Smithsonian / USGS Weekly Volcanic Activity Report 5-11 July 2023

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


Smithsonian / USGS Weekly Volcanic Activity Report

5-11 July 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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxua4CgUX0$ 
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpTi9In1I$>





New Activity/Unrest: Bagana, Bougainville (Papua New Guinea)  | Eldey,
Reykjanes Peninsula  | Fagradalsfjall, Iceland  | Kirishimayama, Kyushu
(Japan)  | Klyuchevskoy, Central Kamchatka (Russia)  | Kuchinoerabujima,
Ryukyu Islands (Japan)  | Mayon, Luzon (Philippines)  | Nishinoshima, Izu
Islands  | Piton de la Fournaise, Reunion Island (France)  | San Cristobal,
Sierra de los Marrabios  | Shishaldin, Fox Islands (USA)  | Ubinas, Peru



Ongoing Activity: Ebeko, Paramushir Island (Russia)  | Etna, Sicily
(Italy)  | Fuego, South-Central Guatemala  | Great Sitkin, Andreanof
Islands (USA)  | Karangetang, Sangihe Islands  | Merapi, Central Java  |
Popocatepetl, Mexico  | Santa Maria, Southwestern Guatemala  | Semeru,
Eastern Java  | Sheveluch, Central Kamchatka (Russia)  | Tofua, Tonga Ridge





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



An explosive eruption at Bagana on 7 July send a large ash, gas, and steam
plume to high altitudes and caused significant ashfall in local
communities. A report issued by the Autonomous Bougainville Government
(Torokina District, Education Section) on 10 July noted that significant
ash began falling during 2000-2100 on 7 July and covered most areas in the
Vuakovi, Gotana (9 km SW), Koromaketo, Laruma and Atsilima villages. By
about 2200 on 7 July the eruption plume had reached upper tropospheric
altitudes based on satellite images. Sulfur dioxide detections in satellite
images from 8 July indicated that the plume, likely a mixture of gases,
ice, and ash, had risen to 16-18 km (52,500-59,100 ft) a.s.l., reaching the
tropopause. Ashfall reportedly continued until 9 July. The ashfall covered
vegetation, destroying bushes and gardens, and contaminated rivers and
streams used for washing and drinking water; residents drank from coconuts
and used fresh ground water accessible through bamboo pipes.



Geologic Summary. Bagana volcano, occupying a remote portion of central
Bougainville Island, is one of Melanesia's youngest and most active
volcanoes. 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 frequent and characterized by non-explosive effusion
of viscous lava that maintains a small lava dome in the summit crater,
although explosive activity occasionally producing pyroclastic flows also
occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up
to 50 m thick with prominent levees that descend the flanks on all sides.



Sources: Andrew Tupper, Natural Hazards Consulting
https://urldefense.com/v3/__http://naturalhazardsconsulting.com/web/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuW-PdajH$ 
<https://urldefense.com/v3/__http://naturalhazardsconsulting.com/web/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpJUIPzs4$>
;

Simon Carn https://urldefense.com/v3/__http://www.volcarno.com/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxud5h6YdO$ 
<https://urldefense.com/v3/__http://www.volcarno.com/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpbNm-vpY$>
;

Rabaul Volcano Observatory (RVO) ;

Autonomous Bougainville Government





Eldey  | Reykjanes Peninsula  | 63.733°N, 23°W  | Summit elev. 70 m



Icelandic Meteorological Office (IMO) reported that at 2330 on 6 July
earthquake activity increased in an area close to Eldey and by 1500 on 7
July the seismic network had detected over 480 events. The earthquakes were
located at depths of around 8 km, with several of the events over M 3 and
six over M 4; the largest event was a M 4.5 recorded at 0506 on 7 July.
Activity that strong had not previously been detected in conjunction with
seismic swarms related to magma intrusions in Fagradalsfjall. The Aviation
Color Code was raised to Yellow (the second level on a four-color scale).
On 11 July IMO noted that seismicity had decreased during the past few days
so at 1640 the Aviation Color Code was lowered to Green.



Geologic Summary. The Eldey volcanic system is located on the northernmost
part of the Reykjanes Ridge and is submarine with the exception of Eldey
Island and the skerries (small rocky islands) Eldeyjardrangur,
Geirfugladrangur, and Geirfuglasker. Maximum water depth within the system
is about 250 m. Eldey has been moderately active in Holocene time.
Characteristic activity consists of explosive submarine basaltic eruptions.
Six small eruptions have been located within this system during the last
1,100 years, the last occurring in 1926 CE.



