Smithsonian / USGS Weekly Volcanic Activity Report 14-20 June 2023

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


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


Smithsonian / USGS Weekly Volcanic Activity Report

14-20 June 2023



Sally Sennert - Weekly Report Editor (kuhns@xxxxxx)

Zac Hastings - contributor (zhastings@xxxxxxxx)

JoAnna Marlow - contributor (jmarlow@xxxxxxxx)

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqJyadYz5$ 
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UojYMj_3M$>





New Activity/Unrest: Kilauea, Hawaiian Islands (USA)  | Lokon-Empung,
Sulawesi  | Mayon, Luzon (Philippines)  | Rincon de la Vieja, Costa Rica  |
Ubinas, Peru



Ongoing Activity: Ahyi, Mariana Islands (USA)  | Aira, Kyushu (Japan)  |
Cotopaxi, Ecuador  | Ebeko, Paramushir Island (Russia)  | Fuego,
South-Central Guatemala  | Great Sitkin, Andreanof Islands (USA)  |
Karangetang, Sangihe Islands  | Krakatau, Sunda Strait  | Lewotolok,
Lembata Island  | Merapi, Central Java  | Popocatepetl, Mexico  |
Sabancaya, Peru  | Sangay, Ecuador  | Semeru, Eastern Java  | Stromboli,
Aeolian Islands (Italy)  | 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





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



HVO reported that the eruption on the floor of Kilaueaâ??s Halema'uma'u
Crater continued during 14-20 June. Activity was characterized by effusion
primarily from the vent on the SW wall of the crater, circulation within
the crater lakes, slow rise of the crater floor, eruptive tremor, and
elevated sulfur dioxide levels (4,500-6,300 tonnes per day). Lava flows
from vents at the base and top of a cone on the SW wall of Halema'uma'u
entered the lava lake in the far SW portion of the crater; intermittent
spattering from the cone was visible at night. Other eruptive vents within
the SW lava lake (previously dome fountains) had ceased by 13 June. The
surface of the SW lava lake slowly rose about 0.5 m per day during 13-15
June. Additionally, lava circulation continued within the central basin. At
0800 on 15 June the top of the SW wall cone collapsed, leading to nearly
constant spattering from the top vent and a change in activity from the
base vent. The central basin level has been dropping relative to the rising
crater floor (due to lava accumulation underneath), allowing several flows
from the SW lava lake to cascade into the basin.



By 16 June, renewed activity on the SW wall was producing vigorous
fountaining to at least 10 m high with some higher spatters, with lava
flowing into the SW lake. This activity continued into 19 June as the
crater floor continued to rise, circulation in central basin slowed, and
flows from the base of the SW wall cone changed paths. Around 1600 on 19
June activity rapidly declined, shown by a drop in the SW lake surface,
decreased seismicity, and a transition to inflationary tilt from the
deflationary trend of the previous two days. Seismic activity remained low
and on 20 June HVO reported that the eruption had paused.



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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqH8rZldu$ 
<https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo8of0bpI$>





Lokon-Empung  | Sulawesi  | 1.358°N, 124.792°E  | Summit elev. 1580 m



In a press release PVMBG reported increased emissions at Lokon-Empung on 13
June with dense white plumes rising 400 m above the rim of Tompaluan Crater
and drifting S; a total of 12 earthquakes indicating emissions were
recorded by the seismic network. The emissions were followed by a period of
continuous tremor during 1835-2100. White steam-and-gas emissions of
variable densities rose as high as 500 m and drifted N, W, and S during
14-20 June. During 2023 white emissions generally rose 20-150 m above the
crater rim and seismicity was generally dominated by 1-2 daily shallow
volcanic earthquakes. The volcano Alert Level remained at 2 (on a scale of
1-4) and the public was reminded not to approach the crater within a radius
of 1.5 km.



