Smithsonian / USGS Weekly Volcanic Activity Report 7-13 July 2021

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



5-5-5-5-5-5-5-5-5-5-5-5-5-5


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


Smithsonian / USGS Weekly Volcanic Activity Report

7-13 July 2021



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

URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dcIroRlM$ 
<https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyMYw6aCE$>





New Activity/Unrest: Bagana, Bougainville (Papua New Guinea)  | Krakatau,
Indonesia  | Pavlof, United States  | Sarychev Peak, Matua Island (Russia)
| Suwanosejima, Ryukyu Islands (Japan)  | Taal, Luzon (Philippines)



Ongoing Activity: Aira, Kyushu (Japan)  | Dukono, Halmahera (Indonesia)  |
Ebeko, Paramushir Island (Russia)  | Etna, Sicily (Italy)  | Karymsky,
Eastern Kamchatka (Russia)  | Krysuvik-Trolladyngja, Iceland  | Lewotolok,
Lembata Island (Indonesia)  | Merapi, Central Java (Indonesia)  | Nevados
de Chillan, Chile  | Popocatepetl, Mexico  | Semeru, Eastern Java
(Indonesia)  | Semisopochnoi, Aleutian Islands (USA)  | Sheveluch, Central
Kamchatka (Russia)  | Sinabung, Indonesia  | Veniaminof, United States





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



Based on satellite and wind model data, the Darwin VAAC reported that on 9
July an ash plume from Bagana rose to 1.8 km (6,000 ft) a.s.l. and drifted
W.



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.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dxYKJB60$ 
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUykIlWZ_4$>





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



The Darwin VAAC reported that on 7 July ash plumes from Anak Krakatau rose
to 1.5 km (5,000 ft) a.s.l. and drifted NW.



Geologic Summary. The renowned volcano Krakatau (frequently misstated as
Krakatoa) lies in the Sunda Strait between Java and Sumatra. Collapse of
the ancestral Krakatau edifice, perhaps in 416 or 535 CE, formed a
7-km-wide caldera. Remnants of this ancestral 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, the 2nd
largest in Indonesia during historical time, caused more than 36,000
fatalities, most as a result of devastating 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: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dxYKJB60$ 
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUykIlWZ_4$>





Pavlof  | United States  | 55.417°N, 161.894°W  | Summit elev. 2493 m



At 1140 on 9 July AVO raised the Volcano Alert Level and Aviation Color
Code at Pavlof to Advisory and Yellow, respectively, noting that seismicity
had increased during the previous 16 hours and was characterized by
near-continuous tremor. Seismicity decreased and was more periodic during
10-13 July, but remained above background levels.



Geologic Summary. The most active volcano of the Aleutian arc, Pavlof is a
2519-m-high Holocene stratovolcano that was constructed along a line of
vents extending NE from the Emmons Lake caldera. Pavlof and its twin
volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of
symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and
Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW
flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof
Sister, Pavlof has been frequently active in historical time, typically
producing Strombolian to Vulcanian explosive eruptions from the summit
vents and occasional lava flows. The active vents lie near the summit on
the north and east sides. The largest historical eruption took place in
1911, at the end of a 5-year-long eruptive episode, when a fissure opened
on the N flank, ejecting large blocks and issuing lava flows.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dKidF7_w$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUycm6Ho5s$>





Sarychev Peak  | Matua Island (Russia)  | 48.092°N, 153.2°E  | Summit elev.
1496 m



SVERT reported that on 29 June and 1 July brief ash emissions from Sarychev
Peak rose to 3 km (10,000 ft) a.s.l. A weak thermal anomaly identified in
satellite data persisted through 12 July; SVERT lowered the Alert Level to
Green (the lowest level on a four-color scale).



Geologic Summary. Sarychev Peak, one of the most active volcanoes of the
Kuril Islands, occupies the NW end of Matua Island in the central Kuriles.
The andesitic central cone was constructed within a 3-3.5-km-wide caldera,
whose rim is exposed only on the SW side. A dramatic 250-m-wide, very
steep-walled crater with a jagged rim caps the volcano. The substantially
higher SE rim forms the 1496 m high point of the island. Fresh-looking lava
flows, prior to activity in 2009, had descended in all directions, often
forming capes along the coast. Much of the lower-angle outer flanks of the
volcano are overlain by pyroclastic-flow deposits. Eruptions have been
recorded since the 1760s and include both quiet lava effusion and violent
explosions. Large eruptions in 1946 and 2009 produced pyroclastic flows
that reached the sea.



