Sumatra Coral Radiocarbon Data --------------------------------------------------------------------- NOAA Paleoclimatology Program and World Data Center for Paleoclimatology, Boulder --------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Sumatra Coral Radiocarbon Data LAST UPDATE: 11/2004 (Original Receipt by WDC Paleo) CONTRIBUTOR: Nancy Grumet, Woods Hole Oceanographic Institute IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2004-066 SUGGESTED DATA CITATION: Grumet, N.S., et al. 2004. Sumatra Coral Radiocarbon Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series #2004-066. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Grumet, N.S., N.J. Abram, J.W. Beck, R.B. Dunbar, M.K. Gagan, T.P. Guilderson, W.S. Hantoro, and B.W. Suwargadi. 2004. Coral radiocarbon records of Indian Ocean water mass mixing and wind-induced upwelling along the coast of Sumatra, Indonesia. Journal of Geophysical Research - Oceans. Vol. 109, C05003. doi:10.1029/2003JC002087. ABSTRACT: Radiocarbon (14C) in the skeletal aragonite of annually banded corals track radiocarbon concentrations in dissolved inorganic carbon (DIC) in surface seawater. As a result of nuclear weapons testing in the 1950s, oceanic uptake of excess 14C in the atmosphere has increased the contrast between surface and deep ocean 14C concentrations. We present accelerator mass spectrometric (AMS) measurements of 14C/12C ratios (d14C) in Porites corals from the Mentawai Islands, Sumatra (0°S, 98°E) and Watamu, Kenya (3°S, 39°E) to document the temporal and spatial evolution of the 14C zonal gradient in the tropical Indian Ocean. The rise in d14C in the Sumatra coral, in response to the maximum in nuclear weapons testing, is delayed by 2–3 years relative to the rise in coral d14C from the coast of Kenya. Kenya coral d14C values rise quickly because surface waters are in prolonged contact with the atmosphere. In contrast, wind-induced upwelling and rapid mixing along the coast of Sumatra entrains 14C-depleted water from the subsurface, which dilutes the effect of the uptake of bomb-produced 14C by the surface ocean. Bimonthly AMS d14C measurements on the Mentawai coral reveal mainly interannual variability with minor seasonal variability. Singular spectrum analysis of the Sumatra coral d14C record reveals a significant 3-year periodicity. These results lend support to the concept that interannual variability in Indian Ocean upwelling and sea surface temperatures is related to ENSO-like teleconnections over the Indo-Pacific basin. GEOGRAPHIC REGION: Eastern Indian Ocean, Sumatra, Indonesia PERIOD OF RECORD: 1944 -1990 AD DESCRIPTION: We present accelerator mass spectrometric (AMS) measurements of radiocarbon isotope (d14C) in Porites corals from the Mentawai Islands, Sumatra (0ºS, 98ºE), and compare them to d14C data from Watamu, Kenya (3ºS, 39ºE) to document the temporal and spatial evolution of the 14C zonal gradient in the tropical Indian Ocean. The rise in d14C in the Sumatra coral, in response to the maximum in nuclear weapons testing, is delayed by 2-3 years relative to the rise in coral d14C from the coast of Kenya. Our intrabasin comparison between coral d14C records from the coasts of Sumatra and Kenya reveals a distinct difference in water mass mixing processes across the equatorial Indian Ocean basin. The Watamu data are also available at the WDC Paleo: ftp://ftp.paleo.noaa.gov/paleo/coral/indian_ocean/watamu_c14.txt Data are from a 2.7m Core (PG2) from a massive Porites sp. coral. Collection site ~400m. offshore of Penang Island, Mentawais Islands, Sumatra, Indonesia. (0 deg. 08'S, 98 deg., 31' E, 6m. water depth) DATA: 1. Penang Island, Sumatra Coral Radiocarbon Data Column 1: Time, Calendar Year Column 2: d14C, per mil Year d14C 1944.5 -55.21 1944.67 -67.62 1944.84 -70.69 1945.01 -70.26 1945.17 -62.41 1945.34 -62.58 1945.51 -68.74 1945.67 -81.38 1945.84 -73.89 1946.01 -75.18 1946.17 -76.1 1946.34 -72.52 1946.51 -57.87 1946.68 -69.4 1946.84 -57.92 1947.01 -60.48 1947.18 -63.2 1947.34 -67.16 1947.51 -69.76 1947.68 -63.48 1947.84 -57.77 1948.01 -64.95 1948.18 -63.46 1948.35 -59.67 1948.51 -65.1 1948.68 -64.89 1948.85 -60.96 1949.01 -62.45 1949.18 -63.05 1949.35 -71.76 1949.51 -68.75 1949.68 -64.39 1949.85 -61.47 1950.02 -63.21 1950.18 -64.01 1950.35 -62.5 1950.52 -62.7 1950.68 -66.99 1950.85 -71.43 1951.02 -68.08 1951.18 -70.8 1951.35 -72.66 1951.52 -65.81 1951.69 -68.57 1951.85 -62.59 1952.02 -58.2 1952.19 -67.81 1952.35 -71.52 1952.52 -66.73 1952.69 -65.15 1952.85 -64.73 1953.02 -64.3 1953.19 -63.88 1953.36 -65.04 1953.52 -67.74 1953.69 -63.07 1953.86 -65.62 1954.02 -60.73 1954.19 -57.01 1954.36 -64.61 1954.52 -61.43 1954.69 -64.53 1954.86 -63.86 1955.03 -64.82 1955.19 -65.56 1955.36 -67.69 1955.53 -57.99 1955.69 -60.27 1955.86 -63.95 1956.03 -64.52 1956.19 -62.4 1956.36 -60.08 1956.53 -60.29 1956.7 -55.47 1956.86 -56.85 1957.03 -58.07 1957.2 -63.6 1957.36 -62.13 1957.53 -55.41 1957.7 -60.77 1957.86 -59.31 1958.03 -60.54 1958.2 -53.46 1958.37 -51.63 1958.53 -54.73 1958.7 -55.38 1958.87 -49.93 1959.03 -46.33 1959.2 -51.59 1959.37 -51.28 1959.53 -48.45 1959.7 -50.3 1959.87 -44.94 1960.04 -39.67 1960.2 -37.03 1960.37 -37.29 1960.54 -39.93 1960.7 -40.57 1960.87 -32.87 1961.04 -33.94 1961.2 -27.72 1961.37 -27.5 1961.54 -22.49 1961.71 -31.11 1961.87 -42.56 1962.04 -33.99 1962.21 -22.07 1962.37 -15.89 1962.54 -22.98 1962.71 -17.28 1962.87 -18.33 1963.04 -20.65 1963.21 -21.86 1963.38 -9.91 1963.54 -11.47 1963.71 -14.3 1963.88 -2.19 1964.04 9.92 1964.21 17.54 1964.38 21.54 1964.54 24.53 1964.71 24.51 1964.88 35.71 1965.05 42.01 1965.21 41.55 1965.38 45.76 1965.55 51.47 1965.71 61.11 1965.88 66.67 1966.05 70.43 1966.21 74.2 1966.38 74.07 1966.55 71.41 1966.72 77.69 1966.88 86.56 1967.05 85.87 1967.22 85.31 1967.38 85.64 1967.55 88.93 1967.72 97.18 1967.88 99.46 1968.05 100.85 1968.22 104.25 1968.39 102.85 1968.55 100.2 1968.72 100.77 1968.89 98.08 1969.05 87.26 1969.22 101.5 1969.39 98.71 1969.55 95.96 1969.72 103.19 1969.89 106.51 1970.06 119.43 1970.22 109.28 1970.39 115.08 1970.56 108.63 1970.72 115 1970.89 110.05 1971.06 115.19 1971.22 117.5 1971.39 111.38 1971.56 106.97 1971.73 109.91 1971.89 111.29 1972.06 108.6 1972.23 107.91 1972.39 108.74 1972.56 111.7 1972.73 114.13 1972.89 114.29 1973.06 114.11 1973.23 113.53 1973.4 113.56 1973.56 113.58 1973.73 109.59 1973.9 107.98 1974.06 104.69 1974.23 110.98 1974.4 112.28 1974.56 109.84 1974.73 111.79 1974.9 115.57 1975.07 120.66 1975.23 117.15 1975.4 111.28 1975.57 110.11 1975.73 110.17 1975.9 110.22 1976.07 109.58 1976.23 109.18 1976.4 108.05 1976.57 109.54 1976.74 106.2 1976.9 105.67 1977.07 105.74 1977.24 105.13 1977.4 97.98 1977.57 90.83 1977.74 99.26 1977.9 98.15 1978.07 108.09 1978.24 100.12 1978.41 99.58 1978.57 103.29 1978.74 99.15 1978.91 91.26 1979.07 80.01 1979.24 95.18 1979.41 93.84 1979.57 96.73 1979.74 89.66 1979.91 85.03 1980.08 94.32 1980.24 97.57 1980.41 101.65 1980.58 103.68 1980.74 99.12 1980.91 100.82 1981.08 98.49 1981.24 92.65 1981.41 89.7 1981.58 93.91 1981.75 88.72 1981.91 80.79 1982.08 78.72 1982.25 71.39 1982.41 78.01 1982.58 88.55 1982.75 96.57 1982.91 95.44 1983.08 88.53 1983.25 91.84 1983.42 81.89 1983.58 92.76 1983.75 93.27 1983.92 89.29 1984.08 98.87 1984.25 85.73 1984.42 85.69 1984.58 94.37 1984.75 85.3 1984.92 87.34 1985.09 83.73 1985.25 81.86 1985.42 85.84 1985.59 81.69 1985.75 79.51 1985.92 81.11 1986.09 88.64 1986.25 81.13 1986.42 85.09 1986.59 80.59 1986.76 85.08 1986.92 84.67 1987.09 91.45 1987.26 91.47 1987.42 77.27 1987.59 71.96 1987.76 76.69 1987.92 77.37 1988.09 75.8 1988.26 74.2 1988.43 74.11 1988.59 76.97 1988.76 76.23 1988.93 82.63 1989.09 74.17 1989.26 66.16 1989.43 71.3 1989.59 57.97 1989.76 66.44 1989.93 64.71 1990.1 69.07 1990.26 71.57 1990.43 70.7 1990.6 74.27