Geologic Summary. The Lokong-Empung volcanic complex, rising above the
plain of Tondano in North Sulawesi, includes four peaks and an active
crater. Lokon, the highest peak, has a flat craterless top. The
morphologically younger Empung cone 2 km NE has a 400-m-wide, 150-m-deep
crater that erupted last in the 18th century. A ridge extending 3 km WNW
from Lokon includes the Tatawiran and Tetempangan peaks. All eruptions
since 1829 have originated from Tompaluan, a 150 x 250 m crater in the
saddle between Lokon and Empung. These eruptions have primarily produced
small-to-moderate ash plumes that sometimes damaged croplands and houses,
but lava-dome growth and pyroclastic flows have also occurred.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM)https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDOYU2P3$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo7OHk4Gs$>





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



PHIVOLCS reported that lava-dome extrusion at Mayonâ??s summit crater
continued during 14-20 June, generating frequent lava flows and pyroclastic
density currents (PDCs, or pyroclastic flows), and additional evacuations.
Sulfur dioxide emissions ranged from 149-193 tonnes per day (t/d) during
13-14 June, rising to 826-1,004 t/d during 15-18 June (above normal
baseline values of 500 t/d), and then dropping to 389 t/d on 19 June. The
total number of rockfalls ranged from 265-309 events per day, resulting
from partial collapses of the growing lava dome and lava flows. PDCs were
recorded during 13-14 June (7), 14-15 June (3), 15-16 June (13), 16-17 June
(9), 17-18 June (11), 18-19 June (5), and 19-20 June (2); each event lasted
2-6 minutes based on seismic signals. Lava flows remained active, with
debris collapses throughout the week sending material into the Mi-Isi (S)
and Bonga (SE) drainages. By 20 June lava flows reached 2.5 km down the
Mi-Isi and 1.8 km down the Bonga drainages, and debris flows extended 3.3
km from the crater. Ashfall during 15-16 June was reported in the
communities of Buga (36 km W), Nabonton (9 km W), Ligao (16 km W), Purok 7
(12 km S), and San Francisco (11 km SW). The Disaster Response Operations
Monitoring and Information Center (DROMIC) reported that by 20 June there
had been 38,975 people affected, 20,139 displaced, and 18,749 taking
shelter in 28 evacuation centers across Albay. The Alert Level remained at
3 (on a 0-5 scale), and residents were reminded to stay away from the
6-km-radius Permanent Danger Zone (PDZ).



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



Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqG_pd6yE$ 
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uoscqzoa0$>
;

Disaster Response Operations Monitoring and Information Center (DROMIC)
https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDm4sRfA$ 
<https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UomtAr_vU$>





Rincon de la Vieja  | Costa Rica  | 10.83°N, 85.324°W  | Summit elev. 1916 m



OVSICORI-UNA reported that small phreatic explosions continued at Rincón de
la Vieja during 14-19 June and gas-and-steam emissions were sometimes
continuous. There were 1-3 daily events during 14-16 and 18 June; most were
not observed due to darkness. A small event at 1804 on 18 June produced a
steam-and-gas plume that rose 2 km above the crater rim.



Geologic Summary. Rincón de la Vieja, the largest volcano in NW Costa Rica,
is a remote volcanic complex in the Guanacaste Range. The volcano consists
of an elongated, arcuate NW-SE-trending ridge constructed within the
15-km-wide early Pleistocene Guachipelín caldera, whose rim is exposed on
the south side. Sometimes known as the "Colossus of Guanacaste," it has an
estimated volume of 130 km3 and contains at least nine major eruptive
centers. Activity has migrated to the SE, where the youngest-looking
craters are located. The twin cone of Santa María volcano, the highest peak
of the complex, is located at the eastern end of a smaller, 5-km-wide
caldera and has a 500-m-wide crater. A Plinian eruption producing the 0.25
km3 Río Blanca tephra about 3,500 years ago was the last major magmatic
eruption. All subsequent eruptions, including numerous historical eruptions
possibly dating back to the 16th century, have been from the prominent
active crater containing a 500-m-wide acid lake located ENE of Von Seebach
crater.



Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad
Nacional (OVSICORI-UNA) https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqPJLBR60$ 
<https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoJsUA1eo$>





Ubinas  | Peru  | 16.355°S, 70.903°W  | Summit elev. 5672 m



Instituto Geofísico del Perú (IGP) reported that seismicity at Ubinas had
been increasing since mid-May, and that during 1-18 June fumarolic plumes
rose 500 m above the crater rim. The Gobierno Regional de Moquegua raised
the Alert Level to Yellow (the second lowest level on a four-color scale)
on 20 June based on the recommendation from IGP.



