ellipticipy 1.0.0

Package for the calculation of ellipticity corrections for teleseismic waves

EllipticiPy

A python package for the calculation of ellipticity corrections for seismic phases in elliptical planetary models.

Authors:

• Stuart Russell
• John F. Rudge
• Jessica C. E. Irving
• Sanne Cottaar

The workings of this package are described in the main paper:

Russell, S., Rudge, J., Irving, J. and Cottaar, S., 2022. A re-examination of ellipticity corrections for seismic phases. Geophysical Journal International, 231(3), pp.2095-2101. https://doi.org/10.1093/gji/ggac315

Please cite this publication when publishing work that has made use of this package.

Installation

The package can be installed using pip, the same as many python packages:

pip install ellipticipy

This package depends on ObsPy. For information regarding ObsPy please see the relevant documentation: https://docs.obspy.org/

Usage

This package is intended to be used in Python:

>>> from obspy.taup import TauPyModel
>>> from ellipticipy import ellipticity_correction
>>> model = TauPyModel('prem')
>>> arrivals = model.get_ray_paths(source_depth_in_km = 124,
    distance_in_degree = 65, phase_list = ['pPKiKP'])
>>> ellipticity_correction(arrivals, azimuth = 39, source_latitude = 45)
[-0.7731978967098823]

For users that do not wish to directly interact with Python, there is a command line wrapper for calculating ellipticity corrections in src/ellip. The Python package must be installed before the wrapper can be used.

> ./ellip -d 134 -deg 64 -az 15 -sl 23 -ph P,PcP,PKiKP -mod ak135
    
Model: ak135
Distance   Depth   Phase        Ray Param   Spherical   Ellipticity   Elliptical
  (deg)     (km)   Name         p (s/deg)   Travel      Correction    Travel    
                                            Time (s)        (s)       Time (s)  
--------------------------------------------------------------------------------
   64.00   134.0   P                6.536     619.05        -0.45       618.60
   64.00   134.0   PcP              4.110     653.31        -0.48       652.83
   64.00   134.0   PKiKP            1.307    1020.55        -0.75      1019.80    

Examples

Further examples of code usage in Jupyter Notebook format can be found in src/. The first of these demonstrates the main usage case.

• src/example_corrections.ipynb
• src/example_coefficients.ipynb
• src/ellipticity_of_figure.ipynb

License

This package is licenced under the GNU Lesser General Public License v3.0.