18xx Month day (time GMT) - Magnitude 0.0 Place, County  (Epicenter coordinates:-1xx.x, 3y.y)

M(area) = 0.0 -  Toppozada, T. R. and D. Branum (2002) California M >= 5.5 earthquakes, history and areas damaged, in Lee, W. H., Kanamori, H. and Jennings, P., International Handbook of Earthquake and Engineering Seismology, International Association of Seismology and Physics of the Earth's Interior.