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Balance de masa positivo de las corrientes de hielo de Ross, Antártida Occidental
1Jet Propulsion Laboratory, California Institute of Technology, Mailstop 300-235, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. ian@radar-sci.jpl.nasa.gov
Science (New York, N.Y.)
|January 19, 2002
Resumen
Una nueva investigación sobre las corrientes de hielo de Ross en la Antártida Occidental revela un crecimiento significativo de la capa de hielo, no un déficit. Esta reevaluación del equilibrio de masas de las capas de hielo sugiere un posible final del retroceso del Holoceno de estas cruciales corrientes de hielo antártico.
Área de la Ciencia:
- Glaciología glaciología.
- Ciencias del clima Ciencias del clima Ciencias del clima
- La detección remota con sensores.
Sus antecedentes:
- El equilibrio de masas de las capas de hielo de la Antártida es fundamental para comprender el aumento global del nivel del mar.
- Las estimaciones anteriores sugirieron un balance de masa negativo para las corrientes de hielo de Ross, lo que indica la pérdida de hielo.
Objetivo del estudio:
- Para reevaluar el equilibrio de masas de las corrientes de hielo de Ross utilizando mediciones avanzadas de velocidad de flujo de hielo.
- Para investigar el estado actual y los cambios recientes en la estabilidad de estas principales corrientes de hielo de la Antártida Occidental.
Principales métodos:
- Se utilizó un radar de apertura sintética (SAR) para obtener mediciones precisas de la velocidad de flujo del hielo.
- Los datos de velocidad analizados para calcular los cambios en el volumen de hielo y determinar el balance de masas.
Principales resultados:
- Fuertes evidencias indican un crecimiento global de las capas de hielo de +26,8 gigatoneladas por año, lo que contradice las estimaciones previas de un déficit.
- Se observó un engrosamiento promedio de aproximadamente el 25% de la tasa de acumulación, principalmente en la corriente de hielo C.
- La Corriente de Hielo de Whillans está cerca del equilibrio, contrariamente a las expectativas de una pérdida de masa significativa, debido a su desaceleración.
Conclusiones:
- Las corrientes de hielo de Ross están ganando masa, lo que sugiere un balance de masa positivo.
- Este crecimiento puede significar una transición lejos de la retirada a largo plazo observada durante la época del Holoceno.
- Los hallazgos destacan la naturaleza dinámica de las corrientes de hielo de la Antártida y la importancia de los datos de observación actualizados.
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