Geologic Summary. A small, 1.4-km-wide caldera cuts the top of Ubinas,
Perú's most active volcano, giving it a truncated appearance. It is the
northernmost of three young volcanoes located along a regional structural
lineament about 50 km behind the main volcanic front. The growth and
destruction of Ubinas I was followed by construction of Ubinas II beginning
in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic
Ubinas II stratovolcano are composed primarily of andesitic and
trachyandesitic lava flows and steepen to nearly 45 degrees. The
steep-walled, 150-m-deep summit caldera contains an ash cone with a
500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits
from the collapse of the SE flank about 3,700 years ago extend 10 km from
the volcano. Widespread Plinian pumice-fall deposits include one of
Holocene age about 1,000 years ago. Holocene lava flows are visible on the
flanks, but historical activity, documented since the 16th century, has
consisted of intermittent minor-to-moderate explosive eruptions.



Sources: Instituto Geofísico del Perú (IGP) https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqL0TKnY0$ 
<https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UocAPJTV4$>
;

Gobierno Regional de Moquegua https://urldefense.com/v3/__http://www.regionmoquegua.gob.pe/web13/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqFC2WBVs$ 
<https://urldefense.com/v3/__http://www.regionmoquegua.gob.pe/web13/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoIe5T7XE$>





Ongoing Activity





Ahyi  | Mariana Islands (USA)  | 20.42°N, 145.03°E  | Summit elev. -75 m



Unrest at Ahyi Seamount possibly continued during 13-20 June. A few small
hydroacoustic signals coming from the direction of the seamount were
detected by pressure sensors on Wake Island (2,270 km E) during 16-17 June.
No surface activity was visible in satellite images. The Aviation Color
Code remained at Yellow (the second lowest level on a four-color scale) and
the Volcano Alert Level remained at Advisory (the second lowest level on a
four-level scale).



Geologic Summary. Ahyi seamount is a large conical submarine volcano that
rises to within 75 m of the sea surface about 18 km SE of the island of
Farallon de Pajaros (Uracas) in the northern Marianas. Water discoloration
has been observed there, and in 1979 the crew of a fishing boat felt shocks
over the summit area of the seamount, followed by upwelling of
sulfur-bearing water. On 24-25 April 2001 an explosive eruption was
detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago.
The event was well constrained (+/- 15 km) at a location near the southern
base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers,
hydroacoustic sensors, and seismic stations.



Source: US Geological Survey https://urldefense.com/v3/__https://www.usgs.gov/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqNIKanIa$ 
<https://urldefense.com/v3/__https://www.usgs.gov/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uog-DNoMs$>





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



JMA reported ongoing activity at both Minamidake Crater and Showa Crater
(Aira Calderaâ??s Sakurajima volcano) during 13-19 June. Ash plumes from
Showa were recorded at 1412 on 16 June that rose 1.3 km above the rim and
drifted S, with another at 0710 on 17 June that rose up to 1 km and drifted
E. Crater incandescence was observed at Minamidake crater during the night
of 18 June. 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 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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqITq6S02$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UodAyCWbo$>





Cotopaxi  | Ecuador  | 0.677°S, 78.436°W  | Summit elev. 5911 m



IG reported that moderate eruptive activity continued at Cotopaxi during
13-20 June. Small gas-and-steam emissions rose as high as 200 m above the
crater rim and drifted W and SW during 13-14 and 17 June. Several gas
emissions with minor ash content rose 100 m on 15 June, and several seismic
signals possibly indicating similar emissions were detected on 16 June.
Gas-and-ash plumes rose 500-700 m on 18 June. Gas-and-steam plumes with
minor ash content rose 100-700 m and drifted W and SW during 19-20 June.
Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained
the Alert Level at Yellow (the second lowest level on a four-color scale).



Geologic Summary. The symmetrical, glacier-covered, Cotopaxi stratovolcano
is Ecuador's most well-known volcano and one of its most active. The
steep-sided cone is capped by nested summit craters, the largest of which
is about 550 x 800 m in diameter. Deep valleys scoured by lahars radiate
from the summit of the andesitic volcano, and large andesitic lava flows
extend to its base. The modern edifice has been constructed since a major
collapse sometime prior to about 5,000 years ago. Pyroclastic flows (often
confused in historical accounts with lava flows) have accompanied many
explosive eruptions, and lahars have frequently devastated adjacent
valleys. Strong eruptions took place in 1744, 1768, and 1877. Pyroclastic
flows descended all sides of the volcano in 1877, and lahars traveled more
than 100 km into the Pacific Ocean and western Amazon basin. Smaller
eruptions have been frequent since that time.



Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG)
https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqGIGR6hD$ 
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UojUPz_lo$>
;

Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)
https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqHR2_uHM$ 
<https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoOASZncs$>





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



KVERT reported that moderate activity at Ebeko was ongoing during 8-15
June. A thermal anomaly was identified in satellite images throughout the
week. According to volcanologists in Severo-Kurilsk (Paramushir Island,
about 7 km E), explosions during 8-9 and 11-13 June generated ash plumes
that rose as high as 4 km (11,500 ft) a.s.l. and drifted both NE and SE.
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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqNjOwlJm$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo8ubnRyY$>





Fuego  | South-Central Guatemala  | 14.473°N, 90.88°W  | Summit elev. 3763 m



INSIVUMEH reported that 1-6 explosions per hour were recorded at Fuego
during 14-20 June, generating daily ash plumes that rose as high as 1.1 km
above the crater rim. The explosions were often accompanied by avalanches,
shock waves, and minor rumbling sounds. The ash plumes drifted 10-30 km W
and SW, causing daily ashfall in areas downwind including Morelia (9 km
SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), Ceylon, El
Porvenir (8 km ENE), Sangre de Cristo (8 km WSW), Yepocapa (8 km NW), La
Rochela, San Andrés Osuna, and Finca Palo Verde.



Geologic Summary. Volcán Fuego, one of Central America's most active
volcanoes, is also one of three large stratovolcanoes overlooking
Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta,
lies between Fuego and Acatenango to the north. Construction of Meseta
dates back to about 230,000 years and continued until the late Pleistocene
or early Holocene. Collapse of Meseta may have produced the massive
Escuintla debris-avalanche deposit, which extends about 50 km onto the
Pacific coastal plain. Growth of the modern Fuego volcano followed,
continuing the southward migration of volcanism that began at the mostly
andesitic Acatenango. Eruptions at Fuego have become more mafic with time,
and most historical activity has produced basaltic rocks. Frequent vigorous
historical eruptions have been recorded since the onset of the Spanish era
in 1524, and have produced major ashfalls, along with occasional
pyroclastic flows and lava flows.



Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e
Hidrologia (INSIVUMEH)https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqGyEceHH$ 
<https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo62WLIMY$>





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



AVO reported that slow lava effusion continued at Great Sitkin during 14-20
June. The thick lava flow remained confined to the summit crater, and
several small earthquakes were recorded daily. Elevated surface
temperatures were observed during periods of clear satellite views during
16-17 June; weather clouds obscured webcam and satellite views on the other
days. The Volcano Alert Level remained at Watch (the second highest level
on a four-level scale) and the Aviation Color Code remained at Orange (the
second highest level on a four-color scale).



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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqMbEDGZp$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UopJXEcb4$>





Karangetang  | Sangihe Islands  | 2.781°N, 125.407°E  | Summit elev. 1797 m



PVMBG reported that dense white gas-and-steam plumes from Karangetang were
visible rising as high as 75 m and drifting in multiple directions during
14-20 June. Weather clouds obscured views at times on 14, 16, and 18 June.
Webcam images published in the reports showed incandescence at Main Crater
(S crater) and from material on the flanks of Main Crater at 0007 on 17
June and 0440 on 18 June. The Alert Level remained at 3 (on a scale of 1-4)
and the public were advised to stay 2.5 km away from Main Crater with an
extension to 3.5 km on the S and SE flanks.



Geologic Summary. Karangetang (Api Siau) volcano lies at the northern end
of the island of Siau, about 125 km NNE of the NE-most point of Sulawesi.
The stratovolcano contains five summit craters along a N-S line. It is one
of Indonesia's most active volcanoes, with more than 40 eruptions recorded
since 1675 and many additional small eruptions that were not documented
(Neumann van Padang, 1951). Twentieth-century eruptions have included
frequent explosive activity sometimes accompanied by pyroclastic flows and
lahars. Lava dome growth has occurred in the summit craters; collapse of
lava flow fronts have produced pyroclastic flows.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM)https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDOYU2P3$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo7OHk4Gs$>





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



PVMBG reported that daily white gas-and-steam plumes rose as high as 200 m
above Krakatauâ??s summit during 14-20 June. At 0822 on 19 June a dense
white-to-gray ash plume rose 1.5 km and drifted SE. 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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDOYU2P3$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo7OHk4Gs$>





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



PVMBG reported that the eruption at Lewotolok continued during 14-20 June.
White-and-gray ash plumes rose as high as 400 m above the summit and
drifted W and NW during 15 and 17-18 June; white steam-and-gas emissions
were visible on the other days. Strombolian explosions at the summit crater
were visible in webcam images at 2242 on 14 June, 2137 on 17 June, and 2213
on 18 June. The Alert Level remained at 2 (on a scale of 1-4) and the
public was warned to stay at least 2 km away from the summit crater in all
directions.