Source: Icelandic Meteorological Office (IMO) https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuWt2X-Zg$ 
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpSDQiwOQ$>





Fagradalsfjall  | Iceland  | 63.895°N, 22.258°W  | Summit elev. 250 m



Icelandic Meteorological Office (IMO) reported that a new fissure eruption
in the Fagradalsfjall volcanic system began on 10 July after intensifying
seismicity over the previous month and inflation that was first noted in
April. At 1055 on 5 July IMO raised the Aviation Color Code to Orange (the
third level on a four-color scale). By 1330 on 7 July there had been more
than 7,000 earthquakes detected in the swarm that began on 3 July.
Epicenters were aligned NE-SW between Fagradalsfjall and the Keilir cone,
NNE from the 2021 and 2022 eruptions, and mostly concentrated just N of the
Litli Hrútur hill. Deformation data (GPS and radar interferometry) showed
uplift in the same area, suggesting a magmatic dike intrusion that reached
to 1 km depth by early on 6 July. Seismicity decreased during 6-7 July and
the rate of deformation slowed, with analysis showing that by 9-10 July the
dike had propagated 1 km further NE.



Tremor was detected at 1425 on 10 July and continued to intensify, leading
to an eruption at 1640 just NW of Litli-Hrútur. Webcam images showed
visible gas emissions and incandescence, but no major ash emissions. IMO
raised the Aviation Color Code to Red (the highest level on a four-color
scale) at 1707. Flowing lava from a NE-SW fissure that was about 200 m long
was confirmed by people present in the area and webcam images; at 1724 the
Aviation Color Code was lowered back to Orange. The fissure was mainly
located in a depression and bisected the E and NE flanks of Litli Hrútur.
Based on observations from drone video the fissure quickly reached about
900 m long according to estimates from Institute of Earth Sciences. Lava
fountaining occurred along the fissure, sending lava flows S. Gas-and-steam
emissions drifted NW. According to Almannavarnadeild ríkislögreglustjóra,
the police closed the area around the eruption to tourists due to the high
concentrations of volcanic gases and particulates from burning vegetation.



Tremor levels peaked between 2100 on 10 July and 0000 on 11 July, then
steadily declined through 1100. By 1250 on 11 July the intensity of the
eruption had noticeably decreased, with fewer active lava fountains. Only
one vent with an elongated crater and multiple lava fountains was active by
1635. Gas plumes rose as high as 4 km above the vent. Lava flows mostly
traveled SE and flowed into a shallow valley S of Litli-Hrútur. IMO noted
that if lava continued to flow S it may come into contact with the 2022
Merardalir lava flow. A 10-km-long trail from the road up to the eruption
site was opened to the public.



Geologic Summary. Although the Fagradalsfjall fissure swarm has previously
been considered a split or secondary swarm of the Krýsuvíkâ??Trölladyngja
volcanic system, as of September 2022 Icelandic volcanologists managing the
Catalogue of Icelandic Volcanoes made the decision to identify it as a
distinct separate system. The recent eruptions and related reports have
been reassigned here, and other content will be prepared and adjusted as
appropriate.



Sources: Icelandic Meteorological Office (IMO) https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuWt2X-Zg$ 
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpSDQiwOQ$>
;

Almannavarnadeild ríkislögreglustjóra (National Commissioner of the
Icelandic Police and Department of Civil Protection and Emergency
Management) https://urldefense.com/v3/__https://www.almannavarnir.is/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuVLzCn7s$ 
<https://urldefense.com/v3/__https://www.almannavarnir.is/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp_5o0YDo$>
;

Institute of Earth Sciences https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuYgW_RIE$ 
<https://urldefense.com/v3/__http://www.earthice.hi.is/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpbDtiwKM$>





Kirishimayama  | Kyushu (Japan)  | 31.934°N, 130.862°E  | Summit elev. 1700
m



JMA reported that global navigation satellite system (GNSS) data indicated
minor inflation beginning in May at shallow depths beneath Ioyama, located
on the NW flank of the Karakuni-dake stratovolcano in the Kirishimayama
volcano group. Volcanic tremor was recorded at 1650 on 7 July for the first
time since 19 June 2018. JMA raised the Alert Level to 2 (on a 5-level
scale) at 1715 on 7 July and warned the public to stay 1 km away from
Ioyama. A few shallow volcanic earthquakes were recorded during 7-10 July.
Weather conditions mostly prevented visual observations of the fumarolic
areas near the crater.



