Model help:Subside

Subside

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

First tab header

Second tab header

Etc. tab header

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)

Nomenclature

Symbol	Description	Unit
w	deflection of earth's crust	-
λ	flexural parameter	-
r	distance from the point load	L
q	point load	-
Kei	Kelvin function	-
ρd	density of the asthenosphere	M / L3
g	acceleration due to gravity	L / T2
d	flexural rigidity of the earth's crust	-
w0	equilibrium deflection	-
t	time since the load was applied	T
t0	response time associated with mantle viscosity	T
D	grain size (usually in mm or μm)	L

Notes

• 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 (( ρ_d )/(ρ_d - ρ_w ))^1.25 (Angevine et al., 1990). Using ρ_d = 3300 kg / m³, and ρ_w 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).

Examples

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:

• Upload file: https://csdms.colorado.edu/wiki/Special:Upload
• Create link to the file on your page: [[Image:<file name>]].

See also: Help:Images or Help:Movies

Developer(s)

Eric Hutton

References

• 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]

Links

• Model:Subside