Geophysical and petrologic studies
of the Toba Caldera, north Sumatra
Rob McCaffrey, Dave Wark, Peter Zwick, Fauzi, Masturyono,
Colleen Stevens, John Nabelek, Volcanological Survey of Indonesia, Meteorology
and Geophysics Agency
Using 30 short-period and 10 broad-band PASSCAL seismographs, we monitored
seismicity around Toba caldera for 4 months in early 1995. We produced
tomographic images of the crustal and upper mantle structure using arrival
time data and examined the velocity structure with receiver function
methods.
We are also
analysing seismological data from global networks and from a local Indonesian
seismic network in the vicinity of Toba Caldera.
Maps
Publications
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Fauzi, R. M., R. McCaffrey, D. Wark, P.Y. Prih Haryadi, and Sunarjo, Lateral variation in slab orientation
beneath Toba caldera, northern Sumatra, Geophys. Res. Letters 23, 443-446, 1996.
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Masturyono, R. McCaffrey, D. A. Wark, S. W. Roecker, Fauzi, G. Ibrahim, and Sukhyar,
Distribution of magma beneath Toba Caldera, North Sumatra, Indonesia, Constrained by 3-dimensional P-wave velocities,
seismicity, and gravity data, Geochemistry, Geophysics & Geosystems, in press, 2001.
Abstracts
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Fauzi, R. M., Sunaryo, R. Sutardjo, and R. McCaffrey, Analysis of digital seismic data from the Sumatran fault, EOS 73, 310, 1992.
- Zwick, P., Masturyono, Fauzi, I. Purnama, Sunaryo, Hendra S., Suharyadi, Suhardjono, Wandono, Kristianto, Sjafra, Hendra G., Mowardi, Rifwar, Sofyan, Sunardi, Yanuar, C. Stevens, R. McCaffrey, D. Wark, J. Nabelek, and P. Friberg, The Toba Seismic Experiment: Imaging a large silicic magma chamber EOS 77, S182, 1996.
- Zwick, P., Masturyono, Fauzi, I. Purnama, Sunaryo, Hendra S., Suharyadi, Suhardjono, Wandono, Kristianto, Sjafra, Hendra G., Mowardi, Rifwar, Sofyan, Sunardi, Yanuar, C. Stevens, R. McCaffrey, D. Wark, J. Nabelek, P. Friberg, The Toba '95 PASSCAL Seismic Experiment: Imaging a large silicic magma system, IRIS Workshop, 1996.
- Masturyono, R McCaffrey, P Zwick, D Wark, S Roecker, Imaging magma system of Toba Caldera using P velocity tomography, EOS 78, 1997.
- Armitage, J., S. Roecker, Masturyono, R. McCaffrey, J. Nabelek, and D. Wark, Receiver function analysis of broadband data in Toba Caldera, Sumatra AGU Fall 1999.
- Wark, D.A., Masturyono, R. McCaffrey, G.L.Farmer, Mawardi Rani, and R. Sukhyar, Plumbing of the Toba Magma System: Petrologic and Geophysical Evidence of Two Shallow Reservoirs and Their Mantle Roots, AGU Fall 2000.
Field Photos
