Why was Parkfield, California selected for major earthquake study in the 1990’s, prior to SAFOD, and what were some of the measurements made, and

Why was Parkfield, California selected for major earthquake study in the 1990’s, prior to SAFOD, and what were some of the measurements made, and.

Why was Parkfield, California selected for major earthquake study in the 1990’s, prior to SAFOD, and what were some of the measurements made, and what were the main results of this study (at least so far). 

Why was Parkfield, California selected for major earthquake study in the 1990’s, prior to SAFOD, and what were some of the measurements made, and