Model help:Subside

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The CSDMS Help System


The Subside is a 1D and 2D flexure model, and a part of the Sedflux model.

Model introduction

The model is used to simulate the lithospheric load changes as the model evolves. Depending upon how the load distribution develops, this flexure can result in the basin uplifting or subsiding (or both). The pattern of subsidence in time and space largely determines the gross geometry of time-bounded units because it controls the rate at which space is created for sedimentation.

Model parameters

Parameter Description Unit
First parameter Description parameter [Units]
Parameter Description Unit
First parameter Description parameter [Units]

Uses ports

This will be something that the CSDMS facility will add

Provides ports

This will be something that the CSDMS facility will add

Main equations

  • Deflection of Earth's crust
[math]\displaystyle{ w \left (\lambda r \right ) = {\frac{q \lambda}{2 \pi \rho_{d}g}} Kei \left (\lambda r \right ) }[/math] (1)
  • Flexural parameter
[math]\displaystyle{ \lambda = \left ({\frac{D}{\rho_{d}g}}\right )^ \left ({\frac{-1}{4}}\right ) }[/math] (2)
  • Time delay between the addition of load and the lithosphere's response
[math]\displaystyle{ w \left (t \right ) = w_{0} \left ( 1 - exp \left (- t / t_{0} \right ) \right ) }[/math] (3)


  • Equation 1 predicts the deflection due to a point load; it does not account for the additional weight of material that fills the deflection. For instance, a rise in sea level will cause a deflection that will be filled with additional water, which in turn will cause further deflection. If we know the density of material that fills the deflection, the total deflection is increased by a factor of (( ρd )/(ρd - ρw ))1.25 (Angevine et al., 1990). Using ρd = 3300 kg / m3, and ρw 1030 kg / m3, this amounts to an increase in deflection by a factor of 1.6. Unfortunately, in general, we do not know the density of the added (or removed) material as it could be either air or water. Thus, we solve for the total deflection by iteratively solving equation 1 and updating the load after successive iterations until the solution converges.
  • Because the viscous asthenosphere has to flow out of the way before the lithosphere can deflect, there will be a time delay between the addition of load and the lithosphere’s response. equation (3) expresses this time delay as an exponential (Peltier, 1998).In reality, response time is a function of the viscosity of the underlying mantle (Peltier, 1998) Typical relaxation times vary from about 1500 to 5000 years (Peltier, 1998; Huybrechts, 2002; Paulson et al., 2005).


An example run with input parameters, BLD files, as well as a figure / movie of the output

Follow the next steps to include images / movies of simulations:

See also: Help:Images or Help:Movies


Eric Hutton


  • Hutton, E. W. H. and Syvitski, J. P. M., 2008. Sedflux 2.0: An advanced process-response model that generates three-dimensional stratigraphy. Computer & Geosciences, 34: 1319~1337, Doi: [10.1016/j.cageo.2008.02.013]