The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberings00hood Year: 1981 BERING SEA SCOUR DEPRESSION EXTENSIVE AREA OF SCOUR RIPPLE BEDFORMS ZONE OF MEAN BOTTOM CURRENT >20 cm/sec ZONE OF STORM SAND LAYERS, I-20 cm thick 00 Km 164 162 Figure 15-6. Location of scour depressions, extensive scour and ripple zones, and strong bottom currents in Norton Sound, showing area of storm sand deposition (modified from Larsen et al. 1979b). from the obstruction (Young and Southard 1978). The large scour depressions observed in Norton S
The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberings00hood Year: 1981 BERING SEA SCOUR DEPRESSION EXTENSIVE AREA OF SCOUR RIPPLE BEDFORMS ZONE OF MEAN BOTTOM CURRENT >20 cm/sec ZONE OF STORM SAND LAYERS, I-20 cm thick 00 Km 164 162 Figure 15-6. Location of scour depressions, extensive scour and ripple zones, and strong bottom currents in Norton Sound, showing area of storm sand deposition (modified from Larsen et al. 1979b). from the obstruction (Young and Southard 1978). The large scour depressions observed in Norton Sound may be a characteristic erosional bedform developed during storms when strong currents and high wave energy are focused on silt-covered slopes where local topographic disruptions set off flow separation and downcurrent scour. Sandwaue dynamics Strong geostrophic currents prevail throughout much of the northern Bering Sea, particularly where westward land projects into the northward flow, as in the eastern Bering Strait area (Fleming and Heggarty 1966, Coachman et al. (1975). In such regions large bedforms develop and migrate, forming an unstable sea floor (Nelson et al. 1978a). These large bedforms include large-scale sand waves 1-2 m high with wavelengths to 200 m, and small-scale sand waves m high with wavelengths of 10 m. They occupy the crests and some flanks of a series of linear sand ridges 2-5 km wide and as much as 20 km long between Port Clarence and King Island. Sand-wave movement and bedload transport take place during calm weather (Nelson et al. 1978a), but maximum change apparently occurs when severe southwesterly storms generate sea-level setup in the eastern Bering Sea that enhances northerly currents. In contrast, strong north winds from the Arctic reduce the strength of the northerly currents and thereby arrest bedform migration. Sediment gas charging The distribution of acoustic anomalies suggests that almost 7,000 km^ of sea floor in Norton Sound
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