Reviews the earthquake phenomenon and its possible relation to ionospheric disturbances. Discusses the basic physical principles involved and the methods upon which instrumentation is being developed for possible use in a tsunami disaster warning system. (GA)

Describes a demonstration of P and S (longitudinal and transverse waves), using students' bodies as media, to explain seismic waves in a geology course. (GA)

Leeuwenhoek's demonstration proving the Earth's rotation, which leads to some significant errors in reasoning, can be reproduced from this article and used to provide an interesting discussion in undergraduate astronomy and physics courses or clubs. (LZ)

Considers cosmic rays and relationship to fields of geophysics and astrophysics. Reveals importance of solar eclipses in the study of cosmic radiation. (CP)

Presents a mathematical explanation for the development of tidal activity. (MVL)