Smithsonian / USGS Weekly Volcanic Activity Report 17-23 April 2024

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


Smithsonian / USGS Weekly Volcanic Activity Report

17-23 April 2024



Sally Sennert - Weekly Report Editor (kuhns@xxxxxx)

URL: https://volcano.si.edu/reports_weekly.cfm
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOSq7GBXw$>





New Activity/Unrest: Bagana, Bougainville (Papua New Guinea)  | Poas, Costa
Rica  | Ruang, Sangihe Islands  | Semeru, Eastern Java  | Taal, Luzon
(Philippines)



Ongoing Activity: Aira, Kyushu (Japan)  | Dukono, Halmahera  | Ebeko,
Paramushir Island (Russia)  | Fernandina, Isla Fernandina (Galapagos)  |
Great Sitkin, Andreanof Islands (USA)  | Ibu, Halmahera  | Kavachi, Solomon
Islands  | Krakatau, Sunda Strait  | Lateiki, Tonga Ridge  | Lewotobi,
Flores Island  | Lewotolok, Lembata Island  | Marapi, Central Sumatra  |
Merapi, Central Java  | Popocatepetl, Mexico  | Reykjanes, Reykjanes
Peninsula  | Sheveluch, Central Kamchatka (Russia)  | Stromboli, Aeolian
Islands (Italy)  | Suwanosejima, Ryukyu Islands (Japan)





The Weekly Volcanic Activity Report is a cooperative project between the
Smithsonian's Global Volcanism Program and the US Geological Survey's
Volcano Hazards Program. Updated by 2300 UTC every Wednesday, these reports
are preliminary and subject to change as events are studied in more detail.
This is not a comprehensive list of all of Earth's volcanoes erupting
during the week, but rather a summary of activity at volcanoes that meet
criteria discussed in detail in the "Criteria and Disclaimers" section.
Carefully reviewed, detailed reports about recent activity are published in
issues of the Bulletin of the Global Volcanism Network.



Note that many news agencies do not archive the articles they post on the
Internet, and therefore the links to some sources may not be active. To
obtain information about the cited articles that are no longer available on
the Internet contact the source.







New Activity/Unrest





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



The Darwin VAAC reported that an ash plume from Bagana was identified in
satellite images rising to 2.1 km (7,000 ft) a.s.l. and drifting SW at 0820
on 22 April. The plume had dissipated by 1420.



Geologic Summary. Bagana volcano, in a remote portion of central
Bougainville Island, is frequently active. This massive symmetrical cone
was largely constructed by an accumulation of viscous andesitic lava flows.
The entire edifice could have been constructed in about 300 years at its
present rate of lava production. Eruptive activity is characterized by
non-explosive effusion of viscous lava that maintains a small lava dome in
the summit crater, although occasional explosive activity produces
pyroclastic flows. Lava flows with tongue-shaped lobes up to 50 m thick and
prominent levees descend the flanks on all sides.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIMjFiDteg$>





Poas  | Costa Rica  | 10.2°N, 84.233°W  | Summit elev. 2697 m



OVSICORI-UNA reported continuing gas-and-steam emissions rose from vents
Boca A and Boca B on the crater floor of Poás. Ash ceased to be detected in
the emissions at some point during 16-17 April but was again present during
22-23 April.



Geologic Summary. The broad vegetated edifice of Poás, one of the most
active volcanoes of Costa Rica, contains three craters along a N-S line.
The frequently visited multi-hued summit crater lakes of the
basaltic-to-dacitic volcano are easily accessible by vehicle from the
nearby capital city of San José. A N-S-trending fissure cutting the complex
stratovolcano extends to the lower N flank, where it has produced the Congo
stratovolcano and several lake-filled maars. The southernmost of the two
summit crater lakes, Botos, last erupted about 7,500 years ago. The more
prominent geothermally heated northern lake, Laguna Caliente, is one of the
world's most acidic natural lakes, with a pH of near zero. It has been the
site of frequent phreatic and phreatomagmatic eruptions since an eruption
was reported in 1828. Eruptions often include geyser-like ejections of
crater-lake water.



Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad
Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/
<https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIM0cZU5lg$>





Ruang  | Sangihe Islands  | 2.3°N, 125.37°E  | Summit elev. 725 m



PVMBG raised the Alert Level for Ruang to 2 (on a scale of 1-4) at 1300 on
16 April due to intensifying seismicity. A minor eruption began at around
1337 on 16 April and produced dense white emissions; at 1600 the Alert
Level was raised to 3 (on a scale of 1-4). Explosive activity began at 2145
and ash plumes rose 2 km above the summit. Activity continued to escalate.
An explosive pulse was recorded at 0108 on 17 April. According to the
Darwin VAAC ash plumes had risen to 9.1 km (30,000 ft) a.s.l. and drifted W
by 0230, and at 0300 they reached 12.2 km (40,000 ft) a.s.l. and detached
from the summit. Ash plumes at a lower altitude of 4.6 km (15,000 ft)
a.s.l. drifted WSW. BNPB reported that 828 people from Pumpente and
Laingpatehi villages evacuated to neighboring Tagulandang Island to the NE
and the communication network in Laingpatehi village was non-operational.
Photos showed incandescent material being ejected above the summit,
incandescent material on the flanks, pyroclastic density currents
descending the flanks, and dense ash plumes with lightning rising into
dark, nighttime skies. Another explosive pulse was recorded at 0505
according to PVMBG, and the VAAC noted that by 0600 ash plumes had risen to
13.7 km (45,000 ft) a.s.l. and drifted W and NW. The plume was detached
from the summit by 0713. Additional smaller eruptive events produced ash
plumes that rose to 1.5 km (5,000 ft) a.s.l. and drifted E.



PVMBG recorded bigger eruptive pulses at 1800 and 2015 on 17 April. Roaring
and booming noises were sometimes heard, with gray-to-black ash plumes at
2015 and a felt earthquake. According to the VAAC ash plumes rose to 15.2
km (50,000 ft) a.s.l. by 2000 and at least to 19.2 km (63,000 ft) a.s.l. by
2020; the plumes drifted NW. PVMBG raised the Alert Level to 4, the highest
level, at 2100 on 17 April noting that seismicity continued to increase,
ash plumes were getting taller, and incandescent rocks were ejected as far
as 5 km with some reaching Tagulandang Island. The public was warned to
stay 6 km away from Ruangâ??s main crater. Several residents in Tagulandang
were hit with tephra and some received medical treatment according to BNPB.
Ashfall was recorded in as many as 10 villages in two sub-districts on
Tagulandang and in several sub-districts of North Minahasa Regency (75 km
SSW) including West Likupang, Wori, East Likupang, and South Likupang.
Communication networks in Lumbo Village on Tagulandang were not properly
functioning. An estimated 6,045 people living in the W part Tagulandang
evacuated. According to a news article, there was damage to more than 3,000
homes, two churches, and an elementary school.



Multiple ash layers were identified in a satellite image 2310 on 17 April
according to the VAAC; ash at 16.8 km (55,000 ft) a.s.l. drifted NW and E
and ash at 14.3 km (47,000 ft) a.s.l. drifted WSW. At 0310 on 18 April ash
plumes rose to 12.2 km and drifted WNW and W and detached from the volcano
by 0600; earlier high-level plumes continued to expand as they drifted NW.
According to a news report the Sam Ratulangi International Airport, 98 km
SW in Manado, North Sulawesi, closed on 18 April due to the presence of ash.



The VAAC continued to track the plumes; lower-altitude plumes at 7.6 km
(25,000 ft) a.s.l. drifted SE. The higher plumes, between 10.7-15.2 km
(35,000-50,000 ft) a.s.l., continued to drift NW and WNW and had dissipated
by 1710 on 19 April, though sulfur dioxide continued to be tracked W.
Weather clouds began to obscure the plumes. On 19 April PVMBG reported that
ash plumes rose 400-750 m above the summit and drifted S. During 20-21
April the VAAC issued notifications of ash plumes rising 1.5-2.1 km
(5,000-7,000 ft) a.s.l. and drifting S and SW based on satellite images and
information from PVMBG. The closure of the Sam Ratulangi International
Airport affected 150 flights and about 19,085 passengers as of 20 April
based on a news report; the airport resumed operations at noon on 22 April.
PVMBG reported that during 21-23 April dense white steam-and-gas plumes
rose as high as 200 m and drifted SW, W, and NW. The Alert Level was
lowered to 3 at 0900 on 22 April because activity had decreased. Residents
were warned to stay 4 km away from the crater.



