1 March. During an overflight on 25 February scientists
observed no changes in the fumarolic areas or other morphological changes
on the volcano.



Geologic Summary. The massive Ontakesan stratovolcano, the second highest
volcano in Japan, lies at the southern end of the Northern Japan Alps.
Ascending this volcano is one of the major objects of religious pilgrimage
in central Japan. It is constructed within a largely buried 4 x 5 km
caldera and occupies the southern end of the Norikura volcanic zone, which
extends northward to Yakedake volcano. The older volcanic complex consisted
of at least four major stratovolcanoes constructed from about 680,000 to
about 420,000 years ago, after which Ontakesan was inactive for more than
300,000 years. The broad, elongated summit of the younger edifice is cut by
a series of small explosion craters along a NNE-trending line. Several
phreatic eruptions post-date the roughly 7300-year-old Akahoya tephra from
Kikai caldera. The first historical eruption took place in 1979 from
fissures near the summit. A non-eruptive landslide in 1984 produced a
debris avalanche and lahar that swept down valleys south and east of the
volcano. Very minor phreatic activity caused a dusting of ash near the
summit in 1991 and 2007. A significant phreatic explosion in September
2014, when a large number of hikers were at or near the summit, resulted in
many fatalities.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-Ok3RytE$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9TsQDy40$>





Telica  | Sierra de los Marrabios  | 12.606°N, 86.84°W  | Summit elev. 1036
m



Based on satellite and webcam images, the Washington VAAC reported that
during 21-24 and 27-28 February multiple ash emissions at Telica rose as
high as 1.5 km (5,000 ft) a.s.l. and drifted as far as 55 km W, WSW, and SW.



Geologic Summary. Telica, one of Nicaragua's most active volcanoes, has
erupted frequently since the beginning of the Spanish era. This volcano
group consists of several interlocking cones and vents with a general NW
alignment. Sixteenth-century eruptions were reported at symmetrical Santa
Clara volcano at the SW end of the group. However, its eroded and breached
crater has been covered by forests throughout historical time, and these
eruptions may have originated from Telica, whose upper slopes in contrast
are unvegetated. The steep-sided cone of Telica is truncated by a
700-m-wide double crater; the southern crater, the source of recent
eruptions, is 120 m deep. El Liston, immediately E, has several nested
craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE
of Telica, form a prominent geothermal area frequented by tourists, and
geothermal exploration has occurred nearby.



Source: Washington Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-Fh2etGc$ 
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9AiGol6E$>





Ongoing Activity





Ambae  | Vanuatu  | 15.389°S, 167.835°E  | Summit elev. 1496 m



On 24 February the Vanuatu Meteorology and Geo-Hazards Department (VMGD)
reported that explosions at the cone in Ambaeâ??s Lake Voui continued to
produce steam and ash emissions. The Alert Level remained at 2 (on a scale
of 0-5) and the public was warned to stay outside of the Danger Zone
defined as a 2-km radius around the active vents in Lake Voui and away from
drainages during heavy rains.



Geologic Summary. The island of Ambae, also known as Aoba, is a massive
2,500 km3 basaltic shield that is the most voluminous volcano of the New
Hebrides archipelago. A pronounced NE-SW-trending rift zone dotted with
scoria cones gives the 16 x 38 km island an elongated form. A broad
pyroclastic cone containing three crater lakes (Manaro Ngoru, Voui, and
Manaro Lakua) is located at the summit within the youngest of at least two
nested calderas, the largest of which is 6 km in diameter. That large
central edifice is also called Manaro Voui or Lombenben volcano.
Post-caldera explosive eruptions formed the summit craters about 360 years
ago. A tuff cone was constructed within Lake Voui (or Vui) about 60 years
later. The latest known flank eruption, about 300 years ago, destroyed the
population of the Nduindui area near the western coast.



Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)
https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-fbMRl5U$ 
<https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9G-ZWhWY$>





Ambrym  | Vanuatu  | 16.25°S, 168.12°E  | Summit elev. 1334 m



On 24 February the Vanuatu Meteorology and Geo-Hazards Department (VMGD)
reported that nighttime crater incandescence from Ambrymâ??s Benbow Crater
was no longer visible, though steam emissions persisted. The Alert Level
remained at 2 (on a scale of 0-5). VMGD warned the public to stay outside
of the Permanent Danger Zone A, defined as a 1-km radius around Benbow
Crater and a 2-km radius around Marum Crater, and additionally to stay 500
m away from the ground cracks created by the December 2018 eruption.



Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide
caldera, is one of the most active volcanoes of the New Hebrides Arc. A
thick, almost exclusively pyroclastic sequence, initially dacitic then
basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera
was formed during a major Plinian eruption with dacitic pyroclastic flows
about 1,900 years ago. Post-caldera eruptions, primarily from Marum and
Benbow cones, have partially filled the caldera floor and produced lava
flows that ponded on the floor or overflowed through gaps in the caldera
rim. Post-caldera eruptions have also formed a series of scoria cones and
maars along a fissure system oriented ENE-WSW. Eruptions have apparently
occurred almost yearly during historical time from cones within the caldera
or from flank vents. However, from 1850 to 1950, reporting was mostly
limited to extra-caldera eruptions that would have affected local
populations.



Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)
https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-fbMRl5U$ 
<https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9G-ZWhWY$>





Davidof  | Aleutian Islands (USA)  | 51.97°N, 178.33°E  | Summit elev. 328 m



According to AVO the earthquake swarm that began on 24 January in the
vicinity at Davidof continued at least through 1 March with a few small
earthquakes recorded each day. The swarm was either related to tectonic
processes or volcanic unrest. The Aviation Color Code remained at Yellow
and the Volcano Alert Level remained at Advisory.



Geologic Summary. A cluster of small islands between Segula and Little
Sitkin in the western Aleutians, the largest of which is Davidof, are
remnants of a stratovolcano that collapsed during the late Tertiary,
forming a 2.7-km-wide caldera. The islands include Khvostof, Pyramid, Lopy,
and Davidof; the latter three form the eastern rim of the mostly submarine
caldera, sometimes referred to as the "Aleutian Krakatau." The islands were
constructed above a roughly 100-m-deep submarine platform extending NW to
Segula Island; the floor of the caldera lies 80 m below sea level. The
islands are vegetated, but lava flows are recognizable, and Smith et al.
(1978) suggested a possible Holocene age.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-TtUoZEw$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc90Li9L54$>





Etna  | Sicily (Italy)  | 37.748°N, 14.999°E  | Summit elev. 3320 m



INGV reported that during 23-25 February activity at Etnaâ??s Southeast
Crater (SEC) was characterized by Strombolian activity and occasional ash
emissions that rapidly dispersed to the SSW and SSE. At 1338 on 24 February
a forceful ash emission from Northeast Crater drifted SSE. A diffuse ash
emission rose from the same crater at 1642. Emissions at Bocca Nuova Crater
consisted mainly of gas with occasional minor ash content during 21-27
February.



Geologic Summary. Mount Etna, towering above Catania, Sicily's second
largest city, has one of the world's longest documented records of
historical volcanism, dating back to 1500 BCE. Historical lava flows of
basaltic composition cover much of the surface of this massive volcano,
whose edifice is the highest and most voluminous in Italy. The Mongibello
stratovolcano, truncated by several small calderas, was constructed during
the late Pleistocene and Holocene over an older shield volcano. The most
prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km
horseshoe-shaped caldera open to the east. Two styles of eruptive activity
typically occur, sometimes simultaneously. Persistent explosive eruptions,
sometimes with minor lava emissions, take place from one or more summit
craters. Flank vents, typically with higher effusion rates, are less
frequently active and originate from fissures that open progressively
downward from near the summit (usually accompanied by Strombolian eruptions
at the upper end). Cinder cones are commonly constructed over the vents of
lower-flank lava flows. Lava flows extend to the foot of the volcano on all
sides and have reached the sea over a broad area on the SE flank.



