The following constitutes the new activity and unrest report from the
Weekly Volcanic Activity Report, a cooperative project between the Smithsonian's
Global Volcanism Program and the US Geological Survey's
Volcano Hazards Program.
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| The Ijen volcano. |
IJEN Eastern Java (Indonesia) 8.058°S, 114.242°E; summit elev. 2799 m
CVGHM
reported that during 1-30 April white plumes from Ijen rose 100-200 m
above the crater; during 1-11 May diffuse white plumes rose 50-100 m.
From the beginning of April until 13 May the amplitude and number of
earthquakes gradually decreased and the crater lake water temperature
decreased by eight degrees Celsius. The Alert Level was lowered to 2
(on a scale of 1-4) on 13 May.
Map
KARANGETANG [API SIAU] Siau I 2.78°N, 125.40°E; summit elev. 1784 m
Based on analyses of satellite imagery, the Darwin
VAAC reported that on 14 May an
ash plume from Karangetang rose to an altitude of 3.7 km (12,000 ft)
a.s.l.
and drifted 130 km SE. On 16 May an ash plume again rose to an altitude
of 3.7 km (12,000 ft) a.s.l. then drifted about 110 km SE. Karangetang (also known as Api Siau) lies at the northern end of the
island of Siau, N of Sulawesi, and contains five summit craters strung
along a N-S line. One of Indonesia's most active volcanoes, Karangetang
has had more than 40 recorded eruptions since 1675. Twentieth-century
eruptions have included frequent explosions, sometimes accompanied by
pyroclastic flows and lahars.
Map
KARTHALA Grand Comore Island 11.75°S, 43.38°E; summit elev. 2361 m
Observers in the villages of Mde and Mkazi, on the W flank of
Karthala, reported increased incandescence from the summit during the
night of 9-10 May. The southernmost and largest of the two
shield volcanoes forming Grand Comore Island (also known as Ngazidja), Karthala contains a 3 x 4 km summit
caldera generated by repeated collapse. Elongated
rift
zones extend to the NNW and SE from the summit of the Hawaiian-style
shield, which has an asymmetrical profile that is steeper to the S.
Historical eruptions have modified the morphology of the compound,
irregular summit caldera. More than twenty eruptions have been recorded
since the 19th century from both summit and flank vents. Many
lava
flows have reached the sea on both sides of the island, including
during many 19th-century eruptions from the summit caldera and vents on
the northern and southern flanks.
Map
POPOCATEPETL México 19.023°N, 98.622°W; summit elev. 5426 m
CENAPRED
reported that during 8-10 May multiple gas-and-ash plumes rose 1.5 km
above Popocatépetl's crater and drifted NE. Incandescent fragments
ejected from the crater landed on the N and E flanks as far as 500 m
away. According to a news article an airport in Puebla was closed due to
ash
plumes on 8 and 10 May. Seismicity increased on 11 May. Ash plumes rose 3
km above the crater and drifted NE and incandescent fragments ejected
from the crater rolled 1 km down the flanks. Gas-and-ash plumes rose 2.5
km and drifted ENE. On 12 May gas-and-ash plumes rose 4 km above the
crater. Incandescent
tephra
was ejected 2 km above the crater and again rolled 1 km down the
flanks. Ashfall was reported in most municipalities within the state of
Tlaxcala (50 km NE of the volcano), in addition to smaller towns nearer
to the volcano such as Santiago Xalitzintla (15 km NE) and San Nicolás
de los Ranchos (16 km ENE). An airport in Puebla was again closed due to
ash. During 13-15 May gas-and-ash plumes rose from the crater and
drifted NE, and incandescent tephra was ejected from the crater. The
Alert Level remained at Yellow Phase Three.
Map
SIRUNG Pantar Island (Indonesia) 8.508°S, 124.13°E; summit elev. 862 m
CVGHM reported that on 8 May a three-hour long
ash
eruption from Sirung was accompanied by loud sounds and incandescence
that reached 10 m above the crater. An ash plume rose 3.5 km above the
crater and drifted N, producing ashfall up to 4 mm thick near the
crater. During 9-12 May white plumes rose 30-50 m above the crater. A
sulfur odor was reported in areas up to 3 km away on 12 May. That same
day CVGHM raised the Alert Level to 3 (on a scale of 1-4) and
recommended that visitors not approach the volcano within a 2.5 km
radius. Based on a report from a ground-based observer and analyses of satellite imagery, the Darwin
VAAC noted that on 12 May an
ash plume rose to an altitude of 3 km (10,000 ft)
a.s.l. and drifted about 95 km SW.
Map
For the complete list of ongoing volcanic activity and additional geological summary, click
HERE or select the specific volcano name below for additional details:
ONGOING ACTIVITY: Cleveland, Chuginadak Island
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Karymsky, Eastern Kamchatka (Russia)
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Kilauea, Hawaii (USA)
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Pagan, Mariana Islands
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Sakura-jima, Kyushu
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Santa MarÃa, Guatemala
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Shiveluch, Central Kamchatka (Russia)
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Soufrière Hills, Montserrat
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Tungurahua, Ecuador