Source: Sakhalin Volcanic Eruption Response Team (SVERT) https://urldefense.com/v3/__http://www.imgg.ru/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6df6RVOTU$ 
<https://urldefense.com/v3/__http://www.imgg.ru/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyjfyNDNc$>





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



JMA reported that 96 explosions at Suwanosejima's Ontake Crater produced
eruption plumes that generally rose 2-2.4 km above the crater rim during
5-12 July. Large volcanic bombs were ejected mainly 400 m from the crater
and crater incandescence was visible nightly. Eruption sounds were
sometimes heard in Toshima village (4 km SSW). An explosion at 0439 on 8
July ejected large bombs 800 m NW and an explosion at 1319 on 12 July
produced an ash plume that rose 3 km. The Alert Level remained at 3 and the
public was warned to stay 2 km away from the crater.



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



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6d-EluXyg$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyNmnr0Mk$>





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



PHIVOLCS reported that an eruption at Taal continued during 7-13 July. A
series of short-lived phreatomagmatic explosions were recorded at 0518,
0847, 0915, 0926, 1156, and 2141 on 7 July and jetted ash plumes as high
has 700 m. Another series was recorded at 0647, 1806, 2121, 2150 on 8 July
and 0259 on 9 July, jetting ash 200 m high.



During 7-13 July daily plumes of steam and sulfur dioxide gas rose 1-1.5 km
from the lake and drifted NW, W, and SW. Sulfur dioxide emissions averaged
4,149-11,397 tonnes/day. Low-level background tremor continued with as many
as 185 volcanic earthquakes and 44 low-frequency volcanic earthquakes
recorded per day. There were also 5-176 daily episodes of volcanic tremor,
each lasting between 1 and 97 minutes. The network also detected 2-10 daily
hybrid earthquakes during 6-9 July. The DROMIC report stated that 10,408
people were in evacuation centers or private residences by 12 July. The
Alert Level remained at 3 (on a scale of 0-5) and PHIVOLCS reminded the
public that the entire Taal Volcano Island is a Permanent Danger Zone (PDZ)
and to not enter the high-risk barangays of Agoncillo and Laurel.
Activities on Taal Lake were strictly prohibited.



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
historical eruptions. The island is composed of coalescing small
stratovolcanoes, tuff rings, and scoria cones that have grown about 25% in
area during historical time. Powerful pyroclastic flows and surges from
historical eruptions have caused many fatalities.



Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dtxYUiGw$ 
<https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyqJ2VpU8$>
;

Disaster Response Operations Monitoring and Information Center (DROMIC)
https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6d4GkL7Do$ 
<https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyHbSorXo$>





Ongoing Activity





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



JMA reported that very small eruptive events were occasionally recorded at
Minamidake Crater (at Aira Calderaâ??s Sakurajima volcano). Crater
incandescence was visible at night during 9-12 July. The Alert Level
remained at 3 (on a 5-level scale), and residents were warned to stay 2 km
away from the crater.



Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay
contains the post-caldera Sakurajima volcano, one of Japan's most active.
Eruption of the voluminous Ito pyroclastic flow accompanied formation of
the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera
was formed during the early Holocene in the NE corner of the Aira caldera,
along with several post-caldera cones. The construction of Sakurajima began
about 13,000 years ago on the southern rim of Aira caldera and built an
island that was finally joined to the Osumi Peninsula during the major
explosive and effusive eruption of 1914. Activity at the Kitadake summit
cone ended about 4850 years ago, after which eruptions took place at
Minamidake. Frequent historical eruptions, recorded since the 8th century,
have deposited ash on Kagoshima, one of Kyushu's largest cities, located
across Kagoshima Bay only 8 km from the summit. The largest historical
eruption took place during 1471-76.



Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6d-EluXyg$ 
<https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyNmnr0Mk$>





Dukono  | Halmahera (Indonesia)  | 1.693°N, 127.894°E  | Summit elev. 1229 m



Based on satellite and wind model data, the Darwin VAAC reported that
during 8 and 11-13 July ash plumes from Dukono rose to 2.1 km (7,000 ft)
a.s.l. and drifted N, NW, W, and SW. The Alert Level remained at 2 (on a
scale of 1-4), and the public was warned to remain outside of the 2-km
exclusion zone.