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



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM)https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDOYU2P3$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo7OHk4Gs$>





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



BPPTKG reported that the eruption at Merapi (on Java) continued during 9-15
June and seismicity remained at elevated levels. The SW lava dome produced
119 lava avalanches that traveled as far as 2 km down the SW flank
(upstream in the Bebeng drainage). Morphological changes to the SW lava
dome were due to continuing 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)https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqK2WoQAZ$ 
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoN2GGhEA$>





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



CENAPRED reported that ongoing activity at Popocatépetl during 14-20 June
included 39-180 daily steam-and-gas emissions, sometimes containing minor
amounts of ash. According to the Washington VAAC, daily ash plumes rose to
maximum altitudes of 5.8-6.7 km (19,000-22,000 ft) a.s.l., or up to 1.3 km
above the summit, and drifted generally drifted S, SW, and W, causing
ashfall in local communities. At 0337 on 17 June CENAPRED noted a moderate
explosion that ejected ballistic material as far as 2.5 km from the crater.
Minor ashfall was reported in Hueyapan (16 km SSW), Tetela del Volcán (18
km SW), Yecapixtla (29 km SW) and Ayala (47 km SW) in Morelos, as well as
Amecameca (18 km NW) and Atlautla (16 km W) in the State of Mexico during
14-15 June. Minor ashfall during 15-16 June was reported in Amecameca,
Ayapango (21 km NW), Chalco (37 km NW), Ecatzingo (15 km SW), Temamatla (30
km NW), Tepetlixpa (20 km W), Tlalmanalco (26 km NW) and Tenango del Aire
(28 km NW) in the State of Mexico. Reports of minor ashfall came from
Ixtapaluca (42 km NW), Valle de Chalco (44 km NW), La Paz (50 km NW),
Nezahualcóyotl (56 km NW), Amecameca, Atlautla, Ayapango, Cocotitlan (34 km
NW), Chalco, Ecatzingo, Temamatla, Tenango del Aire, Tepetlixpa and
Tlalmanalco in the State of Mexico during 16-17 June. Minor ashfall during
18-19 June was again reported in Tepoztlan (49 km W), Cuernavaca (63 km
WSW), Ocuituco (24 km SW), Cuautla (43 km SW), Atlatlahucan (30 km SW),
Jiutepec (59 km SW) and Emiliano Zapata (62 km SW), Morelos; Ixtapaluca, La
Paz, Valle de Chalco, Nezahualcóyotl (54 km NW), Chicoloapan (48 km NW),
Atlautla, Ecatzingo, Tonatico in the State of Mexico. Seismicity included
periods of low-to-moderate amplitude, high-frequency tremor for 274-567
minutes each day, three volcano-tectonic earthquakes of M 1.2-1.5 were
recorded during 15-16 June, and 19 minutes of low-amplitude, harmonic
tremor during 16-17 June. 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://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqLuGb95_$ 
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UodhmY1uU$>
;

Washington Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqJg6fhkY$ 
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo46YfVTM$>





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 12-18 June with a daily average of 18 explosions.
Gas-and-ash plumes rose as high as 1.5 km above the summit and drifted SE,
E, and NE. Five 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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqL0TKnY0$ 
<https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UocAPJTV4$>





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



IG reported a high level of activity at Sangay during 13-20 June and the
seismic network recorded 327-2,190 daily explosions. Gas, steam, and ash
plumes were occasionally observed in IG webcam images or described in
Washington VAAC volcanic activity notifications, though weather clouds
sometimes prevented observations. Ash-and-gas plumes rose as high as 1.8 km
above the summit and drifted W during 13-15 June. Gas-and-steam plumes rose
less than 1 km during 16-17 June. Ash plumes rose as high as 1.2 km and
drifted W on 18 June. Incandescence at the summit was visible in webcam
images. Overnight during 18-19 June the lava flow on the SE flank was
incandescent and pyroclastic material descended the SE flank as far as 500
m several times. During 19-20 June several ash-and-gas emissions rose as
high as 550 m above the summit and drifted SW. Incandescence at the summit
was visible multiple times. Minor ashfall was reported in Llagos parish,
Chunchi (73 km SW) on 20 June. Servicio Nacional de Gestión de Riesgos y
Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest
level on a four-color scale).



