One of the made-up facts in media reporting of earthquakes is the obligatory statement that the quake was felt from x location to y location, and usually to 3rd location because reporters love sequences of three. The observations, however, are anecdotal and typically kind of random based on what the reporter has heard and how well he or she understands maps and California geography. The USGS publishes shake maps that show generally where a quake was likely felt, which add a little actual data to the process. But after Sunday's South Napa earthquake, Jawbone — maker of one of those devices some people wear on their wrist to monitor their movement and sleeping — added a new wrinkle to quake reporting. Actual data from those users shows a very graphic spike in when Up wearers started moving. Turns out that almost everybody in the Napa and Vallejo areas got up when the quake hit at 3:20 a.m. and half of those stayed up the rest of the night. In San Francisco and Oakland, just 55 percent of Up users got up.
From the company's blog, which fed reporters the story and has the graphic in a bigger form:
Napa, Sonoma, Vallejo, and Fairfield were less than 15 miles from the epicenter. Almost all (93%) of the UP wearers in these cities suddenly woke up at 3:20AM when the quake struck. Farther from the epicenter, the impact was weaker and more people slept through the shaking. In San Francisco and Oakland, slightly more than half (55%) woke up. As we look even farther, the effect becomes progressively weaker — almost no UP wearers in Modesto and Santa Cruz (and others between 75 and 100 miles from the epicenter) were woken up by the earthquake, according to UP data.