The obliquely convergent Sumatran plate boundary is an extraordinary natural laboratory for understanding the influence of fault geometry on rupture processes and the sequential rupture of active faults. We are working on both principal components of the system - the Sumatran fault and the Sumatran subduction zone.

The Sumatran subduction zone is an exceptional natural laboratory for investigating the behavior of a large fault through several earthquake cycles. This is because the corals fringing the islands of its outer-arc ridge provide an unusually complete and long record of strain accumulation and relief above a subduction interface. As part of the Sumatran Project of the Tectonics Observatory, we have installed a network of continuously recording GPS stations and seismic instruments there. Some of these instruments recorded coseismic and postseismic deformations of the giant 2004 and 2005 earthquakes.

Corresponding papers:

Sieh, K., and D. Natawidjaja, 2000, Neotectonics of the Sumatran fault, Indonesia: Journal of Geophysical Research 105, 28,295-28,326.

Briggs, R., Sieh, K., Amidon, W., Galtetzka, J., Prayudi, D., Suprihanto, I., Sastra, N., Farr, T. (2008) Persistent elastic behavior above a megathrust rupture patch: Nias Island, West Sumatra, JGR Solid Earth

M. Chlieh, J.-P. Avouac, K. Sieh, Natawidjaja, D. H., J. Galetzka (2007), Heterogeneous coupling on the Sumatra megathrust constrained from geodetic and paleogeodetic measurements, J. Geophys. Res.

Shen, C.-C., Li, K.-S., Sieh, K., Natawidjaja, D., Cheng, H., Wang, X., Edwards, R.L., Lam, D.D., Hsieh, Y.-T., Fan, T.-Y., Meltzner, A.J., Taylor, F.W., Quinn, T.M., Chiang, H.-W., Kilbourne, K.H., Variation of initial 230Th/232Th and limits of high precision U-Th dating of shallow-water corals, Geochimica et Cosmochimica Acta (2008), doi: 10.1016/j.gca.2008.06.011

McClosky, J., Antonioli, A., Piatanesi, A., Sieh, Steacy, S., K., Nalbant, S., Cocco, M., Giunchi, C., Huang, J.D., Dunlop, P., Near-field propagation of tsunamis from megathrust earthquakes, Geophysical Research Letters, VOL 34, I4316, doi:10.1029/2007GL030494, 2007.

Natawidjaja, D., K. Sieh, J. Galetzka, B. Suwargadi, H. Cheng, R.L. Edwards ,Interseismic deformation above the Sunda megathrust recorded in coral microatolls of the Mentawai islands, West Sumatra, Journal of Geophysical Research, VOL 112, B02404, doi:10.1029/2006JB004450, 2007.

Chlieh, M., Avouac, J-P., Hjorleifsdottir, V., Song, T-R. A., Chen, J., Sieh, K., Sladen, A., Herbert, H., Prawirodirdjo, L., Bock, Y., Galetzka, J., Coseismic Slip and Afterslip of the Great (Mw9.15) Sumatra-Andaman Earthquake of 2004Bull. Seism. Soc. Am., Vol.97, No 1A, pp.S152-S173, January 2007, doi: 10.1785/0120050631

Konca, A. O., Hjorleifsdottir, V., Song, T-R. A., J-P. Avouac, Helmberger, D. V., Chen, J., Sieh, K. Briggs, R., Meltzner, A., Rupture Kinematics of the 2005, Mw 8.6 , Nias-Simeulue Earthquake from the Joint Inversion of Seismic and Geodetic data. Bull. Seism. Soc. Am., Vol. 97, No. 1A, pp. S307-S322, January 2007, doi: 10.1785/0120050632.

Bilek, S.L., Satake, K., and Sieh, K., Introduction to the Special Issue on the 2004 Sumatra-Andaman Earthquake and the Indian Ocean Tsunami, Bulletin of the Seismological Society of America, Vol. 97, No. 1A, pp. S1-S5, January 2007, doi:10.1785/0120050633

Borrero, J., Sieh, K., Chlieh, M., Synolakis, C., Tsunami forecasts for Western Sumatra. PNAS 2006 Vol 103, no. 52, Pgs. 19673-19677; doi:10.1073/pnas.0604069103.

