- Our Research
Paleoclimate and environmental changes by isotope geochemistry, Earth systems and sustainability sciences, Geochronology developments and their applications, Kinematics of seismogenic faults and seismic hazard mitigation
Kuo, Y.T., Ayoub, F., Leprince, S., Chen, Y.G.*, Avouac, J.P., Shyu, J.B.H., Lai, K.Y., Kuo, Y.J. (2014). Coseismic thrusting and folding in the 1999 Mw 7.6 Chi-Chi Earthquake: A high resolution approach by aerial photos taken from Tsaotun, Central Taiwan. J. Geophys. Res. - Sol. Ea. , 119(1), 645-660.
Simoes, M.*, Chen, Y.G., Shinde, D. P., Singhvi, A. K. (2014). Lateral variations in the long-term slip rate of the Chelungpu fault, Central Taiwan, from the analysis of deformed fluvial terraces. J. Geophys. Res. - Sol. Ea., 119(4), 3740-3766.
Huang, S.Y.*, Chen, Y.G., Burr, G.S., Jaiswal, M.K., Lin, Y.N., Yin, G., Liu, J., Zhao, S., Cao, Z. (2014). Late Pleistocene sedimentary history of multiple glacially dammed lake episodes along the Yarlung-Tsangpo River, southeast Tibet. Quaternary Research, 82(2), 430-440.
Chen, C.Y., Lee, J.C.*, Chen, Y.G., Chen, R.F. (2014). Campaigned GPS on Present-day crustal deformation in northernmost Longitudinal Valley preliminary results, Hualien Taiwan. TAO, 25(3), 337-357.
Yang, T.N., Lee, T.Q., Lee, M.Y., Huh, C.A., Meyers, P.A.*, Lowemark, L., Wang, L.C., Kao, W.Y., Wei, K.Y., Chen, R.F., Chen, H.F., Chen, S.H., Wu, J.T., Shiau, L.J., Chen, Y.G., Hsieh, Y.C. (2014). Paleohydrological changes in northeastern Taiwan over the past 2ky inferred from biological proxies in the sediment record of a floodplain lake. PPP, 410, 401-411.
Le Béon, M., Suppe, J., Jaiswal, M.K., Chen, Y.G., Ustaszewski, M.E. (2014) Deciphering cumulative fault slip vectors from fold scarps: Relationships between long-term and coseismic deformations in central Western Taiwan. J. Geophys. Res. - Sol. Ea., 119(7), 5943-5978.
Yu, T.L., Wang, B.S., You, C.F.*, Burr, G. S., Chung, C.H., Chen, Y.G. (2015). Geochemical effects of biomass burning and land degradation on Lanyu Islet, Taiwan. Limnology and Oceanography, 60(2), 411-418.
Chang, C.C.*, Burr, G. S., Jull, A.J.T., Russell, J.L., Biddulph, D., White, L., Prouty, N.G., Chen, Y.G., Shen, C.C., Zhou, W.J., Lam, D.D. (2016) Reconstructing surface ocean circulation with 129I time series records from corals. J. Environ. Radioact. 165, 144-150.
Yu, T.L., Wang, B.S., Shen C.C.*, Wang, P.L. Frank T.Y., Burr, G.S., Chen, Y.G. (2017) Improved analytical techniques of sulfur isotopic composition in nanomole quantities by MC-ICP-MS. Analytica Chimica Acta, 988, 34-40.
Nguyen, D.C., Chen, Y.G.*, Chiang, H.W.*, Shen, C.C., Wang, X., Doan, L.D., Yuan, S., Lone, M.A., Yu, T.L., Lin, Y., Kuo,Y.T. (2020) A decadal-resolution stalagmite record of strong Asian summer monsoon from northwestern Vietnam over the Dansgaard–Oeschger events 2–4. J. Asian Earth Sci.- X 3, 100027.
