Codes and data used to generate the results and figures in the study , “3-D Attenuation Model of Sierra Negra Volcano, Galapagos Archipelago”, is provided in 3DAttenuationModelSierraNegra.tar. Follow the steps below to run the codes and view the data:

1. Untar using tar -xvf 3DAttenuationModelSierraNegra.tar
2. Generates the subdirectories ANALYSIS, CODE, DATA, and FIGS
	a. CODE-necessary codes to run galap_atten.R
	b. DATA-necessary data to run galap_atten.R
	c. ANALYSIS-results in R Data format
        d. FIGS-directories to save figures
3. If not already installed, install R from R CRAN website
4. Install sp, splancs, RPMG, RTOMO, RSEIS, Matrix, PEIP, GEOmap, abind, TeachingDemos, maps, and geomapdata in R
5. Run the galap_atten.R script to obtain attenuation results, run various tests, and generate figures