Identification:
Title:
A high resolution paleo-climate and -oceanographic record of MIS 11 as an analogue for understanding the current and past (MIS 31) interglacial periods
Year:
2010
Source:
In: Hoskin, Paul (editor), Hikuroa, Daniel C. H. (editor), Eccles, Jennifer (editor), GeoNZ 2010; geoscience, geothermal; joint meeting including the Geoscience Society of New Zealand, the New Zealand geothermal workshop, day in common with the New Zealand Branch of AusIMM; abstract volume
Publisher:
Geological Society of New Zealand, Lower Hutt, New Zealand
Volume:
129A
Issue:
Pages:
58
Abstract:
Marine isotope stage 11 (MIS 11) was an interglacial stage that occurred at 0.428 to 0.397 Ma when Earth's orbital parameters were most similar to the present day interglacial. Primarily this study will measure trace element chemistry and stable isotopes of planktic foraminifera sampled from sediments in Ocean Drilling Program core 1123 and aims to provide new quantitative insights into the paleoclimatic and paleoceanographic change for the MIS 11 interglacial and provide insight into what lies ahead for the Holocene. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) will be used to measure in situ ratios of elements Li, B, Mg, Al, Mn, Zn, Sr and Ba/Ca in the CaCO3 tests of the planktic species Globigerina bulloides and Globigerinoides ruber. These data can be used to quantify past surface and thermocline water temperatures as well as changes in oceanic water masses and ocean acidity using calibrations between ocean conditions and foraminifera chemistry previously established for modern foraminifera. Site 1123 is located at the northern limit of the Subtropical Front and as such records sensitively changes in the mixing of the two main surface water masses east of New Zealand -- Subtropical and Subantarctic waters that influence the climate and marine biological productivity off eastern New Zealand. Trace element chemistry coupled with oxygen isotope measurements of the foraminfera will also be used to infer past changes in the the oxygen isotope composition of seawater in response to changes in global ice volume and temperature, and will thus highlight any changes in MIS 11 surface water masses in response to melting or growth of Earth's cryosphere. Results will be compared with the cooler super-interglacial MIS 31 (ca. 1.09 to 1.07 Ma) when significant collapse of the Ross Ice shelf and parts of the Antarctic ice sheets may have occurred. The comparison of MIS 11 and MIS 31 will enable a direct comparison of the changes in ocean temperatures and circulation, and global ice volume that took place in two Quaternary super-interglacial periods, which appear to have had markedly different effects on the Antarctic cryosphere.
Language:
English
Genre:
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