P. Soupy Dalyander
Joseph W. Long
Nathaniel G. Plant
David M. Thompson
2012
Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Ratio of the wave- and current-induced shear stress to the critical value for oil-tar balls and sediment mobilization over a tidal cycle
1.0
vector digital data
U.S. Geological Survey Open-File Report
2012-1234
St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
U.S. Geological Survey, Coastal and Marine Geology Program
https://pubs.usgs.gov/of/2012/1234/datafiles.html
Nathaniel G. Plant
Joseph W. Long
P.Soupy Dalyander
David M. Thompson
2012
Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance
1.0
U.S. Geological Survey Open-File Report
2012-1234
St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL
U.S. Geological Survey, Coastal and Marine Geology Program
https://pubs.usgs.gov/of/2012/1234/
The U.S. Geological Survey has developed a method for estimating the mobility and potential alongshore transport of heavier-than-water sand and oil agglomerates (tarballs or surface residual balls, SRBs). During the Deepwater Horizon spill, some oil that reached the surf zone of the northern Gulf of Mexico mixed with suspended sediment and sank to form sub-tidal mats. If not removed, these mats can break apart to form SRBs and subsequently re-oil the beach. A method was developed for estimating SRB mobilization and alongshore movement. A representative suite of wave conditions was identified from buoy data for April, 2010, until August, 2012, and used to drive a numerical model of the spatially-variant alongshore currents. Potential mobilization of SRBs was estimated by comparing combined wave- and current-induced shear stress from the model to critical stress values for several sized SRBs. Potential alongshore flux of SRBs was also estimated to identify regions more or less likely to have SRBs deposited under each scenario. This methodology was developed to explain SRB movement and redistribution in the alongshore, interpret observed re-oiling events, and thus inform re-oiling mitigation efforts.
This GIS layer contains an estimate of the ratio of combined wave- and current- induced shear stress in the shallow northern Gulf of Mexico (Alabama and portion of the Florida coast) to the critical stress of surface residual balls (SRB) of various sizes and local sediment. This layer is part of a series of data layers (naming convention Tidal_mobility_TT.xxx, where TT is an hourly time step and is also indicated in attributes within the file) demonstrating the variability with tidal fluctuations in this ratio for a fixed set of wave conditions over a 24 hour period. The wave conditions in the file correspond to waves at NOAA NDBC buoy 42040 of between 1.5-2 m, coming from between 135-157.50 degrees relative to north (corresponding to scenario H4_D7 in the included wave_scenarios.txt file). The time steps (e.g., HH in the file names) of maximum flood and maximum ebb for various inlets in the domain are indicated in the included inlet_flood_ebb_tides.txt. Values greater than one indicate the threshold for incipient motion is exceeded, and the SRB or sediment is likely mobilized. Characteristics of SRB classes and the sediment properties used may be found in the look-up table included in the GIS zip file, SRB_casses.txt. This data layer is intended to show regions of likely mobilization for intended use by individuals in SRB mitigation attempting to explain redistribution or burial of SRBs, and displays variability over a tidal cycle.
This data layer is a subset of USGS Open-File Report 2012-1234, Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance. This layer is part of a series of data layers (naming convention Tidal_mobility_TT.xxx, where TT is an hourly time step, ranging from 1 to 24, and is also indicated in attributes within the file) demonstrating the variability with tidal fluctuations in this ratio for a fixed set of wave conditions over a 24 hour period. The wave conditions in the file correspond to waves at NOAA NDBC buoy 42040 of between 1.5-2 m, coming from between 135-157.50 degrees relative to north (corresponding to scenario H4_D7 in the included wave_scenarios.txt file). SRB class and sediment properties may be found in the look-up table included in the GIS zip file, SRB_casses.txt. The time steps (e.g., HH in the file names) of maximum flood and maximum ebb for various inlets in the domain are indicated in the included inlet_flood_ebb_tides.txt.
