RICHTER classifies the effects of earthquakes into two main categories: primary effects and secondary effects.
- Primary effects
These include all such effect that are Directly related to the cause of origin of an earthquake.the tectonic earthquakes are often responsible for producing many important changes in the geological structure of an area:creation of slopes or scraps,fissures ,warping of strata , emergence or subsidence of coastlines;changes in the courses of streams; origin of new springs and creation of sandy dykes in which saturated layers of sand may be forced up into existing cracks and crevices.
2 . secondary effects
All those effects which are related to passsage of seismic waves and associated shaking motion of the ground during an earthquake are broadly grouped as secondary effects.the distinction is ,of course, subtle and more of theoretical rather than of practical importance.the secondary effects are observed on construction of all types.
