A series of cores from east of New Zealand have been examined to determine the paleoceanographic history of the late Quaternary in the SW Pacific using planktonic foraminiferal data. Distinct shifts of species can be seen between glacial and interglacial times especially south of Chatham Rise east of South Island. Foraminiferal fragmentation ratios and benthic/planktonic foraminiferal ratios both show increased dissolution during glacials, especially isotope stage 2 to the south of Chatham Rise. The present-day Subtropical Convergence appears to be tied to the Chatham Rise at 44°S, but during glacial times this rise separated cold water to the south from much warmer water to the north, with an associated strong thermal gradient across the rise. We estimate that this gradient could have presented as much as an 8°C temperature change across 4°C of latitude during the maximum of the last ice age. There is only weak evidence of the Younger Dryas cool event, but there is a clear climatic optimum between 8 and 6.4 ka with temperatures 1°-2°C higher than the present day. The marine changes compare well with vegetational changes on both South and North Island.
Median Latitude: -43.951750 * Median Longitude: 176.719000 * South-bound Latitude: -45.523500 * West-bound Longitude: 174.948000 * North-bound Latitude: -42.380000 * East-bound Longitude: 178.490000
Date/Time Start: 1983-01-03T00:00:00 * Date/Time End: 1983-01-03T00:00:00
90-594 * Latitude: -45.523500 * Longitude: 174.948000 * Date/Time: 1983-01-03T00:00:00 * Elevation: -1204.0 m * Penetration: 505.1 m * Recovery: 300.7 m * Location: South Pacific/CONT RISE * Campaign: Leg90 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 50 cores; 475.3 m cored; 28.8 m drilled; 63.3 % recovery
Datasets listed in this publication series
- Weaver, PPE; Carter, L; Neil, HL (1998): Distribution of planktonic foraminifera in DSDP Hole 90-594 east of New Zealand. https://doi.org/10.1594/PANGAEA.691460
- Weaver, PPE; Carter, L; Neil, HL (1998): Distribution of planktonic foraminifera in sediment core R657 east of New zealand. https://doi.org/10.1594/PANGAEA.691459