Download to read offline
Uploaded byRandhawa Velly
Earthquakes notes
The document discusses earthquakes, explaining their causes, types, and measurements, including the use of seismographs and scales like the Richter and Mercalli. It highlights the devastating impact of major earthquakes, particularly in regions like Japan and India, and emphasizes the inevitability of such natural calamities. The conclusion suggests that while earthquakes cannot be prevented, future scientific advancements may provide remedies.
Earthquakes notes
- 1. •Akal Academy Dhindsa •Project: S.St. • Session: 2012-2013 • Submitted to: Renu Bala • Submitted by: Harshpreet Singh
- 2.
- 3. Introduction • Earthquake isa terrible kind of natural calamity. where earthquake occurs the earth shakes. If the earth shakes violently, the result is disastrous. Man may escape other kinds of calamity. But if earthquake occurs, there is no way out.
- 4. What is anearthquake? • Used to describe both sudden slip on a fault, and the resulting ground shaking and radiated seismic energy caused by the slip • Caused by volcanic or magmatic activity, • Caused by other sudden stress changes in the earth.
- 5. Three Types ofFaults Strike-Slip Thrust Normal
- 6. What causes earthquakes? •Tectonic plates move past each other causing stress. Stress causes the rock to deform – Plastic deformation – does not cause earthquakes – Elastic deformation – rock stretches then reaches a breaking point, releasing energy.
- 7. Elastic Rebound –deformed rock goes back to its original shape
- 8. Focus – pointinside the Earth where an earthquake begins Epicenter – point on Earth’s surface above focus
- 9. How Seismographs Work thependulum remains fixed as the ground moves beneath it
- 10.
- 11. Primary Waves (PWaves) • A type of seismic wave that compresses and expands the ground • The first wave to arrive at an earthquake
- 12. Secondary Waves (S Waves) •A type of seismic wave that moves the ground up and down or side to side
- 13.
- 14. Surface Waves • Movealong the Earth’s surface • Produces motion in the upper crust – Motion can be up and down – Motion can be around – Motion can be back and forth • Travel more slowly than S and P waves • More destructive
- 15. How do scientistscalculate how far a location is from the epicenter of an earthquake? • Scientists calculate the difference between arrival times of the P waves and S waves • The further away an earthquake is, the greater the time between the arrival of the P waves and the S waves
- 16.
- 17.
- 18.
- 19. How are EarthquakesMeasured? Richter Scale
- 20. How are EarthquakesMeasured? Mercalli Intensity Scale
- 21. Earthquake Waves &Earth’s Interior
- 22.
- 23.
- 24. Formation of atsunami
- 25.
- 26. Largest earthquake inthe world • More than 2,000 killed, 3,000 injured, 2,000,000 homeless, and $550 million damage in southern Chile • tsunami caused 61 deaths • $75 million damage in Hawaii; • 138 deaths and $50 million damage in Japan; • 32 dead and missing in the Philippines; • and $500,000 damage to the west coast of • the United States.
- 27. Conclusion • Earthquakes arenot new to the world. It is a very common thing on many parts of the earth. Japan is the constant victim of earthquakes. So, the Japanese make houses of paper boards. India, too is not altogether free from this natural calamity. But in India, it is very few and far between. In 1993 Maharashtra had faced a terrible shock from a divesting earthquake and the Latoor are was completely damaged. Earthquake cannot be prevented. They catch up by surprise. Hence, let us wait for the scientific developments that may find a remedy to this terrible upsurge.
Editor's Notes
- #6 Three types of faults Form depending on type of plate motion and complex reaction of earth’s lithospheric blocks Strike-slip Normal Thrust