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Tropical South China Sea Surface 14C Record in an Annually-Banded Coral

Published online by Cambridge University Press:  18 July 2016

Takehiro Mitsuguchi ,
Phong X Dang ,
Hiroyuki Kitagawa ,
Minoru Yoneda  and
Yasuyuki Shibata
Takehiro Mitsuguchi*
Affiliation:
National Institute for Environmental Studies, Tsukuba 305–8506, Japan Institute for Asian PaleoClimate, Konan 483–8226, Japan
Phong X Dang
Affiliation:
Institute of Geography, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam. Also: Japan Society for the Promotion of Science Graduate School of Environmental Studies, Nagoya University, Nagoya 464–8601, Japan
Hiroyuki Kitagawa
Affiliation:
Graduate School of Environmental Studies, Nagoya University, Nagoya 464–8601, Japan
Minoru Yoneda
Affiliation:
National Institute for Environmental Studies, Tsukuba 305–8506, Japan
Yasuyuki Shibata
Affiliation:
National Institute for Environmental Studies, Tsukuba 305–8506, Japan
*
Corresponding author. Email: aal53740@nyc.odn.ne.jp
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Abstract

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A surface-water Δ14C record of AD 1948–1999 in the tropical South China Sea (SCS) has been reconstructed from accelerator mass spectrometric radiocarbon measurements of annual bands of a Pontes coral collected from Con Dao Island, Vietnam. Results gave the following Δ14C time series: a steady state of −47.8 ± 2.8‰ (mean ± SD, n = 8) during 1948–1955 (i.e. in the pre-bomb period); a sharp increase during 1956–1966; a gradual increase during 1967–1973; a relatively high maximum value of ∼174‰ in 1973; and a gradual decrease for the following period to ∼86‰ in 1999. This Δ14C record having a sharp increase and a relatively high peak is similar to the records of subtropical corals (latitudes 21–27°) and is distinctly different from the records of equatorial/tropical corals (latitudes <10°), although our coral sample was collected from an equatorial/tropical region (8°39′N, 106°33′E). This can be explained by the geographic, oceanographic, and climatic setting of our study site. The SCS is a semi-enclosed marginal sea in the far western tropical Pacific and is little influenced by equatorial upwelling or related ocean currents. Our study site is located in the southwestern SCS, where an enormous submerged plain (the Sunda Shelf) spreads out with very shallow waters (mean depth <100 m). Furthermore, in the SCS, the East Asian monsoon (a strong, seasonally reversing wind system) enhances air-sea gas exchange especially in the mainland coastal waters, including our study site. Such semi-enclosed shallow waters with enhanced ventilation were probably very sensitive to the atmospheric nuclear explosions in the late 1950s and early 1960s and caused the sharp increase and high peak in the coral Δ14C record. Our coral Δ14C values in the southwestern SCS are significantly higher than the values in the northwestern SCS (Xisha Islands), which seems to suggest that meridional mixing of surface waters is not active in the SCS and that the open-ocean water intruding into the northern SCS (i.e. the Kuroshio intrusion) has only a limited influence on the southern SCS.