20100401
20120801
ground condition
As needed
-88.715420
-85.412233
30.692506
29.405594
USGS Metadata Identifier
USGS:19233989-3ed6-4030-a223-020d37e5024b
None
bottom shear stress
U.S. Geological Survey
USGS
Woods Hole Coastal and Marine Science Center
WHCMSC
Coastal and Marine Geology Program
CMGP
wave
current
Delft3D
St. Petersburg Coastal and Marine Science Center
SPCMSC
tarballs
surface residual balls
SRBs
sediment mobility
surf zone
alongshore currents
wave-driven currents
oceans and estuaries
oceans and coastal
ISO 19115 Topic Category
oceans
environment
geoscientificInformation
Data Categories for Marine Planning
predictions
physical/chemical features
Marine Realms Information Bank (MRIB) Keywords
coastal processes
numerical modeling
pollution
petroleum spills
USGS Thesaurus
coastal processes
contaminant transport
industrial pollution
mathematical modeling
ocean processes
petroleum
Geographic Names Information System
Gulf of Mexico
Florida
Alabama
United States
North America
Atlantic Ocean
Mobile Bay
Pensacola Bay
Choctawhatchee Bay
Santa Rosa
Fort Pickens
Gulf Shores
Panama City
Little Lagoon
None
seafloor
None
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
P. Soupy Dalyander
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
(508) 548-8700 x2290
(508) 457-2310
sdalyander@usgs.gov
model_bathymetry.jpg
Graphic showing the numerical model domain over which analysis is conducted.
JPEG
Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095
The attributes in this layer are the ratio of combined wave-current shear stress to critical stress for sediment and several sized SRBs. This layer is part of a series of data layers (naming convention Tidal_mobility_HH.xxx, where HH is an hourly time step, ranging from 1 to 24, and is also indicated in attributes within the file) demonstrating the variability with tidal fluctuations in this ratio for a fixed set of wave conditions over a 24 hour period. The wave conditions in the file correspond to waves at NOAA NDBC buoy 42040 of between 1.5-2 m, coming from between 135-157.50 degrees relative to north (corresponding to scenario H4_D7 in the included wave_scenarios.txt file). SRB class and sediment properties may be found in the look-up table included in the GIS zip file, SRB_casses.txt. Statistical values will vary if a different numerical model is used for the hydrodynamics, or if a different method is used in calculating wave-current stress or critical stress.
No duplicate features are present. All polygons are closed, and all lines intersect where intended. No undershoots or overshoots are present.
This statistic was calculated at all locations (wet grid cells) where model output exists. Because of differences between the scenarios, not all grid cells may be included in all scenarios. This layer is part of a series of data layers (naming convention Tidal_mobility_TT.xxx, where TT is an hourly time step, ranging from 1 to 24, and is also indicated in attributes within the file) demonstrating the variability with tidal fluctuations in this ratio for a fixed set of wave conditions over a 24 hour period. The wave conditions in the file correspond to waves at NOAA NDBC buoy 42040 of between 1.5-2 m, coming from between 135-157.50 degrees relative to north (corresponding to scenario H4_D7 in the included wave_scenarios.txt file). SRB class and sediment properties may be found in the look-up table included in the GIS zip file, SRB_casses.txt. The bottom shear stress was calculated from wave and current estimates generated with Delft3D, and would vary if different models were used or if different model inputs (such as bathymetry, forcing winds, and boundary conditions) or parameterizations were chosen. Calculated currents were depth-averaged and therefore the calculated mobility values are expected to be most valid in well-mixed regions, e.g., the surf zone. Mobility estimates would vary for different size or density objects and/or if a different formulation for calculating the critical stress value is used.
Numerical models are used in the generation of hydrodynamic conditions used in creating this data layer. Because the overall horizontal accuracy of the data set depends on the accuracy of the model, the underlying bathymetry, forcing values used, and so forth, the spatial accuracy of this data layer cannot be meaningfully quantified.
