Capacity: 
The
resources of communties to cope with a threat or resist the imapct of the harazd.

Risk:

The Probabilty/likelihood of disaster happening. 
Vulnerability: 
The degree to which communities are susceptible to
loss,damage, suffering and death, in disaster.(also nature of
bulding,types,ages etc.) 
Hazard: 
The physical event that can potenially triggger a
disaster.Such a phyiscal event in itself need not necessaily result in disaster. 
Disaster Proneness: 
Likeihood of location being affected by disaster. 
Earthquake: 
Shaking of the Earth caused by a sudden
movement of rock beneath its surface. (USGS National Earthquake Information
Center, 1999) The release of stored
elastic energy caused by sudden fracture and movement of rocks inside the Earth. Part of
the energy released produces seismic waves, like P, S, and surface waves, that travel
outward in all directions from the point of initial rupture. These waves shake the ground
as they pass by. An earthquake is felt if the shaking is strong enough to cause ground
accelerations exceeding approximately 1.0 centimeter/second squared. (Noson, et.al.,
1988

Epicenter: 
That point on the Earth's surface directly
above the hypocenter of an earthquake. (USGS National Earthquake Information Center,
1999) The location on the surface of the Earth directly above the focus, or place
where an earthquake originates. An earthquake caused by a fault that offsets features on
the Earth's surface may have an epicenter that does not lie on the trace of that fault on
the surface. This occurs if the fault plane is not vertical and the earthquake occurs
below the Earth's surface. (Noson, et.al., 1988) 
Fault 
A break in the Earth along which movement
occurs. Sudden movement along a fault produces earthquakes. Slow movement produces
aseismic creep. (Noson, et.al., 1988) 
Focus: 
That point within the Earth from which
originates the first motion of an earthquake and its elastic waves. (USGS National
Earthquake Information Center, 1999) 
Intensity: 
A measure of severity of shaking at a
particular site. It is usually estimated from descriptions of damage to buildings and
terrain. The intensity is often greatest near the earthquake epicenter. Today, the
Modified Mercalli Scale is commonly used to rank the intensity from I to XII according to
the kind and amount of damage produced. Before 1931 earthquake intensities were often
reported using the RossiForel scale. (Noson, et.al., 1988) A measure of the effects of an earthquake at a particular place on
humans, structures and (or) the land itself. The intensity at a point depends not only
upon the strength of the earthquake (magnitude) but also upon the distance from the
earthquake to the opint and the local geology at that point. (USGS National Earthquake
Information Center, 1999)

Magnitude: 
A quantity characteristic of the total
energy released by an earthquake, as contrasted with intensity, which describes its
effects at a particular place. A number of earthquake magnitude scales exist, including
local (or Richter) magnitude, body wave magnitude, surface wave magnitude, moment
magnitude, and coda magnitude. As a general rule, an increase of one magnitude unit
corresponds to ten times greater ground motion, an increase of two magnitude units
corresponds to 100 times greater ground motion, and so on in a logarithmic series.
Commonly, earthquakes are recorded with magnitudes from 0 to 8, although occasionally
large ones (M=9) and very small ones (M= 1 or 2) are also recorded. Nearby earthquakes
with magnitudes as small as 2 to 3 are frequently felt. The actual ground motion for, say,
a magnitude 5 earthquake is about 0.04 millimeters at a distance of 100 kilometers from
the epicenter; it is 1.1 millimeters at a distance of 10 kilometers from the epicenter. (Noson,
et.al., 1988) A numerical expression of the
amount of energy released by an earthquake, determined by measuring earthquake waves on
standardized recording instruments (seismographs). The number scale for magnitudes is
logarithmic rather than arithmetic; therefore, deflections on a seismograph for a
magnitude 5 earthquake, for example, are 10 times greater than those for a magnitude 4
earthquake, 100 times greater than for a magnitude 3 earthquake, and so on. (Foxworthy
and Hill, 1982)

Richter Magnitude
Scale 
The Richter magnitude scale was developed in
1935 by Charles F. Richter of the California Institute of Technology as a mathematical
device to compare the size of earthquakes. The magnitude of an earthquake is determined
from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are
included for the variation in the distance between the various seismographs and the
epicenter of the earthquakes. On the Richter Scale, magnitude is expressed in whole
numbers and decimal fractions. For example, a magnitude 5.3 might be computed for a
moderate earthquake, and a strong earthquake might be rated as magnitude 6.3. Because of
the logarithmic basis of the scale, each whole number increase in magnitude represents a
tenfold increase in measured amplitude; as an estimate of energy, each whole number step
in the magnitude scale corresponds to the release of about 31 times more energy than the
amount associated with the preceding whole number value. (USGS National Earthquake
Information Center, 1998) 