“And in the case of these maps, we have increased the hazard in many areas because we have added new details on the soils and how they modify the ground shaking," Petersen told weather.com in an ...

"Hazard maps for California as well as Japan ... including the extent that ground shaking depends on local geology, but none of these were big enough to explain the problem," Gallahue said.

The first main earthquake hazard (danger) is the effect of ground shaking. Buildings can be damaged by the shaking itself or by the ground beneath them settling to a different level than it was before ...