mount merapi
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Mount Merapi. Brendan McNeill, Ellie Oakford , Anthony Shimamoto GE 151 Volcanology. Geography. Latitude: 7.5333° S Longitude: 110.4333° E Situated in South-Central Java 28 kilometers north of Yogyakarta. Tectonics. - PowerPoint PPT PresentationTRANSCRIPT
Mount Merapi“Mountain of Fire”Java, Indonesia
Matt Treveloni & Ryder ArsenaultDepartment of Geology @ Colby College
LocationPacific Ring of Fire
30 km North of Yogyakarta, Indonesia
Destructive plate margin (Indo-Australian Plate & Eurasian Plate)
Form & Dimensions
Stratovolcano
Elevation: 2,930 m,1,356 m above ground
Summit is higher on the North, lahars and pyroclastic flows run down the South side
Years of eruptions created distinct trench
EruptionsFault line: Sunda-Banda Arc
Subduction of Indo-Australian Plate under the Eurasian Plate (twice as thick)Erupts: Hot gas, ashes, volcanic bombs (pyroclastic flows, lahars)
Mt. Merapi erupts every 4-5 years with bigger eruptions every decade (2010), but smoke is seen emerging 300 days a year!
Most of the lavas from Merapi are high potassium basaltic andesites.
The lava from Mt. Merapi is mainly porphyritic. Plagioclase and clinopyroxene are the most common phenocrysts.
Silica content ranges from 52 to 57%.
Rocks & Deposits
Phenocrysts can occupy up to 60% of the total rock volume in Mt. Merapi’s lava.
2010 Eruption
Effects of the 2010 Eruption
Dome Collapse
Crop Destruction
The safe zone for the 2010 eruption was 20 km from the volcano. Over 4 million people live within 30 km.
Fun Facts
Over 300,000 people were forced to evacuate their homes.
Why is Mt. Merapi So Dangerous?
● Mt. Merapi has produced more pyroclastic flows than any other volcano in the world
● Only 30 km away from Yogyakarta (population ~400K) which lies directly in flow path
● Indonesia’s intense rainfall causes massive lahars
Culture & Other Info● Considered sacred by local people, they believe
that a supernatural kingdom exists at the summit and a priest makes an offering once a year
● Ash leads to fertile soil● Conservation area (unsafe to live) and illegal to
climb to summit● Tourism lies in museums● No geothermal energy or hydrothermal activity
Monitoring● Seismology
○ There are 8 seismograph stations in the network.● Volcanomagnetism
○ Since 1977 they monitor the magnetism beneath the Earth’s surface.
● Deformation○ Three GPS signals measure to make sure the distance and
angles between all three remain the same.○ In 1990 they introduced tilt monitors to measure deformation.
● Geochemistry○ There are two solfatara fields used for measuring the volcanic
gases.● Lahar Detection
○ Lahars are usually triggered by heavy rainfall.○ An acoustic sensor measures the noise given off by a lahar in
order to detect when one begins moving.
ReferencesMarliyani, G.I., 2010: An Overview of Merapi Volcano, Central Java, Indonesia, at
http://mountmerapi.net/mount-merapi/ (accessed 22 January, 2015)Leontiou, A., 2010: FAQ: A Look Inside Mount Merapi, at
http://www.livescience.com/11081-faq-mount-merapi.html (accessed 24 January, 2015)Lavigne, F. & Thouret, J.C., 2003: Sediment transportation and deposition by rain-triggered
lahars at Merapi Volcano, Central Java, Indonesia, at http://www.sciencedirect.com/science/article/pii/S0169555X02001605 (accessed 23 January, 2015)
Seach, J., 2012: Merapi Volcano, at http://www.volcanolive.com/merapi.html (accessed 25 January, 2015)
Simkin, T. & Siebert, L., 1994: Volcanoes of the World, at http://volcano.oregonstate.edu/oldroot/volcanoes/merapi/merapi.html (accessed 25 January, 2015
References
Boston.com 2010: Mount Merapi’s eruptions at http://www.boston.com/bigpicture/2010/11/mount_merapis_eruptions.html (Accessed 25 January, 2015) Geotalk, 2012. Mt. Merapi Eruption at
http://www.geotalk.info/#!mt-merapi/c21bv (Accessed 25 January, 2015) Gertisser, R. 2003: Temporal Variations in magma composition at Merapi
Volcano at http://www.sciencedirect.com/science/article/pii/S0377027303000258 (Accessed 25 January, 2015) Smithsonian Institution, 2013: Global Volcanism Program at http://volcano.si.edu/volcano.cfm?vn=263250 (Accessed 25 January, 2015)
Youtube 2010: Merapi Eruption: Travel chaos as volcano spews massive clouds of ash at https://www.youtube.com/watch?v=nEBTfQ79Z7A (Accessed 25 January, 2015)