Geologic Summary. Ruang volcano is the southernmost volcano in the Sangihe
Island arc, north of Sulawesi Island; it is not the better known Raung
volcano on Java. The 4 x 5 km island volcano is across a narrow strait SW
of the larger Tagulandang Island. The summit contains a crater partially
filled by a lava dome initially emplaced in 1904. Explosive eruptions
recorded since 1808 have often been accompanied by lava dome formation and
pyroclastic flows that have damaged inhabited areas.



Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>
;

Badan Nacional Penanggulangan Bencana (BNPB) http://www.bnpb.go.id/
<https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIP1DZfTyA$>
;

Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIMjFiDteg$>
;

Antara News
https://en.antaranews.com/news/311370/manado-airport-focusing-on-flight-safety-due-to-mt-ruang-eruption
<https://urldefense.com/v3/__https://en.antaranews.com/news/311370/manado-airport-focusing-on-flight-safety-due-to-mt-ruang-eruption__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIMjyINMKg$>
;

Antara News
https://en.antaranews.com/news/311343/mt-ruang-eruption-damages-498-houses-public-facilities-bnpb
<https://urldefense.com/v3/__https://en.antaranews.com/news/311343/mt-ruang-eruption-damages-498-houses-public-facilities-bnpb__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOPHQQq-g$>
;

Tempo
https://en.tempo.co/read/1859499/manado-airport-reopens-after-closure-due-to-mount-ruang-eruption
<https://urldefense.com/v3/__https://en.tempo.co/read/1859499/manado-airport-reopens-after-closure-due-to-mount-ruang-eruption__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIP4Nv-xMw$>
;

VOI https://voi.id/en/news/375214
<https://urldefense.com/v3/__https://voi.id/en/news/375214__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOWMETYxQ$>





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



PVMBG reported that eruptive activity continued at Semeru during 17-23
April. White-and-gray or occasionally white-to-brown ash plumes rose
300-1,500 m above the summit and drifted in multiple directions on most
days. Eruptive events were recorded during 17, 19-20, and 22-23 April; no
emissions were visible, possibly due to weather conditions. BNPB reported
that intense rain on 18 April caused lahars in the Regoyo River basin and
in the Mujur and Glidik watersheds in the Lumajang Regency during 18-19
April. Three deaths were reported: one person was buried by landslides in
the Pronojiwo District and two were swept away by lahars in the Candipuro
District. Lahars damaged nine bridges and destroyed an additional eight
bridges, flooded the Candipuro National Road, and damaged three houses. As
many as 32 families self-evacuated. The Alert Level remained at 3 (the
third highest level on a scale of 1-4). The public was warned to stay at
least 5 km away from the summit in all directions, 13 km from the summit to
the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from
the summit, and to avoid other drainages 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.



Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>
;

Badan Nacional Penanggulangan Bencana (BNPB) http://www.bnpb.go.id/
<https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIP1DZfTyA$>





Taal  | Luzon (Philippines)  | 14.0106°N, 120.9975°E  | Summit elev. 311 m



PHIVOLCS reported that sulfur dioxide emissions at Taal had decreased the
last week and averaged 2,104 tonnes per day (t/d) on 18 April; despite the
decrease averages in 2024 remained high at 9,698 t/d. Short-lived phreatic
events were recorded during 0850-0852, 0909-0912, 1102-1107, and 1710-1714
on 20 April based on seismic data and webcam images. White steam plumes
rose 300-600 m above Main Crater and drifted WSW, SW, and NW. During 21-23
April emissions rose 600-900 m and drifted NW and SW and observers noted
pronounced upwelling of gases and hot fluids in the lake. 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) and to
take extra precautions around Main Crater, when boating on Taal Lake, and
along the Daang Kastila fissure.



