Smithsonian / USGS Weekly Volcanic Activity Report 30 October-5 November 2019

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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

30 October-5 November 2019



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

URL: https://volcano.si.edu/reports_weekly.cfm





New Activity/Unrest: Kikai, Japan  | Klyuchevskoy, Central Kamchatka
(Russia)  | Metis Shoal, Tonga Islands  | Shishaldin, Fox Islands (USA)



Ongoing Activity: Aira, Kyushu (Japan)  | Dukono, Halmahera (Indonesia)  |
Ebeko, Paramushir Island (Russia)  | Ibu, Halmahera (Indonesia)  |
Karangetang, Siau Island (Indonesia)  | Kerinci, Indonesia  | Sabancaya,
Peru  | Sangeang Api, Indonesia  | Semeru, Eastern Java (Indonesia)  |
Sheveluch, Central Kamchatka (Russia)  | Stromboli, Aeolian Islands
(Italy)  | Suwanosejima, Ryukyu Islands (Japan)  | Yasur, Vanuatu





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



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







New Activity/Unrest





Kikai  | Japan  | 30.793°N, 130.305°E  | Summit elev. 704 m



An eruption at Satsuma Iwo-jima, a subaerial part of Kikaiâ??s NW caldera
rim, was detected at 1735 on 2 November, prompting JMA to raise the Alert
Level to 2 (on a 5-level scale). A grayish-white plume rose 1 km above the
Iodake crater rim. The report noted that the number of volcanic earthquakes
has been low, with no variations before or after the event. The next day
during an overflight conducted by the Coast Guard and the Japan
Meteorological Agency Mobile Survey Team (JMA-MOT) observers noted no
changes to the geothermal field and no new deposits from the event the day
before. Views of the crater were obscured by white plumes rising 300 m
above the crater rim.



Geologic Summary. Kikai is a mostly submerged, 19-km-wide caldera near the
northern end of the Ryukyu Islands south of Kyushu. Kikai was the source of
one of the world's largest Holocene eruptions about 6300 years ago.
Rhyolitic pyroclastic flows traveled across the sea for a total distance of
100 km to southern Kyushu, and ashfall reached the northern Japanese island
of Hokkaido. The eruption devastated southern and central Kyushu, which
remained uninhabited for several centuries. Post-caldera eruptions formed
Iodake lava dome and Inamuradake scoria cone, as well as submarine lava
domes. Historical eruptions have occurred in the 20th century at or near
Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island
forming part of the NW caldera rim. Showa-Iojima lava dome (also known as
Iojima-Shinto), a small island 2 km east of Tokara-Iojima, was formed
during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive
eruptions have occurred during the past few decades from Iodake, a
rhyolitic lava dome at the eastern end of Tokara-Iojima.



Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/





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



KVERT reported that ash plumes and steam-and-gas plumes with some ash
drifted 130 km SW on 25 October according to video and satellite data. A
weak thermal anomaly was identified in satellite images during 26-27 and 30
October. The Aviation Color Code remained at Orange.



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)
http://www.kscnet.ru/ivs/kvert/index_eng.php





Metis Shoal  | Tonga Islands  | 19.18°S, 174.87°W  | Summit elev. 43 m



GeoNet reported that by 1 November the eruption at Metis Shoal (Lateiki)
had formed an elongated island, with no visible evidence of the old 1995
dome. According to a news article the new island is about 100 m wide and
400 m long, and had emerged at a location 120 m away from the former
island. The article noted that the eruption had ceased.



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



Sources: GeoNet http://www.geonet.org.nz/;

Matangi Tonga Online https://matangitonga.to/2019/11/06/eruption-lateiki





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



AVO reported that by 28 October two stalled lava flows extended as far as
1.8 km down Shishaldinâ??s NW flank, lahars had traveled at least 4 km down
the NW flank, and trace ash deposits on the N flank were identified in
satellite images. Activity paused during 29-30 October but resumed on 31
October. Numerous small explosions were detected by the local seismic
network during 31 October-1 November and incandescence was visible in
webcam images. There was no evidence of active lava flows outside of the
summit crater. During 1-2 November seismicity remained elevated
characterized by periods of high-amplitude tremor. Small explosions were
recorded in seismic and infrasound data. Elevated surface temperatures were
detected in satellite images and incandescence was observed in webcam
images overnight. A pilot observed a lava flow in the morning of 2
November. Sporadic incandescence recorded by the webcam overnight during
2-3 November suggested minor explosive activity and/or lava fountaining. On
3 November lava overflowed the summit crater and traveled at least 400 m
down the NW flank and 300 m down the SE flank. By 4 November the flow on
the NW flank had branched and lengthened to 1 km. Lahars were as long as 2
km on the N and S flanks. Spatter deposits from explosions or fountaining
were visible on the summit cone. The Aviation Color Code remained at Orange
and the Volcano Alert Level remained at Watch.



