1. EPSC 330 - Earthquake Detection Systems
Yousef Eshaq & Numan Malik
March 27th

2. Earthquakes
Destructive nature of earthquakes requires the need for detection systems. Particularly early detection systems.

3. Energy released by Earthquakes
log10 E = M
Where M is the magnitude of earthquake in Richter Scale.
Ex. An Earthquake of M=4.5, Releases:
 3.55E+20 J
An Earthquake of M=9, Releases energy enough to cover 60% of the annual Canadian household consumption.
Equivalent to 25,000 Nuclear bombs

4. Earthquake Detection. Earliest Seismoscope 132 A.D
Invented by the Chang Heng
Instrument is reported to have detected a 400 mile distant Earthquake.

5. Europe 18th Century
J. de la Haute Feuille—Bowl of Mercury. (Responds to tilting of the Earth’s surface rather than horizontal displacements)
Nicholas Cirillo (1747)—Pendulums (Amplitude of oscillations)
Andrea Bina (1751)—Pendulum with pointer attached.
D. Domemico Salsano—Pendulum with ink.
Note: Calabrian Earthquakes (1783) induced a lot of interest.

6. 19th Century Forbes Seismometer.
Inverted pendulum supported by wire with
adjustable stiffness.
Friction due to pencil affected readings.

7. Explosion Seismology
Robert Mallet (1851)— Measured speed of elastic waves from Dynamite explosions to approximate the velocity of Earthquake waves.

8. Palmieri’s Seismoscope
 Using tubes of mercury and electricity, he was able to record earthquake time and intensity

9. Important dates preceding Palmier’s Seismograph (5)
1879- Seismographs developed in Japan.
1903-International Seismological Association Formed
1906 - Galitzin electromagnetic seismograph
developed in Russia
1935 - Charles Richter publishes Richter Scale measuring intensity of earthquake energy

10. Modern Earthquake Detection
Seismometer
Seismograph

11. CMG-40T Triaxial Broadband Seismometer
Lightweight for quick installation
Digital Output
Force Feedback
Waterproof

12. Model S-13
Period adjust Simplified field maintenance Excellent stability over long periods of time More than 4500 units in operation

13. Teleseismometers CMG-40TOBS
A low frequency 3-direction seismometers A small mass is confined by electric forces Using feedback control the mass is kept steady as the container moves. Forces required to keep mass steady are recorded.

14. Working Principle of Seismometer
Using a mass, spring, and damper system, seismometers can record the vibrations of the case. Typically using large mass and low spring stiffness. As the base moves the suspended mass remains still. Modern seismometer record the movements of the earthquake digitally.

15. Early Warning Earthquake Detection Systems
Detecting P-waves, to provide early warning before the arrival of an S-wave.

16. Conclusion
Seismometer are important tools to understand and study earthquakes. Early warning systems are proven to be effective, if implemented into an existing infrastructure correctly.

17. Refrences http://www.math.wichita.edu/~richardson/earthquake.html
tectonics-earth-structure-user-submitted-questions/what-energy
eng.htm