temperate and Arctic regions
epeat multibeam surveys of the prodelta slope of fjord deltas are used to monitor and compare the temporal evolution of the surficial morphology. Six multibeam surveys of the temperate Squamish River Delta, over a period of 4 years, illustrate the cyclic evolution of the feeder gullies, axial channe...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.466.8 http://www.omg.unb.ca/omg/papers/JHC_Lerici_for_Web.pdf |
| Summary: | epeat multibeam surveys of the prodelta slope of fjord deltas are used to monitor and compare the temporal evolution of the surficial morphology. Six multibeam surveys of the temperate Squamish River Delta, over a period of 4 years, illustrate the cyclic evolution of the feeder gullies, axial channels, and distributary lobes. The temporal evolution clearly indicates that slope–transverse undulations are upslope-migrating bedforms, rather than slope creep phenomena. A second monitoring program has been initiated using the same methods but in the fjords of Baffin Island. Maintaining the same survey accuracy at high latitudes is much more difficult due to low satellite geometries and lack of precise vertical control. Introduction. Fjord deltas usually represent sites of enhanced sedimentation and mass wasting. The main depocentres usually lie within a few kilometres of the river mouth at depths of 100-200 m, and are therefore readily accessible by surface-mounted multibeam sonars. The time scales of morphological evolution are short, with measurable annual change. As such, they represent useful small-scale analogs for much less frequent, deeper-water mass wasting environments. The physical processes active on a fjord delta reflect both the volume and type of input |
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