Exploring climate-varve relationships in a sediment sequence from Lake Ohau, South Island, New Zealand
Abstract
Comprehensive understanding of natural climate-system dynamics requires high-resolution paleoclimate records extending beyond the instrumental period into the Holocene. A number of highly resolved terrestrial paleoclimate records have been recovered in the Northern Hemisphere, however, there is a need to develop comparable records from the Southern Hemisphere mid-latitudes, where the timing and amplitude of regional and hemispheric-scale climatic events is less well-constrained. A 2,000 year varved sediment sequence recovered from Lake Ohau, Mackenzie Basin, New Zealand (44.234°S, 169.854°E) offers a unique opportunity explore the hydrology and climate of this region at annual-to-decadal resolution. This record will aid investigations into the dynamics of large-scale climate patterns such as the Southern Annual Mode, Interdecadal Pacific Oscillation, and ENSO over the last two millennia. The utility of this record for paleoclimate studies critically depends on a quantitative understanding of the relationship between hydrometeorology and lake sedimentation. We present initial climate-varve relationships developed through detailed meteorological and hydrological monitoring combined with ITRAX mirco-XRF elemental data and measured layer thicknesses. We also explore initial results using back-trajectory analysis and sedimentology, which demonstrates strong relationships between sediment characteristics (grain size and accumulation) and storm origin and trajectory.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP14A..02R
- Keywords:
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- 1637 GLOBAL CHANGE Regional climate change;
- 1861 HYDROLOGY Sedimentation;
- 1631 GLOBAL CHANGE Land/atmosphere interactions;
- 1845 HYDROLOGY Limnology