Geologic Summary. Reports from this remote volcano in northernmost
Halmahera are rare, but Dukono has been one of Indonesia's most active
volcanoes. More-or-less continuous explosive eruptions, sometimes
accompanied by lava flows, occurred from 1933 until at least the mid-1990s,
when routine observations were curtailed. During a major eruption in 1550,
a lava flow filled in the strait between Halmahera and the north-flank cone
of Gunung Mamuya. This complex volcano presents a broad, low profile with
multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of
the summit crater complex, contains a 700 x 570 m crater that has also been
active during historical time.



Sources: Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dxYKJB60$ 
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUykIlWZ_4$>
;

Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dVAXMGj8$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyROAR8_0$>





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



According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7
km E of Ebeko, explosions during 2, 4, and 6-8 July produced ash plumes
that rose as high as 3 km (10,000 ft) a.s.l. and drifted E and SE. A
thermal anomaly was identified in satellite images during 5-7 July. The
Aviation Color Code remained at Orange (the second highest level on a
four-color scale).



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!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dnfROjCM$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyQ6Jlktk$>





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



INGV reported continuing Strombolian activity and two episodes of lava
fountaining Etnaâ??s Southeast Crater (SEC) during 5-11 July. The first
episode began at 1130 on 6 July with Strombolian activity at SEC. The
intensity and frequency of explosions progressively intensified and formed
lava fountains. Ash plumes rose to 1.5 km (5,000 ft) a.s.l. and drifted S,
causing ashfall in areas downwind. A small lava flow originated from the S
side of the cone and traveled SW, stopping at 2,800 m elevation. During
fieldwork on 7 July scientist observed deposits of bombs, 1 m in diameter,
on the N flank and smaller bombs scattered farther away. A second episode
began at 2100 on 8 July with Strombolian activity which again intensified
and formed lava fountains. Ash plumes rose to 3.4 km (11,000 ft) a.s.l. and
drifted SE, causing ashfall in downwind areas. Lava flowed SW to 2,350 m
elevation.



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



Source: Sezione di Catania - Osservatorio Etneo (INGV)
https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dSXT_zUg$ 
<https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyZlUvFqM$>





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



KVERT reported that a thermal anomaly over Karymsky was idenitifed in
satellite images during 5-8 July and ash plumes were visible drifting 60 km
W and E during 6-8 July. The Aviation Color Code remained at Orange (the
second highest level on a four-color scale).



Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern
volcanic zone, is a symmetrical stratovolcano constructed within a
5-km-wide caldera that formed during the early Holocene. The caldera cuts
the south side of the Pleistocene Dvor volcano and is located outside the
north margin of the large mid-Pleistocene Polovinka caldera, which contains
the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding
Karymsky eruptions originated beneath Akademia Nauk caldera, located
immediately south. The caldera enclosing Karymsky formed about 7600-7700
radiocarbon years ago; construction of the stratovolcano began about 2000
years later. The latest eruptive period began about 500 years ago,
following a 2300-year quiescence. Much of the cone is mantled by lava flows
less than 200 years old. Historical eruptions have been vulcanian or
vulcanian-strombolian with moderate explosive activity and occasional lava
flows from the summit crater.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dnfROjCM$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyQ6Jlktk$>





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



The fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic
system, close to Fagradalsfjall on the Reykjanes Peninsula, continued
during 7-13 July. Lava fountaining and overflows from the fifth vent were
sometimes visible, and lava from the crater flowed in tubes as well as on
the surface. Visible activity at the vent occasionally paused for various
lengths of time, though sub-surface lava likely continued flowing through
the tube system. Weather conditions prevented views of the crater on some
days and also created hazardous conditions. The Aviation Color Code
remained at Orange due to the lack of ash and tephra emissions, though IMO
warned of the potential for lapilli and scoria fallout within a 650 m
radius of the active vent. Authorities warned of increased gas emissions
hazards.



Geologic Summary. The Krýsuvík-Trölladyngja volcanic system is described by
the Catalogue of Icelandic Volcanoes as an approximately 50-km-long
composite fissure swarm trending about N38°E, including a 30-km-long swarm
of fissures, with no central volcano. It is one of the volcanic systems
arranged en-echelon along the Reykjanes Peninsula west of Kleifarvatn lake.
The Fagradalsfjall and Krýsuvík fissure swarms are considered splits or
secondary swarms of the Krýsuvíkâ??Trölladyngja volcanic system. Small shield
volcanoes have produced a large portion of the erupted volume within the
system. Several eruptions have taken place since the settlement of Iceland,
including the eruption of a large basaltic lava flow from the Ogmundargigar
crater row around the 12th century. The latest eruption, identified through
tephrochronology, took place during the 14th century.



