Constarium
← Search

Archive · collection · 2018

Composite depth, benthic foraminiferal oxygen isotope and bio-marker records of sediment core GeoB16602

Listed in PANGAEA

Precipitation isotope reconstructions derived from speleothems and plant waxes are important archives for understanding hydroclimate dynamics.

Description

Their climatic significance in East Asia, however, remains controversial. Here we present terrestrial plant-wax stable hydrogen isotope (δDwax) records over periods covering the last four interglacials and glacial terminations from sediment cores recovered from the northern South China Sea (SCS) as an archive of regionally-integrated precipitation isotope changes in Southeast China.

Combined with previous precipitation isotope reconstructions from China, we find that the SCS δDwax and Southwest-Central China stalagmite O records show relatively enriched and depleted isotopic values, respectively, during interglacial peaks; but relatively similar isotopic variations during most sub-interglacials and glacial periods over the past 430 thousand years. During interglacial peaks, strong summer insolation should have intensified the convection intensity, the isotopic fractionation along moisture trajectories and the seasonality, which are all in favor of causing isotopically-depleted rainfall over the East Asian monsoon regime.

Read the rest (2 more)

These effects in combination with a relatively high proportion of Indian Ocean- versus Pacific-sourced moisture influx should have resulted in strongly depleted precipitation isotopes (stalagmite O) over most parts of China. However, Southeast China should have been affected by a relatively low ratio of Indian Ocean- versus Pacific-sourced moisture influx, which dominated over effects yielding depleted precipitation isotopes and led to enriched precipitation isotopes (δDwax).

It is thus concluded that glacial boundary conditions and insolation forcing are the two most important factors for causing regional differences in precipitation isotope compositions over subtropical East Asia on orbital timescales.

Links

Where it is published

Catalogue records · 1

Topics

Inferred from text
Isotope geochemistry 76%
Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
PANGAEAoai:pangaea.de:doi:10.1594/PANGAEA.89301111 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · PANGAEAconnector:pangaea@1.0.0
concepts[field].anzsrc:field:370303enrichment · PANGAEAtaxonomy-embedding@1.1.0title+keywords+description (76%)
concepts[field].local:field:earth-environmentalmapping · PANGAEAconnector:pangaea@1.0.0
descriptionsource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/description
licensesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/rights
publication_datesource · PANGAEAconnector:pangaea@1.0.0
spatialsource · PANGAEAconnector:pangaea@1.0.0
titlesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/title