A $3.3 million mapping effort will see researchers in an airplane flying back and forth along the California coast shooting thousands of laser pulses per second at the rocks, beaches, and cliffs along the 1,200-mile shoreline from Mexico to Oregon, generating ultra-detailed 3-D images of the contours of the land in huge computer files; findings could be used to figure out where to build sea walls, or expand wetlands to reduce flooding, or where to move existing development