Geologic Summary. Kirishimayama is a large group of more than 20 Quaternary
volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene
dominantly andesitic group consists of stratovolcanoes, pyroclastic cones,
maars, and underlying shield volcanoes located over an area of 20 x 30 km.
The larger stratovolcanoes are scattered throughout the field, with the
centrally located Karakunidake being the highest. Onamiike and Miike, the
two largest maars, are located SW of Karakunidake and at its far eastern
end, respectively. Holocene eruptions have been concentrated along an E-W
line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent
small-to-moderate explosive eruptions have been recorded since the 8th
century.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxufI8NKaA$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp9_Ql-sM$>





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



KVERT reported that the minor Strombolian eruption at Klyuchevskoy
continued during 29 June-6 July. A daily thermal anomaly was identified in
satellite images. Small ash plumes were occasionally observed over the
crater during 4-6 July. The Aviation Color Code remained at Yellow (the
second level on a four-color scale).



Geologic Summary. Klyuchevskoy (also spelled Kliuchevskoi) is Kamchatka's
highest and most active volcano. Since its origin about 6000 years ago, the
beautifully symmetrical, 4835-m-high basaltic stratovolcano has produced
frequent moderate-volume explosive and effusive eruptions without major
periods of inactivity. It rises above a saddle NE of sharp-peaked Kamen
volcano and lies SE of the broad Ushkovsky massif. More than 100 flank
eruptions have occurred during the past roughly 3000 years, with most
lateral craters and cones occurring along radial fissures between the
unconfined NE-to-SE flanks of the conical volcano between 500 m and 3600 m
elevation. The morphology of the 700-m-wide summit crater has been
frequently modified by historical eruptions, which have been recorded since
the late-17th century. Historical eruptions have originated primarily from
the summit crater, but have also included numerous major explosive and
effusive eruptions from flank craters.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuRhoDkvj$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpktT498Y$>





Kuchinoerabujima  | Ryukyu Islands (Japan)  | 30.443°N, 130.217°E  | Summit
elev. 657 m



JMA reported that shallow volcanic earthquakes at Kuchinoerabujima had been
occurring frequently starting in late June with most epicenters located
near Furudake Crater, and some near Shindake Crater (just N of Furudake).
Both the number and magnitude of the volcanic earthquakes increased on 9
June and remained elevated through 12 July; there were 151 events on 9
July, 319 on 10 July, 276 on 11 July, and 172 by 1500 on 12 July. The
public was previously warned that ejected blocks and pyroclastic flows may
affect areas within 2 km of Shindake, and at 1600 on 10 June the public was
also warned to stay 2 km away from Furudake. The Alert Level remained at 3
(on a scale of 1-5).



Geologic Summary. A group of young stratovolcanoes forms the eastern end of
the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu
Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones
were erupted from south to north, respectively, forming a composite cone
with multiple craters. All historical eruptions have occurred from
Shindake, although a lava flow from the S flank of Furudake that reached
the coast has a very fresh morphology. Frequent explosive eruptions have
taken place from Shindake since 1840; the largest of these was in December
1933. Several villages on the 4 x 12 km island are located within a few
kilometers of the active crater and have suffered damage from eruptions.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxufI8NKaA$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp9_Ql-sM$>





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



PHIVOLCS reported that eruptive activity continued at Mayon during 5-11
July. Daily steam-and-gas emissions rose as high as 1 km above the crater
and drifted in multiple directions. Average daily measurements of sulfur
dioxide emissions fluctuated between 721 and 1,621 tonnes per day. Slow
lava effusion from the summit crater continued to feed lava flows on the
flanks. The length of the lava flow in the Mi-Isi (S) drainage remained at
2.8 km. The flow in the Bonga (SE) drainage advanced 100 m during 10-11
July, with a total length of 1.4 km. The growing lava dome remained
unstable and produced incandescent rockfalls and pyroclastic density
currents (PDCs, or pyroclastic flows) that descended the Basud (E) drainage
as far as 4 km. Seismic stations recorded 216-511 daily rockfall events,
5-39 daily PDC events (from dome and lava front collapse) lasting 1-3
minutes, and 1-109 volcanic earthquakes. Ashfall was reported during 10-11
July in Legazpi City (13 km SSE), and Budiao (8.1 km S), Salvacion (8.6 km
S), Daraga (12 km S), and Camalig (11 km SSW), in Albay. The Disaster
Response Operations Monitoring and Information Center (DROMIC) reported
that as of 1800 on 10 July, the number of displaced persons and total
number of overall affected persons from 26 barangays in the province of
Albay increased to 20,141 and 38,376, respectively. The Alert Level
remained at 3 (on a 0-5 scale). Residents were reminded to stay away from
the 6-km-radius Permanent Danger Zone (PDZ), and PHIVOLCS recommended that
civil aviation authorities advise pilots to avoid flying close to the
summit.



