Surface deformation associated with dip‐slip faulting

A fault surface may be represented by a rectangular surface of horizontal length 2L, width W, and dip δ embedded in an elastic half-space with the top of the fault a depth h below the free surface. The vertical displacement of the free surface for a dip-slip motion Δu on such a fault surface can be calculated from the theory of Maruyama. This calculation has been made for fault models of three different earthquakes, and the results compared with the observed surface deformation in each case. For each calculation the dip of the fault plane was taken from the P wave fault plane solution. The preferred fault models are as follows: Alaska earthquake of March 28, 1964 (magnitude 8.4), 2L = 600 km, W = 200 km, δ = 9°, h = 20 km, and Δu = 10 m. Fairview Peak, Nevada, earthquake of December 16, 1954 (magnitude 7.1), 2L = 24 to 48 km, W = 6 km, δ = 62°, h = 0 km, and Δu = 2 m. Hebgen Lake, Montana, earthquake of August 18, 1959 (magnitude 7.1), 2L = 30 km, W = 15 km, δ = 54°, h = 0.4 km, and Δu = 10 m.