Unfortunately, many buildings and communities are built on ground types that resemble the bowl of gelatin. Ancient lake beds are characterized by a thick layer of soft clay. The result is that buildings constructed on soft clay are shaken off their foundations. If they were built over bedrock, many buildings would withstand an earthquake and remain intact. The ground changes its properties rapidly, so that it no longer acts as a solid, but instead as more of a liquid.
Liquids are unable to support heavy structures, so the buildings collapse.
On the other hand, light objects such as underground storage tanks can float up to the surface. Fill is poured into a shallow water area to create more land. The most severe damage done by an earthquake is commonly concentrated in areas where sediment is saturated with water. Early Childhood Opportunity Young children can explore the effect of vibrations on a block structure using a radio. Lay the radio flat and have the children stack several small wooden or plastic blocks on top of one of the speakers.