Calculator for Paleomagnetic Inclination-only Data
Þórður Arason > Web calculator

In paleomagnetic analysis, the arithmetic mean of inclination-only data is known to introduce a shallowing bias. Arason and Levi developed a robust maximum likelihood method for estimating the unbiased mean inclination from such data.

Inclination-only data
input box

Insert inclination values,
(in degrees), one in each line.
Then press the Calculate-button.
Results
Arithmetic mean
Number of samples:
Arithmetic mean:
Inverse variance:

Arason-Levi inclination-only method
Number of samples (N):
Mean inclination (I):
Precision parameter (κ):
Angular standard deviation (θ63):
95% confidence limits (α95):
Error flag:

References
Arason, Þ. and S. Levi (2010). Maximum likelihood soultion for inclination-only data in paleomagnetism, Geophysical Journal International, 182, p. 753-771, doi: 10.1111/j.1365-246X.2010.04671.x [ abstract, full text ]

More references ...

Open source
You are free to use, copy and distribute this web-calculator. If you modify the program code, you must clearly identify your changes. You can download our web-calculator to run it locally on your computer or on your own website. For a local run of the calculator, you should download the following files to a common directory. By opening the index.html file in your local directory, with your browser, you start the inclination-only calculator locally.
[ index.html, pal.js, palstyle.css, aralev.txt, refs.html ]
Our complete Fortran source code for the calculations is available [ ARALEV Fortran source code ]

Alternative sites
http://hergilsey.is/arason/paleomag/
http://www.vedur.is/~arason/paleomag/
http://brunnur.vedur.is/pub/arason/paleomag/

Web calculator written by Ari Þórðarson and Þórður Arason, August 2009