Wang, Y., Lin, Y.N.*, Ota, Y., Chung, L.H., Shyu, J.B.H., Chiang, H.W., Chen, Y.G., Hsu, H.H., Shen, C.C. (2022). Mud Diapir or Fault-Related Fold? On the Development of an Active Mud-Cored Anticline Offshore Southwestern Taiwan. Tectonics 41(9), e2022TC007234
Lin, K.*, Shen, C.C., Duan, W., Tan, L., Kong, X., Lee, S.Y., Chen, Y.G., Wang, X. (2022). Early anthropogenic impacts on the Indian summer monsoon induced by land-use and land-cover changes. J. Geophys. Res. Atmos. 127, e2022JD036754
Hsu, W.H., Byrne, T.B., Lewis, J.C., Chen, Y.G.*, Yeh, P.Y. (2022). Synorogenic extension and extrusion in southern Taiwan. Tectonophysics 840, 229562
Precipitation response to Heinrich Event-3 in the northern Indochina as revealed in a high-resolution speleothem record The Heinrich Event (HE), a millennial-scale cold event in the North Atlantic, is characterized by the occurrence of a large amount of coarse terrigenous grains in marine sediments. There are 7 HEs in the past 70 thousand years (HE-6 to HE-0). Among HEs, HE-3 and HE-6 have been categorized as unusual events due to lower proportions of lithic grains found in their corresponding sedimentary layers. In tropical Asia, HE-3 manifestations prominently appear in proxy records from China, Myanmar, northern Borneo, and India. It supports the climatic link between the low latitudes and the North Atlantic. However, the mechanism remains challenging because monsoon intensity may respond to HEs in different magnitudes.
Here, we report a new dataset of speleothem δ18O from northwestern Vietnam, which covers the duration of the HE-3 with decadal scale resolution. The δ18O data implies a pronounced excursion in precipitation beginning at around 30.8 thousand years ago (ka), reaching the minimum at 30.3 ka, and then turning to increase in precipitation at 30.2 ka, and finally returning to a higher level at 29.5 ka. It shows a gradual, discontinuous onset and termination of altered conditions with steps inferred to be on the order of several hundred years. This contrasts to the abrupt HE-3 onset and termination observed by previous studies in Asian monsoon region.
We used a coupled slab ocean model (CAM3) to evaluate effects of different degrees of cooling associated with glacial boundary conditions. Magnitudes of cooling ranged from 6 °C and 10 °C (low and high scenarios respectively) around the British Isles relative to the control simulation. The simulated summer (June-July-August) precipitation near northwestern Vietnam presents an ~10% decline which resulted from a southward shift of Indian Ocean’s warm pool and summer ITCZ by the cooling in the North Atlantic. (Nguyen et al. 2022)
Synorogenic extension and extrusion in southern Taiwan Extensional deformation is documented in many contractional orogenic belts, which are characterized by high topography, thickened crust, and synorogenic extensional structures at high elevations or on steep topographic slopes. The direction of extension is generally perpendicular or parallel to the orogen. In southern Taiwan, those high rocks in the core of the orogenic belt are dominated by the extension, whereas the lower is dominated by the contraction. In contrast, the mountain heights and crust thickness in southern Taiwan are lower and thinner than in those classic orogens. In addition, the direction of extension is oblique to the orogen rather than orthogonal or parallel to the orogen. These observations suggest a more complicated tectonic process may be responsible for the extension in the core of southern Taiwan. This study integrates late-stage structures and their palestress inversion, with GPS and earthquake focal mechanisms to assess different hypotheses for the origin of synorogenic normal faults in the study area. This study further proposes a southwestward extrusion model in which the lateral and vertical movement of the lower crust in southern Taiwan accommodates the shortening between the obliquely colliding Peikang High and the Luzon Arc. The northeast extension normal faults in the upper crust can be interpreted as to accommodate the lateral and vertical movement of the lower crust in the southern Central Range. This study infers that this southwestward extrusion process may be younger the 0.5 Ma based on thermochronological result and the proposed onset of extrusion in southwest Taiwan is late Pleistocene. (Hsu et al. 2022)