NOAA National Centers for Environmental Prediction (NCEP)
20110601
NOAA/NCEP Global Forecast System (GFS) Atmospheric Model
Camp Springs, MD
NOAA National Centers for Environmental Prediction
http://nomads.ncdc.noaa.gov/data.php
online
20100401
20120531
publication date
NOAA GFS
Wind speed data at 10 m above the sea surface from the NOAA Global Forecast System (GFS) 0.5 degree model is interpolated by NOAA to the 4' Wavewatch3 grid and archived. These archived data are used to drive the numerical wave and circulation model that creates estimated of bottom shear stress.
NOAA National Centers for Environmental Prediction (NCEP
20121001
NOAA/NWS/NCEP 4' Wavewatch III Operational Wave Forecast
Camp Springs, MD
NOAA National Centers for Environmental Prediction
http://polar.ncep.noaa.gov/waves/index2.shtml
online
20100401
20120531
publication date
NOAA WW3
Boundary conditions for the wave model were provided by the 4' NOAA/NWS/NCEP Wavewatch III operational ocean wave forecast.
Gary Egbert
Lana Erofeeva
20120801
The OSU TOPEX/Poseidon Global Inverse Solution TPXO
model
Corvallis, OR
Oregon State University
http://volkov.oce.orst.edu/tides/global.html
online
20100401
20120817
publication date
TPXO Tides
The OSU TOPEX/Poseidon tidal prediction software package and associated data were used to develop a prediction of the tides at the offshore boundaries of the model domain in order to compute the phase lags between the two corners.
National Oceanic and Atmospheric Administration
20120801
Dauphin Island, AL, Tide Gauge Data (Station 8735180)
tabular digital data
Silver Spring, MD
NOAA Center for Operational Oceanographic Products and Services (CO-OPS)
http://tidesandcurrents.noaa.gov/data_menu.shtml?stn=8735180 Dauphin Island, AL&type=Tide Data
online
20100401
20120817
publication date
Dauphin Tides
Observed tides from the NOAA Dauphin Island, AL, tide gauge (station 8735180) were used to reconstruct a morphological tide used to force tidal variations in the simulation.
Analyze the water level elevation data from the NOAA tide gauge at Dauphin Island, AL, (8735180), for the period of April 1, 2010, to August 17, 2012, using T_TIDE (a Mathworks MATLAB software package described in Pawlowicz et al, 2002, , based on algorithms and FORTRAN code previously developed by Godin, 1972, and Foreman, 1977, 1978). Following the method prescribed in Lesser, 2009, develop the morphological tide, e.g., an equivalent description of the tidal variation responsible for the bulk of the morphological dynamics. A TPXO tidal prediction was then made at the two offshore points and analyzed with the T_TIDE software, and a phase lag between the M2 and C1 constituents was calculated.
Foreman, M.G.G., 1977. Manual for tidal heights analysis and prediction. Pacific Marine Science Report 77-10, Institute of Ocean Sciences, Patricia Bay, Sidney, BC.
Foreman, M.G.G., 1978. Manual for tidal currents analysis and prediction. Pacific Marine Science Report 78-6, Institute of Ocean Sciences, Patricia Bay, Sidney, BC.
Godin, G., 1972. The Analysis of Tides. University of Toronto Press, Toronto.
Lesser, G.R., 2009. An Approach to Medium-term Coastal Morphological Modelling. Dissertation. Delft University of Technology.
Pawlowicz, R., Beardsley, B., Lentz, S., 2002. Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE. Comput. Geosci. 28, 929-937.
