(I suppose I should give a little context: I have a lengthy history of earthquake experience, and areas that don’t get very many are oftentimes vulnerable to disaster when surprises hit so I was genuinely relieved to hear people were largely ok from this temblor! I’ve lived on the Ring of Fire my whole life and am something of an earthquake pro just by circumstance, including participating in disaster response efforts in the aftermath. I kicked off with Loma Prieta in California in the 80s - I was 3 and I still remember it. My mom and I and our neighbor mom and her kids were walking our dogs, the street asphalt rippled like water and a lady came rushing screaming into the street only half-wrapped in a towel. She had been in the shower when it hit and I still have a visual of this poor woman from my 3yo perspective, a good 34 years later! Our power went out and our street all pooled resources- a chicken that had been in a CrockPot, people’s soda stashes or chips, a battery-operated TV, some radios for news… we turned it into an earthquake block party!
I’ve been through a number of other “major” quakes - a handful in the 6-8 range over the years, including several 7s in Southeast Asia that didn’t get name recognition - but my biggest one was the 2011 Tohoku quake. I was living there teaching English in that region of Japan when that one hit, followed by the tsunami and nuke meltdown. The Richter scale is logarithmic not linear, so worth remembering that when you see magnitudes reported! Loma Prieta was a 6.9 and Tohoku was a 9.1. Tohoku was the fourth-largest earthquake ever recorded. Both struck in regions that were well-prepared and they still did major damage, so I was prepared for bad news off the East Coast! Thank goodness everyone seems mostly ok just shook up some. Mother Nature is scary when she’s mad! 
)
To tie this back to swimming, in Loma Prieta everyone who was in the pool at our local YMCA literally got washed up on deck during the quake! Our across the street neighbor and her whole water aerobics class ended up next to the bleachers. Only minor injuries though thankfully!