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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuUGMQ41w$ 
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpCdAQ6ng$>
;

Disaster Response Operations Monitoring and Information Center (DROMIC)
https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuWEnsPrq$ 
<https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIparR6GIM$>





Nishinoshima  | Izu Islands  | 27.247°N, 140.874°E  | Summit elev. 100 m



JMA reported that at around 1300 on 9 July an eruption plume from
Nishinoshima rose 1.6 km above the crater and drifted N. Satellite images
acquired at 1420 and 2020 on 9 July and 0220 on 10 July showed continuing
emissions rising 1.3-1.6 km and drifting NE and N.



Geologic Summary. The small island of Nishinoshima was enlarged when
several new islands coalesced during an eruption in 1973-74. Another
eruption that began offshore in 2013 completely covered the previous
exposed surface and enlarged the island again. Water discoloration has been
observed on several occasions since. The island is the summit of a massive
submarine volcano that has prominent satellitic peaks to the S, W, and NE.
The summit of the southern cone rises to within 214 m of the ocean surface
9 km SSE.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxufI8NKaA$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp9_Ql-sM$>





Piton de la Fournaise  | Reunion Island (France)  | 21.244°S, 55.708°E  |
Summit elev. 2632 m



OVPF reported that the eruption that began on 2 July at Piton de la
Fournaise was ongoing during 5-11 July. Though there were multiple active
fissures at the start of the eruption, as of 3 July only the SE flank
fissure was active, located on the upper part of Grandes Pentes at
approximately 1,720 m a.s.l. Volcano-tectonic earthquake events (VTs)
fluctuated throughout the week but remained low relative to the onset of
the eruption. The amplitude of the volcanic tremor dropped abruptly at 2105
on 4 July following a M 2.3 earthquake directly below Dolomieu Crater, and
again on 7 July. Lava ejections continued to build a cone over the active
vent throughout the week. During an overflight on 7 July, a team from
OVPF-IPGP determined that the lava flow had reached 1.8 km from the road
but had not advanced since 5 July. The flow front did not extend any
further to the E, but by 7 July active flows were moving through a lava
tube. During 10-11 July flows traveled through lava tubes and were active
at elevations above 1,300 m. Although clouds often prevented measurements,
satellite analysis showed that lava flow rates fluctuated between 1.5 and
24 cubic m/s. The total volume of lava effused since the beginning of the
eruption was an estimated 5.5 million cubic m. Deflation of the whole
edifice during 3-6 July ended by 8 July, and no significant deformation was
observed the rest of the week.



Geologic Summary. Piton de la Fournaise is a massive basaltic shield
volcano on the French island of Réunion in the western Indian Ocean. Much
of its more than 530,000-year history overlapped with eruptions of the
deeply dissected Piton des Neiges shield volcano to the NW. Three scarps
formed at about 250,000, 65,000, and less than 5,000 years ago by
progressive eastward slumping, leaving caldera-sized embayments open to the
E and SE. Numerous pyroclastic cones are present on the floor of the scarps
and their outer flanks. Most recorded eruptions have originated from the
summit and flanks of Dolomieu, a 400-m-high lava shield that has grown
within the youngest scarp, which is about 9 km wide and about 13 km from
the western wall to the ocean on the E side. More than 150 eruptions, most
of which have produced fluid basaltic lava flows, have occurred since the
17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and
1986, have originated from fissures outside the scarps.



Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
https://urldefense.com/v3/__http://www.ipgp.fr/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxua9VBfsY$ 
<https://urldefense.com/v3/__http://www.ipgp.fr/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpxPeMKhY$>





San Cristobal  | Sierra de los Marrabios  | 12.702°N, 87.004°W  | Summit
elev. 1745 m



SINAPRED reported that on 5 July a small explosion at San Cristóbal
produced a moderately-sized ash-and-gas plume. The emissions in photos
posted by SINAPRED appeared to be dense and gray, and pyroclastic flows
were visible on the upper flanks. According to news articles, a strong
sulfur odor was reported in nearby communities along with the fall of ash
and larger tephra, most notably in La Grecia (12 km WSW). Fine ash
particles in the air ash continued to impact residents the next day. A dark
narrow deposit extending about 10 km W from the summit crater was visible
in a 9 July Sentinel satellite image.