Sources: Icelandic Meteorological Office (IMO) https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6d3QaEALk$ 
<https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyOGv6Nxc$>
;

Icelandic National Broadcasting Service (RUV)
https://urldefense.com/v3/__https://www.ruv.is/frett/2021/07/06/eg-held-ad-thetta-se-bara-thessi-nyi-taktur__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dFR_W8z4$ 
<https://urldefense.com/v3/__https://www.ruv.is/frett/2021/07/06/eg-held-ad-thetta-se-bara-thessi-nyi-taktur__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyUJPjXXQ$>
;

Icelandic National Broadcasting Service (RUV)
https://urldefense.com/v3/__https://www.ruv.is/frett/2021/07/13/hraunstraumur-rennur-fagurlega-nidur-i-meradali__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dhhX14H4$ 
<https://urldefense.com/v3/__https://www.ruv.is/frett/2021/07/13/hraunstraumur-rennur-fagurlega-nidur-i-meradali__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyqiosad0$>





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



PVMBG reported that daily white-and-gray plumes from Lewotolok rose as high
as 1.1 km and drifted SW, W, and NW during 6-12 July. Incandescent material
was ejected from the summit vent on 6, 8, and 10 July; on 6 July material
landed as far as 300 m away. The Darwin VAAC noted that on 7 July an ash
plume rose 2.7 km (9,000 ft) a.s.l. and drifted E, based on satellite data
and information from PVMBG. The Alert Level remained at 3 (on a scale of
1-4) and the public was warned to stay 3 km away from the summit crater.



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.



Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dVAXMGj8$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyROAR8_0$>
;

Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dxYKJB60$ 
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUykIlWZ_4$>





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



BPPTKG reported that the lava dome just below Merapiâ??s SW rim and the lava
dome in the summit crater both remained active during 2-8 July. The SW rim
lava-dome volume was an estimated 1.815 million cubic meters by 8 July and
continued to shed material down the flank. The volume of the summit lava
dome was 2,741 million cubic meters. A total of 17 pyroclastic flows
traveled a maximum of 2 km down the SW flank and as far as 1.5 km SE. As
many as 125 incandescent avalanches traveled a maximum of 2 km down the SW
flank and 1.8 km down the SE flank. The Alert Level remained at 3 (on a
scale of 1-4), and the public was warned to stay 5 km away from the summit.



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!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dD5Ad6Bs$ 
<https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUydZfekL8$>





Nevados de Chillan  | Chile  | 36.868°S, 71.378°W  | Summit elev. 3180 m



SERNAGEOMIN reported continuing explosive and effusive activity at Nevados
de Chillánâ??s Nicanor Crater during 16-30 June, alomg with increased sulfur
dioxide emissions and thermal anomalies. Explosions generated ash plumes
that rose as high as 1.4 km above the crater rim and crater incandescence
at night; incandescent material was ejected as far as 500 m onto the N, E,
and S flanks. The L5 and L6 lava flows continued to be active, with
increased effusion rates during 17-19 and 27-28 June. During the periods of
increased effusion rates the flow temperatures were higher, nighttime
incandescence was more intense, emissions rose higher, and more pyroclastic
flows were recorded. The pyroclastic flows traveled less than 500 m down
the NE flank and were sourced from collapses at the sides of L6 and the
front of L5. The average temperature was 131 degrees Celsius with a maximum
of 174 degrees for L5 and an average of 163 degrees Celsius with a maximum
of 181 degrees for L6. Temperatures at the vents at Nicanor Crater were as
high as 360 degrees Celsius during explosive phases. Satellite images
indicated that the L5 lava flow was 1,033 m long and L6 was 894 m long, and
that the distal end of L6 had thickened. The average sulfur dioxide
emission rate was 694 (± 43) tons/day, reaching a high value of 903 on 19
June. There was a total of 35 thermal anomalies. The Alert Level remained
at Yellow, the second lowest level on a four-color scale. ONEMI stated that
Alert Level Yellow (the middle level on a three-color scale) remained in
place for the communities of Pinto and Coihueco, noting that the public
should stay at least 2 km away from the crater.



