Influencia de la geometría glaciar en los cambios de Campos de Hielo de la Patagonia
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Date
2024
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Universidad de Concepción
Abstract
El cambio climático está provocando una disminución de los glaciares en todo el mundo, con la posibilidad de que algunos desaparezcan durante este siglo. Hallazgos recientes postulan que la configuración geométrica glaciar-topografía tiene la capacidad de limitar el adelgazamiento de los glaciares flujo arriba. Los Campos de Hielo de la Patagonia, con 15.900 km² de glaciares, son la mayor reserva glaciar de agua dulce del mundo después de la Antártica y Groenlandia. En las últimas décadas, ha sido una de las zonas con mayor pérdida de masa en todo el mundo debido al cambio climático. En este trabajo se explora la relación entre la geometría de los glaciares y los cambios en Campos de Hielo de la Patagonia para determinar las regiones vulnerables al adelgazamiento. Se estudiaron los 45 principales glaciares terminan en mar y lagos utilizando el número de Péclet (Pe) basado en el modelo de onda cinemática difusiva para determinar el estado geométrico de los glaciares y como medida de vulnerabilidad al adelgazamiento difusivo. Las localizaciones con Pe ≤ 8 experimentaron un mayor adelgazamiento y retroceso, lo que sugiere un límite empírico que abarca más del 90% del adelgazamiento. El límite empírico está relacionado con un cambio significativo en el gradiente de pendiente y rugosidad de la topografía subglacial. De media, el ~53% del flujo total de hielo de los glaciares está por debajo del límite de adelgazamiento. El límite de adelgazamiento empírico proporciona señales de glaciares prioritarios a investigar teniendo en cuenta las proyecciones actuales de cambio climático.
Climate change is causing a decline in glaciers worldwide, with the possibility that some may disappear during this century. Recent findings postulate that the geometric glacier-topography configuration has the capacity to limit upstream glacier thinning. The Patagonian Icefields, with 15,900 km² of glaciers, are the largest glacial freshwater reservoir in the world after Antarctica and Greenland. In recent decades, it has been one of the areas with the greatest mass loss worldwide due to climate change. This study explores the relationship between glacier geometry and changes in the Patagonian Icefields to determine regions vulnerable to thinning. The 45 main marine- and lake-terminating glaciers were studied using the Péclet number (Pe) based on the diffusive kinematic wave model to determine the geometric state of glaciers and as a measure of vulnerability to diffusive thinning. Locations with Pe ≤ 8 experienced greater thinning and retreat, suggesting an empirical limit that encompasses more than 90% of thinning. The empirical limit is related to a significant change in the gradient of slope and roughness of the subglacial topography. On average, ~53% of the total glacier ice flow is below the thinning limit. The empirical thinning limit provides signals of priority glaciers to investigate given current climate change projections.
Climate change is causing a decline in glaciers worldwide, with the possibility that some may disappear during this century. Recent findings postulate that the geometric glacier-topography configuration has the capacity to limit upstream glacier thinning. The Patagonian Icefields, with 15,900 km² of glaciers, are the largest glacial freshwater reservoir in the world after Antarctica and Greenland. In recent decades, it has been one of the areas with the greatest mass loss worldwide due to climate change. This study explores the relationship between glacier geometry and changes in the Patagonian Icefields to determine regions vulnerable to thinning. The 45 main marine- and lake-terminating glaciers were studied using the Péclet number (Pe) based on the diffusive kinematic wave model to determine the geometric state of glaciers and as a measure of vulnerability to diffusive thinning. Locations with Pe ≤ 8 experienced greater thinning and retreat, suggesting an empirical limit that encompasses more than 90% of thinning. The empirical limit is related to a significant change in the gradient of slope and roughness of the subglacial topography. On average, ~53% of the total glacier ice flow is below the thinning limit. The empirical thinning limit provides signals of priority glaciers to investigate given current climate change projections.
Description
Tesis presentada para optar la grado de Magíster en Ingeniería Agrícola
Keywords
Glaciares - Chile, Cambio climático