Figure F2. Instrument installation technique. The instrument string hangs on 4-in casing pipe, which in turn hangs on the riser support just below the reentry cone. Cables from the sensors are strapped to the casing pipe and protected by centralizers. Cement is pumped through the casing pipe, through the strainmeter, and out the bottom of the stinger. Sufficient cement is pumped to fill the bare hole and to extend into the 10-in casing. The sensors are thus intimately connected to the bare rock. A circulating dart follows the cement/water column down the drill pipe; this dart opens a port in the casing pipe ~400 m above the instruments. This enables flushing of the drill pipe without uncoupling from the seafloor assembly, which is required to guide the battery frame into position later.