Geologic Summary. The compound volcano of Nevados de Chillán is one of the
most active of the Central Andes. Three late-Pleistocene to Holocene
stratovolcanoes were constructed along a NNW-SSE line within three nested
Pleistocene calderas, which produced ignimbrite sheets extending more than
100 km into the Central Depression of Chile. The largest stratovolcano,
dominantly andesitic, Cerro Blanco (Volcán Nevado), is located at the NW
end of the group. Volcán Viejo (Volcán Chillán), which was the main active
vent during the 17th-19th centuries, occupies the SE end. The new Volcán
Nuevo lava-dome complex formed between 1906 and 1945 between the two
volcanoes and grew to exceed Volcán Viejo in elevation. The Volcán Arrau
dome complex was constructed SE of Volcán Nuevo between 1973 and 1986 and
eventually exceeded its height.



Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6d2o0Xr-4$ 
<https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUytxigMJE$>
;

Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dPheUM2A$ 
<https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyc_8ZIyI$>





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



CENAPRED reported that each day during 6-13 July there were 47-112
steam-and-gas emissions from Popocatépetl. Some emissions contained ash
during 8-13 July. Almost daily periods of low-amplitude tremor lasted from
10 minutes to five hours. A few volcano-tectonic earthquakes were recorded.
Crater incandescence was visible at night during 12-13 July. The Alert
Level remained at Yellow, Phase Two (middle level on a three-color scale).



Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for
smoking mountain, rises 70 km SE of Mexico City to form North America's
2nd-highest volcano. The glacier-clad stratovolcano contains a
steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is
modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier
volcano. At least three previous major cones were destroyed by
gravitational failure during the Pleistocene, producing massive
debris-avalanche deposits covering broad areas to the south. The modern
volcano was constructed south of the late-Pleistocene to Holocene El Fraile
cone. Three major Plinian eruptions, the most recent of which took place
about 800 CE, have occurred since the mid-Holocene, accompanied by
pyroclastic flows and voluminous lahars that swept basins below the
volcano. Frequent historical eruptions, first recorded in Aztec codices,
have occurred since Pre-Columbian time.



Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dPFCLZxo$ 
<https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyOWqSFA8$>





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



Semeru continued to erupt during 7-13 July. Inclement weather often
prevented visual observations, though a gray-and-white ash plume was seen
rising 500 m above the summit and drifting SW on 6 July. The Alert Level
remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km
and extensions to 5 km in the SSE sector.



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!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dVAXMGj8$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyROAR8_0$>
;

Darwin Volcanic Ash Advisory Centre (VAAC)
https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dxYKJB60$ 
<https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUykIlWZ_4$>





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



AVO reported that continuous volcanic tremor at Semisopochnoi began at 1200
on 12 July and explosive activity was recorded by the infrasound network.
Emissions began at 1300 and lasted tens of minutes; a sulfur dioxide gas
plume possibly containing ash was identified in satellite images drifting S
at an altitude less than 1.5 km (5,000 ft) a.s.l. The Aviation Color Code
was raised to Orange and the Volcano Alert Level was raised to Watch.
Volcanic tremor decreased to low levels after several hours.



Geologic Summary. Semisopochnoi, the largest subaerial volcano of the
western Aleutians, is 20 km wide at sea level and contains an 8-km-wide
caldera. It formed as a result of collapse of a low-angle, dominantly
basaltic volcano following the eruption of a large volume of dacitic
pumice. The high point of the island is Anvil Peak, a double-peaked
late-Pleistocene cone that forms much of the island's northern part. The
three-peaked Mount Cerberus was constructed within the caldera during the
Holocene. Each of the peaks contains a summit crater; lava flows on the N
flank of Cerberus appear younger than those on the south side. Other
post-caldera volcanoes include the symmetrical Sugarloaf Peak SSE of the
caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake
in the NE part of the caldera. Most documented eruptions have originated
from Cerberus, although Coats (1950) considered that both Sugarloaf and
Lakeshore Cone could have been recently active.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dKidF7_w$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUycm6Ho5s$>





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



KVERT reported that a thermal anomaly over Sheveluch was identified in
satellite images during 2-9 July. A plume of re-suspended ash drifted 90 km
E during 6-7 July. The Aviation Color Code remained at Orange (the second
highest level on a four-color scale).



