DEWPython 1.2.0

Python-Implemented Deep Earth Water Model

DEWPython

V1.2.0

The DEW package allows the user to compute the thermodynamic and elastic properties of various aqueous inputs for a general range of 100-1200C and a pressure range of 1.0-60 Kb. It is based on the DEW spreadsheet and behaves similarly.The DEW package additionally provides integrated support for SUPCRTBL and can be used to directly import and compare species between the two models.

Getting Started

This section provide a basic example on the running of DEW. Because the input fields are interactive, it relies on user input in order to function (which cannot be demonstrated here). Full documentation for the class is available externally.

Download

Download and install using using

pip install DEWPython

Running DEW

Import DEWPython and DEWPython.DEWModel

import DEWPython
from DEWPython import DEWModel as dm

You are now ready to use the DEW module! This command will execute the imports of packages and the initialization of the model. If you wish to change base parameters please see the documentation. The only non-standard package that DEW is dependent on is the "pandas" package, however a full list of dependencies is included below.

Using the Model

DEW is an object-oriented class dependent on the DEWEquations class. To run it, first initialize a DEW object:

reaction = dm.DEW()

From here, set the inputs, outputs, and preferences interactively. Throughout every stage in the model, parameters can be queried for debugging. See the documentation for more details.

reaction.set_inputs()
# Initialize the LHS of the reaction
reaction.set_outputs()
# Initialize the RHS of the reaction
reaction.set_preferences()
# By default, the reaction runs at Psat conditions (see documentation). The set_preferences() method interactively changes this.

If custom options are selected in the preferences, the relevant CSV files must be updated. Otherwise, you must run the following command:

reaction.set_TPRho()

This command will interactively initialize temperature and pressure arrays. Finally, run

reaction.calculate()

You can now query

reaction.delG
# Gibbs of Formation
reaction.delV
# Volume change of Formation
reaction.logK
# The log K value of the reaction
reaction.make_plots()
# Automatically constructs the plots for the model.

Running supcrt

Included in the DEW_Folder is supcrt96 and SUPCRTBL, a similar program to calculate the properties of species at different temeperature and pressure conditions. The defauly is set to supcrt96.

reaction.run_supcrt()

This command will interactively run SUPCRTBL inline and create output files. It automatically updates "reaction.supcrtFile", a variable that stores the most recently produced Supcrt file.

Now run:

reaction.calculate_supcrt()

This function takes one optional argument of a SUPCRTBL output file. For the input file or the file previously calculated it will calculate "reaction.supcrtOut", a dictionary that can be queried for 'delG', 'delV', 'LogK', 'delH', 'delS', 'delCp', 'DH2O', 'Temperature', and 'Pressure'.

Finally, run:

reaction.make_supcrt_plots()

To produce the same plots as DEW.

Range of validity

Certain equations within DEW are valid to certain values (as are the properties of specific mineral species). For more information please see the DEW website

Dependencies

• Pandas
• Numpy
• Sys
• Threading
• Subprocess
• Os
• Json
• Matplotlib
• Matplotlib Toolkits
• Collections

References

• Huang, F., & Sverjensky, D. A. (2019). Extended Deep Earth Water Model for predicting major element mantle metasomatism. Geochimica et Cosmochimica Acta, 254, 192-230.
• Facq, S., Daniel, I., Montagnac, G., Cardon, H., & Sverjensky, D. A. (2016). Carbon speciation in saline solutions in equilibrium with aragonite at high pressure. Chemical Geology, 431, 44-53.
• Facq, S., Daniel, I., Montagnac, G., Cardon, H., & Sverjensky, D. A. (2014). In situ Raman study and thermodynamic model of aqueous carbonate speciation in equilibrium with aragonite under subduction zone conditions. Geochimica et Cosmochimica Acta, 132, 375-390.
• Johnson, J.W., Oelkers, E.H. and Helgeson, H.C. (1992) SUPCRT92 - A software package for calculating the standard molal thermodynamic properties of minerals, gases, aqueous species, and reactions from 1-bar to 5000-bar and 0C to 1000C. Computer and Geosciences 18:899-947.
• Sverjensky, D. A., Harrison, B., & Azzolini, D. (2014). Water in the deep Earth: The dielectric constant and the solubilities of quartz and corundum to 60kb and 1200 C. Geochimica et Cosmochimica Acta, 129, 125-145.
• Pan, D., Spanu, L., Harrison, B., Sverjensky, D. A., & Galli, G. (2013). Dielectric properties of water under extreme conditions and transport of carbonates in the deep Earth. Proceedings of the National Academy of Sciences, 110(17), 6646-6650.
• Zimmer, K., Zhang, Y.L., Lu, P., Chen, Y.Y., Zhang, G.R., Dalkilic, M. and Zhu, C. (2016) SUPCRTBL: A revised and extended thermodynamic dataset and software package of SUPCRT92. Computer and Geosciences 90:97-111.

Authors

• Andrew Chan - Div. of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA 91125
• Mohit Melwani Daswani - Group 3226 (Planetary Interiors and Geophysics). NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109
• Steven Vance - Group 3226 (Planetary Interiors and Geophysics). NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109

Change log

Changes since 1.0.3

• Updated package to allow usage by MacOS

Planned updates

License

This project is licensed under the MIT License :

Copyright (c) 2020, A. Chan

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files, to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Acknowledgments

This work was produced with the financial support provided by the NASA Jet Propulsion Laboratory, the California Institute of Technology Summer Undergraduate Research Fellowship program, and the Caltech Assocaites.