posted on 2022-03-01, 02:40authored byRachael Rhodes
The Ross Sea is the most biologically productive sector of the Southern
Ocean and a region of substantial bottom water formation. Modulation of
these processes has the potential to influence both regional and global
climate. Analysis of snow pit and ice core samples from Mt Erebus Saddle
(MES) on Ross Island allows reconstruction of Late Holocene climate of
this key region of Antarctica.
The biogenic sulphur species, methylsulphonate (MS-), is shown to be a
quantitative proxy for Ross Sea Polynya conditions. MS- concentrations
of the snow pit, dating from 1999-2005 AD, strongly correlate (R2 >
0.9) with interannual changes in open water area and surface ocean
primary productivity caused by the sea-ice-damming effect of large
icebergs.
Trace element analysis of ice core samples allows delineation between:
1) terrestrial and marine sources, 2) anthropogenic Pb pollution, and 3)
volcanic trace element deposition. To assess the contribution of
mineral dust leaching to trace element concentrations, powdered rock
standards were leached in 1 wt.% HNO3 and periodically sampled for
analysis. Results demonstrate that trace element leaching in acidified
samples is time- and mineral-dependent. Incongruent leaching of trace
elements from dust causes errors in crustal enrichment factors and
produces trace element ratios, which do not reflect dust provenance.
History
Copyright Date
2011-06-16
Date of Award
2011-06-16
Publisher
Te Herenga Waka—Victoria University of Wellington
Rights License
Author Retains All Rights
Degree Discipline
Geology
Degree Grantor
Te Herenga Waka—Victoria University of Wellington
Degree Level
Doctoral
Degree Name
Doctor of Philosophy
Victoria University of Wellington Item Type
Awarded Doctoral Thesis
Language
en_NZ
Victoria University of Wellington School
School of Geography, Environment and Earth Sciences