scholarly journals Effects of River Discharge and Sediment Load on Sediment Plume Behaviors in a Coastal Region: The Yukon River, Alaska and the Bering Sea

Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 45
Author(s):  
Kazuhisa A. Chikita ◽  
Tomoyuki Wada ◽  
Isao Kudo ◽  
Sei-Ichi Saitoh ◽  
Mitsuhiro Toratani
Keyword(s):  
Suspended Sediment ◽  
Bering Sea ◽  
River Sediment ◽  
Sediment Load ◽  
Coastal Region ◽  
Bottom Layer ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Yukon River ◽  
The Bering Sea

In the Bering Sea around and off the Yukon River delta, surface sediment plumes are markedly formed by glacier-melt and rainfall sediment runoffs of the Yukon River, Alaska, in June– September. The discharge and sediment load time series of the Yukon River were obtained at the lowest gauging station of US Geological Survey in June 2006–September 2010. Meanwhile, by coastal observations on boat, it was found out that the river plume plunges at a boundary between turbid plume water and clean marine water at the Yukon River sediment load of more than ca. 2500 kg/s. Grain size analysis with changing salinity (‰) for the river sediment indicated that the suspended sediment becomes coarse at 2 to 5‰ by flocculation. Hence, the plume’s plunging probably occurred by the flocculation of the Yukon suspended sediment in the brackish zone upstream of the plunging boundary, where the differential settling from the flocculation is considered to have induced the turbid water intrusion into the bottom layer.

scholarly journals Behaviors of the Yukon River Sediment Plume in the Bering Sea: Relations to Glacier-Melt Discharge and Sediment Load

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2646
Author(s):  
Kazuhisa A. Chikita ◽  
Tomoyuki Wada ◽  
Isao Kudo ◽  
Sei-Ichi Saitoh ◽  
Toru Hirawake ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Surface Sediment ◽  
Bering Sea ◽  
River Sediment ◽  
Sediment Load ◽  
Satellite Image ◽  
Sediment Runoff ◽  
Yukon River ◽  
Glacier Melt ◽  
The Bering Sea

Sediment plumes, released to the Bering Sea from the delta front of the Yukon River, Alaska, are initiated mainly by glacier-melt sediment runoffs in the glacierized regions of the Yukon River drainage basin. The surface sediment plumes are extended around the fan-shaped Yukon River delta, which is followed by the northwestward dispersion. During continuous measurements of the Yukon River discharge and sediment load, behaviors of the sediment plumes were explored by shipboard and coastal observations in the Bering Sea. At the high river sediment load of ca. 2500 kg/s, the plume partially plunged into the sea bottom layer. The plunging probably originated in the nepheloid-layer formation from the flocculation of river-suspended sediment, of which more than 90% wt. is silt and clay (grain size d < 63 μm). In order to numerically obtain the area of the surface sediment plumes, a satellite image analysis was performed by using three near-infrared bands in MODIS/Aqua or MODIS/Terra. The plume area was significantly correlated (R2 = 0.735, p < 0.01) to the sediment load averaged for the two days with time lags of 20 days and 21 days to the date of a certain satellite image. Hence, the dispersion of plume-suspended sediment appears to be controlled by the sediment runoff events in the Yukon River rather than the northward “Alaskan Coastal Water”.

scholarly journals Behaviors of the Yukon River Sediment Plume in the Bering Sea: Relations to Glacier-Melt Discharge and Sediment Load

2021 ◽  
Author(s):  
Kazuhisa Augistine Chikita ◽  
Tomoyuki Wada ◽  
Isao Kudo ◽  
Sei-Ichi Saitoh ◽  
Toru Hirawake ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Surface Sediment ◽  
Bering Sea ◽  
River Sediment ◽  
Sediment Load ◽  
Satellite Image ◽  
Sediment Runoff ◽  
Yukon River ◽  
Glacier Melt ◽  
The Bering Sea

Sediment plumes, released to the Bering Sea from the delta front of the Yukon River, Alaska, are initiated mainly by glacier-melt sediment runoffs in the glacierized regions of the Yukon River drainage basin. The surface sediment plumes are extended around the fan-shaped Yukon River delta, which is followed by the northwestward dispersion. During continuous measure-ments of the Yukon River discharge and sediment load, behaviors of the sediment plumes were explored by shipboard observations in the Bering Sea offshore from the Yukon delta. At the high river sediment load of ca. 3000 kg/s, the plume partially plunged into the sea bottom layer. The plunging probably originated in the nepheloid-layer formation from the flocculation of river-suspended sediment, of which more than 90 %wt. is silt and clay (grain size d &lt; 0.063 mm). In order to numerically obtain the area of the surface sediment plumes, a satellite image analy-sis was performed by using three near-infrared bands in MODIS/Aqua or MODIS/Terra. The plume area was significantly correlated (R2=0.735, p&lt;0.01) to the sediment load averaged for the two days with time lags of 20 days and 21 days to the date of a certain satellite image. Hence, the dispersion of plume-suspended sediment appears to be controlled by the sediment runoff events in the Yukon River rather than the northward “Alaskan Coastal Water”.

