Residents of the San Ramon Valley are set to hear from a seismologist about a recent surge in earthquake activity that has drawn attention across the region. A researcher from the Berkeley Seismological Laboratory will speak Friday at the San Ramon Community Center, addressing why nearly 100 earthquakes have been recorded in the valley over the past 30 days. The most significant event occurred on the morning of February 2, when a magnitude 4.2 tremor shook the area. The quake was wi