Model:GFlex

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Revision as of 11:42, 23 December 2010 by Awickert (talk | contribs) (→‎Help: email me)

Contact

Name Andy Wickert
Type of contact Model developer
Institute / Organization University of Colorado
Postal address 1 Department of Geological Sciences, UCB 399
Postal address 2 2200 Colorado Ave
Town / City Boulder
Postal code 80309
State Colorado
Country US"US" is not in the list (Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, ...) of allowed values for the "Country" property.
Email address wickert@colorado.edu
Phone
Fax



GFlex


Metadata

Summary

Also known as
Model type
Model part of larger framework
Note on status model
Date note status model

Technical specs

Supported platforms
Unix, Linux
Other platform
Programming language

Python

Other program language
Code optimized Single Processor
Multiple processors implemented
Nr of distributed processors
Nr of shared processors
Start year development 2010
Does model development still take place? Yes
If above answer is no, provide end year model development
Code development status
When did you indicate the 'code development status'?
Model availability As code, As teaching tool
Source code availability
(Or provide future intension)
Through owner"Through owner" is not in the list (Through web repository, Through CSDMS repository) of allowed values for the "Source code availability" property., Through CSDMS repository
Source web address
Source csdms web address
Program license type GPL v3
Program license type other
Memory requirements
Typical run time Minutes to populate cofactor matrix, ~1 second for solution


In/Output

Describe input parameters
  • Elastic thickness map (ASCII)
  • Load map (ASCII)
  • dx, dy
  • Material properties
    • Young's modulus
    • Poisson's ratio
    • density of load
    • density of infilling material (optional; this can also be done via iteration for more complicated situations

Only the elastic thickness and load need to be actual input files. The rest (scalars) can be specified at the command line interface.

Input format ASCII
Other input format
Describe output parameters Cofactor matrix (*.mtx sparse matrix file; ASCII)

Flexural response map (ASCII)

Output format ASCII
Other output format
Pre-processing software needed? No
Describe pre-processing software
Post-processing software needed? No
Describe post-processing software
Visualization software needed? No
If above answer is yes
Other visualization software


Process

Describe processes represented by the model Response of a lithospheric plate, potentially with nonuniform elastic thickness, to an applied surface load
Describe key physical parameters and equations We solve the PDE for lithospheric flexure in 2 dimensions:

'"`UNIQ--math-00000000-QINU`"'

Here, $D$ is the flexural rigidity, $w$ is the vertical displacement at each $(x,y)$, $\Delta \rho$ is the mantle density minus the density of infilling material, $g$ is gravitational acceleration, and $q$ is the applied load. We follow Wees and Cloetingh (1994) in acknowledging that flexural rigidity is a tensor property:

'"`UNIQ--math-00000001-QINU`"'

Describe length scale and resolution constraints Insufficiently tested to know.
Describe time scale and resolution constraints Currently does not time-evolve. I would like to couple this to a 3D viscoelastic mantle at some point, but this hasn't happened yet.
Describe any numerical limitations and issues Insufficiently tested to know.


Testing

Describe available calibration data sets
Upload calibration data sets if available:
Describe available test data sets
Upload test data sets if available:
Describe ideal data for testing


Other

Do you have current or future plans for collaborating with other researchers?
Is there a manual available? No
Upload manual if available:
Model website if any
Model forum / discussion board
Comments

Introduction

The model flexure computes a direct Thomas algorithm finite difference solution to the flexure equations for a lithospheric plate of nonuniform elastic thickness via a thin plate assumption. It consists of two modules, the first of which is used to generate the coefficient matrix for the Thomas algorithm solution and the second of which actually generates that solution (using the coefficient matrix produced by the first module as an input file). The first module is slow, but the second is very fast, making this a poor technique for a one-off equilibrium flexure calculation, but a good choice for situations in which flexural response needs to be calculated many times in a row. Such situations in which this model would excel include:

  • Numerical models that require frequent updating of flexural deformations of the lithosphere
  • Simulations with forcings that take place on a time-scale that is comparable to the time-scale of Earth response to loading and unloading (e.g., ice and water loading during glacial cycles)
  • Calculations of mixed sediment and/or water loading, or water loading with onlap and offlap, such that a constant fill density cannot be assumed and solutions must be produced iteratively.

History

Flexure was developed first in MATLAB (Spring / early Summer 2010) and then in python (translated October 2010).

The next planned step in development is to make flexure be IRF- and CMT-compliant.

Planned development will proceed slowly through Spring 2011 (though this will go faster if I get a solid day or two to work on it). Because the program is based on a set of functions in a python module, we plan on adding additional functionality for 1D and 2D analytical solutions, a 1D Thomas algorithm solution, and a 2D alternating direction implicit (ADI) iterative solution. If all goes as planned, this should be a one-stop shop for flexure solutions.

Papers

Issues

Help

Email Andy Wickert (see contact info in box at top).

Input Files

The coefficient matrix for the 2D Thomas algorithm solution requires a map of elastic thicknesses in *.txt / ASCII format. This elastic thickness map must be two cells wider on each side than the map of loads; this is because the finite difference solution must "look" two cells in every direction. It also requires the specification of several parameters, including:

  • Young's modulus (defaults to 1011 Pa)
  • Poisson's ratio (defaults to 0.25)
  • Mantle density (defaults to 3300 kg/m3)
  • Density of infilling material (defaults to 0 kg/m3)

This outputs an ASCII sparse matrix file (Matrix Market *.mtx format).

The flexural solution requires the ASCII file for the sparse coefficient matrix generated above and an imposed array of loads (also ASCII), along with the specification of input and output file names.

Output Files

Download

Template:Download Model

Source

Command-Line Access

If you plan to make changes, use this command to check out the code as yourself using HTTPS:

# Project members authenticate over HTTPS to allow committing changes.
svn checkout https://csdms.colorado.edu/svn/flexure

When prompted, enter your CSDMS Subversion password.
Non-members may only check out a read-only working copy of the project source.
To obtain a CSDMS Subversion account or to become a member of this project, please email csdms@colorado.edu.
Need help with Subversion? Go to the subversion help page.

GUI and IDE Access

This project's Subversion repository may be accessed using many different client programs and plug-ins. See your client's documentation for more information.