Benthic Flux and Submarine Groundwater Discharge

 Home

• Calculators:
  • Wave-forced q_bf and SGD component on a single-unit medium of infinite thickness
  • Wave-forced q_bf and SGD component on a single-unit medium of finite thickness
  • Wave-forced q_bf and SGD component on a dual-unit system

ABOUT FLORIDA SCIENCE

• Office Information:
  • Florida Water Science Center office locations
  • Information Requests

• National Information:
  • USGS Phonebook
  • USGS Science Strategy
  • Employment

Ask Florida USGS

OFFICES

Orlando - 407-803-5500
Ft. Lauderdale - 954-377-5900
Ft. Myers - 239-275-8448
Tampa - 813-498-5000
Tallahassee - 850-553-3640

Benthic Flux and Submarine Groundwater Discharge

Calculator: Benthic flux and submarine groundwater discharge component forced by surface gravity waves on a single-unit medium of infinite thickness

This calculator solves for average benthic water discharge flux q̄_bd forced by surface gravity waves on a plane bed composed of a homogeneous, isotropic porous medium of infinite thickness (Figure 1A). Submarine groundwater discharge (SGD) is q_bd to a marine water body.

Figure 1. Two-dimensional, vertically oriented cross sections, in x and z dimensions, of wave-forced benthic recharge flux qbr.w and wave-forced benthic discharge flux qbd.w, with a water surface at z = η oscillating about a still water surface at z = 0. The bed of the water body is located at z = -h;. The following domain geometry is used to solve two-dimensional boundary value problems in King et al. (2009): (A) Case I, hydrogeologic unit of infinite thickness; (B) Case II, hydrogeologic unit of finite thickness; and (C) Case III, dual-unit system, which consists of a unit of finite thickness over a unit of infinite thickness. The wave-forced velocity field transports constituents within the porous domain, over -h > z > -h - ζ

King et al. (2009) state that this model "assumes a two-dimensional x-z oriented system; linear wave; incompressible pore fluid; irrotational, inviscid flow in the surface water domain; horizontal, plane bed; rigid, homogeneous, isotropic, porous medium; laminar and viscous flow in the porous medium; case-specific, no-flow boundary conditions; Darcy's law; Equations 4 to 11 of King et al. (2009); λ_i<<1; R<<1; and the hydrogeologic unit concept. In a strict sense, some of these assumptions, such as a two-dimensional system, are never valid for practical applications. The abstraction process permits conclusions about the prototype to be drawn from the behavior of the model. Clearly, because Riedl et al. [1972] showed agreement between model a and observed a off Bogue Bank;" and the model "compares favorably with Yamamoto et al. [1978], it is possible to draw ... meaningful conclusions about ... natural or laboratory systems from the abstracted model."

Reference

King, J. N., A. J. Mehta, and R. G. Dean (2009), Generalized analytical model for benthic water flux forced by surface gravity waves, J. Geophys. Res., 114, C04004, doi:10.1029/2008JC005116.

Riedl, R. J., N. Huang, and R. Machan (1972), The subtidal pump: A mechanism of interstitial water exchange by wave action, Mar. Biol., 13, 210–221.

Yamamoto, T., H. L. Koning, H. Sellmeijer, and E. P. Van Hijum (1978), Response of a poro-elastic bed to water-waves, J. Fluid Mech., 87, 193–206.

Contact: jking@usgs.gov