Geologic Summary. The high, isolated massif of Sheveluch volcano (also
spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya
volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most
active volcanic structures. The summit of roughly 65,000-year-old Stary
Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera
breached to the south. Many lava domes dot its outer flanks. The Molodoy
Shiveluch lava dome complex was constructed during the Holocene within the
large horseshoe-shaped caldera; Holocene lava dome extrusion also took
place on the flanks of Stary Shiveluch. At least 60 large eruptions have
occurred during the Holocene, making it the most vigorous andesitic volcano
of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions
have provided valuable time markers for dating volcanic events in
Kamchatka. Frequent collapses of dome complexes, most recently in 1964,
have produced debris avalanches whose deposits cover much of the floor of
the breached caldera.



Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dnfROjCM$ 
<https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyQ6Jlktk$>





Sinabung  | Indonesia  | 3.17°N, 98.392°E  | Summit elev. 2460 m



PVMBG reported that on most days during 6-13 July white gas-and-steam
plumes from Sinabung rose as high as 500 m above the summit. At 0925 on 13
July an eruptive or collapse event produced an ash plume that rose 500 m
and drifted ESE. The Alert Level remained at 2 (on a scale of 1-4), and the
public was warned to remain outside of the 2-km exclusion zone.



Geologic Summary. Gunung Sinabung is a Pleistocene-to-Holocene
stratovolcano with many lava flows on its flanks. The migration of summit
vents along a N-S line gives the summit crater complex an elongated form.
The youngest crater of this conical andesitic-to-dacitic edifice is at the
southern end of the four overlapping summit craters. The youngest deposit
is a SE-flank pyroclastic flow 14C dated by Hendrasto et al. (2012) at
740-880 CE. An unconfirmed eruption was noted in 1881, and solfataric
activity was seen at the summit and upper flanks in 1912. No confirmed
historical eruptions were recorded prior to explosive eruptions during
August-September 2010 that produced ash plumes to 5 km above the summit.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dVAXMGj8$ 
<https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUyROAR8_0$>





Veniaminof  | United States  | 56.17°N, 159.38°W  | Summit elev. 2507 m



AVO changed both the Aviation Color Code and Volcano Alert Level for
Veniaminof to Green and Normal, respectively, on 8 July, noting that
seismic stations were back online. The monitoring network consists of local
and regional seismic stations, regional infrasound networks, lightning
detection, and satellite image monitoring.



Geologic Summary. Veniaminof, on the Alaska Peninsula, is truncated by a
steep-walled, 8 x 11 km, glacier-filled caldera that formed around 3,700
years ago. The caldera rim is up to 520 m high on the north, is deeply
notched on the west by Cone Glacier, and is covered by an ice sheet on the
south. Post-caldera vents are located along a NW-SE zone bisecting the
caldera that extends 55 km from near the Bering Sea coast, across the
caldera, and down the Pacific flank. Historical eruptions probably all
originated from the westernmost and most prominent of two intra-caldera
cones, which rises about 300 m above the surrounding icefield. The other
cone is larger, and has a summit crater or caldera that may reach 2.5 km in
diameter, but is more subdued and barely rises above the glacier surface.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dKidF7_w$ 
<https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Moq_xhVRI8wVuDLRWqGN28I9Yx9MBgQp9RRE2FI9blJyL_4q1XFY6pUycm6Ho5s$>


5-5-5-5-5-5-5-5-5-5-5-5-5-5



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



Volcano Listserv is a collaborative venture among Arizona State University
(ASU), Portland State University (PSU), the Global Volcanism Program (GVP)
of the Smithsonian Institution's National Museum of Natural History, and
the International Association for Volcanology and Chemistry of the Earth's
Interior (IAVCEI).



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

PSU - https://urldefense.com/v3/__http://pdx.edu/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dF1rfpm8$ 

GVP - https://urldefense.com/v3/__http://www.volcano.si.edu/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dhyVMo7s$ 

IAVCEI - https://urldefense.com/v3/__https://www.iavceivolcano.org/__;!!IKRxdwAv5BmarQ!MLToFC68BpFVaw6wxLs3AguOiOkSrYxG3tEqjeEMWsUCicAUiClkKu6dMJ7nU_o$ 



To unsubscribe from the volcano list, send the message:

signoff volcano

to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx.



To contribute to the volcano list, send your message to:

volcano@xxxxxxx.  Please do not send attachments.



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

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

End of Volcano Digest - 12 Jul 2021 to 14 Jul 2021 (#2021-64)
*************************************************************



[Index of Archives]     [Yosemite Backpacking]     [Earthquake Notices]     [USGS News]     [Yosemite Campgrounds]     [Steve's Art]     [Hot Springs Forum]

  Powered by Linux