TAIGER

TAIGER project (PI: Francis T. Wu/State University of New York at Binghamton)

Based on the large amount of existing geological and geophysical research in Taiwan, a range of tectonic models has been proposed that differ significantly in details. From these models many deductions, especially regarding the structures at depth, can be made. The ongoing TAIGER project calls for a comprehensive set of geophysical experiments to determine the locations and moment tensors of earthquakes, especially those offshore, and obtain multi-scale images of the crust and upper-mantle. The results will be used to check against the deductions and thus test existing models. We will also explore existing and geodynamical models that are consistent with new data.

The experimental targets include a) the internal structures inside the orogen and their along-strike variations, in the foothills and in the metamorphic core, b) the crustal structures under the island as well as under the Philippine Sea, as a measure of the integrated deformation over time, c) the plate contact between the Philippine Sea and Eurasian plates in the northeast and in the south, d) kinematics of plate boundary motions from earthquakes, e) the crustal variations from the foothills to the core of the Central Range, f) active or inactive Eurasian subduction zones in the upper mantle, g) the electrical conductivity in the crust as an indicator of possible fluids, and h) seismic velocity anisotropy in the crust and mantle.

The experiments planned for completion before the end of 2008 are (1) deployment of land broadband instruments to enhance the existing broadband networks for recording both local earthquakes and teleseisms, 2) land explosions for low-fold wide angle reflections across the island along three transects, 3) land explosions for CMP-style reflection profile across the main divide between the Foothills and the Central Range, 4) marine broadband deployment around the island to increase the aperture of the available broadband networks, 5) marine MCS and reversed sea-land wide-angle profiling using airgun signals along six transects, 6) Magnetotellurics along several transects, and 7) petrophysics.

In this talk the main tectonic features of the orogen as currently understood will be discussed and so will the range of models considered. Taiwan, being a very young and active orogen that has already attained significant stature, can be considered a perfect testing ground for ideas concerning orogeny. The TAIGER experiments provide an excellent opportunity toward model improvement.

The project is a collaborative project on the US side among nine investigators from six institutes, as well as one from a Canadian university; it is supported by the Continental Dynamics Program of the US National Science Foundation.We are in cooperation with Taiwan scientists from five national universities and Academia Sinica, supported by the National Science Council of Taiwan.

Publications

24. Wu,F, Z. E. Ross,D. Okaya, Y. Ben-Zion, C-Y. Wang, H. Kuo-Chen, W.-T. Liang (2016) Dense Network, intense seismicity and Tectonics of Taiwan, Tectonophysics, in press.

23. Van Avendonk, H,J.A., K. McIntosh, H. Kuo-Chen, L.L. Lavier, D.A. Okaya, F.T. Wu, C.-Y. Wang, C.-S. Lee, C.-S. Liu (2016) A lithospheric profile across northern Taiwan: From arc-continent collision to extension, Geophysical Journal International, doi:10.1093/gji/ggv468.

22. Van Avendonk, H,J.A., K. McIntosh, H. Kuo-Chen, L.L. Lavier, D.A. Okaya, F.T. Wu, C.-Y. Wang, C.-S. Lee, C.-S. Liu (2015) A lithospheric profile across northern Taiwan: From arc-continent collision to extension, Geophysical Journal International, accepted.

21. Doo, W.-B., C.-L. Lo, H. Kuo-Chen, D. Brown, S.-K. Hsu (2015) Exhumation of serpentinized peridotite in the northern Manila subduction zone inferred from forward gravity modeling, Geophys. Res. Lett., accepted.

20. Kuo, Y.W., C.Y. Wang, H. Kuo-Chen*, X. Jin, H.T. Cai, J.Y. Lin, F.T. Wu, H.Y. Yen, B.S. Huang, W.T. Liang, D. Okaya, and L. Brown (2015) Crustal structures from the Wuyi-Yunkai orogen to the Taiwan orogen: the onshore-offshore wide-angle seismic experiments of the TAIGER and ATSEE projects, Tectonophysics, accepted.

19. Cai, H.-T., H. Kuo-Chen*, X. Jin, C.-Y. Wang, B.-S. Huang, H.-Y. Yen (2015) A three-dimensional Vp, Vs and Vp/Vs crustal structure in Fujian, Southeast China, from active and passive source experiments, J. Asian Earth Sci., doi: http://dx.doi.org/10.1016/j.jseaes.2015.06.014.

18. Wu, F. T., and H. Kuo-Chen, K. McIntosh (2014). Subsurface imaging, TAIGER experiments and tectonic models of Taiwan, J. Asian Earth Sci., doi:10.1016/j.jseaes.2014.03.024.

17. Van Avendonk, H., H. Kuo-Chen, K. McIntosh , L. Lavier , D. Okaya, F. Wu, C.-Y. Wang, C. S. Lee, C.S. Liu (2014) Deep crustal structure of an arc-continent collision: Constraints from seismic travel times in central Taiwan and the Philippine Sea, J. Geophys. Res., doi: 10.1002/2014JB011327.

