Application was created to determine the deformation of the Earth’s crust, as a response to the surface loading caused by continental water. Presented algorithm uses spherical Earth as a reference surface to calculate deformations.
Presented algorithm heavily use NaN values for hydrosphere data cells that
has no determined water quantity and nanmean function that is part of
statistics package from Octave Forge.
It may be also necessary to install io package from Octave Forge.
To install package, execute following command in Octave prompt:
pkg install statistics
To load package into Octave, execute following command in application prompt:
pkg load statistics
Presented algorithm requires creating two files with necessary data:
grn1.txt.
For purpose of this study, Greens functions coefficient were taken for
the Earth model ’A’, developed jointly by Gutenberg and Bullen
(Farrell, 1972. Deformation of the earth by surface loads).
It is important to name that file grn1.mat. Octave users can create such
file with following commands executed from application's command prompt:load grn1.txt;
save(-mat7-binary,grn1.mat,grn1);
WGHM.txt.
This file should contain hydrosphere data in a grid with spacing of 0.5 degrees.
Octave users can create such file with following command executed from
application's command prompt, given that source data is stored in WGHM.txt
file.load WGHM.txt; WGHM(WGHM==-9999) = NaN;
save(-mat7-binary, WGHM.mat, WGHM);
File months.m is a script that starts calculation of deformations
for all epochs in WGHM.mat file for specified coordinates.
Results are stored in txt file as:
fi la n e u
where:
| symbol | meaning |
|---|---|
fi |
point's latitude (decimal degrees) |
la |
point's longitude (decimal degrees) |
n |
deformations in direction of meridian (millimetres) |
e |
deformations in direction of prime vertical (millimetres) |
u |
deformations in direction of plumb line (millimetres) |
In case of any questions related to used algorithm or obtained results, please send message to m.zygmunt87@wp.pl.