Geologic Summary. Taal is one of the most active volcanoes in the
Philippines and has produced some powerful eruptions. 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, with several submerged eruptive centers. 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)
http://www.phivolcs.dost.gov.ph/
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOcnMuYkw$>





Ongoing Activity





Aira  | Kyushu (Japan)  | 31.5772°N, 130.6589°E  | Summit elev. 1117 m



JMA reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s
Sakurajima volcano) during 15-22 April with nighttime crater incandescence.
Very small eruptive events were occasionally recorded. The Alert Level
remained at 3 (on a 5-level scale), and the public was warned to stay 2 km
away from both craters.



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 caldera, along
with several post-caldera cones. The construction of Sakurajima began about
13,000 years ago on the southern rim and built an island that was joined to
the Osumi Peninsula during the major explosive and effusive eruption of
1914. Activity at the Kitadake summit cone ended about 4,850 years ago,
after which eruptions took place at Minamidake. Frequent eruptions since
the 8th century have deposited ash on the city of Kagoshima, located across
Kagoshima Bay only 8 km from the summit. The largest recorded eruption took
place during 1471-76.



Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPG3PMbcg$>





Dukono  | Halmahera  | 1.6992°N, 127.8783°E  | Summit elev. 1273 m



PVMBG reported that the eruption at Dukono was ongoing during 17-23 April.
Gray-and-white ash plumes rose 100-1,200 m above the summit and drifted E,
N, and W almost daily; emissions were not observed on 22 April. The Alert
Level remained at Level 2 (on a scale of 1-4), and the public was warned to
remain outside of the 3-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, have occurred since 1933. During a major
eruption in 1550 CE, a lava flow filled in the strait between Halmahera and
the N-flank Gunung Mamuya cone. 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) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





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



KVERT reported that moderate explosive activity was ongoing at Ebeko during
11-18 April. According to volcanologists in Severo-Kurilsk (Paramushir
Island, about 7 km E), explosions during 12-17 April generated ash plumes
that rose as high as 4 km (13,100 ft) a.s.l. and drifted SW, SE, and E. A
thermal anomaly was identified in satellite images on 13 and 16-17 April;
on other days either no activity was observed or weather conditions
prevented views. The Aviation Color Code remained at Orange (the third
level on a four-color scale). Dates are UTC; 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)
http://www.kscnet.ru/ivs/kvert/index_eng.php
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIM39UcPzg$>





Fernandina  | Isla Fernandina (Galapagos)  | 0.37°S, 91.55°W  | Summit
elev. 1476 m



Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that the
eruption at Fernandina continued during 16-23 April. Daily thermal
anomalies were identified in satellite images. Sulfur dioxide emissions,
measured using satellite data, fluctuated between about 207 and 1,418 tons
per day. Gas-and-steam emissions rose from the area where lava entered the
ocean; a 16 April photo showed three bright areas where lava entered the
water and gas-and-steam plumes rising from the entries. During 21-22 April
satellite images showed another lobe of lava low on the flank, descending
towards the shoreline.



Geologic Summary. Fernandina, the most active of Galápagos volcanoes and
the one closest to the Galápagos mantle plume, is a basaltic shield volcano
with a deep 5 x 6.5 km summit caldera. The volcano displays the classic
"overturned soup bowl" profile of Galápagos shield volcanoes. Its caldera
is elongated in a NW-SE direction and formed during several episodes of
collapse. Circumferential fissures surround the caldera and were
instrumental in growth of the volcano. Reporting has been poor in this
uninhabited western end of the archipelago, and even a 1981 eruption was
not witnessed at the time. In 1968 the caldera floor dropped 350 m
following a major explosive eruption. Subsequent eruptions, mostly from
vents located on or near the caldera boundary faults, have produced lava
flows inside the caldera as well as those in 1995 that reached the coast
from a SW-flank vent. Collapse of a nearly 1 km3 section of the east
caldera wall during an eruption in 1988 produced a debris-avalanche deposit
that covered much of the caldera floor and absorbed the caldera lake.



Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
http://www.igepn.edu.ec/
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPzxhcxbQ$>





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



AVO reported that slow lava effusion continued in Great Sitkinâ??s summit
crater during 17-23 April. Slightly elevated surface temperatures were
identified in satellite images during 17-18 April. Seismicity was low with
a few small daily earthquakes recorded by the seismic network. Weather
clouds partly or mostly obscured satellite and webcam views during most of
the week. The Volcano Alert Level remained at Watch (the third level on a
four-level scale) and the Aviation Color Code remained at Orange (the third
color on a four-color scale).



