Saturday, February 18, 2012

[Geology2] Volcano News 02-18-2012

Merapi volcano (Central Java): increased seismic activity could indicate the start of a new lava dome growth

Friday Feb 17, 2012 11:05 AM | Age: 1 days

BY: T

Seismic activity has increased beneath Mount Merapi volcano in Central Java, Indonesia, in the last few days. The increase in so-called multiphase earthquakes is thought to indicate the beginning of the formation of a new lava dome.
A volcanologist from the Selo observation post on the north side of the volcano is quoted "there is movement in the magma chamber in the form of a new lava dome formation. But we do not know the emission point because from Selo it is not visible". It is planned to check the situation at the summit in the near future. "The status of Merapi still active normal."

Starting around 11 February, Mount Merapi showed increased seismic activity, especially in multi-phase (MP) earthquakes, which are believed to correspond to movements in the magma chamber and conduits. During the week of 29 January and 4 Feb 29, 18 such quakes were recorded, but that figure rose sharply during the following week, when about 100 were recorded. The peak occurred on 12 February, when 63 MP as well as 6 shallow volcanic earthquakes were recorded.
On 13 February earthquake activity decreased to 34 MP quakes, 3 avalanche, and 9 shallow volcanic and tectonic quakes. On 14 February, there were 25 MP and 14 shallow volcanic quakes.

The Head of the Regional Disaster Management Agency (BPBD) Mr Boyolali Hasanudin confirmed that the increased activity of Mount Merapi is a normal phenomenon frequently seen at the volcano, and still within the range of normal fluctuations. The official alert level remains at 1 out of 4 (normal activity).
People living on the slopes of Mount Merapi, particularly those living higher up the slopes and near the major drainage valley are encouraged to remain vigilant. A major hazard for these areas are floods and mud flows, particularly now in the rainy season.

http://www.volcanodiscovery.com/view_news/5467/Merapi-volcano-Central-Java-increased-seismic-activity-could-indicate-the-start-of-a-new-lava-dome-g.html

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Capitol monitors volcano cracks

By Teresa Ellera-Dulla

Saturday, February 18, 2012

THE Provincial Disaster Management Team (PDMT) is closely monitoring cracks that were found in some portions of Kanlaon Volcano.

Portions of the volcano were found to have cracks due to the 6.9-magnitude earthquake that hit the Visayas last February 6. The cracks might threaten the collapse of some parts of the volcano.

Governor Alfredo G. Marañon Jr. reported that Mount Kanlaon Natural Park Superintendent Cecil Canada said a reconnaissance survey revealed some parts of the volcano were affected by the tremor.

Accredited trained guides and members of rescue groups based in La Carlota conducted the reconnaissance survey, Canada said.

He said that with the approaching peak season for trekking and mountaineering, the present situation in Mt. Kanlaon poses danger.

Due to the threat, Canada temporarily prohibited trekking, camping and other mountaineering activities in Mt. Kanlaon Natural Park.

The park has to be closed, he said.

He added that his office is concerned about the extent of the damages, especially on mountain trails and eco-tourism areas of the park.

The report revealed portions of Kanlaon Volcano crater were affected. Cracks on land surfaces were seen and traces of landslides were evident, he said.

Canada stressed that with the current situation where aftershocks and unpredictable heavy rains usually occur in the mountains, there is fear that the affected portion of the volcano may collapse and might result to landslide.

It poses a threat to the life and safety of the trekkers and mountain climbers and tourists.

With this, Canada said all bookings are cancelled and the trekking and mountain activities at the Kanlaon Natural Park are temporarily suspended.

She also said that they are closely coordinating with Phivolcs on monitoring the said cracks; and that they are scheduled to conduct more ocular inspections on the site of the said cracks.