C. D. Farrar D. L. Galloway S. N. Hamlin R. J. Laczniak E.A. Roeloffs M.L. Sorey D.E. Woodcock E.G. Quilty 1995 <p>This report compiles hydrologic observations in southern California associated with the 1994 Mw = 6.7 Northridge, California earthquake. In southern California, the largest ground water level change was a drop of 52 cm at Crystalaire. Most of the steplike water-level changes recorded following the Northridge earthquake agreed in direction with the sign of the calculated coseismic volume strain field. A spring discharge increase at Southern Pacific Springs was reported to have preceded the earthquake by several days. Outside of southern California, water-level changes were also observed, but are not consistent in sign or size with the static strain field of the earthquake sequence.</p> application/pdf 10.3133/ofr95813 en U.S. Geological Survey Hydrologic effects associated with the January 17, 1994 Northridge, California, earthquake reports