No Loma Prieta is at least 90 miles from where the San Andreas heads out to sea. Most of the San Andreas is in what is geographically known as Northern California. (Basically that which is north of the ridge line of the Tehachapi)
Also, very little of the plate moved significantly during that quake; just portions in Santa Cruz and Santa Clara counties. The rest of the plate had already made its move long before.
Uh, no.
San Andreas runs all the way to the Southern edge of California, and beyond into the Gulf of California. Heading from the southern border, it turns and cuts across much of southern California, before heading along towards the Santa Cruz mountains. It finally heads offshore immediately south of San Francisco, although I admit I didn’t realize it skirts back onshore for brief segments north of San Francisco. Nonetheless, the whopping majority of the onshore portion of San Andreas is in the southern half of California.
Loma Prieta is just under 30 miles from where the San Andreas first heads out so sea, just south of San Francisco. Out of 800+ miles, that’s what I refer to as “near the northern edge.”