Geologic Summary. The San Cristóbal volcanic complex, consisting of five
principal volcanic edifices, forms the NW end of the Marrabios Range. The
symmetrical 1745-m-high youngest cone, named San Cristóbal (also known as
El Viejo), is Nicaragua's highest volcano and is capped by a 500 x 600 m
wide crater. El Chonco, with several flank lava domes, is located 4 km W of
San Cristóbal; it and the eroded Moyotepe volcano, 4 km NE of San
Cristóbal, are of Pleistocene age. Volcán Casita, containing an elongated
summit crater, lies immediately east of San Cristóbal and was the site of a
catastrophic landslide and lahar in 1998. The Plio-Pleistocene La Pelona
caldera is located at the eastern end of the complex. Historical eruptions
from San Cristóbal, consisting of small-to-moderate explosive activity,
have been reported since the 16th century. Some other 16th-century
eruptions attributed to Casita volcano are uncertain and may pertain to
other Marrabios Range volcanoes.



Sources: Sistema Nacional para la Prevención, Mitigación y Atención de
Desastres (SINAPRED) https://urldefense.com/v3/__http://www.sinapred.gob.ni/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuSz7WLQn$ 
<https://urldefense.com/v3/__http://www.sinapred.gob.ni/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpwcClQJQ$>
;

La Prensa (Nicaragua)
https://urldefense.com/v3/__https://www.laprensalatina.com/nicaraguas-san-cristobal-volcano-spews-ash-gas/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuQIxnePL$ 
<https://urldefense.com/v3/__https://www.laprensalatina.com/nicaraguas-san-cristobal-volcano-spews-ash-gas/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpQbG-LTg$>
;

Sentinel Hub https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxucgfAcDT$ 
<https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp6sQB93A$>
;

European Pressphoto Agency https://urldefense.com/v3/__https://epaimages.com/home.pp__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuXQd8Bkt$ 
<https://urldefense.com/v3/__https://epaimages.com/home.pp__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp3I5SzCE$>





Shishaldin  | Fox Islands (USA)  | 54.756°N, 163.97°W  | Summit elev. 2857 m



AVO reported that intermittent tremor and low-frequency earthquakes
recorded at Shishaldin over the past week had gradually become more regular
and consistent during 10-11 July. Strongly elevated surface temperatures at
the summit were identified in satellite images during 10-11 July. The
Volcano Alert Level was raised to Advisory (the second level on a
four-level scale) and the Aviation Color Code was raised to Yellow (the
second color on a four-color scale) at 1439 on 11 July, but AVO noted that
the increased activity may or may not lead to an eruption.



Geologic Summary. The symmetrical glacier-covered Shishaldin is the highest
and one of the most active volcanoes of the Aleutian Islands. It is the
westernmost of three large stratovolcanoes in the eastern half of Unimak
Island. The Aleuts named the volcano Sisquk, meaning "mountain which points
the way when I am lost." Constructed atop an older glacially dissected
edifice, it is largely basaltic in composition. Remnants of an older
ancestral volcano are exposed on the W and NE sides at 1,500-1,800 m
elevation. There are over two dozen pyroclastic cones on its NW flank,
which is blanketed by massive aa lava flows. Frequent explosive activity,
primarily consisting of Strombolian ash eruptions from the small summit
crater, but sometimes producing lava flows, has been recorded since the
18th century. A steam plume often rises from the summit crater.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuUY7HiQz$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpUFzVxD4$>





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



IGP and INGEMMET reported that the eruption at Ubinas continued during 5-12
July. According to IGP there were 67 volcano-tectonic earthquakes
indicating rock fracturing and 47 long-period earthquakes signifying the
movement of gas and magma recorded during 5-9 July. A period of continuous
ash-and-gas emissions was visible on 5 July with the plumes drifting more
than 10 km SE and E. The Washington VAAC reported that ash plumes and
periodic puffs of ash rose 5.5-9.1 km (18,000-30,000 ft) a.s.l. and drifted
N and NE. On 6 July explosions recorded at 0747 and 2330 produced
ash-and-gas plumes that rose as high as 3.5 km above the crater rim and
drifted within 30 km NW, NE, SE, and S. According to the VAAC the explosion
at 0747 produced a plume of ash and gas that rose to 9.1 km a.s.l., drifted
SW, and gradually dissipated, while a lower-altitude plume at 7.6 km
(25,000 ft) a.s.l. drifted NE. Gobierno Regional de Moquegua declared a
state of emergency for districts in the Moquegua region, along with
Coalaque Chojata, Icuña, Lloque, Matalaque (17 km SE), Ubinas, and Yunga of
the General Sánchez Cerro province, to be in effect for 60 days.



On 7 July the VAAC reported that at 0320 an ash plume rose to 7.3 km
(24,000 ft) a.s.l. and drifted E. At 0900 and 1520 steam plumes with
diffuse ash rose to 6.7 km (22,000 ft) a.s.l. and drifted SE. Diffuse gas
emissions were visible in satellite images drifting SE at 2120. Very small
ash puffs visible in satellite and webcam images at 0920 and 1520 on 8 July
rose as high as 6.4 km (21,000 ft) a.s.l. and drifted SE. INGEMMET reported
that during 9-11 July sulfur dioxide emissions were low at 300 tons per
day. Gas-and-steam plumes rose 150-400 m and drifted S. The Alert Level
remained at Orange (the third level on a four-color scale) and the public
was warned to stay 4 km away from the crater.



