Measurements of oxygen and hydrogen stable isotopes in precipitation (δ18OPand δ2HP) provide a valuable tool for understanding modern hydrological processes and the empirical foundation for interpreting paleoisotope archives. However, long‐term data sets of modern δ18OPand δ2HPin southern Alaska are entirely absent, thus limiting our insight and application of regionally defined climate‐isotope relationships in this proxy‐rich region. We present and utilize a 13‐year‐long record of event‐based δ18OPand δ2HPdata from Anchorage, Alaska (2005–2018,
Stable isotope data from tests of four planktonic foraminifer species in core tops on the Rio Grande Rise (RIO) fail a field test of reproducibility until corrections are made for various environmental effects. The regionally uniform and strongly stratified surface ocean hydrography across RIO allows the identification of causes of variability in δ18O and δ13C data in addition to the effects of surface ocean temperature and nutrient content. A previously calibrated calcite dissolution proxy indicates that the dissolution of foraminifer shells in sediments has no effect on δ18O and δ13C in tests of foraminifers from core tops on RIO. Furthermore, vital effects within and among foraminifer species are not sufficient to explain the large variability of δ18O and δ13C data observed on RIO. Instead, correctly estimating species‐specific habitat depth ranges and adjusting δ13C values for ocean/atmosphere carbon exchange are necessary to accurately reconstruct the hydrography of surface waters on RIO.
more » « less- NSF-PAR ID:
- 10457783
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Paleoceanography and Paleoclimatology
- Volume:
- 35
- Issue:
- 3
- ISSN:
- 2572-4517
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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