- 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.
Nguyena, 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. JAES (in press)
A decadal-resolution record of Asian summer monsoon (ASM) around D-O 4 A high-resolution δ18O record retrieved from a stalagmite from northern Vietnam demonstrates ASM variation in glacial time from 23 to 30ka. Our data show strong coherence with Chinese and North Indian speleothem, suggesting that the ASM has synchronously responded over a broad region, which can be also correlated to Dansgaard-Oeschger (D-O) events in the North Atlantic. Additionally, we observed that the onset timing and change pattern of D-O 4 varied spatially. It seems to be an earlier commencement and less abrupt at sites located with a connection to the modern Intertropical convergence Zone (ITCZ) than sites off the influence from ITCZ. It implies that the tropics may play a critical role in global climate system. Furthermore, this high-resolution record also clearly show a few centennial events with a duration of ~200 years, which probably correlates with the Suess cycle of solar activity. (Nguyen et al. 2020)
Reconstructing surface ocean circulation by coral recorded 129I The long-lived radionuclide 129I is used as an environmental tracer. At present, the global 129I in surface water is about 1-2 orders of magnitude higher than pre-1960 levels. Nuclear weapons testing was the primary 129I source in the Western Pacific in the latter part of the 20th Century. Since the 1990s, anthropogenic 129I produced from industrial nuclear fuels reprocessing plants has been the primary source of 129I in marine surface waters of the Atlantic and around the globe. Presented in this study are four coral 129I time series records from: Con Dao (Vietnam), Xisha Islands (the South China Sea), Rabaul (Papua New Guinea) and Guam. The Con Dao record shows a sudden increase in 1959. The Xisha coral also shows similar peaking values but fluctuated with lows, probably reflecting local upwelling in the South China Sea. The Rabaul coral experienced relatively gradual increases in the 1970s, similar to a published record from the Solomon Islands. The Guam’s values are generally higher but with two distinct large peaks, in 1955 and 1959. The 1955 peak and above mentioned Con Dao 1959 increase are likely from the 1954 Castle Bravo nuclear test; on the other hand, the 1959 peak can be attributed to the Operation Hardtack I test. The coral 129I time series data provide a broad picture of the surface distribution and depth penetration of 129I in the Pacific Ocean over the past 60 years. ( Chang et al. 2016)