A MODERATE UNDERSEA QUAKE STRUCK WESTERN GREECE ON FRIDAY, CAUSING NO DAMAGE OR INJURIES, OFFICIALS SAID, ACCORDING TO AP. THE ATHENS GEODYNAMIC INSTITUTE SAID THE QUAKE HAD A PRELIMINARY MAGNITUDE OF 4.6 AND OCCURRED AT 9:15 A.M. (0615GMT) IN THE GULF OF CORINTH, 100 KILOMETERS (62 MILES) NORTHWEST OF ATHENS.