“…Results of monitoring of hydraulic fracturing experiments have been reported (e.g., JUPE et al, 1992;CORNET et al, 1997;PHILLIPS et al, 1997;SASAKI, 1998). The analysis of microseismic locations provides information on the fracture growth, the main¯ow direction, and the drilling target of a new well, while the focal mechanisms of the microseismic events provide other information on the stress state (e.g., CORNET and JULIEN, 1989;CORNET and YIN, 1995;TEZUKA and NIITSUMA, 2000).…”