Seismic Zonal info

1. CONTENTS
•Introduction
•Definition: seismic zoning
•Need of Seismic zoning
•Levels of zoning
•conclusion

2. Introduction
 Earthquakes are the shaking, rolling or sudden shock of the
earth’s surface .these are the natural means of releasing stress.
 Usually last less than a minute but can be felt over large areas. It
can’t be predicted.
 There are many plates along the earth’s surface moves
continuously as these plates move they put forces on themselves
when these forces are large enough the crust is forced to break
and results in release of stored energy.
 Then it moves through the earth in the form of waves that we
feel and call as an Earthquake.

3. Seismic Zonation
Seismic zonation is a process of subdividing the territory into
regions with respect to the level of seismic hazard. The result of
seismic zonation is usually presented as a map, which is based
on seismic hazard map.
Need of Seismic Zonation
Seismic zonation helps to identify vulnerable region to provide
necessary inputs for the earthquake resistant design.

4. Levels of seismic zonation
 Seismic zonation is carried out at three different levels based on
the aerial extent of the region, importance of site, and
population.
 They are Macro, Meso, and Micro levels.
 Macro-level zonation is generally carried carried out for large
landmass such as a state or a country. In this Earthquake hazard
parameters are evaluated with less reliabilty. The typical example
of a macro-level zonation is the seismic zonation map of india
where entire india is divided into four seismic zones

5.  Seismic zonation at the Meso-level is carried out for cities and
urban centers with a population greater than 5,00,000. the
earthquake hazard parameters for the meso-level zonation are
evaluated with greater degree of reliability compared to the
macro-level zoning.
 The Micro-level zonation is carried out for sites which host
critical installations such as nuclear power plant (NPPs). As the
NPPs are considered very sensitive structures, the earthquake
parameters are estimated with highest degree of reliability.
 The top soil conditions are properly counted for carrying out
micro as well as the meso-level zonation.

6. How to carry out seismic zonation
 Hazard estimation- ground shaking, liquefaction, landslides,
tsunami.
 It’s spatial distribution- hazard distribution pattern.
 Hazard integration- representation of consolidated effect all
earthquake hazards.

7. Conclusions
 Seismic zoning map of country is not only guiding to the seismic
status and susceptibility of a region but also indicates the
direction of future work basically aimed at designing.
 Micro level zonation is preferred for critical structures like NPP.
 Meso level is suitable for cities and urban centers.
 Macro level zonation is preferred for a large landmass such as
state or country.

8. THANK YOU