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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuZ0ca3F-$ 
<https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp8weFjuE$>
;

Instituto Geológico Minero y Metalúrgico (INGEMMET)
https://urldefense.com/v3/__http://www.ingemmet.gob.pe/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxufEfIe7F$ 
<https://urldefense.com/v3/__http://www.ingemmet.gob.pe/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpNcSyFH0$>
;

Gobierno Regional de Moquegua https://urldefense.com/v3/__http://www.regionmoquegua.gob.pe/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuSYQX19o$ 
<https://urldefense.com/v3/__http://www.regionmoquegua.gob.pe/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpybTHVCo$>
;

Washington Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuQNqQirZ$ 
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpzuxCzYA$>





Ongoing Activity





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



KVERT reported that moderate activity at Ebeko was ongoing during 29 June-6
July. According to volcanologists in Severo-Kurilsk (Paramushir Island,
about 7 km E), explosions on 4 July generated ash plumes that rose as high
as 2.2 km (7,200 ft) a.s.l and drifted to the NW. On 4 and 6 July thermal
anomalies were observed in satellite images; weather clouds obscured views
on other days. The Aviation Color Code remained at Orange (the second
highest level on a four-color scale). Dates are based on UTC times;
specific events are in local time where noted.



Geologic Summary. The flat-topped summit of the central cone of Ebeko
volcano, one of the most active in the Kuril Islands, occupies the northern
end of Paramushir Island. Three summit craters located along a SSW-NNE line
form Ebeko volcano proper, at the northern end of a complex of five
volcanic cones. Blocky lava flows extend west from Ebeko and SE from the
neighboring Nezametnyi cone. The eastern part of the southern crater
contains strong solfataras and a large boiling spring. The central crater
is filled by a lake about 20 m deep whose shores are lined with steaming
solfataras; the northern crater lies across a narrow, low barrier from the
central crater and contains a small, cold crescentic lake. Historical
activity, recorded since the late-18th century, has been restricted to
small-to-moderate explosive eruptions from the summit craters. Intense
fumarolic activity occurs in the summit craters, on the outer flanks of the
cone, and in lateral explosion craters.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuRhoDkvj$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpktT498Y$>





Etna  | Sicily (Italy)  | 37.748°N, 14.999°E  | Summit elev. 3357 m



INGV reported that during 9-10 July explosive activity at Etnaâ??s SE Crater
produced ash emissions that rapidly dispersed near the summit.



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



Source: Sezione di Catania - Osservatorio Etneo (INGV)
https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuRG0axfw$ 
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIptG4sHFM$>





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



INSIVUMEH reported that eruptive activity continued at Fuego during 5-11
July. Steam-and-gas emissions rose 300-540 m above the crater rim and
drifted SW, W, and NW. Daily counts of weak and sometimes moderate
explosions averaged 2-7 per hour. Explosions triggered weak and moderate
avalanches that descended the Honda (E), El Jute (ESE), Las Lajas (SE),
Trinidad (S), Ceniza (SSW), and Seca (W) ravines. Sometimes explosions were
accompanied by ash plumes that rose as high as 1 km above the crater and
drifted as far as 20 km SW, W, and NW. Degassing sounds (similar to a jet
engine) lasting 1-2 minutes were reported on most days. Minor ashfall was
reported in areas downwind, including El Porvenir (8 km SE), Panimaché I (7
km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Panimaché II (8 km WSW),
Finca Palo Verde (10 km WSW), Sangre de Cristo (8 km W), and Yepocapa (9 km
WNW).



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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuQ2dRqeT$ 
<https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpJXlrRKM$>





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 5-11
July. Several local earthquakes were recorded daily during 6-11 July. Minor
degassing was observed in satellite data on 6 July and in webcam images
during 10-11 July. Weather clouds obscured satellite and webcam views on
other days. Elevated surface temperatures at the summit were identified in
satellite images during 10-11 July. 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 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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuUY7HiQz$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpUFzVxD4$>





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



PVMBG reported that daily dense white gas-and-steam plumes from Karangetang
were visible rising as high as 300 m and drifting multiple directions
during 5-11 July. Periodic webcam images published in the reports showed
incandescence at Main Crater (S crater) and from material on the flanks of
Main Crater. PVMBG issued Volcano Observatory Notices for Aviation (VONAs)
about eruptive events at 0759 and 0850 on 10 July; images showed what
appeared to be pyroclastic flows descending the S flank of Main Crater. 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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxucWMRH5M$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpJQ-3WFs$>





