Model help:MARSSIM: Difference between revisions
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= Rock and Surface Deformation = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Switch to use rock deformation | |||
|width="60%"| DEFORMUSE, 0 or 1, not implemented in current version | |||
|width="20%"| - | |||
|- | |||
| Deformation scale factor | |||
| Not implemented in current version | |||
| - | |||
|- | |||
|} | |||
= Groundwater flow = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Switch to model groundwater seepage | |||
|width="60%"| If set to 1, groundwater seepage is modeled (SEEPUSE, 0 or 1) | |||
|width="20%"| - | |||
|- | |||
| Seepage iteration interval | |||
| Number of iterations between recalculation of groundwater flow | |||
| - | |||
|- | |||
| Switch for permeability rescaling | |||
| If set to 1, permeability in exponential vertical decay of permeability is scaled to the present land surface elevation. Otherwise it is scaled to the original land surface elevation (at the start of the simulation) | |||
| - | |||
|- | |||
| Switch to show groundwater calculations | |||
| If set to 1, show groundwater calculations | |||
| - | |||
|- | |||
| Switch for exponential permeability decay | |||
| If set to 1, permeability is constant through an aquifer of constant thickness. Otherwise, it decays with depth below the surface | |||
| - | |||
|- | |||
| Yearly recharge rate | |||
| - | |||
| meters/year | |||
|- | |||
| Viscosity of water | |||
| - | |||
| - | |||
|- | |||
| Permeability, in darcies | |||
| Permeability | |||
| darcies | |||
|- | |||
| Groundwater depth scale | |||
| For exponential permeability, this is the depth to the half value of permeability. For constant permeability, it is the acquiter thickness | |||
| meters | |||
|- | |||
| Groundwater flow fraction | |||
| The fraction of surface water flow that becomes groundwater flow, set to 1 for all groundwater flow | |||
| - | |||
|- | |||
| Initial groundwater depth | |||
| Initial depth beneath the land surface for calculation of steady state groundwater surface | |||
| meters | |||
|- | |||
| Depth decay of permeability power | |||
| Set this to 1 for normal exponential decay | |||
| - | |||
|- | |||
| Max. groundwater iterations | |||
| Max number of iterations, permitted in calculating steady state groundwater table | |||
| - | |||
|- | |||
| Max. groundwater error | |||
| Max residual error permitted in calculating steady state groundwater table | |||
| - | |||
|- | |||
| Groundwater relaxation coeff | |||
| Coefficient used for SOR (Successive Over Relaxation) | |||
| - | |||
|- | |||
| Switch to use groundwater flux | |||
| If set to 0, the groundwater flow term used for seepage calculation of surface flows and weathering rate is the groundwater flux divergence (Seepage rate to surface). Otherwise, it is the groundwater flow rate per unit aquifer width | |||
| - | |||
|- | |||
| Switch to use seepage averaging | |||
| If set to 1, the groundwater flow term used in further calculations is a 9 point average value of raw calculated value | |||
| - | |||
|- | |||
|} | |||
= Eolian Erosion/Deposition = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Eolian event probability | |||
|width="60%"| Probability of an eolian deposition/erosion event per unit time (year or iteration) | |||
|width="20%"| - | |||
|- | |||
| Eolian time increment | |||
| Scales the overall Eolian Erosion/Deposition rate | |||
| - | |||
|- | |||
| Switch to use total exposure | |||
| If set to 1, all cells within the calculation window are used to compute the exposure index. Otherwise, only cells visible to the local cell are used | |||
| - | |||
|- | |||
| Switch to use default eolian process | |||
| If set to 1, eolian erosion and deposition occur normal to the topographic surface. Otherwise, erosion and deposition are modeled as vertical additions or subtractions | |||
| - | |||
|- | |||
| Minimum eolian deposition rate | |||
| This can be negative (If eolian erosion of exposed locations) | |||
| - | |||
|- | |||
| Maximum eolian deposition rate | |||
| Generally unity and scaled by Eolian_time_increment determines Eolian_constant_1 and Eolian_constant_2 | |||
| - | |||
|- | |||
| Eolian parameter code | |||
| Code that determines how next 2 parameters are used: (1) Exposure_10_percent, Exposure_90_percent; (2) Exposure_50_percent, Exposure_90_percent; (3) Zero_percent_exposure, Exposure_90_percent; (4) Rate0, exposure_50_percent | |||
| - | |||
|- | |||
| Exposure parameter 1 | |||
| Used to determine Eolian_constant_3 that defines the shape of eolian erosion/deposition curve as related to the exposure index | |||
| - | |||
|- | |||
| Exposure parameter 2 | |||
