<Li> Primary effects: which are the surface expression of the seismogenic source (e.g., surface faulting), normally observed for crustal earthquakes above a given magnitude threshold (typically M = 5.5--6.0); </Li> <Ol> <Li> Secondary effects: mostly this is the intensity of the ground shaking (e.g., landslides, liquefaction, etc .). </Li> </Ol> <Li> Secondary effects: mostly this is the intensity of the ground shaking (e.g., landslides, liquefaction, etc .). </Li> <P> The importance of a tool to measure earthquake Intensity was already outlined early in the 1990s . In 2007 the Environmental Seismic Intensity scale (ESI scale) was released, a new seismic intensity scale based only on the characteristics, size and areal distribution of earthquake environmental effects . </P>

The effect caused by earthquake on the environment of south africa