Geologic Summary. The Great Sitkin volcano forms much of the northern side
of Great Sitkin Island. A younger 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
older edifice and produced a submarine debris avalanche. Deposits from this
and an even 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. Eruptions have been recorded
since the late-19th century.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://avo.alaska.edu/
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOWxvNckw$>





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



PVMBG reported that Ibu continued to erupt during 17-23 April.
White-and-gray ash plumes rose 200-2,500 m above the summit and drifted in
multiple directions on 17 and 21 April. White steam-and-gas plumes rose
200-600 m above the summit and drifted in multiple directions on the other
days. The Alert Level remained at 2 (the second highest level on a
four-level scale), with the public advised to stay outside of the 2 km
hazard zone and 3.5 km away from the N area of the active crater.



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) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





Kavachi  | Solomon Islands  | 8.991°S, 157.979°E  | Summit elev. -20 m



Satellite data showed an area of yellow-green discolored water that was
about 4.2 km in diameter in the vicinity of the submarine Kavachi volcano
on 19 April. A more diffuse plume of discolored water extended another ~11
km NE before dissipating.



Geologic Summary. Named for a sea-god of the Gatokae and Vangunu peoples,
Kavachi is located in the Solomon Islands south of Vangunu Island.
Sometimes referred to as Rejo te Kvachi ("Kavachi's Oven"), this shallow
submarine basaltic-to-andesitic volcano has produced ephemeral islands up
to 1 km long many times since its first recorded eruption during 1939.
Residents of the nearby islands of Vanguna and Nggatokae (Gatokae) reported
"fire on the water" prior to 1939, a possible reference to earlier
eruptions. The roughly conical edifice rises from water depths of 1.1-1.2
km on the north and greater depths to the SE. Frequent shallow submarine
and occasional subaerial eruptions produce phreatomagmatic explosions that
eject steam, ash, and incandescent bombs. On a number of occasions lava
flows were observed on the ephemeral islands.



Source: Copernicus https://www.copernicus.eu/en
<https://urldefense.com/v3/__https://www.copernicus.eu/en__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgINskSQ_SA$>





Krakatau  | Sunda Strait  | 6.1009°S, 105.4233°E  | Summit elev. 285 m



On 19 April PVMBG lowered the Alert Level for Krakatau to 2 (on a scale of
1-4) based on visual observations and instrumental data. The public was
warned to stay at least 2 km away from the crater.



Geologic Summary. The renowned Krakatau (frequently mis-named as Krakatoa)
volcano lies in the Sunda Strait between Java and Sumatra. Collapse of an
older 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 the Rakata, Danan, and Perbuwatan cones 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 Danan and Perbuwatan
cones. Anak Krakatau has been the site of frequent eruptions since 1927.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





Lateiki  | Tonga Ridge  | 19.18°S, 174.87°W  | Summit elev. 43 m



Satellite data showed an area of yellowish-green discolored water that was
about 5 km long in the N-S direction and about 3 km in the E-W direction,
in the vicinity of the submarine Lateiki volcano on 21 April. A more
diffuse plume of discolored water extended another ~12 km WNW before
dissipating.



Geologic Summary. Lateiki, previously known as Metis Shoal, is a submarine
volcano midway between the islands of Kao and Late that has produced a
series of ephemeral islands since the first confirmed activity in the
mid-19th century. An island, perhaps not in eruption, was reported in 1781
and subsequently eroded away. During periods of inactivity following
20th-century eruptions, waves have been observed to break on rocky reefs or
sandy banks with depths of 10 m or less. Dacitic tuff cones formed during
the eruptions in 1967 and 1979 were soon eroded beneath the ocean surface.
An eruption in 1995 produced an island with a diameter of 280 m and a
height of 43 m following growth of a lava dome above the surface.