Source: Sezione di Catania - Osservatorio Etneo (INGV)
https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-9A_gmUc$ 
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9juG3Bww$>





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



AVO reported that slow lava effusion at Great Sitkin likely continued
during 23 February-1 March and very low seismicity persisted. Weakly
elevated surface temperatures at the summit were detected during 25-28
February. 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-TtUoZEw$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc90Li9L54$>





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



KVERT reported that a thermal anomaly over Karymsky was visible in
satellite images during 20 and 23-24 February. The volcano was either quiet
or obscured by clouds on the other days during 18-25 February. 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-hHIc0NE$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9vgX1S1E$>





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



HVO reported that lava effusion at the vent of the main cone in the lower W
wall of Kilaueaâ??s Halema`uma`u Crater continued at variable rates during 22
February-1 March. Effusion from the vent sometimes paused, including from
the early afternoon on 23 February to 2115 on 27 February, from 1500 on 26
February to 1000 on 27 February, and again beginning at 0130 on 1 March.
When the vent was active lava flowed S and W, into the W part of the lava
lake. Lava occasionally oozed out from the margins of the lake. The lake
level fluctuated through the week, likely reflecting the lava supply along
with periods of inflation and deflation. 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-7_Oidpc$ 
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9GjWSU5Y$>





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



BPPTKG reported that both of Merapiâ??s two lava domes, situated just below
the SW rim and in the summit crater, effused lava during 18-24 February.
Based on analysis of drone data the volumes of the SW and central domes
were an estimated 1.58 and 3.23 million cubic meters, respectively.
Seismicity remained at high levels. In the SW-flank Bebeng drainage there
were as many as 173 lava avalanches that traveled a maximum of 2 km and one
pyroclastic flow that extended 1.8 km. Minor ashfall was reported in the
Pakem District on 18 February. The Alert Level remained at 3 (on a scale of
1-4), and the public was warned to stay 3-5 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-LCLRHjc$ 
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9WE5tsog$>





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



AVO reported that the eruption at Pavlof was ongoing during 23 February-1
March. Lava effusion continued from a vent just E of the summit and sent a
lava flow a short distance down the NE flank. Seismicity was higher with
periods of tremor, and elevated surface temperatures were periodically
identified in satellite images; both were consistent with continuing lava
effusion. Small explosions were detected during 24 and 26-28 February. 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-TtUoZEw$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc90Li9L54$>





Sabancaya  | Peru  | 15.787°S, 71.857°W  | Summit elev. 5960 m



Instituto Geofísico del Perú (IGP) reported moderate levels of activity at
Sabancaya during 21-27 February with a daily average of 35 explosions.
Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted NW,
W, SW, and S. Three thermal anomalies originating from the lava dome in the
summit crater were identified in satellite data. Minor inflation continued
to be detected near Hualca Hualca (4 km N). The Alert Level remained at
Orange (the second highest level on a four-color scale) and the public were
warned to stay outside of a 12-km radius.



Geologic Summary. Sabancaya, located in the saddle NE of Ampato and SE of
Hualca Hualca volcanoes, is the youngest of these volcanic centers and the
only one to have erupted in historical time. The oldest of the three,
Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene
age. The name Sabancaya (meaning "tongue of fire" in the Quechua language)
first appeared in records in 1595 CE, suggesting activity prior to that
date. Holocene activity has consisted of Plinian eruptions followed by
emission of voluminous andesitic and dacitic lava flows, which form an
extensive apron around the volcano on all sides but the south. Records of
historical eruptions date back to 1750.



Source: Instituto Geofísico del Perú (IGP) https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-m4OsSnI$ 
<https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9wX9UlRA$>





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



IG reported a high level of activity at Sangay during 22 February-1 March.
Weather clouds and rain often prevented visual and webcam observations of
the volcano, though daily ash-and-gas plumes were identified in satellite
images by the Washington VAAC or in webcam views; plumes rose as high as 2
km above the volcano and drifted N, NW, W, and SW. Multiple daily thermal
anomalies over the volcano were visible in satellite data.



