Figure 4.-- Comparison of 1905 main-scarp photograph (A) by Whitman Cross to September 1992 photograph (B) from same position by the authors. The two photographs indicate that, during this 87-year period, considerable material was removed from midheight of the main scarp in the area between the two arrows of the 1905 photograph. The approximate camera position is depicted as a circled "4" on figure 6.