scholarly journals Suspended sediment delivery to Puget Sound from the lower Nisqually River, western Washington, July 2010–November 2011

Author(s):  
Christopher A. Curran ◽  
Eric E. Grossman ◽  
Christopher S. Magirl ◽  
James R. Foreman
Radiocarbon ◽  
2015 ◽  
Vol 57 (5) ◽  
pp. 917-941 ◽  
Author(s):  
Ian Hutchinson

Surface-breaking ruptures on shallow crustal faults in the southern Puget Lowland in western Washington State about a millennium ago prompted abrupt changes in land level and triggered tsunamis in Puget Sound. The displacement on the Seattle fault most likely occurred in the 1050–1020 cal BP interval. Structures further south (the Tacoma and Olympia faults, and one or more faults in the southern Hood Canal zone) ruptured at about the same time, or slightly earlier. The low frequency of radiocarbon ages from archaeological sites in the region in the aftermath of the “millennial series” of earthquakes, when compared to bootstrapped samples from a database of 1255 ages from the Pacific Northwest as a whole, suggests that these very large earthquakes had significant socioeconomic consequences. The cultural record from coastal archaeological sites shows that although survivors camped on the shore in the aftermath, many coastal villages appear to have been abandoned, and were not reoccupied for several centuries. There is little evidence, however, to suggest that people migrated from southern Puget Sound to neighboring areas, and no evidence of social conflict in the adjacent areas that might have served as havens.


2018 ◽  
Vol 33 (4) ◽  
pp. 493-509 ◽  
Author(s):  
Amit Kumar ◽  
Akshaya Verma ◽  
Anupam Anand Gokhale ◽  
Rakesh Bhambri ◽  
Anshuman Misra ◽  
...  

2020 ◽  
Author(s):  
J. Jotautas Baronas ◽  
Edward T. Tipper ◽  
Michael J. Bickle ◽  
Robert G. Hilton ◽  
Emily I. Stevenson ◽  
...  

<p>A large portion of freshwater and sediment is exported to the ocean by just several of the world's major rivers. Many of these mega-rivers are under significant anthropogenic pressures, such as damming and sand mining, which are having a significant impact on water and sediment delivery to deltaic ecosystems. However, accurately measuring the total sediment flux and its mean physicochemical composition is difficult in large rivers due to hydrodynamic sorting of sediments. To account for this, we developed an updated semi-empirical Rouse modeling framework, which synoptically predicts sediment concentration, grain size distribution, and mean chemical composition (organic carbon wt%, Al/Si ratio) with depth and across the river channel.</p><p>We applied this model to derive new sediment flux estimates for the Irrawaddy and the Salween, the last two free-flowing mega-rivers in Southeast Asia, using a newly collected set of suspended sediment depth samples, coupled to ADCP-measured flow velocity data. Constructing sediment-discharge rating curves, we calculated an annual sediment flux of 326 (68% confidence interval of 256-417) Mt/yr for the Irrawaddy and 159 (109-237) Mt/yr for the Salween, together accounting for 2-3% of total global riverine sediment discharge. The mean flux-weighted sediment exported by the Irrawaddy is significantly coarser (D<sub>84</sub> = 193 ± 13 µm) and OC-poorer (0.29 ± 0.08 wt%) compared to the Salween (112 ± 27 µm and 0.59 ± 0.16 wt%, respectively). Both rivers export similar amounts of particulate organic carbon, with a total of 1.9 (1.0-3.3) Mt C/yr, contributing ~1% of the total riverine POC export to the ocean. These results underline the global significance of the Irrawaddy and Salween rivers and warrant continued monitoring of their sediment fluxes, given the increasing anthropogenic pressures on these river basins.</p>


2014 ◽  
Vol 50 (4) ◽  
pp. 3523-3535 ◽  
Author(s):  
Tapio Tuukkanen ◽  
Hannu Marttila ◽  
Bjørn Kløve

Author(s):  
Hamish Biggs ◽  
Arman Haddadchi ◽  
Murray Hicks

Aquatic vegetation, hydraulics and sediment transport have complex interactions that are not yet well understood. These interactions are important for sediment conveyance, sediment sequestration, phasing of sediment delivery from runoff events, and management of ecosystem health in lowland streams. To address this knowledge gap detailed field measurements of sediment transport through natural flexible aquatic vegetation are required to supplement and validate laboratory results. This paper contributes a field study of suspended sediment transport through aquatic vegetation and includes mechanical removal of aquatic vegetation with a weed cutting boat. It also provides methods to quantify vegetation cover through remote sensing with Unmanned Aerial Vehicles (UAVs) and estimate biomass from ground truth sampling. Suspended sediment concentrations were highly dependent on aquatic vegetation abundance, and the distance upstream that had been cleared of aquatic vegetation. When the study reach was fully vegetated (i.e. cover >80%), the maximum recorded SSC was 14.6 g/m (during a fresh with discharge of 2.47 m/s), during weed cutting operations SSC was 76.8 g/m at 0.84 m/s (weedcutting boat 0.5-1 km upstream from study reach), however following weed cutting operations (4.6 km cleared upstream), SSC was 139.0 g/m at a discharge of 1.52 m/s. The data indicates that fine sediment was being sequestered by aquatic vegetation and likely remobilised after vegetation removal. Investigation of suspended sediment spatial dynamics illustrated changes in particle size distribution due to preferential settling of coarse particles within aquatic vegetation. Hydraulic resistance in the study reach (parameterized by Manning’s n) dropped by over 70% following vegetation cutting. Prior to cutting hydraulic resistance was discharge dependent, while post cutting hydraulic resistance was approximately invariant of discharge. Aerial surveying captured interesting changes in aquatic vegetation cover, where some very dense regions of aquatic vegetation were naturally removed leaving behind unvegetated riverbed and fine sediment.


2018 ◽  
Vol 28 (6) ◽  
pp. 830-835 ◽  
Author(s):  
Michelle M. Moyer ◽  
Jaqueline King ◽  
Gary Moulton

The Puget Sound American Viticulture Area (AVA), located west of the Cascade Mountain Range in Washington State, is a large and uniquely situated area with diverse topography and mesoclimates. Given the young age of the AVA, little formal information exists on the appropriate rootstock–scion combination in wine grapes (Vitis vinifera) for the region. This project reports on a series of rootstock trials from 2003 to 2007, which evaluated the influence of ‘420A Millardet et de Grasset’, ‘3309 Couderc’, ‘101-14 Millardet et de Grasset’ (all Vitis hybrids), and a self-rooted control on basic harvest metrics of the wine grape scion ‘Pinot noir clone 02A’. At the warmer site in Everson, WA, rootstocks had no effect on final juice harvest metrics measured by soluble solids, titratable acidity (TA), and pH. At the cooler site in Mount Vernon, WA, the use of rootstocks did not always influence soluble solids or pH but did reduce final harvest TA, a desired effect for the region that is typified by low sugar–high TA wines. Even with a reduction in TA in some rootstock–scion combinations, overall, TA remained at the upper end or above the range typically desired for many wine styles.


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