More than a dozen small earthquakes were reported in the Fontana area over the past day, including one of magnitude 2.3 Thursday morning. Weak shaking from the quake reported just before 8 a.m. Thursday was reported in Arcadia, Rancho Cucamonga, Fontana, Riverside and other inland communities. The shallow quake had a depth of 3.2 kilometers. Depths of 0 to 70km are considered shallow, according to the USGS, which can impact how and where shaking is felt.