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



BPPTKG reported that the eruption at Merapi (on Java) continued during
23-29 June and seismicity remained at elevated levels. The SW lava dome
produced 130 lava avalanches that traveled as far as 2 km down the SW flank
(upstream in the Boyong drainage) and one that traveled 300 m NW down the
Senowo 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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxueLApoxf$ 
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIp1IsPLVU$>





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



CENAPRED reported that eruptive activity continued at Popocatépetl during
5-11 July. Long-period events totaling 25-123 per day were accompanied by
steam-and-gas plumes that sometimes contained minor amounts of ash. Seismic
activity also included variable-amplitude volcanic tremors (total of 35
hours), harmonic tremor (9.5 hours), explosions, and volcano-tectonic
earthquakes (maximum magnitude 1.6 at 0441 on 9 July). Ash plumes
identified in webcam and satellite images were described in daily aviation
notices issued by the Washington VAAC; some plumes rose as high as 2.2 km
above the summit and drifted NE, SW, W, or NW. Minor explosions occurred at
2336 on 4 July, at 1955 on 6 July, at 0911 and 1937 on 7 July, at 1016 on 8
July, and at 0209 and 0335 on 11 July. Moderate explosions were recorded at
0007 on 9 July and at 0816 on 11 July. At 0843 on 10 July the VAAC reported
an ash plume that rose 1 km above the summit and drifted as far as 28 km
NW. At 0930 on 10 July ashfall was reported in the municipalities of
Ayapango (24 km WNW), Tenango del Aire (29 km WNW), Amecameca (19 km NW),
and Temamatla (33 km NW), all within the State of México. The VAAC reported
that the plume drifted as far as 185 km NW by noon, and the Secretaría de
Gestión Integral de Riesgos y Protección Civil (SGIRPC) of the City of
México reported ashfall in Milpa Alta (46 km WNW), Xochimilco (56 km WNW),
Coyoacán (65 km WNW), Tlalpan (67 km WNW), La Magdalena Contreras (70 km
WNW), �lvaro Obregón (72 km WNW), Cuajimalpa (80 km WNW), Tláhuac (49 km
NW), and Iztapalapa (59 km NW). On the morning of 11 July ashfall was
reported in the municipalities of Ozumba (18 km W) and Juchitepec (30 km
WNW) within the State of México. 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!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuRNBtHwg$ 
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpqnlR0vc$>
;

Washington Volcanic Ash Advisory Center (VAAC)
https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuQNqQirZ$ 
<https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpzuxCzYA$>
;

Secretaría de Gestión Integral de Riesgos y Protección Civil (SGIRPC)
https://urldefense.com/v3/__https://www.proteccioncivil.cdmx.gob.mx/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuVwVgiPH$ 
<https://urldefense.com/v3/__https://www.proteccioncivil.cdmx.gob.mx/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpmodvJpg$>





Santa Maria  | Southwestern Guatemala  | 14.757°N, 91.552°W  | Summit elev.
3745 m



INSIVUMEH reported that eruptive activity continued at Santa Mariaâ??s
Santiaguito lava dome complex during 5-11 July. Lava effusion at Caliente
dome fed lava flows, and occasionally produced both avalanches and
pyroclastic flows that traveled short distances down the S, SW, and W
flanks. Daily weak and sometimes moderate explosions ejected ash plumes as
high as 900 m above the dome that drifted W and NW, and triggered
avalanches down the E, SE, and S flanks. Incandescence was observed at the
crater and along lava flow margins during most nights and early mornings.



Geologic Summary. Symmetrical, forest-covered Santa María volcano is part
of a chain of large stratovolcanoes that rise above the Pacific coastal
plain of Guatemala. The sharp-topped, conical profile is cut on the SW
flank by a 1.5-km-wide crater. The oval-shaped crater extends from just
below the summit to the lower flank, and was formed during a catastrophic
eruption in 1902. The renowned Plinian eruption of 1902 that devastated
much of SW Guatemala followed a long repose period after construction of
the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito
lava-dome complex has been growing at the base of the 1902 crater since
1922. Compound dome growth at Santiaguito has occurred episodically from
four vents, with activity progressing W towards the most recent, Caliente.
Dome growth has been accompanied by almost continuous minor explosions,
with periodic lava extrusion, larger explosions, pyroclastic flows, and
lahars.



Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e
Hidrologia (INSIVUMEH) https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuQ2dRqeT$ 
<https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpJXlrRKM$>





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



PVMBG reported that eruptive activity continued at Semeru during 5-11 July,
though weather conditions prevented summit observations on most days. On 10
July a dense white plumes rose as high as 600 m above the summit and
drifted N, NW, W, and SW. However, emergency management agencies Badan
Nasional Penanggulangan Bencana (BNPB) and Badan Penanggulangan Bencana
Daerah (BPBD) reported that on 7 July continuous heavy rainfall caused
flooding and lahars that affected the following locations in the Lumajang
Regency: Kloposawit Village and Tumpeng Village in the Candipuro
Subdistrict, Sumerwuluh Village, Pronojiwo Village, Jugosari Village, and
Sidomulyo Village in the Pronojiwo Subdistrict, and Nguter Village in the
Pasirian Subdistrict. Starting at 0010, lahars descended Semeruâ??s flanks
and damaged 13 bridges, 12 homes, over 80 hectares of crops, and affected
livestock. As of 2035 on 10 July, a total of 1,294 people had evacuated to
18 shelter locations. 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.



Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxucWMRH5M$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpJQ-3WFs$>
;

Badan Nacional Penanggulangan Bencana (BNPB) https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuU6H4Fcf$ 
<https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpv1mP92w$>
;

Badan Penanggulangan Bencana Daerah Provinsi Jawa Timur (East Java BPBD)
https://urldefense.com/v3/__https://web.bpbd.jatimprov.go.id/__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuVCZgmQ9$ 
<https://urldefense.com/v3/__https://web.bpbd.jatimprov.go.id/__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpVl9ngxI$>





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



KVERT reported that eruptive activity continued at Sheveluch during 29
June-6 July. Daily thermal anomalies were observed in satellite images and
intense fumarolic activity was visible from both the active crater and lava
dome. An aviation notice on 2 July described a gas-and-steam plume with
some ash that rose 3.5 km a.s.l. and drifted 39 km W. Additional aviation
notices caused by resuspended ash were issued on 30 June and 1, 4, and 5
July; plumes rose up to 3 km a.s.l. and drifted as far as 95 km ESE, SE, W,
and WNW. The Aviation Color Code remained at Orange (the second highest
level on a four-color scale). Dates are based on UTC times; specific events
are in local time where noted.



Geologic Summary. The high, isolated massif of Sheveluch volcano (also
spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's
largest and most active volcanic structures, with at least 60 large
eruptions during the Holocene. The summit of roughly 65,000-year-old Stary
Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera
breached to the south. Many lava domes occur on its outer flanks. The
Molodoy Shiveluch lava dome complex was constructed during the Holocene
within the large open caldera; Holocene lava dome extrusion also took place
on the flanks of Stary Shiveluch. Widespread tephra layers from these
eruptions have provided valuable time markers for dating volcanic events in
Kamchatka. Frequent collapses of dome complexes, most recently in 1964,
have produced debris avalanches whose deposits cover much of the floor of
the breached caldera.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxuRhoDkvj$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpktT498Y$>





Tofua  | Tonga Ridge  | 19.75°S, 175.07°W  | Summit elev. 515 m



Tonga Geological Services issued a public notice on 7 July noting the
ongoing eruption at Tofua and requesting that the public contact them with
any information, including photos and video. Data and observations
indicated that the activity was normal and no significant seismic activity
nor thermal anomalies were recorded.



Geologic Summary. The low, forested Tofua Island in the central part of the
Tonga Islands group is the emergent summit of a large stratovolcano that
was seen in eruption by Captain Cook in 1774. The summit contains a
5-km-wide caldera whose walls drop steeply about 500 m. Three post-caldera
cones were constructed at the northern end of a cold fresh-water caldera
lake, whose surface lies only 30 m above sea level. The easternmost cone
has three craters and produced young basaltic-andesite lava flows, some of
which traveled into the caldera lake. The largest and northernmost of the
cones, Lofia, has a steep-sided crater that is 70 m wide and 120 m deep and
has been the source of historical eruptions, first reported in the 18th
century. The fumarolically active crater of Lofia has a flat floor formed
by a ponded lava flow.



Source: Tonga Geological Services, Government of Tonga
https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!adTouW_BJev13ULMmVWsR-LuS-GxukJJn4RR02hJvyprXZbyFee7k69nvyTMDjvyfiPdfZaxudGWc8OJ$ 
<https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!d0G38h_Qu6ESJDzr9tJhhPQVjER06Ju0tbcvOgSbet_UCGN3UVt1DDWm1WNGITxN_NIpMLX-3T0$>



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End of Volcano Digest - 10 Jul 2023 to 12 Jul 2023 (#2023-69)
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