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Vulnerabilidad de las plataformas de hielo de la Antártida a la fractura provocada por el agua de deshielo
Ching-Yao Lai1, Jonathan Kingslake2,3, Martin G Wearing4
1Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA. cylai@ldeo.columbia.edu.
Nature
|August 28, 2020
Resumen
El calentamiento atmosférico pone en riesgo el colapso de la plataforma de hielo antártica a través de la fractura hidráulica. Un nuevo estudio revela que el 60% de las plataformas de hielo de refuerzo son vulnerables a este proceso si el agua de deshielo las inunda, lo que podría acelerar el aumento del nivel del mar.
Área de la Ciencia:
- Glaciología
- Ciencias del clima
- La geofísica
Sus antecedentes:
- El calentamiento atmosférico aumenta el derretimiento de la superficie, lo que representa una amenaza para las plataformas de hielo antárticas a través de la fractura hidráulica.
- La fractura hidráulica, donde el agua de deshielo agranda las fracturas, puede conducir al colapso de la plataforma de hielo, acelerando el flujo de hielo y el aumento del nivel del mar.
- La vulnerabilidad de las regiones de la plataforma de hielo antártica a la hidrofractura sigue siendo en gran medida desconocida.
Objetivo del estudio:
- Evaluar la vulnerabilidad de las regiones de refuerzo de la plataforma de hielo antártica a la hidrofractura.
- Identificar áreas específicas en riesgo de inestabilidad inducida por la hidrofractura.
Principales métodos:
- Entrenó una red neuronal convolucional profunda (DCNN) para mapear las fracturas superficiales en las plataformas de hielo antárticas utilizando imágenes satelitales.
- Desarrolló un diagrama de estabilidad de fractura basado en la mecánica de fractura elástica lineal para predecir la formación de fracturas.
- Teoría aplicada de la mecánica de la fractura para predecir la inestabilidad bajo escenarios de inundación de agua.
Principales resultados:
- Un DCNN mapeó con éxito fracturas, mostrando acuerdo con las predicciones teóricas.
- El 60% ± 10% de las plataformas de hielo antárticas que sustentan la capa de hielo son vulnerables a la hidrofractura si se inundan con agua.
- Se identificaron regiones vulnerables generalizadas en las que el aumento de la fusión superficial podría desencadenar la fractura hidráulica.
Conclusiones:
- Muchas regiones de la plataforma de hielo antártica son vulnerables a la hidrofractura, a pesar de la resistencia actual al agua de deshielo.
- El aumento del derretimiento de la superficie debido al calentamiento atmosférico podría inundar estas áreas vulnerables, provocando inestabilidad.
- Estas regiones vulnerables representan áreas críticas donde el cambio climático puede afectar significativamente el equilibrio de masa de las capas de hielo y el aumento del nivel del mar.
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