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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-YcOUX04$ 
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9LQaM8I0$>





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



PVMBG reported that eruptions at Semeru recorded at 0605 on 24 February,
0538, 0557, and 0755 on 25 February, 0535 on 27 February, and 0555 on 29
February generated ash plumes that rose 500-700 m above the summit and
drifted N and SW. The Alert Level remained at 3 (on a scale of 1-4). The
public was warned to stay at least 500 m away 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-bIHmLIM$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc93jjSIR8$>





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



AVO reported that low-level eruptive activity at Semisopochnoi's North
Cerberus cone continued during 23 February-1 March. Seismicity was elevated
with low-level tremor and daily small explosions. Weather clouds sometimes
prevented satellite and webcam views of the volcano, though low ash clouds
from the summit were visible on most days. Ash deposits on the N flank were
visible in a few 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-TtUoZEw$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc90Li9L54$>





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



KVERT reported that a thermal anomaly over Sheveluch was identified in
satellite images during 18-25 February. 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-hHIc0NE$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9vgX1S1E$>





Stromboli  | Aeolian Islands (Italy)  | 38.789°N, 15.213°E  | Summit elev.
924 m



INGV reported that during 21-27 February activity at Stromboli was
characterized by ongoing explosions from three vents in Area N (North
Crater area) and three vents in Area C-S (South-Central Crater area).
Explosions from Area N vents (N1 and N2) averaged 2-5 events per hour;
explosions from the N1 vent ejected lapilli and bombs 80-150 m high and
those at two N2 vents ejected material less than 80 m high. N2 produced
weak and occasional spattering. No explosions occurred at the S1 and C
vents in Area C-S; low-intensity explosions at the two S2 vents occurred at
a rate of 4-9 per hour and ejected coarse material no higher than 80 m.



Geologic Summary. Spectacular incandescent nighttime explosions at this
volcano have long attracted visitors to the "Lighthouse of the
Mediterranean." Stromboli, the NE-most of the Aeolian Islands, has lent its
name to the frequent mild explosive activity that has characterized its
eruptions throughout much of historical time. The small island is the
emergent summit of a volcano that grew in two main eruptive cycles, the
last of which formed the western portion of the island. The Neostromboli
eruptive period took place between about 13,000 and 5,000 years ago. The
active summit vents are located at the head of the Sciara del Fuoco, a
prominent horseshoe-shaped scarp formed about 5,000 years ago due to a
series of slope failures that extend to below sea level. The modern volcano
has been constructed within this scarp, which funnels pyroclastic ejecta
and lava flows to the NW. Essentially continuous mild Strombolian
explosions, sometimes accompanied by lava flows, have been recorded for
more than a millennium.



Source: Sezione di Catania - Osservatorio Etneo (INGV)
https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-9A_gmUc$ 
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9juG3Bww$>





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



JMA reported that 13 explosions were recorded at Suwanosejima's Ontake
Crater during 21-28 February. The explosions produced ash plumes that rose
as high as 2.2 km above the crater rim and ejected blocks 300-400 m away
from the crater. Ashfall was reported in Toshima village (3.5 km SSW) and
crater incandescence was visible nightly. The Alert Level remained at 3 and
the public was warned to stay 2 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!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-Ok3RytE$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9TsQDy40$>





Turrialba  | Costa Rica  | 10.025°N, 83.767°W  | Summit elev. 3340 m



OVSICORI-UNA reported that a point of incandescence on the SW wall of
Turrialbaâ??s Cráter Oeste was visible on 23 February and was coincident with
the area of strongest gas emissions. At 1955 on 27 February an eruption
produced a diffuse ash plume that rose 300 m above the summit and drifted
NE. Rumbling heard on 28 February was sometimes coincident with minor ash
emissions.



Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene
volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located
across a broad saddle NE of Irazú volcano overlooking the city of Cartago.
The massive edifice covers an area of 500 km2. Three well-defined craters
occur at the upper SW end of a broad 800 x 2200 m summit depression that is
breached to the NE. Most activity originated from the summit vent complex,
but two pyroclastic cones are located on the SW flank. Five major explosive
eruptions have occurred during the past 3500 years. A series of explosive
eruptions during the 19th century were sometimes accompanied by pyroclastic
flows. Fumarolic activity continues at the central and SW summit craters.



Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad
Nacional (OVSICORI-UNA) https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-94LbAyo$ 
<https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9_sSpMeY$>





Wolf  | Isla Isabela (Galapagos)  | 0.02°N, 91.35°W  | Summit elev. 1710 m



IG reported that the eruption at Wolf continued during 23 February-1 March.
Daily thermal alert counts, as high as around 253, indicated active and
advancing lava flows on the SE flank.



Geologic Summary. Wolf, the highest volcano of the Galápagos Islands,
straddles the equator at the north end of the archipelago's largest island,
Isabela. The 1710-m-high edifice has steeper slopes than most other Isabela
volcanoes, reaching angles up to 35 degrees. A 6 x 7 km caldera, at 700 m
one of the deepest of the Galápagos Islands, is located at the summit. A
prominent bench on the west side of the caldera rises 450 above the caldera
floor, much of which is covered by a lava flow erupted in 1982. Radial
fissures concentrated along diffuse rift zones extend down the north, NW,
and SE flanks, and submarine vents lie beyond the north and NW fissures.
Similar unvegetated flows originating from a circumferential chain of
spatter and scoria cones on the eastern caldera rim drape the forested
flanks to the sea. The proportion of aa lava flows at Volcán Wolf exceeds
that of other Galápagos volcanoes. An eruption in in 1797 was the first
documented historical eruption in the Galápagos Islands.



Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-YcOUX04$ 
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9LQaM8I0$>





Yasur  | Vanuatu  | 19.532°S, 169.447°E  | Summit elev. 361 m



The Vanuatu Meteorology and Geohazards Department (VMGD) reported that
activity at Yasur continued at a high level of â??major unrest,â?? as defined
by the Alert Level 2 status (the middle level on a scale of 0-4).
Ash-and-gas emissions and loud explosions continued to be recorded, with
bombs falling in and around the crater. The public was reminded not to
enter the restricted area within 600 m around the cone, defined by Danger
Zone A on the hazard map.



Geologic Summary. Yasur, the best-known and most frequently visited of the
Vanuatu volcanoes, has been in more-or-less continuous Strombolian and
Vulcanian activity since Captain Cook observed ash eruptions in 1774. This
style of activity may have continued for the past 800 years. Located at the
SE tip of Tanna Island, this mostly unvegetated pyroclastic cone has a
nearly circular, 400-m-wide summit crater. The active cone is largely
contained within the small Yenkahe caldera, and is the youngest of a group
of Holocene volcanic centers constructed over the down-dropped NE flank of
the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the
Siwi ring fracture, a 4-km-wide, horseshoe-shaped caldera associated with
eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along
the Yenkahe horst accompanying eruptions has raised Port Resolution harbor
more than 20 m during the past century.



Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)
https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-fbMRl5U$ 
<https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!NUpFu3ipe7bd_B38MbTSGtdXhhpju5xBTs2B_XHAqgZeN24Fb6VU5wc9G-ZWhWY$>



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



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



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

PSU - https://urldefense.com/v3/__http://pdx.edu/__;!!IKRxdwAv5BmarQ!PVtIHC4WU8reUjAvlK_qgTYa028pqydp3MoMpra3Lka7VjXcR1cIKsM-0EXzPCw$ 

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End of Volcano Digest - 1 Mar 2022 to 2 Mar 2022 (#2022-26)
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