As I'm sure you know, California was hit with a 7.1 earthquake last week. The quake caused widespread damage and result in smaller (6.4) aftershocks. I have never thought about the effect of an earthquake on a swimming pool. I know that sounds stupid but, I've never really even thought about it! A lot of people went viral filming their pools swaying during the quake. Some pools shook more than others, some had high waves, some barely moved. This woman's pool became an angry wave pool. She seems to have problems getting up off the deck during the quake. Is she trying to protect her phone? That would be the last thing I'd be worried about. But I guess when you're used to earthquakes, you just keep calm and protect your phone.
Here's another video I found from the 6.1 earthquake in the Philippines. The water cascading down the side of the building is from a penthouse swimming pool! Thankfully nobody was in the pool at the time. They could have possibly been tossed out of the pool and over the edge of the building.