Shaken awake: 6.4 Humboldt County temblor puts state’s quake app to the test in Bay Area

Some Bay Area residents were promptly woken up by a ShakeAlert app notification 10 seconds before a 6.4-magnitude earthquake in Humboldt County early Tuesday morning.

At 2:34 a.m., emergency officials released an alert via the ShakeAlert system operated by the U.S. Geological Survey telling people to drop, cover and hold on for an earthquake that occurred about 8 miles offshore of Ferndale, a town more than 250 miles north of San Francisco.