10 Feb 2014 PVMBG (Pusat Vulkanologi dan Mitigasi Bencana Geologi) raised the alert status of Kelud mountain (Kelut, Gunung Kelud) to level III (of IV) from yellow alert (waspada) to orange alert (siaga). Gunung Kelud is a 1,731 m high stratovolcano located in East Java in Indonesia. Like many Indonesian volcanoes and others on the Pacific Ring of Fire, Kelud is known for large explosive eruptions up to VEI 5 throughout its history (Wikipedia), about 30 times since the 13th century. The latest eruptions were in 1901, 1919 (killing 5000), 1951, 1966, 1990 and in 2007/2008. An estimated 135,000 people live within a 10 km radius around the crater.
Kelud volcano (also spelled Kelut)
is one of East Java's most active volcanoes. The volcano has a spectacular
large crater that contains a lake, which was a popular weekend destination but
also the origin of devastating mud flows (lahars). In Oct-Nov 2007, a new lava
dome grew within the lake to form an island, replacing most of the water.
Kelut is notorious among Indonesia's
volcanoes for its violent, and often deadly explosive eruptions. One of the
worst volcanic disasters occurred during the 1919 eruption, when the (then very
large) crater lake drained and formed lahars that killed at least 5160 people.
An eruption in 1586 is believed to have caused even more than 10,000
fatalities.
Gunung Kelud is known for its deadly
and explosive eruptions. At least 1 VEI-5 is known and a further minimum of 6
VEI-4 eruptions have occured at the volcano. After the volcano killed more than
5000 people the volcano was rebuilt by humans to lower the risk of lahars and
pyroclastic flows. This has been done twice and that meant that a very small
crater lake existed as Gunung started to quietly extrude a lava dome inside the
crater.
The lava dome quickly emptied out
the remnant crater lake. Normally the crater lake would by now have flooded
repeatedly and as such the active mitigation has been an un-precedented success
this time around since no floods or lahars has happened. As seen in the image
above the amount of shallow volcanic earthquakes have increased dramatically
during the last few days, a probable sign of new magma moving upwards in the
system.
Keluds activity has sofar limited
itself to the peacefull and very beautifull extrusion of the lavadome, but this
is unlikely to continue if new magma is arriving from depth. And since the
volcano has a highly explosive history it is likely that it will suffer an
explosive eruption in the end. If that happens it is likely to be in the range
of a VEI-3 or a VEI-4. Smaller is unlikely since the activity is centered at
the central part of the crater, and bigger is also unlikely judging from the
current level of activity.
The relatively inconspicuous,
1731-m-high Kelud stratovolcano contains a summit crater lake that has been the
source of some of Indonesia's most deadly eruptions. A cluster of summit lava
domes cut by numerous craters has given the summit a very irregular profile.
Satellitic cones and lava domes are also located low on the eastern, western,
and SSW flanks. Eruptive activity has in general migrated in a clockwise
direction around the summit vent complex. More than 30 eruptions have been
recorded from Gunung Kelud since 1000 AD. The ejection of water from the crater
lake during Kelud's typically short, but violent eruptions has created
pyroclastic flows and lahars that have caused widespread fatalities and
destruction.
After more than 5000 persons were
killed during an eruption in 1919, an ambitious engineering project sought to
drain the crater lake. This initial effort lowered the lake by more than 50 m,
but the 1951 eruption deepened the crater by 70 m, leaving 50 million cubic
meters of water after repair of the damaged drainage tunnels. After more than
200 deaths in the 1966 eruption, a new deeper tunnel was constructed, and the
lake's volume before the 1990 eruption was only about 1 million cubic meters.
Sumber : https://storify.com/davidmpyle/the-eruption-of-kelut-gunung-kelud-java-february-2
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