Type
Articles
Information
Radiocarbon , Volume 49 , Issue 2 , 2007 , pp. 905 - 914
Copyright
Copyright © 2007 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Barnes, DJ, Taylor, RB. 2001. On the nature and causes of luminescent lines and bands in coral skeletons. Coral Reefs 19(3):221–30.Google Scholar
Buddemeier, RW, Maragos, JE, Knutson, DW. 1974. Radiographic studies of reef coral exoskeletons: rates and patterns of coral growth. Journal of Experimental Marine Biology and Ecology 14(2):179–200.CrossRefGoogle Scholar
Dang, PX, Mitsuguchi, T, Kitagawa, H, Shibata, Y, Kobayashi, T. 2004. Marine reservoir correction in the south of Vietnam estimated from an annually-banded coral. Radiocarbon 46(2):657–60.CrossRefGoogle Scholar
Druffel, ERM. 1981. Radiocarbon in annual coral rings from the eastern tropical Pacific Ocean. Geophysical Research Letters 8(1):59–62.Google Scholar
Druffel, ERM. 1987. Bomb radiocarbon in the Pacific: annual and seasonal timescale variations. Journal of Marine Research 45:667–98.Google Scholar
Druffel, ERM. 1997. Geochemistry of corals: proxies of past ocean chemistry, ocean circulation, and climate. Proceedings of the National Academy of Sciences USA 94(16):8354–61.CrossRefGoogle ScholarPubMed
Druffel, ERM, Griffin, S. 1995. Regional variability of surface ocean radiocarbon from southern Great Barrier Reef corals. Radiocarbon 37(2):517–24.CrossRefGoogle Scholar
Farris, A, Wimbush, M. 1996. Wind-induced Kuroshio intrusion into the South China Sea. Journal of Oceanography 52(6):771–84.Google Scholar
Grumet, NS, Abram, NJ, Beck, JW, Dunbar, RB, Gagan, MK, Guilderson, TP, Hantoro, WS, Suwargadi, BW. 2004. Coral radiocarbon records of Indian Ocean water mass mixing and wind-induced upwelling along the coast of Sumatra, Indonesia. Journal of Geophysical Research 109(C05003): doi: 10.1029/2003JC002087.CrossRefGoogle Scholar
Guilderson, TP, Schrag, DP. 1998. Abrupt shift in subsurface temperatures in the tropical Pacific associated with changes in El Niño. Science 281(5374):240–3.CrossRefGoogle ScholarPubMed
Guilderson, TP, Schrag, DP, Kashgarian, M, Southon, J. 1998. Radiocarbon variability in the western equatorial Pacific inferred from a high-resolution coral record from Nauru Island. Journal of Geophysical Research 103(C11):24,641–50.Google Scholar
Guilderson, TP, Schrag, DP, Goddard, E, Kashgarian, M, Wellington, GM, Linsley, BK. 2000. Southwest subtropical Pacific surface water radiocarbon in a high-resolution coral record. Radiocarbon 42(2):249–56.Google Scholar
Guilderson, TP, Schrag, DP, Cane, MA. 2004. Surface water mixing in the Solomon Sea as documented by a high-resolution coral 14C record. Journal of Climate 17(5):1147–56.2.0.CO;2>CrossRefGoogle Scholar
Isdale, P. 1984. Fluorescent bands in massive corals record centuries of coastal rainfall. Nature 310(5978):578–9.Google Scholar
Knutson, DW, Buddemeier, RW, Smith, SV. 1972. Coral chronometers: seasonal growth bands in reef corals. Science 177(4045):270–2.CrossRefGoogle ScholarPubMed
Konishi, K, Tanaka, T, Sakanoue, M. 1982. Secular variation of radiocarbon concentration in seawater: sclero-chronological approach. Proceedings of the Fourth International Coral Reef Symposium 1:181–5.Google Scholar
Levin, I, Kromer, B, Schoch-Fischer, H, Bruns, M, Münnich, M, Berdau, D, Vogel, JC, Münnich, KO. 1985. 25 years of tropospheric 14C observations in central Europe. Radiocarbon 27(1):1–19.CrossRefGoogle Scholar
Levin, I, Kromer, B, Schoch-Fischer, H, Bruns, M, Münnich, M, Berdau, D, Vogel, JC, Münnich, KO. 1994. Δ14CO2 records from sites in central Europe. Trends '93: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, ORNL/CDIAC 65:203–22.Google Scholar
Manning, MR, Melhuish, WH. 1994. Atmospheric Δ14C record from Wellington. Trends '93: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, ORNL/CDIAC 65:193–202.Google Scholar
Metzger, EJ, Hurlburt, HE. 1996. Coupled dynamics of the South China Sea, the Sulu Sea, and the Pacific Ocean. Journal of Geophysical Research 101(C5):12,331–52.Google Scholar
Mitsuguchi, T, Kitagawa, H, Matsumoto, E, Shibata, Y, Yoneda, M, Kobayashi, T, Uchida, T, Ahagon, N. 2004. High-resolution 14C analyses of annually-banded coral skeletons from Ishigaki Island, Japan: implications for oceanography. Nuclear Instruments and Methods in Physics Research B 223–224:455–9.Google Scholar
Moore, MD, Schrag, DP, Kashgarian, M. 1997. Coral radiocarbon constraints on the source of the Indonesian throughflow. Journal of Geophysical Research 102(C6):12,359–65.CrossRefGoogle Scholar
Nitani, H. 1972. Beginning of the Kuroshio. In: Stommel, H, Yoshida, K, editors. Kuroshio, Physical Aspects of the Japan Current. Seattle: University of Washington. p 129–63.Google Scholar
Nydal, R, Lövseth, K. 1983. Tracing bomb 14C in the atmosphere 1962–1980. Journal of Geophysical Research 88(C6):3621–42.CrossRefGoogle Scholar
Qu, T, Du, Y, Meyers, G, Ishida, A, Wang, D. 2005. Connecting the tropical Pacific with Indian Ocean through South China Sea. Geophysical Research Letters 32(L24609): doi: 10.1029/2005GL024698.Google Scholar
Schmidt, A, Burr, GS, Taylor, FW, O'Malley, J, Beck, JW. 2004. A semiannual radiocarbon record of a modern coral from the Solomon Islands. Nuclear Instruments and Methods in Physics Research B 223–224:420–7.CrossRefGoogle Scholar
Shen, CD, Yi, WX, Yu, KF, Sun, YM, Yang, Y, Zhou, B. 2004. Interannual 14C variations during 1977–1998 recorded in coral from Daya Bay, South China Sea. Radiocarbon 46(2):595–601.Google Scholar
Southon, J, Kashgarian, M, Fontugne, M, Metivier, B, Yim, WW-S. 2002. Marine reservoir corrections for the Indian Ocean and Southeast Asia. Radiocarbon 44(1):167–80.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.CrossRefGoogle Scholar
Stuiver, M, Reimer, PJ, Bard, E, Beck, JW, Burr, GS, Hughen, KA, Kromer, B, McCormac, G, van der Plicht, J, Spurk, M. 1998a. IntCal98 radiocarbon age calibration, 24,000–0 cal BP. Radiocarbon 40(3):1041–83.Google Scholar
Stuiver, M, Reimer, PJ, Braziunas, TF. 1998b. High-precision radiocarbon age calibration for terrestrial and marine samples. Radiocarbon 40(3):1127–51.CrossRefGoogle Scholar
Toggweiler, JR, Dixon, K, Broecker, WS. 1991. The Peru upwelling and the ventilation of the South Pacific thermocline. Journal of Geophysical Research 96(C11):20,467–97.Google Scholar
Yoneda, M, Shibata, Y, Tanaka, A, Uehiro, T, Morita, M, Uchida, M, Kobayashi, T, Kobayashi, C, Suzuki, R, Miyamoto, K, Hancock, B, Dibden, C, Edmonds, JS. 2004. AMS 14C measurement and preparative techniques at NIES-TERRA. Nuclear Instruments and Methods in Physics Research B 223–224:116–23.Google Scholar