Dauphin Tides
TPXO Tides
2012
Morpho Tides
David Thompson
U.S. Geological Survey
Oceanographer
mailing and physical address
600 4th Street S
St. Petersburg
FL
33701
USA
(727) 803-8747 x3079
(727) 803-2032
dthompson@usgs.gov
The D-Flow and D-Waves components of the Deltares Delft3D numerical model suite (version 4.00.01) were used to estimate bottom orbital velocity, peak period, peak wave direction, and east and north components of wind and wave-driven velocity for the offshore wave conditions corresponding this scenario Hh_Dd (characteristics of which may be found in the included wave_scenarios.txt file) in each grid cell in the model domain. The wave model D-Waves, based on the Simulating WAves Nearshore (SWAN) model, is a 3rd generation phase-averaged numerical wave model which conserves wave energy subject to generation, dissipation, and transformation processes and resolves spectral energy density over a range of user-specified frequencies and directions. D-Wave was used in stationary mode. D-Flow solves the shallow water Navier Stokes equations and is run in 2-D depth-averaged mode, with linkage to D-Waves allowing the generation of wave-driven currents via wave radiation stress forcing. Default values for model parameters governing horizontal viscosity, bottom roughness, and wind drag were used. Neumann boundary conditions were used along the east, west, and south model boundaries with harmonic forcing set to zero. The southern boundary was designated as a water level boundary with harmonic forcing using the M2 and C1 constituents of the morphological tide. The morphological tide harmonics were applied to the SW corner and the harmonics plus the phase lags were applied at the SE corner.
Significant wave height, dominant wave period, and wave direction were prescribed as D-Wave TPAR format files every 30 grid cells along the model boundary using results from the NOAA Wavewatch III 4' multi-grid model for a representative moment in time corresponding to the offshore wave conditions of the scenario, the specific time of which may be found in the included wave_scenarios.txt file. A JONSWAP (JOint NOrth Sea WAve Project) spectral shape was assumed at these boundary points. Wind forcing was provided using the archived WavewatchIII 4' winds, extracted from the NOAA GFS wind model, for this time. The D-Wave directional space covers a full circle with a resolution was 5 degrees (72 bins). The frequency range was specified as 0.05-1 Hz with logarithmic spacing. Bottom friction calculations used the JONSWAP formulation with a uniform roughness coefficient of 0.067 m2/s3. 3rd-generation physics are activated which accounts for wind wave generation, triad wave interactions and whitecapping (via the Komen et al parameterization). Depth-induced wave breaking dissipation is included using the method of Battjes and Janssen with default values for alpha (1) and gamma (0.73). Wave model outputs of bottom orbital velocity, peak period, and peak wave direction were extracted on the wave model grid, and current model outputs of east and north current velocity component were extracted and interpolated to the wave model grid (staggered points in relation to the current model grid).
NDBC observations from station 42012 for the representative scenario time periods were used to validate the wave model results.
NOAA GFS
NOAA WW3
MORPHO TIDES
2012
DELFT3D
Joseph W. Long
U.S. Geological Survey
Oceanographer
mailing and physical address
600 4th Street S
St. Petersburg
FL
33701
USA
(727) 803-8747 x3024
(727) 803-2032
jwlong@usgs.gov
Use the wave model and current model results to calculate the bottom shear stress within each model grid cell using Mathworks MATLAB software (v2012A). The wave-current stress was calculating following the method of Soulsby (1995) to parameterize four methods giving good overall performance for estimating wave-current stress, based on original formulations by Grant and Madsen (1979), Fredsøe (1984), Huynh-Thanh and Temperville (1991), and Davies et al. (1998). The combined wave-current stress for the individual components of wave and current stress was calculated for hydrodynamic model output following the method prescribed in Soulsby (1997) for each of the four methods. The mean value of the four methodologies was used to estimate the combined wave-current shear stress for the hydrodynamic scenario. Wave direction, bottom orbital velocity, and period, and depth-averaged current magnitude and direction, required for this calculation, are calculated internally by the model. The roughness used is 1/12 the diameter of the SRB or sediment being analyzed, following Soulsby (1997). Stress values are saved in MATLAB .mat format.
The same individual who completed this processing step completed all additional processing steps.
References:
Davies, A.G., Soulsby, R.L., King, H.L. (1988). A numerical model of the combined wave and current bottom boundary layer. J. Geophys. Res. 93, 491-508.
