Cauldron subsidence and subglacial floods
نویسنده
چکیده
Ice cauldrons are depressions which form at the surface of ice sheets when an underlying subglacial lake empties. Notable examples of such cauldrons occur on the surface of the Vatnajökull ice cap in Iceland, and in particular are formed when subglacial volcanic eruptions occur. More generally, cauldrons will form when a subglacial lake empties during a jökulhlaup. The rate of subsidence of the ice surface is related to the rate at which the subglacial water empties from the lake. We use a viscous version of classical beam theory applied to the ice sheet to determine the relation between the subsidence rate and flood discharge, and we use the results to make inferences concerning ring fracture spacings in cauldrons, the consequent effect on flood discharge dynamics, and the likely nature of subsidence events in the Antarctic Ice Sheet.
منابع مشابه
Circulation and thermodynamics in a subglacial geothermal lake under the Western Skaftá cauldron of the Vatnajökull ice cap, Iceland
[1] The subglacial, geothermal lake beneath the Western Skaftá cauldron (depression) in the Vatnajökull ice cap, Iceland, was accessed by hot water drilling through the overlying 300 m-thick ice shelf. Most of the ca. 100-m water column was near 4.7 C, but was underlain by a distinct 10 m-deep water mass at 3.5 C. The sensible heat content of the lake water is approximately twice the potential ...
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Discharge and water temperature measurements in the Skaftá river and measurements of the lowering of the ice over the subglacial lake at the western Skaftá cauldron, Vatnajökull, Iceland, were made during a rapidly rising glacial outburst flood (jökulhlaup) in September 2006. Outflow from the lake, flood discharge at the glacier terminus and the transient subglacial volume of floodwater during ...
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The temporary storage and subsequent release of water at glacial margins can cause severe flooding in downstream areas and substantially impact glacier dynamics. Alpine subglacial lakes may not be identified until they become subaerially exposed or release a jökulhlaup. We use interferometric synthetic aperture radar (InSAR) to identify and characterize three dynamic alpine subglacial lakes of ...
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The occurrence trend of floods in recent years shows that the most of Iran regions located in attacks of destructive floods and loss of life and property of flood damages is increasing. Watershed management practices (WMPs) are one of the superior and appropriate solutions for flood hazards mitigation. The impact of WMPs can be investigated using different approaches. In this study, the direct ...
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The recognition of remnants of large cauldron subsidence complexes along the trend of the Skeena Arch first occurred in the Tahtsa Lake area (MacIntyre, 1985). In subsequent years, evidence for other large subsidence complexes was documented in the Rocher DeBoule, Babine Mountains, Buck Creek and Babine Lake areas (MacIntyre, 2001; Church and Barakso, 1990). Originally all of these structures w...
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