Sleep tracking is one of the best features of the Jawbone Up fitness tracker, but it could serve a purpose beyond helping you feel less groggy in the morning. Jawbones data science team has collated the sleep information from last night in northern California — which was hit by its biggest earthquake in 25 years — and used it to show what percentage of Up wearers in each city were woken up at 3.20AM PT. Napa was among the worst affected areas, whereas Santa Cruz barely registered a tremor, according to the sleep data.