Source: Copernicus https://www.copernicus.eu/en
<https://urldefense.com/v3/__https://www.copernicus.eu/en__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgINskSQ_SA$>





Lewotobi  | Flores Island  | 8.542°S, 122.775°E  | Summit elev. 1703 m



PVMBG reported that during 17-18 and 20-22 April white steam-and-gas plumes
rose as high as 100 m above the summit of Lewotobiâ??s Laki-laki volcano and
drifted N, NE, and E. On 23 April a white-and-gray ash plume rose 100-200 m
and drifted SW and W. The Alert Level remained at 2 (the second lowest
level on a scale of 1-4) and the public was warned to stay outside of the
exclusion zone, defined as a 2-km radius around Laki-laki crater, 3 km to
the NNE, and 5 km on the NE flanks.



Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed
of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan
stratovolcanoes (the "husband and wife"). Their summits are less than 2 km
apart along a NW-SE line. The conical Laki-laki to the NW has been
frequently active during the 19th and 20th centuries, while the taller and
broader Perempuan has had observed eruptions in 1921 and 1935. Small lava
domes have grown during the 20th century in both of the summit craters,
which are open to the north. A prominent cone, Iliwokar, occurs on the E
flank of Perampuan.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





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



PVMBG reported that the eruption at Lewotolok continued during 17-23 April.
White-and-gray ash plumes rose 100-600 m above the summit and drifted SE,
W, and NW almost every day; white emissions rose 300-500 m above the summit
and drifted W and NW during 19-20 April. The Alert Level remained at 3 (on
a scale of 1-4) and the residents of Lamawolo, Lamatokan, and Jontona were
warned to stay 2 km away from the vent and 3 km away from the vent on the S
and SE flanks.



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) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





Marapi  | Central Sumatra  | 0.38°S, 100.474°E  | Summit elev. 2885 m



PVMBG reported that eruptive activity at Marapi (on Sumatra) was ongoing
during 17-22 April. White-and-gray ash plumes rose 250-300 m above the
summit and drifted SE and W on 21 April. White steam-and-gas plumes rose
250-300 m above the summit and drifted in multiple directions on 17, 19,
and 22 April. The Alert Level remained at 3 (on a scale of 1-4), and the
public was warned to stay 4.5 km away from the active crater.



Geologic Summary. Gunung Marapi, not to be confused with the better-known
Merapi volcano on Java, is Sumatra's most active volcano. This massive
complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the
Padang Highlands. A broad summit contains multiple partially overlapping
summit craters constructed within the small 1.4-km-wide Bancah caldera. The
summit craters are located along an ENE-WSW line, with volcanism migrating
to the west. More than 50 eruptions, typically consisting of
small-to-moderate explosive activity, have been recorded since the end of
the 18th century; no lava flows outside the summit craters have been
reported in historical time.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPK0RdWbw$>





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



BPPTKG reported that the eruption at Merapi (on Java) continued during
12-18 April. Seismicity remained at high levels. The SW lava dome produced
111 lava avalanches that traveled as far as 1.7 km down the SW flank. One
pyroclastic flow traveled 1 km SW down the upper part of the Bebeng
drainage. Morphological changes to the SW lava dome were due to continuing
effusion and collapses of material. 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) http://www.merapi.bgl.esdm.go.id/
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIMaI2Wiaw$>





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



CENAPRED reported that eruptive activity continued at Popocatépetl during
16-23 April. The seismic network recorded long-period events totaling
43-171 per day that were sometimes accompanies by steam-and-gas emissions.
The seismic network also recorded 5-14 minutes of tremor each day during
16-19 April and a few volcano-tectonic earthquakes. According to the
Washington VAAC ash plumes visible in webcam and sometimes also satellite
images rose to 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted N, E, and
SE. The Alert Level remained at Yellow, Phase Two (the middle level on a
three-color scale) and the public was warned to stay 12 km away from the
crater.



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.



