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Otolith delta 18O registro de las temperaturas de la superficie del mar a mediados del Holoceno en Perú
C Fred T Andrus1, Douglas E Crowe, Daniel H Sandweiss
1Department of Geology, University of Georgia, Athens, GA 30602-2501, USA. andrus@gly.uga.edu
Science (New York, N.Y.)
|February 23, 2002
Resumen
A mediados del Holoceno, las temperaturas de la superficie del mar en Perú eran más cálidas, como lo demuestran los otolitos de peces. Esta tendencia al calentamiento, junto con la intensificación de la subida, ofrece información sobre los cambios climáticos pasados.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Biología Marina Biología Marina.
- Ictiología Ictiología.
Sus antecedentes:
- Los otolitos de peces, específicamente los otolitos sagitales del bagre de mar peruano (Galeichthys peruvianus), sirven como valiosos archivos para reconstruir las condiciones ambientales pasadas.
- El análisis de isótopos de oxígeno de otolitos proporciona un sustituto para determinar las temperaturas pasadas de la superficie del mar (SST).
Objetivo del estudio:
- Para reconstruir las temperaturas de la superficie del mar (SST) de mediados del Holoceno frente a la costa del Perú utilizando análisis de isótopos de oxígeno de otolitos de peces.
- Investigar correlaciones potenciales entre SSTs pasadas, niveles tróficos y fenómenos oceanográficos como el upwelling.
Principales métodos:
- Excavación y análisis de otolitos sagitales de bagre de mar peruano (Galeichthys peruvianus) de yacimientos arqueológicos (Ostra y Siches).
- Perfilado de isótopos de oxígeno de otolitos para determinar SSTs pasadas.
- Análisis del nivel trófico, la diversidad de la población y la equidad de los conjuntos faunísticos asociados.
Principales resultados:
- Otolitos de Ostra (6010 +/- 90 años B.P.) que se encuentran en la región de Ostra. indicado verano SSTs aproximadamente 3 ° C más cálido que el presente.
- Otolitos de las Siches (6450 +/- 110 años BP) Las temperaturas medias anuales registradas son de 3°C a 4°C más cálidas que las condiciones modernas.
- Los datos de la fauna apoyaron las interpretaciones isotópicas y sugirieron una intensificación de la corriente ascendente de Perú-Chile después de aproximadamente 5000 años B.P.
Conclusiones:
- A mediados del Holoceno, las aguas costeras peruanas experimentaron temperaturas de la superficie del mar significativamente más cálidas en comparación con las actuales.
- La intensificación de la corriente ascendente Perú-Chile después de 5000 años B.P. probablemente influyó en estos cambios de temperatura.
- Los otolitos de peces son registradores confiables de las condiciones oceanográficas y climáticas pasadas en la región.
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