If you watch the video I posted you can see the whole thing live for yourself. Watch the news reporters. The shaking starts about 1 second into it and stops around 14 seconds later. The quake itself is usually only several seconds and the rest of the movement is from either liquifaction or taller buildings swaying.
Once you've felt a big one, it isn't something you look forward to ever feeling again As a kid in the San Francisco East Bay I remember a few quakes that were big enough to rattle the dishes in the kitchen cabinets and I remember my mom running to the kitchen to attempt to hold the cabinet doors closed so the dishes wouldn't fall out.
For the '89 Loma Preita quake I was in Oakland in the corporate office, talking on the phone with someone at a branch office in Concord as I was packing up my stuff and heading home for the day. We felt the quake first, and I remember telling him that and him not feeling anything, then a couple seconds later he felt it and I said I was hanging up and getting under the desk. I was the safety monitor for our floor and kept yelling for everyone to get under their desks. The building shook from side to side as well as up and down. I think the side to side motion was the quake and the up and down motion was from the movement of the building structure. Two of the lateral filing cabinets in my office flipped over as did a tall bookcase. In the outer offices, we had panels from the drop ceiling fall out and the desk surfaces in cubicles collapsed to the floor. In one corner of the building the sheetrock and building frame separated. The odd thing was all the furniture that fell over all fell in the same direction. It was as if a huge hand had pushed against the side of the building and everything fell over in that direction. Our building floats over an underground garage and it felt like the building was going to sink right through it. We then heard and felt the collapsing of the freeway and people running toward the freeway yelling for help. We were afraid to leave the building until we felt it safe to do so. We had to call all 35 of our branch offices and get damage reports from each of them and set up phone trees to tell employees not to attempt to come to work the next day and suggest they be with their families. A couple hours later driving home that night, there were no lights anywhere, no traffic lights, nothing. Vehicles weren't allowed onto the freeways so we had to drive through surface streets. All along the way there were buildings that had collapsed or that had massive damages to the facades. There were piles of debris in the streets that you had to swerve around and you had to be very careful because idiots were plowing through intersections from all directions not realizing there weren't any lights until it was too late. I finally made it home about 6 hours later and then drove to my mom's condo to check on her. I missed being on that collapsed freeway by about 5 minutes. One of the guys I worked with was down the hall on the toilet at the time of the earthquake. When he came back to the office his face was very pale and his pants were soaked with toilet water that had splashed out of the bowl from the quake motion. From my office window I can see the big water fountain in the square below. Most of the water in the fountain had been shook out of the fountain.
Gah, that sensation is etched into my brain. Typing that out was almost like reliving it all again. Like I said, it isn't a sensation I ever look forward to experiencing again. We knew what it was, but we'd never felt one as strong as that before and felt so little control of the situation or our fears. We had some emergency supplies in our office as well as written emergency procedures, but after experiencing the quake, we were woefully inadequately prepared. It was a good wake up call. We implemented more thorough emergency planning and supplies in each of our branch offices because of that quake.
I can't even imagine the terror for people who are inside buildings that have collapsed around them.