scholarly journals Deglacial Land-Ocean Linkages at the Alaskan Continental Margin in the Bering Sea

2021 ◽  
Vol 9 ◽  
Author(s):  
Rong Wang ◽  
Gerhard Kuhn ◽  
Xun Gong ◽  
Boris K. Biskaborn ◽  
Rainer Gersonde ◽  
...  
Keyword(s):  
Bering Sea ◽  
Marked Change ◽  
Sediment Supply ◽  
Grain Size Analysis ◽  
Sediment Provenance ◽  
Size Analysis ◽  
Biological Productivity ◽  
Depositional History ◽  
Terrigenous Sediment ◽  
The Bering Sea

A marine sediment record from the central Bering Sea, spanning the last 20 thousand years (ka), was studied to unravel the depositional history with regard to terrigenous sediment supply and biogenic sedimentation. Methodic approaches comprised the inference of accumulation rates of siliciclastic and biogenic components, grain-size analysis, and (clay) mineralogy, as well as paleoclimatic modelling. Changes in the depositional history provides insight into land-ocean linkages of paleoenvironmental changes. During the finale of the Last Glacial Maximum, the depositional environment was characterized by hemipelagic background sedimentation. A marked change in the terrigenous sediment provenance during the late Heinrich 1 Stadial (15.7–14.5 ka), indicated by increases in kaolinite and a high glaciofluvial influx of clay, gives evidence of the deglaciation of the Brooks Range in the hinterland of Alaska. This meltwater pulse also stimulated the postglacial onset of biological productivity. Glacial melt implies regional climate warming during a time of widespread cooling on the northern hemisphere. Our simulation experiment with a coupled climate model suggests atmospheric teleconnections to the North Atlantic, with impacts on the dynamics of the Aleutian Low system that gave rise to warmer winters and an early onset of spring during that time. The late deglacial period between 14.5 and 11.0 ka was characterized by enhanced fluvial runoff and biological productivity in the course of climate amelioration, sea-level rise, seasonal sea-ice retreat, and permafrost thaw in the hinterland. The latter processes temporarily stalled during the Younger Dryas stadial (12.9-11.7 ka) and commenced again during the Preboreal (earliest Holocene), after 11.7 ka. High river runoff might have fertilized the Bering Sea and contributed to enhanced upper ocean stratification. Since 11.0 ka, advanced transgression has shifted the coast line and fluvial influence of the Yukon River away from the study site. The opening of the Bering Strait strengthened contour currents along the continental slope, leaving behind winnowed sand-rich sediments through the early to mid-Holocene, with non-deposition occurring since about 6.0 ka.

The plume of the Yukon River in relation to the oceanography of the Bering Sea

1989 ◽  
Vol 28 ◽  
pp. 75-84 ◽  
Author(s):  
Kenneson G. Dean ◽  
C.Peter McRoy ◽  
Kristina Ahlnäs ◽  
Alan Springer
Keyword(s):  
Bering Sea ◽  
Yukon River ◽  
The Bering Sea

Siphonaptera from mammals in Alaska. Supplement III. Western Alaska

1982 ◽  
Vol 60 (4) ◽  
pp. 729-732 ◽  
Author(s):  
Glenn E. Haas ◽  
Nixon Wilson ◽  
Randall L. Zarnke ◽  
Richard E. Barrett ◽  
Tim Rumfelt
Keyword(s):  
Bering Sea ◽  
Black Bear ◽  
Domestic Dog ◽  
The Arctic ◽  
Meadow Vole ◽  
Wild Mammals ◽  
Yukon River ◽  
New Localities ◽  
Sea Coast ◽  
The Bering Sea

Nineteen taxa of mammal fleas were recorded from 93 collections from western Alaska. Oropsylla alaskensis (Baker) and O. arctomys (Baker) are additions to this series of reports. The other 17 taxa were recorded from 71 new localities; 46 records were from remote localities. Many range extensions resulted and noteworthy were Ctenocephalides f. felis (Bouché) north to Fairbanks, Corrodopsylla c. curvata (Rothschild) west to the Bering Sea coast, Megabothris abantis (Rothschild) northwest to the lower Yukon River Valley, and Chaetopsylla tuberculaticeps (Bezzi) north of the Arctic Circle. Six hosts were not in our previous records: masked shrew, woodchuck, meadow vole, collared lemming, black bear, and wolverine. In all, 14 species of wild mammals, domestic dog and cat, and man were recorded hosts. Records from bat roosts were included.

Sign in / Sign up

Export Citation Format

Share Document