Hsu, Y.-J., M. Simons, J.P. Avouac, J. Galetzka, K. Sieh, M. Chlieh, D. Natawidjaja, L. Prawirodirdjo, Y. Bock, Frictional afterslip following the Mw 8.7, 2005 Nias-Simeulue earthquake, Sumatra, Science, 30 June 2006 312: 1921-1926 [DOI: 10.1126/science.1126960].

Sieh, K., Sumatran Megathrust Earthquakes - From Science to Saving Lives, Philosophical Transactions of the Royal Society, Vol. 364, N. 1845, August 15, 2006, Pgs. 1947 - 1963, DOI: 10.1098/rsta.2006.1807

Natawidjaja, D., Sieh, K., Chlieh, M., Galetzka, J., Suwargadi, B., Cheng, H., Edwards, R.L., Avouac, J.P., Ward, S., 2006, Source parameters of the great Sumatran megathrust earthquakes of 1797 and 1833 inferred from coral microatolls. J. Geophys. Research, VOL 111, B06403, doi:10.1029/2005JB004025, 2006.

R. Briggs, Sieh, K., Meltzner, A., Natawidjaja, D., Galetzka, J., Suwargadi, B., Hsu, Y-j., Simons, M., Hananto, N., Suprihanto, I., Prayudi, D., Avouac, J.-P., Prawriodirdjo, L., Bock, Y., Deformation and slip along the Sunda megthrust in the Great 2005 Nias-Simeulue Earthquake. Science 31 March 2006 311: 1897-1901 [DOI: 10.1126/science.1122602].

Subarya, C., M. Chlieh, L. Prawirodirdjo, J.-P. Avouac, R. McCaffrey, Y. Bock, K. Sieh,A.J. Meltzner, and D.H. Natawidjaja - Plate boundary deformation associated with the great Aceh-Andaman earthquake. Nature, Vol 440, 2 March 2006, doi:10.1038/nature04522

Meltzner, A.J., K. Sieh, M. Abrams, D.C. Agnew, K.W. Hudnut, J.-P. Avouac, and D.H. Natawidjaja, Uplift and subsidence associated with the great Aceh-Andaman earthquake of 2004, Journal of Geophysical Research, VOL. 111, B02407, doi:10.1029/2005JB003891, 2006.

Sieh, K., Aceh-Andaman earthquake: What happened and what's next?: Nature, 434, pgs. 573-574 doi: 10.1038/434573a, 2005.

Nalbant, S., Steacy, S., Sieh, K., Natawidjaja, D., and McCloskey, J., 2005, Earthquake risk on the Sunda trench: Nature, v. 435, p. 756-757. - doi: 10.1038/nature435756a, 2005.

Hilman N., Danny, K. Sieh, S. Ward, R. L. Edwards, J. Galetzka, B. Suwargadi, 2004,Paleogeodetic records of seismic and aseismic subduction from central Sumatran microatolls, Journal of Geophysical Research, v. 109, B4, B04306, doi:10.1029/2003JB002398.

Rivera, L., K. Sieh, D. Helmberger, and D. Natawidjaja, 2002, A comparative study of the Sumatran subduction-zone earthquakes of 1935 and 1984: Bull. Seism. Soc. Am., 92, no. 5, 1721-1736.

Zachariasen, J., K. Sieh, F. Taylor, and W. Hantoro, 2000, Modern vertical deformation above the Sumatran subduction zone: Paleogeodetic insights from coral microatolls: Seismol. Soc. America Bulletin 90, 897-913.

Sieh, K., S. Ward, D. Natawidjaja and B. Suwargadi, 1999, Crustal deformation at the Sumatran subduction zone revealed by coral rings. Geophysical Research Letters 26, 3141-3144.

Zachariasen, J., K. Sieh, F. Taylor, R. Edwards, and W. Hantoro, 1999, Submergence and uplift associated with the giant 1833 Sumatran subduction earthquake: Evidence from coral microatolls: Journal of Geophysical Research 104, 895-919.