Observations in Chronological order

Day 1, Late Afternoon Oct. 7

Location 1, 133o19.9'E, 35o25.1'N (marked with red dots on map).

Visit to the cemetaries at the Keijuji- and Sousenji-temple: A few gravestones were toppled. The gravestones slipped on the average about 1 cm and some 70 % of them rotated clockwise.
Toppled Gravestones at cemetary Toppled Gravestones at cemetary
As first estimate one can assume that to topple the gravestones an acceleration of 0.33g is necessary since the height to width ratio is 1:3. For the rotation to occur one can assume that the gravestone where slightly tilted in a vertical plane at the same time as accelearated horisontally in a direction perpendicular to the vertical plane. From the slippage observations, assuming a friction ratio of 0.5 (m), and using the formula: (1/2)mv2=mgmD  it is possible to estimate a velocity of 30 cm/s corresponding to the average slippage of 1 cm (D).