Fredsøe, J. (1984). Turbulent boundary layer in wave-current motion. J. Hydraul. Eng. ASCE (110), 1103-1120.
Grant, W.D., Madsen, O.S. (1979). Combined wave and current interaction with a rough bottom. J. Geophys. Res. (84), 1797-1808.
Huynh-Thanh, S., Temperville, A. (1991). A numerical model of the rough turbulent boundary layer in combined wave and current interaction, in Sand Transport in Rivers, Estuaries, and the Sea, eds. R. L. Soulsby and R. Bettess, pp 93-100. Balkema, Rotterdam.
Soulsby, R.L. (1995). Bed shear-stresses due to combined waves and currents, in Advances in Coastal Morphodynamics, eds. M.J.F. Stive, H.J. de Vriend, J. Fredsøe, L. Hamm, R.L. Soulsby, C. Teisson and J.C. Winterwerp, pp. 4-20 and 3-23. Delft Hydraulics, Netherlands.
Soulsby, R.L. (1997). Dynamics of Marine Sands. Thomas Telford Publications: London, 249 pp.
DELFT3D
2012
WC STRESS
P. Soupy Dalyander
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02540
USA
(508) 548-8700 x2290
(508) 457-2310
sdalyander@usgs.gov
Estimate the critical shear stress for 300 micron quartz sediment and 6 SRB size classes and take the ratio of the combined wave-current stress to this critical value at each grid point. The specific characteristics for the sediment and SRB classes may be found in the included SRB_classes.txt file. Calculations are performed in Mathworks MATLAB (v2012A). Critical stress thresholds are calculated using the Shield's parameter following Soulsby (1997) and saved in MATLAB .mat format. In the case of SRBs, the Shield's parameter is identified as a "high" critical stress value, corresponding to instances when an SRB of the identified size is within a uniform bed of similarly sized SRBs. Exposure above the bed, such as may occur with a single SRB on a sand band, reduces the critical shear stress value for incipient motion. Based on field observations of gravel and sand mixtures, a "medium" critical stress value is calculated from a constant non-dimensional Shields parameter of 0.02, and a "low" critical stress value is calculated from a constant non-dimensional Shields parameter of 0.01 (Andrews, 1983; Bottacin-Busolin et al, 2008; Fenton and Abbott, 1977; Wiberg and Smith, 1987; Wilcock, 1998). Because the in-situ sediment is assumed to be of a relatively uniform size, a single critical stress value based on the Shields parameter is used.
References:
Andrews, E.D. (1983). Entrainment of gravel from naturally sorted riverbed material. Geo. Soc. Amer. Bull. (94), 1225-1231.
Bottacin-Busolin, A., Tait, S.J., Marion, A., Chegini, A., Tregnaghi, M. (2008). Probabilistic description of grain resistance from simultaneous flow field and grain motion measurements. Water Resources Res. (44), WO9419.
Fenton, J.D., Abbott, J.E. (1977). Initial movement of grains on a stream bed: the effect of relative protusion. Proc. R. Soc. Lond. A. (352), 523-537.
Soulsby, R., 1997. Dynamics of Marine Sands, a Manual for Practical Applications. Thomas Telford Publications, London.
Wibert, P.L., Smith, J.D. (1987). Calculations of the Critical Shear Stress for Motion of Uniform and Heterogenous Sediments. Water Resources Res. (23), 1471-1480.
Wilcock, P.R. (1998). Two-Fraction Model of Initial Sediment Motion in Gravel-Bed Rivers. Science (280), 410-412.
