Thomas chinnappan geologist keeranur, pudukkottai, tamilnadu, india.

1. PLATE BOUNDARY
RELATED
EARTHQUAKES
BY:
THOMAS CHINNAPPAN . A ,
M.SC.APPLIED GEOLOGY,
PERIYAR UNIVERSITY,
SALEM.

2. Earthquake and plate tectonics
• Earthquake belts and distribution. Earthquakes occur in
well‐defined belts that correspond to active plate tectonic
zones.
• The circum‐Pacific belt (also called the Rim of Fire) follows the
rim of the Pacific Ocean and hosts over 80 percent of the world's
shallow and medium‐depth earthquakes and 100 percent of the
deep earthquakes.

4. • Plate boundaries and associated earthquakes. Distribution
plots reveal that many earthquakes are associated with
andesitic volcanic action
• And oceanic trenches that occur over subduction zones in
the circum‐Pacific belt.
• Oceanic trenches are narrow, deep troughs that mark where
two plates converge, usually along the edge of a continent or
island are where andesitic volcanoes typically occur.

5. They are three types of plate boundaries...

6. There are two kinds of convergent boundaries: subduction
and collision.
 A subduction boundary is marked by
the oceanic crust of one plate that is
being pushed downward beneath the
continental or oceanic crust of another
plate.
 A collision boundary separates two
continental plates that are pushed into
contact; the suture zone is the line of
collision. Both types of boundaries have
distinctive earthquake patterns.

7. Divergent boundaries
 Divergent boundaries are those at
which crustal plates move away
from each other, such as at
midoceanic ridges. These huge
underwater mountains often have
a central graben feature, or rift
valley, that forms at the crest of
the ridge.

8. Transform boundaries
 Transform boundaries where two
plates move past each other. The
earthquakes originate in the
transform fault, or in parallel
strike‐slip faults, probably when a
frictional resistance in the fault
system is overcome and the plates
suddenly move.

9. Thank you...