Archive · dataset · 2009
High resolution color reflectance and hematite and goethite record of ODP Hole 184-1143A in the South China Sea
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Precipitation has a larger variability than temperature in tropical monsoon regions, thus it is an important climate variable.
Description
However, reconstructions of long-term rainfall histories are scarce because of the lack of reliable proxies. Here we document that iron oxide minerals, specifically the ratio of hematite to goethite (Hm/Gt), is a reasonable precipitation proxy.
Using diffuse reflectance spectrophotometry, we measured samples from Ocean Drilling Program (ODP) 1143 drilling site (9°21.72'N, 113°17.11'E, 2777 m water depth) for hematite and goethite, whose formation processes are favored by opposing climate conditions. In order to determine the content of hematite and goethite we produced a set of calibration samples by removing the iron oxides to generate the natural matrix to which hematite and goethite in known percentages were added.
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From these calibration samples we developed a transfer function for determining hematite and goethite concentration from a sample's spectral reflectance. Applying this method to ODP 1143 sediments (top 34 m of a 510 m core with sampling interval of 10 cm) we were able to reconstruct a continuous precipitation history for SE Asia of the past 600 kyr using the Hm/Gt ratio as a proxy of the precipitation variability of Asian monsoon.
The reliability of this Hm/Gt proxy is corroborated by its consistency with the stalagmite delta18O data from South China. Comparing long-term Hm/Gt records with the surface temperature gradient of equatorial Pacific Ocean, we found that monsoon precipitation and El Niño are correlated for the last 600 kyr. The development of El Niño-like conditions decreased SE Asia precipitation, whereas precipitation increases in response to La Niña intensification
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Catalogue records · 1
- OAI-PMH record oai.datacite.org/oai?verb=GetRecord&metadataPrefix=oai_dc&identifier=doi%3A10.1… ↗
metadata API · from gigadb org
Topics
- From keywords
- Earth & Environmental Science · Ocean & Atmospheric Science
Related
Provenance · 1 source records, 7 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| GigaDB | doi:10.1594/pangaea.712911 | 23 h ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · gigadb org | connector:gigadb_org@1.0.0 | |
| concepts[field].local:field:earth-environmental | mapping · gigadb org | connector:gigadb_org@1.0.0 | |
| concepts[field].local:field:ocean-atmospheric | mapping · gigadb org | connector:gigadb_org@1.0.0 | |
| description | source · gigadb org | connector:gigadb_org@1.0.0 | /metadata/dc/description |
| license | source · gigadb org | connector:gigadb_org@1.0.0 | /metadata/dc/rights |
| publication_date | source · gigadb org | connector:gigadb_org@1.0.0 | |
| title | source · gigadb org | connector:gigadb_org@1.0.0 | /metadata/dc/title |