WC STRESS
2012
RATIO
Export the values for each grid cell from MATLAB format into an ArcGIS shapefile using the Mathworks MATLAB Mapping Toolbox (v2012A). Each of 24 hourly time steps from the tidal simulation are output to a seperate GIS layer of naming convention Tidal_mobility_TT.xxx, where TT is the hourly time step. Land grid cells are not exported to Arc. The shapefile is written with the "shapewrite" command. Because MATLAB does not assign a projection, the projection corresponding to the projection associated with the bathymetry used in the numerical models is added in ArcCatalog 9.3. The file was then quality checked in ArcMap to insure values were properly exported to the shapefile from MATLAB.
RATIO
2012
Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.
20170313
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Keywords section of metadata optimized by correcting variations of theme keyword thesauri and updating/adding keywords.
20180403
U.S. Geological Survey
Arnell S. Forde
Geologist
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
727-502-8000
aforde@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20201013
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Gulf of Mexico
Vector
G-polygon
982790
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.257224
North American Vertical Datum of 1988
0.01 m
meters
Explicit elevation coordinate included with horizontal coordinates
Tidal_mobility_TT
Hydrodynamic and Sediment Transport Model Application for OSAT3 Guidance: Ratio of the wave- and current-induced shear stress to the critical value for oil-tar balls and sediment mobilization at a specific time step in a tidal cycle
USGS
FID
Internal feature number.
ESRI
Sequential unique whole numbers that are automatically generated.
Shape
Feature geometry.
ESRI
Coordinates defining the features.
Scenario_H
Scenario wave height number, see wave_scenarios.txt
USGS
1
5
non-dimensional
1
Scenario_D
Scenario wave direction number, see wave_scenarios.txt
USGS
1
16
non-dimensional
1
Time_Step
Time step index into the 24 hour tidal cycle simulation
USGS
1
24
non-dimensional
1
sediment
Unitless ratio of the combined wave- and current-induced shear stress to the critical stress for 300 micron quartz sand calculated from the Shield's parameter. Values greater than one indicate sand is likely mobilized under the wave conditions associated with this scenario.
USGS
0
100
non-dimensional
0.01
SRB1_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 1 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB1_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 1 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB1_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 1 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB2_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 2 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB2_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 2 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB2_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 2 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB3_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 3 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB3_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 3 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB3_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 3 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB4_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 4 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB4_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 4 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB4_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 4 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB5_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 5 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB5_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 5 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB5_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 5 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB6_high
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 6 (see SRB_classes.txt) calculated from the Shield's parameter. The Shield's parameter is a relatively high critical stress estimate and does not account for a reduced critical stress due to potential SRB exposure above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB6_med
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 6 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.02. This critical stress estimate is a mid-range value accounting for a reduced critical stress due to some exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
SRB6_low
Unitless ratio of the combined wave- and current-induced shear stress for this scenario to the critical stress for SRB class 6 (see SRB_classes.txt) calculated from a non-dimensional Shield's parameter of 0.01. This critical stress estimate is a low value accounting for a reduced critical stress due to exposure of the SRB above the seafloor.
USGS
0
100
non-dimensional
0.01
P. Soupy Dalyander
U.S. Geological Survey
Oceanographer
mailing and physical address
384 Woods Hole Road
Woods Hole
MA
02543-1598
USA
(508) 548-8700 x2290
(508) 457-2310
sdalyander@usgs.gov
Tidal_mobility_TT.shp: ratio of combined wave- and current-induced shear stress for hourly time-step TT in a time-series of mobility over a tidal cycle to critical stress for sediment and various size SRBs (see SRB_classes.txt). NOTE: Specific layer name indicates the time-step (TT) for the layer.
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Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
SHP
3.3
ESRI shapefile
WinZip archive file containing the shapefile components. The WinZip file also includes FGDC compliant metadata.
WinZip 12.0 archive
150
https://pubs.usgs.gov/of/2012/1234/datafiles.html
None
These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.
20201013
U.S. Geological Survey
P. Soupy Dalyander
Oceanographer
mailing and physical address
384 Woods Hole Role
Woods Hole
MA
02543-1598
USA
(508) 548-8700 x2290
(508) 457-2310
sdalyander@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
local time
None
None