Geologic Summary. The beautifully symmetrical volcano of Shishaldin is the
highest and one of the most active volcanoes of the Aleutian Islands. The
2857-m-high, glacier-covered volcano is the westernmost of three large
stratovolcanoes along an E-W line in the eastern half of Unimak Island. The
Aleuts named the volcano Sisquk, meaning "mountain which points the way
when I am lost." A steady steam plume rises from its small summit crater.
Constructed atop an older glacially dissected volcano, it is Holocene in
age and largely basaltic in composition. Remnants of an older ancestral
volcano are exposed on the west and NE sides at 1500-1800 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.



Source: US Geological Survey Alaska Volcano Observatory (AVO)
https://avo.alaska.edu/





Ongoing Activity





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



JMA reported that incandescence from Minamidake crater (at Aira Calderaâ??s
Sakurajima volcano) was visible at night during 28 October-5 November.
There were 32 explosions and 16 non-explosive eruptive events detected by
the seismic network. Eruption plumes rose as high as 2.8 km above the
crater rim and large blocks were ejected as far as 1.3 km away. The Alert
Level remained at 3 (on a 5-level scale).



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) http://www.jma.go.jp/jma/





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



Based on satellite and wind model data, and information from PVMBG, the
Darwin VAAC reported that during 30 October-5 November ash plumes from
Dukono rose to an altitude of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and
drifted NE, E, and SE. 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: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/;

Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml





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



Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of
Ebeko, observed explosions during 25-26 and 29-30 October that sent ash
plumes up to 2.5 km (8,200 ft) a.s.l. Ash plumes drifted E and NE. A weak
thermal anomaly was identified in satellite images on 29 October. 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)
http://www.kscnet.ru/ivs/kvert/index_eng.php





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



PVMBG reported that during 1-5 November white-and-gray plumes from Ibu rose
200-800 m above the summit and drifted E and N. The Alert Level remained at
2 (on a scale of 1-4), and the public was warned to stay at least 2 km away
from the active crater, and 3.5 km away on the N side.



Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along
the NW coast of Halmahera Island has large nested summit craters. The inner
crater, 1 km wide and 400 m deep, contained several small crater lakes
through much of historical time. The outer crater, 1.2 km wide, is breached
on the north side, creating a steep-walled valley. A large parasitic cone
is located ENE of the summit. A smaller one to the WSW has fed a lava flow
down the W flank. A group of maars is located below the N and W flanks.
Only a few eruptions have been recorded in historical time, the first a
small explosive eruption from the summit crater in 1911. An eruption
producing a lava dome that eventually covered much of the floor of the
inner summit crater began in December 1998.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/





Karangetang  | Siau Island (Indonesia)  | 2.781°N, 125.407°E  | Summit
elev. 1797 m



PVMBG reported that during 1-5 November lava continued to effuse from
Karangetangâ??s Main Crater (S), traveling as far as 1.5 km down the Nanitu,
Pangi, and Sense drainages on the SW and W flanks. Sometimes dense white
plumes rose to 200 m above the summit. The Alert Level remained at 2 (on a
scale of 1-4).



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
island. 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 in the historical record (Catalog of Active Volcanoes of the
World: 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) http://vsi.esdm.go.id/





Kerinci  | Indonesia  | 1.697°S, 101.264°E  | Summit elev. 3800 m



PVMBG reported that at 0614 on 30 October a brownish-white ash emission
from Kerinci rose around 800 m above the summit and drifted NE, E, and SE.
Brownish ash emissions rose 800 m and drifted WSW at 1721 on 30 October and
to 500 m and drifted ESE at 0543 on 1 November. An eruptive event at 0553
on 2 November generated a brown ash emission that rose 500 m and drifted
ESE. During 3-5 November brown ash plumes rose 100-500 m. The Alert Level
remained at 2 (on a scale of 1-4), and the public was warned to remain
outside of the 3-km exclusion zone.



Geologic Summary. Gunung Kerinci in central Sumatra forms Indonesia's
highest volcano and is one of the most active in Sumatra. It is capped by
an unvegetated young summit cone that was constructed NE of an older crater
remnant. There is a deep 600-m-wide summit crater often partially filled by
a small crater lake that lies on the NE crater floor, opposite the SW-rim
summit. The massive 13 x 25 km wide volcano towers 2400-3300 m above
surrounding plains and is elongated in a N-S direction. Frequently active,
Kerinci has been the source of numerous moderate explosive eruptions since
its first recorded eruption in 1838.



Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known
as CVGHM) http://vsi.esdm.go.id/





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



Instituto Geofísico del Perú (IGP) reported that an average of 28
low-to-medium intensity explosions per day occurred at Sabancaya during 28
October-3 November. Gas-and-ash plumes rose as high as 2 km above the
summit and drifted W, SW, and S. There were nine thermal anomalies
identified in satellite data. The Alert Level remained at Orange (the
second highest level on a four-color scale) and the public were warned to
stay outside of a 12-km radius.



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



Sources: Instituto Geofísico del Perú (IGP) http://www.igp.gob.pe/;

Observatorio Vulcanológico del INGEMMET (OVI) http://ovi.ingemmet.gob.pe/





Sangeang Api  | Indonesia  | 8.2°S, 119.07°E  | Summit elev. 1912 m



The Darwin VAAC reported that during 30-31 October and 3-4 November
discrete and short-lived ash emissions from Sangeang Api rose 2.7-3.5 km
(9,000-11,000 ft) a.s.l. and drifted NW, W, and SW. Thermal anomalies were
visible on 3 and 5 November. The Alert Level remained at 2 (on a scale of
1-4).



Geologic Summary. Sangeang Api volcano, one of the most active in the
Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast of
Sumbawa Island. Two large trachybasaltic-to-tranchyandesitic volcanic
cones, Doro Api and Doro Mantoi, were constructed in the center and on the
eastern rim, respectively, of an older, largely obscured caldera. Flank
vents occur on the south side of Doro Mantoi and near the northern coast.
Intermittent historical eruptions have been recorded since 1512, most of
them during in the 20th century.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml





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



The Darwin VAAC reported that on 30 October an ash plume from Semeru rose
to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted SE and S based on
satellite images and weather models. The Alert Level remained at 2 (on a
scale of 1-4).



Geologic Summary. Semeru, the highest volcano on Java, and one of its most
active, lies at the southern end of a volcanic massif extending north to
the Tengger caldera. The steep-sided volcano, also referred to as Mahameru
(Great Mountain), rises above coastal plains to the south. Gunung Semeru
was constructed south of the overlapping Ajek-ajek and Jambangan calderas.
A line of lake-filled maars was constructed along a N-S trend cutting
through the summit, and cinder cones and lava domes occupy the eastern and
NE flanks. Summit topography is complicated by the shifting of craters from
NW to SE. Frequent 19th and 20th century eruptions were dominated by
small-to-moderate explosions from the summit crater, with occasional lava
flows and larger explosive eruptions accompanied by pyroclastic flows that
have reached the lower flanks of the volcano.



Source: Darwin Volcanic Ash Advisory Centre (VAAC)
http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml





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 25 October-1 November. 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)
http://www.kscnet.ru/ivs/kvert/index_eng.php





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



INGV reported that during 30 October-5 November activity at Stromboli was
characterized by ongoing Strombolian activity and degassing from multiple
vents within the crater terrace. Explosions originated at a rate of 2-13
per hour from vents in Area N (north crater area) and at a rate of 7-16 per
hour from vents in Area C-S (south central crater area). Explosions from
Area N ejected lapilli and bombs no more than 175 m high, while explosions
at Area C-S ejected tephra to heights under 250 m.



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



Source: Sezione di Catania - Osservatorio Etneo (INGV)
http://www.ct.ingv.it/





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



JMA reported that at 1225 on 19 October a very small eruptive event at
Suwanosejimaâ??s Ontake Crater generated a gray plume that rose 300 m above
the crater rim. A small amount of ash fell in Toshima, 4 km SW. Very small
eruptions during 29-30 October generated grayish-white plumes that rose 800
m. Ashfall was reported in Toshima on 29 October. The Alert Level remained
at 2 (on a 5-level scale).



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 of the volcano 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) http://www.jma.go.jp/jma/





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



On 31 October the Vanuatu Meteorology and Geo-Hazards Department (VMGD)
reported that recent observations and data from Yasurâ??s seismic network
confirmed ongoing sometimes strong explosions. The Alert Level remained at
2 (on a scale of 0-4). VMGD reminded residents and tourists that hazardous
areas were near and around the volcanic crater, within a 395-m-radius
permanent exclusion zone, and that volcanic ash and gas could reach areas
impacted by trade winds.



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



Source: Vanuatu Meteorology and Geo-Hazards Department (VMGD)
http://www.geohazards.gov.vu/




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End of Volcano Digest - 4 Nov 2019 to 7 Nov 2019 (#2019-100)
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