Like I said, I'm about five miles south of the epicenter, just south of Oakland. I was already awake for the quake, but still in bed. I noticed some movement of the bed and some windows rattling, but as quakes go, from my location, this one was very mild.
I have experienced quakes in homes built on bedrock, and they sometimes were quite a jolt. Homes built on softer soil tend to have a milder movement, however, there are other dangers associated with softer soils, such as harmonic amplification of the quake waves, as well as liquifaction and ground failure. Location also plays a big part. The Marina in SF and the Cypress Freeway Structure in Oakland were about 80 miles from the Loma Prieta epicenter, but experienced destructive earth movement because of the harmonic amplification, as well as a lens effect from a bowl shaped bedrock deep below the softer alluvial soils and landfill. A home can be right beside a fault and not have much if any damage, while a home miles away can collapse.