| Used to determine Eolian_constant_3 that defines the shape of eolian erosion/deposition curve as related to the exposure index | |||
| - | |||
|- | |||
| Distance decay factor | |||
| In calculation of exposure index, this determines how rapidly the weighting of surrounding cells decays with distance. Also used for accretion/ablation modeling | |||
| - | |||
|- | |||
| Weighting calculation distance | |||
| The maximum distance (in number of cells) that elevations are used to calculate the exposure index. Also used for accretion/ablation modeling | |||
| - | |||
|- | |||
|} | |||
= Lavaflow = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Number of lava sources | |||
|width="60%"| Number of sources (vents, volcanoes) that are present on the surface (Multiple sources not yet supported) | |||
|width="20%"| - | |||
|- | |||
| Lava source I coordinate | |||
| I coordinate column of lava source in DEM | |||
| - | |||
|- | |||
| Lava source J coordinate | |||
| J coordinate column of lava source in DEM | |||
| - | |||
|- | |||
| Lava event probability | |||
| Probability of a lava flow event during a single iteration | |||
| - | |||
|- | |||
| Minimum lava flow slope | |||
| Minimum gradient for laval flow at the flow source | |||
| - | |||
|- | |||
| Lava flow thickness | |||
| Assumed thickness of individual lava flow deposits | |||
| meters | |||
|- | |||
| Minimum lava flow thickness | |||
| Minimum thickness of a lava flow that can flow into adjoining cells | |||
| meters | |||
|- | |||
| New segment interval | |||
| Number of interations before starting a new lava flow source | |||
| - | |||
|- | |||
| Source segment interval | |||
| Number of iterations between changeover to a different lava flow source | |||
| - | |||
|- | |||
| Eruption stop probability | |||
| Probability per iteration, that the existing flow will solidify and stop being active. If this happens, a new flow starts at the source | |||
| - | |||
|- | |||
| No flow probability | |||
| The lower limit of probability for a cell to be a source for a new flow segment. If the probability drops below this value then the cell is no longer considered to be a possible flow source | |||
| - | |||
|- | |||
| Lava gradient weight | |||
| Determines how much the gradient between the edge of a flow and the neighboring point determines the probability of flow in that direction | |||
| - | |||
|- | |||
| Lava duration weight | |||
| Determine how rapidly a new cell diminishes in probability that it can be the source of a flow into a neighboring cell | |||
| - | |||
|- | |||
|} | |||
= Cratering = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Impact probability | |||
|width="60%"| probability of an impact event, per year | |||
|width="20%"| - | |||
|- | |||
| Switch for ejecta wraparound | |||
| If set to 1 and if the domain is periodic in both X and Y, then ejecta deposition can carry over onto the opposite side (IFOLD, 0 or 1) | |||
| - | |||
|- | |||
| Switch for regolith crater | |||
| If set to 1, then crater slopes and ejecta are soft (regolith). Otherwise they are considered to be initially bedrock | |||
| - | |||
|- | |||
| Large crater depth scale | |||
| Based upon scaling of fresh impact craters in Forsberg et al. (2004) and Howard (2007) | |||
| meters | |||
|- | |||
| Large crater depth exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Large crater rim scale | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| meters | |||
|- | |||
| Large crater rim exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| | |||
|- | |||
| Transition diameter | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| meters | |||
|- | |||
| Small crater depth scale | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| meters | |||
|- | |||
| Small crater depth exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Small crater rim scale | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| meters | |||
|- | |||
| Small crater rim exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Large crater shape scale | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Large crater shape exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Small crater shape scale | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Small crater shape exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Crater frequency exponent | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Frequency cutoff scaling | |||
| Based on scaling of fresh impact craters in Forsberg et al (2004) and Howard (2007) | |||
| - | |||
|- | |||
| Smallest possible crater | |||
| Depends on the scale of the simulation, generally in meters, Generally keep at about (4*cellscale) | |||
| - | |||
|- | |||
| Smallest modelled crater | |||
