Using the recent available geoscience technology, the research studies the physical processes and change to a glacier outburst flood (jökulhlaup) in western Greenland.
Glacial lakes can form behind moraine dams (at the glacier terminus) or ice-dams (at the glacier margin), on glaciers themselves, or behind glaciers that advance across main river valleys.
Outburst floods from glacial lakes are thought to be increasing in magnitude and frequency in line with a warming climate and ice recession.
Currently, ice-dammed lakes are particularly vulnerable to outburst because of the reduction in height and stability of the (melting) dam structure. In many regions, such floods are known as jökulhlaups, a term that originated in Iceland to describe volcanic-glacial floods, but is now used rather more generally to describe any glacier-related outburst.
Jökulhlaups can occur without warning, such as when large volumes of meltwater are trapped sub- or en-glacially; others are more predictable, such as when an annual cycle of filling and drainage occurs.
Structure from Motion
The technique of Structure from Motion has come to prominence in the geosciences in the last five years, and offers a surveying solution to the coarse-resolution problem.
Using theory originally developed to aid in computer vision, it is now possible to create very fine resolution 3D topographic data using imagery acquired by consumer-grade digital cameras, and freely-available open-source software.
The resulting point-clouds are comparable in density and in accuracy to those generated by terrestrial laser scanning, and when decimated to 2D data, offer several orders of magnitude more spatial detail than has previously been available. A glacier outburst flood in western Greenland was the case-study.
This gives surveyors, scientists and enthusiasts alike the opportunity to study physical processes on the centimetre-decimetre scale, and also to model extreme flood events with much greater accuracy.
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