Print A magnitude 4.7 earthquake was reported Thursday night 11 miles northwest of Truckee, according to the U.S. Geological Survey. The earthquake early warning app MyShake sent out an earthquake early warning as far away as the San Francisco Bay Area, suggesting a magnitude 6 quake had occurred in Placer County, between the north shore of Lake Tahoe and the town of Truckee. The quake’s magnitude was quickly revised downward to 4.7 on the U.S. Geological Survey’s website for the quake, which struck at 9:35 p.m. The strongest shaking — moderate as defined by the Modified Mercalli Intensity Scale — was calculated by the USGS as only occurring in a remote, mountainous area of the Sierra Nevada northwest of Truckee, along the border of Sierra and Nevada counties.