README_Modification:

If you modify these data in any way, document your modification here,
and if you pass these data on, include this notice with these data.

Original BP distribution Frederic Billette,
BP DWX Houston Mon Jul 18 16:08:15 CST 2005.

Joe Dellinger, BP Advanced Seismic Imaging Development Group
Added density model to distribution, February 2008.