Surface water processes in the Indonesian Throughflow as documented by a high-resolution coral (Delta)14C record

Journal Article · Wed Apr 23 04:00:00 EDT 2008 · Journal of Geophysical Research (Oceans), vol. 113, N/A, September 3, 2008, C09001, doi:10.1029/2008JC004722

OSTI ID:945733

Fallon, S J; Guilderson, T P

To explore the seasonal to decadal variability in surface water masses that contribute to the Indonesian Throughflow we have generated a 115-year bi-monthly coral-based radiocarbon time-series from a coral in the Makassar Straits. In the pre-bomb (pre-1955) era from 1890 to 1954, the radiocarbon time series occasionally displays a small seasonal signal (10-15{per_thousand}). After 1954 the radiocarbon record increases rapidly, in response to the increased atmospheric {sup 14}C content caused by nuclear weapons testing. From 1957 to 1986 the record displays clear seasonal variability from 15 to 60{per_thousand} and the post-bomb peak (163 per mil) occurred in 1974. The seasonal cycle of radiocarbon can be attributed to variations of surface waters passing through South Makassar Strait. Southern Makassar is under the influence of the Northwest Monsoon, which is responsible for the high Austral summer radiocarbon (North Pacific waters) and the Southeast Monsoon that flushes back a mixture of low (South Pacific and upwelling altered) radiocarbon water from the Banda Sea. The coral record also shows a significant {sup 14}C peak in 1955 due to bomb {sup 14}C water advected into this region in the form of CaCO{sub 3} particles (this implies that the particles were advected intact and then become entrapped in the coral skeleton--is this what we really mean? Wouldn't even fine particles settle out over the inferred transit time from Bikini to MAK?) or water particles with dissolved labeled CO{sub 2} produced during fallout from the Castle tests in 1954.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 945733
• Report Number(s): LLNL-JRNL-403252
• Journal Information: Journal of Geophysical Research (Oceans), vol. 113, N/A, September 3, 2008, C09001, doi:10.1029/2008JC004722, Journal Name: Journal of Geophysical Research (Oceans), vol. 113, N/A, September 3, 2008, C09001, doi:10.1029/2008JC004722 Vol. 113
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
BOMBS
CORALS
FALLOUT
MIXTURES
MONSOONS
NUCLEAR WEAPONS
SURFACE WATERS
TESTING
UPWELLING
WATER