| Depends on the scale of the simulation, generally in meters, Generally keep at about (4*cellscale) | |||
| - | |||
|- | |||
| Largest modeled crater | |||
| Depends on the scale of the simulation, generally in meters. Generally keep at about (cell_scale*ncols/2) | |||
| - | |||
|- | |||
| Ejecta thickness variability | |||
| - | |||
| - | |||
|- | |||
| Noisesd | |||
| Standard deviation of random noise used for ejecta thickness | |||
| - | |||
|- | |||
| Inheritance parameter | |||
| - | |||
| - | |||
|- | |||
| Maximum rim gradient | |||
| Maximum gradient of crater rim | |||
| - | |||
|- | |||
|} | |||
= Ocean = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Switch for variable ocean elevation | |||
|width="60%"| If set to 1, ocean elevation varies in time and the times and corresponding sea levels are read in from the file "oceanlevels.dat" | |||
|width="20%"| - | |||
|- | |||
} | |||
= Accretion = | |||
{|{{Prettytable}} class = "wikitable unsortable" cellspacing="0" cellpadding="0" style="margin:0em 0em 0em 0;" | |||
|- | |||
!Parameter!!Description!!Unit | |||
|-valign="top" | |||
|width="20%"| Accretion rate | |||
|width="60%"| Rate of non-fluvial and non-eolian surface accretion and degradation | |||
|width="20%"| - | |||
|- | |||
| Switch for exposure dependent creep | |||
| If set to 1, the mass wasting creep rate depends on exposure | |||
| - | |||
|- | |||
| Switch for solar radiation | |||
| If set to 1, sublimation due to reflected radiation is modeled | |||
| - | |||
|- | |||
| Switch for top exposure | |||
| - | |||
| - | |||
|- | |||
| Switch for inverse exposure | |||
| - | |||
| - | |||
|- | |||
| Switch for exposure smoothing | |||
| - | |||
| - | |||
|- | |||
| Radiation constant | |||
| This scales the rate of radiation-dependent sublimation/deposition | |||
| - | |||
|- | |||
| Radiation dust factor | |||
| Determines the relative amount of re-emitted thermal radiation from dust-covered surface relative to bedrock surface | |||
| - | |||
|- | |||
| Radiation threshold convexity | |||
| Critical value of exposure index for redeposition of sublimated ice | |||
| - | |||
|- | |||
| Radiation deposit rate | |||
| Rate scaling for redeposition of sublimated ice on less-exposed surfaces | |||
| - | |||
|- | |||
} | |||
<headertabs/> | <headertabs/> | ||
</div> | </div> |
Revision as of 15:55, 29 July 2011
MARSSIM
The MARSSIM model is a landform evolution model primarily focuses on relatively long temporal scales (relative to the timescale for noticeable landform change) through fluvial and mass wasting processes.
Model introduction
The program is designed be computationally efficient such that individual runs can be done on a modern microcomputer in no more than a few tens of hours. The more recent additions to the model have focused on processes relevant to planetary landscapes, including lava flows, groundwater seepage and sapping, impact cratering, surface-normal accretion and ablation, and volatile redistribution by radiation-induced sublimation and recondensation. Individual process formulations vary from completely heuristic to modestly mechanistic. Important limitations for some potential applications are the assumption of a single representative bed material grain size in the fluvial system and no tracking of internal stratigraphy of sedimentary deposits.
Model parameters
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
A list of the key equations. HTML format is supported; latex format will be supported in the future
Notes
Any notes, comments, you want to share with the user
Numerical scheme
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: http://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)
Name of the module developer(s)
References
Key papers
Links
Any link, eg. to the model questionnaire, etc.
Parameter | Description | Unit |
---|---|---|
Accretion rate | Rate of non-fluvial and non-eolian surface accretion and degradation | - |
Switch for exposure dependent creep | If set to 1, the mass wasting creep rate depends on exposure | - |
Switch for solar radiation | If set to 1, sublimation due to reflected radiation is modeled | - |
Switch for top exposure | - | - |
Switch for inverse exposure | - | - |
Switch for exposure smoothing | - | - |
Radiation constant | This scales the rate of radiation-dependent sublimation/deposition | - |
Radiation dust factor | Determines the relative amount of re-emitted thermal radiation from dust-covered surface relative to bedrock surface | - |
Radiation threshold convexity | Critical value of exposure index for redeposition of sublimated ice | - |
Radiation deposit rate | Rate scaling for redeposition of sublimated ice on less-exposed surfaces | - |