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Reconstrucción de la Cuenca del Amazonas disponibilidad efectiva de humedad durante los últimos 14.000 años
1Environmental Change Research Centre, Department of Geography, University College London, 26 Bedford Way, London, WC1H 0AP, UK. mmaslin@geog.ucl.ac.uk
Science (New York, N.Y.)
|December 23, 2000
Resumen
La cuenca del Amazonas experimentó una severa sequía hace 14.000 años, reduciendo la descarga del río en un 40%. Después de la sequía, la humedad efectiva aumentó constantemente a lo largo de la época del Holoceno.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Hidrología Hidrología Hidrología.
- Oceanografía La oceanografía es la oceanografía.
Sus antecedentes:
- Comprender la historia de la humedad de la cuenca del Amazonas es crucial para la biodiversidad de la selva y el ciclo del metano.
- La reconstrucción de los cambios hidrológicos pasados informa las evaluaciones de impacto del cambio climático.
Objetivo del estudio:
- Para reconstruir la historia del flujo de salida del río Amazonas en los últimos 14.000 años.
- Para establecer un presupuesto de humedad para la cuenca de drenaje del río Amazonas.
Principales métodos:
- Análisis de la composición isotópica del oxígeno en los foraminíferos planctónicos.
- Examen de un núcleo de sedimentos marinos de la región de descarga del río Amazonas.
Principales resultados:
- La cuenca del Amazonas fue excepcionalmente seca durante el período Younger Dryas.
- La descarga fluvial se redujo en al menos un 40% en comparación con los niveles actuales.
- Un evento de agua de deshielo posterior al Dryas Joven fue seguido por un aumento constante de la humedad en el Holoceno.
Conclusiones:
- El Younger Dryas tuvo un impacto significativo en los niveles de humedad de la cuenca del Amazonas.
- El calentamiento del Holoceno condujo a una recuperación gradual y al aumento de la humedad efectiva.
- Estos hallazgos proporcionan información sobre la dinámica climática a largo plazo y la resiliencia de los ecosistemas.
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