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 the
open 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 eroded by heavy rains into steep-walled canyons up
to 600 m deep. The earliest report of an eruption was in 1628. Almost
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.



Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG)
https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqGIGR6hD$ 
<https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UojUPz_lo$>
;

Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE)
https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqHR2_uHM$ 
<https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoOASZncs$>
;

Washington Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqJg6fhkY$ 
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo46YfVTM$>





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



PVMBG reported that the eruption at Semeru continued during 14-20 June.
White-and-gray ash plumes rose 100-700 m and drifted N, NW, W, and S during
16 and 18-20 June; emissions were not observed on the other days. The Alert
Level remained at 3 (third highest 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.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM)https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqDOYU2P3$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uo7OHk4Gs$>





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



INGV reported ongoing activity at Stromboli during 12-18 June. The
Strombolian activity was centered at two vents in Area N (one each at
craters N1 and N2), within the upper part of the Sciara del Fuoco, and from
four vents in Area C-S (South-Central Crater) in the crater terrace. Low-
and medium-intensity explosions at a rate of 3-7 per hour from Area N2
ejected mainly coarse material (bombs and lapilli), sometimes mixed with
ash, up to 150 m above the vents. Sporadic explosive activity at N1 ejected
mainly ash mixed with smaller amounts of coarse material. Low- to
high-intensity explosions averaged 8-14 per hour from the three vents in
sector S2 (Area C-S), ejecting a mix of coarse material and ash; weak
spattering was sometimes observed. Weak emission of gas sometimes
accompanied explosive events.



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)
https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqEX-qp5T$ 
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UoO4UrMzc$>





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



JMA reported that the eruption at Suwanosejima's Ontake Crater continued
during 14-19 June. A total of 526 volcanic earthquakes, 26 explosions, and
18 eruptive events were recorded by seismic monitoring stations throughout
the week; activity was most notable during 15-16 June with totals of 164
volcanic earthquakes and 10 explosions. Ash plumes were observed daily; the
tallest plumes rose 2 km above the crater rim on 15 and 16 June. Continuous
emissions during 0936-1355 on 16 June rose as high as 2 km and drifted SE
and SW. Some events ejected large volcanic blocks up to 400 m from the
crater during 14-18 June. Incandescent ejecta from explosions during the
nights of 18-19 June were sometimes visible in webcam images. Occasional
ashfall and rumbling noises were reported in Toshima village (3.5 km SSW).
The Alert Level remained at 2 (on a 5-level scale) and the public was
warned to stay at least 2 km away from the crater.



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



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqITq6S02$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6UodAyCWbo$>





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



PHIVOLCS reported continuing low-level unrest at Taal during 13-20 June
characterized by elevated seismicity, upwelling in the lake, and sulfur
dioxide gas emissions. There were 20-38 daily volcanic earthquakes recorded
during 13-17 June and a total of 11 recorded during 19-20 June. There were
2-46 daily periods of tremor, each lasting 2-67 minutes long. Daily white
steam-and-gas plumes (sometimes voluminous) rose as high as 3 km above the
lake and drifted NE, NW, and SW; voggy conditions were reported during
16-17 June. Upwelling gasses and hot fluids in the lake were visible during
14-17 June. Sulfur dioxide emissions averaged 7,643 and 2,177 tonnes per
day on 15 June and 19 June, respectively. 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!a3hWbvsoflB8QVVm4lGg2uEfPBcpsBndCA7vXgCpkbv39xPGegIVkYT2BwCJt3LTKMhIj_QkqG_pd6yE$ 
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!fSel0gnR-si6aNEI5nAX-aAy1D_wHAoHniS_C_bQzJNJk49xVJD2O6Si42uTj_TRu6Uoscqzoa0$>


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End of Volcano Digest - 20 Jun 2023 to 21 Jun 2023 (#2023-61)
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