Petra,

EarthScope, last I heard, and it changes, has four parts:

1. Drilling a hole into the San Andreas Fault - SAFOD
2. Adding lots of seismometers across the country -
USArray
3. Adding various instruments to the faults on the west
coast, mostly strain and some seismometers - PBO
4. A tenuously connected InSAR (satellite-based
geodetic instrument) - no acronym yet.

Each part could cost up to $100M.

John