Sources: Centro Nacional de Prevencion de Desastres (CENAPRED)
https://www.gob.mx/cenapred
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPLwKgVcg$>
;

Washington Volcanic Ash Advisory Center (VAAC)
http://www.ssd.noaa.gov/VAAC/messages.html
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIOF7JrQyA$>





Reykjanes  | Reykjanes Peninsula  | 63.817°N, 22.717°W  | Summit elev. 140 m



IMO reported that the cone just E of Sundhnúk and along the fissure within
the Reykanes volcanic system continued to erupt lava during 15-23 April.
Gas emissions continued to drift downwind and residents were advised to
monitor air quality. Lava flowed a short distance from the crater mostly S
and the flows thickened near the crater. Lava tubes in an area about 1 km
SE transported lava to an active flow field N of Hagafell; webcam images
showed inflation of the part of the flow field located along the barriers E
of Grindavík during 18-23 April. Inflation from magma accumulation beneath
Svartsengi was first detected at the beginning of April and continued at a
steady rate based on modeling of GPS and satellite data.



The average effusion rate was 3-4 cubic meters per second during 1-15
April. Results from a 15 April overflight where scientists acquired images
for mapping showed that the lava-flow field was an estimated 6.15 square
kilometers with an approximate volume of 33.2 (± 0.8) million cubic meters.



Geologic Summary. The Reykjanes volcanic system at the SW tip of the
Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level,
comprises a broad area of postglacial basaltic crater rows and small shield
volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous
with and is considered part of the Reykjanes volcanic system, which is the
westernmost of a series of four closely-spaced en-echelon fissure systems
that extend diagonally across the Reykjanes Peninsula. Most of the
subaerial part of the system (also known as the Reykjanes/Svartsengi
volcanic system) is covered by Holocene lavas. Subaerial eruptions have
occurred in historical time during the 13th century at several locations on
the NE-SW-trending fissure system, and numerous submarine eruptions dating
back to the 12th century have been observed during historical time, some of
which have formed ephemeral islands. Basaltic rocks of probable Holocene
age have been recovered during dredging operations, and tephra deposits
from earlier Holocene eruptions are preserved on the nearby Reykjanes
Peninsula.



Source: Icelandic Meteorological Office (IMO) http://en.vedur.is/
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgINLYJmEYw$>





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



KVERT reported that eruptive activity at Sheveluch continued during 11-18
April with a daily thermal anomaly identified in satellite images. The
Aviation Color Code remained at Orange (the third 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)
http://www.kscnet.ru/ivs/kvert/index_eng.php
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIM39UcPzg$>





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



INGV reported that eruptive activity continued at Stromboli during 15-21
April. Webcam images showed Strombolian activity at two vents in Area N
(one at N1 and one at N2), within the upper part of the Sciara del Fuoco,
and from three vents at S2 in Area C-S (South-Central Crater) in the crater
terrace. Weather conditions and technical difficulties sometimes prevented
observations. At Area N, low- to medium-intensity explosive activity was
observed from sectors N1 and N2 with the eruption of coarse material (bombs
and lapilli) less than 80 m and 150 m above the vents, respectively. The
average frequency of explosions from this area was 4-9 events per hour. At
Area C-S, explosive activity at two vents in sector S2 ejected both coarse
and fine material less than 150 m above the vent. The average explosion
rate was 2-10 events per hour.



Geologic Summary. Spectacular incandescent nighttime explosions at
Stromboli have long attracted visitors to the "Lighthouse of the
Mediterranean" in the NE Aeolian Islands. This volcano 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 scarp
that formed about 5,000 years ago due to a series of slope failures which
extends 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)
http://www.ct.ingv.it/
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIMrLaZtmQ$>





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



JMA reported that eruptive activity at Suwanosejima's Ontake Crater
continued during 15-22 April. Crater incandescence was observed in webcam
images nightly. No explosions were detected but ashfall was reported in
Toshima village (3.5 km SSW); dates were not specified. The Alert Level
remained at 2 (on a 5-level scale) and the public was warned to stay at
least 1.5 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 active
summit craters. The summit is truncated by a large breached crater
extending to the sea on the E 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 covered
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 an open collapse
scarp extending 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) http://www.jma.go.jp/jma/
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fb__paCNtmEgAENx91ENs8GHBvaA_f64BipUpmfl34mDLL6QXzKekGXZknQIdEYojSkGJvnOY9HyaysFgIPG3PMbcg$>


1-1-1-1-1-1-1-1-1-1-1-1-1-1



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End of Volcano Digest - 22 Apr 2024 to 24 Apr 2024 (#2024-36)
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