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Cambio de dirección del flujo de hielo en el interior de la Antártida Occidental
Martin J Siegert1, Brian Welch, David Morse
1Centre for Polar Observation and Modelling, Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK. m.j.siegert@bristol.ac.uk
Science (New York, N.Y.)
|September 28, 2004
Resumen
Un único pliegue de hielo cerca de la estación Byrd sugiere cambios pasados en el flujo de hielo en la Antártida Occidental. Este hallazgo indica que el centro de la Antártida Occidental puede ser más sensible a futuras alteraciones de las corrientes de hielo de lo que se entendía anteriormente.
Área de la Ciencia:
- Glaciología glaciología.
- La geofísica es la geofísica.
- Investigación en la Antártida Investigación antártica.
Sus antecedentes:
- El radar de penetración de hielo revela estructuras de pliegues inusuales debajo de la capa de hielo de la Antártida Occidental.
- Las capas de hielo isócronas se encuentran en niveles inusualmente profundos dentro de esta estructura de pliegue.
Objetivo del estudio:
- Investigar la formación de una estructura de pliegue distintivo en el hielo cerca de la estación Byrd.
- Reconstruir las dinámicas pasadas del flujo de hielo en la Antártida Occidental.
Principales métodos:
- Análisis de datos de radar de penetración en el hielo.
- Interpretación de los isócronos de la capa de hielo y la orientación del eje del pliegue.
- Modelado de la dinámica del flujo de hielo.
Principales resultados:
- Se identificó una gran estructura de pliegue (>50 km de largo), con su eje orientado hasta 45 grados a la dirección actual del flujo de hielo.
- La formación del pliegue es difícil de explicar con el flujo de hielo actual.
- Un régimen de flujo pasado, paralelo al eje del pliegue hace aproximadamente 1500 años, puede explicar la estructura observada.
Conclusiones:
- Los cambios pasados en la dinámica del flujo de hielo en la Antártida Occidental son evidentes en las estructuras subglaciales.
- Estos cambios en el flujo pueden estar relacionados con alteraciones en las corrientes de hielo más cercanas a la costa antártica.
- El hielo del centro oeste de la Antártida puede ser más sensible a los cambios futuros de lo que se suponía anteriormente, lo que afecta las proyecciones de aumento del nivel del mar.
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