High Pacific native Grottoli

Core/Site name:

Fanning Island

Country/Region:

Central equatorial Pacific

Elevation:

0

Archive:

corals

Species:

Porites sp.

Proxy measurement:

radiocarbon measurement in coral skeleton

Sampling resolution:

monthly

Dating information:

radiometric

Startyear:

1922 AD

Endyear:

1956 AD

Description:

Coral skeletal radiocarbon records reflect seawater d14C and are useful for reconstructing the history of water mass movement and ventilation in the tropical oceans. Here, we reconstructed the inter-annual variability in central equatorial Pacific surface water d14C from 1922-1956 using near-monthly radiocarbon measurements in a Porites sp. coral skeleton (FI5A) from the windward side of Fanning Island (3 deg 54'32"N, 159 deg 18'88""W). The most pronounced feature in this record is a large positive shift in d14C between 1947 and 1956 that coincides with the switch of the Pacific Decadal Oscillation (PDO) from a positive to a negative phase in the mid-1940s. Although the absolute d14C values from 1950 - 1955 in FI5A differ from the d14C values of another coral core collected from the opposite side of the island, both records show a large positive shift in their d14C records at that time. The relative increase in d14C of each record is consistent with the premise that a common mechanism is controlling the d14C records within each coral record. Overall, the Fanning d14C data support the notion that a significant amount of subtropical seawater is arriving at the equator but does not allow us to determine the mechanism for its transport."

Data entered by name:

Paniagua, Juan F.

Data entered by email:

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Main reference(s):

Grottoli A.G., Gille S.T., Druffel E.R.M., Dunbar R.B. 2003. Decadal timescale shift in the 14C record of a central equatorial Pacific coral. Radiocarbon 45(1): 91-99

Link to reference 1:

https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/4162/3587

Data storage link 1:

http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:3824372196916792::::P1_STUDY_ID:1879

Data storage link 2:

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/coral/east_pacific/fanning_2003.txt

Current dating method:

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Annual snow acc rate:

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Category: Ocean2k