Theories on earthquake causes

1. Engineering Seismology by A.Jyothirmai is licensed under a Creative Commons Attribution-ShareAlike 4.0
International License.

2. REID’S ELASTIC REBOUND THEORY
oProfessor H.F Reid ,German geologist-Professor at John
Hopkins University , Germany
oStress inside Earth implies pressure developed
oStrain implies the deformation occurred in the rock
oRocks can take 1-2% of elastic strain
oThe gradual accumulation and release of stress and strain
is referred to as “elastic rebound theory”

3. THEORY OF PLATE TECTONICS
oEpicenter
oInterplate/Intraplate
oAlfred Wegener gave the “Continental Drift Theory” in
1915 in the book “ On the Origin of Continents and
Oceans”
oPangaea-huge super continent
oInitially rejected, accepted after 50 years.

4. Major scientific developments
• Demonstration of ruggedness in the form of oceanic
ridges , island arcs, trenches and youthness of the
ocean floor
• Confirmation of repeated reversals of earth magnetic
field I the geologic past
• Emergence of Sea floor spreading hypothesis by Hess
in 1962
• Concentration of Earthquakes and Volcanic activity
along oceanic trenches and submarine mountain
ranges.

5. Narrow Zones
• The Circum - Pacific “Ring of Fire”
• The Alpine - Himalayan Belt
• The World - Circling Oceanic Ridges
12 Major Plates
Antarctica, Africa, Eurasia, India, Australia, Arabia,
Philippines, North America, South America, Pacific,
Nazca & Cocos