16. Eakin, D. H., McIntosh, K. D., Van Avendonk, H. J. A., Lavier, L., Lester, R., Liu, C. S., Lee, C. S. (2014). Crustal‐scale seismic profiles across the Manila subduction zone: The transition from intraoceanic subduction to incipient collision. Journal of Geophysical Research: Solid Earth, 119(1), 1-17.

15. McIntosh, K., Lavier, L., van Avendonk, H., Lester, R., Eakin, D., Liu, C. S. (2014). Crustal structure and inferred rifting processes in the northeast South China Sea. Marine and Petroleum Geology, doi: DOI: 10.1016/j.marpetgeo.2014.03.012.

14. Hsu, S.-K., Y.-C. Yeh, J.-C. Sibuet, W.-B. Doo, C.-H. Tsai (2013). A mega-splay fault system and tsunami hazard in the southern Ryukyu subduction zone, Earth and Planetary Science Letters, 362, 99-107.

13. Kuo-Chen, H., P. Sroda, F.T. Wu, C.-Y. Wang, Y.W. Kuo (2013) seismic anisotropy of the upper crust in the mountain ranges of Taiwan from the TAIGER explosion experiment, Terrestrial, Atmospheric and Oceanic Sciences, doi: 10.3319/TAO.2013.07.30.01(T).

12. McIntosh, K., H. van Avendonk, L. Lavier, W. R. Lester, D. Eakin, F. Wu, C.-S Liu, and C.-S. Lee (2013) Inversion of a hyper-extended rifted margin in the southern Central Range of Taiwan, Geology, doi:10.1130/G34402.1.

11. Lester, R., K. McIntosh, H.J.A. Van Avendonk, L. L., C.-S. Liu , T.K. Wang (2013) Crustal accretion in the Manila trench accretionary wedge at the transition from subduction to mountain-building in Taiwan, Earth and Planetary Science Letters, http://dx.doi.org/10.1016/j.epsl.2013.06.007i.

10. Huang, B.S., C.Y. Chien, D. Okaya, S.J. Lee, Y.C. Lai, F.T. Wu, W.T. Liang, and W.G. Huang (2013) Multiple diving waves and high-velocity gradients in the western Taiwan Coastal Plain – an investigation based on the TAIGER experiment, BSSA, v. 103, n. 2A 925-935, doi: 10.1785/01201100

09. Kuo-Chen, H., F. Wu, D. M. Jenkins, J. Mechie, S. Roecker, C.-Y. Wang, and B.-S. Huang (2012) Seismic evidence for the α-β quartz transition beneath Taiwan from Vp/Vs tomography, Geophys. Res. Lett., doi:10.1029/2012GL053649.

08. Kuo-Chen, H., F. T. Wu, and S. W. Roecker (2012) Three-Dimensional P Velocity Structures of the Lithosphere Beneath Taiwan from the Analysis of TAIGER and Related Seismic Datasets, J. Geophys. Res., 117, B06306, doi:10.1029/2011JB009108.

07. Lester, R., L.L. Lavier, K. McIntosh, H. J. A. Van Avendonk, and F. Wu (2012) Active extension in Taiwan’s precollision zone: A new model of plate bending in continental crust, Geology,

06. Bertrand, E. A., M. J. Unsworth, C.-W. Chiang, C.-S. Chen, C.-C. Chen, F. T. Wu, E. Türkoğlu, H.-L. Hsu, and G. J. Hill (2012), Magnetotelluric imaging beneath the Taiwan orogen: An arc-continent collision, J. Geophys. Res., 117, B01402, doi:10.1029/2011JB008688.

05. Chen, P.-F., C.R. Bina, H. Kuo-Chen, F.T. Wu, C.-Y. Wang, B.-S Huang, C.-H. Chen, and W.-T. Liang (2012) Slab-Induced Waveform Effects as Revealed by the TAIGER Seismic Array: Evidence of Slab beneath Central Taiwan, Phy. Earth Planet. In., 196-197, 62-74.

04. Chiang, C. W., C. C. Chen, M. Unsworth, E. Bertrand, C. S. Chen, T. D. Kieu, and H. L. Hsu (2010) The deep electrical structure of southern Taiwan and its tectonic implications. Terr. Atmos. Ocean. Sci., 21, 879-895, doi: 10.3319/TAO.2010.02.25.01(T)

03. Bertrand E., Unsworth M., Chiang C.W., Chen C.S., Chen C.C., Wu F., Turkoglu E., Hsu H.L., Hill G., (2009). Magnetotelluric evidence for thick-skinned tectonics in central Taiwan, Geology, v. 37, p. 711–714, doi:10.1130/G25755A.1.

02. Kuo-Chen, H., F. T. Wu, D. Okaya, B.-S. Huang, and W.-T. Liang (2009) SKS/SKKS Splitting and Taiwan Orogeny, Geophys. Res. Lett., doi:10.1029/2009GL038148.

01. Wu, F. T., W.-T. Liang, J.-C. Lee, H. Benz, and A. Villasenor (2009). A model for the termination of the Ryukyu subduction zone against Taiwan: A junction of collision, subduction/separation, and subduction boundaries, J. Geophys. Res., 114, B07404, doi:10.1029/2008JB005950.