EARTHQUAKE MAGNITUDE INTENSITY ENERGY POWER LAW RELATIONS AND
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EARTHQUAKE MAGNITUDE, INTENSITY, ENERGY, POWER LAW RELATIONS AND SOURCE MECHANISM Walter D. Mooney U. S. Geological Survey California, USA e-mail: mooney @ usgs. gov
EARTHQUAKE CLASSIFICATION MAGNITUDE M ≥ 8. 0 CLASSIFICATION Great Earthquake 7. 0 ≥ M < 8. 0 Major / Large Earthquake 5. 0 ≥ M < 7. 0 Moderate Earthquake 3. 0 ≥ M < 5. 0 Small Earthquake 1. 0 ≥ M < 3. 0 Microearthquake M < 1. 0 Ultra Microearthquake Hagiwara, 1964
NATURE OF EARTHQUAKES 1) Foreshocks 2) Main shock 3) Aftershocks 4) Earthquake Swarm 5) Normal Seismic activity
TYPES OF EARTHQUAKES 1) Tectonic Earthquake 2) Volcanic Earthquake 3) Collapse Earthquake 4) Explosion Earthquake CLASSIFICATION DISTANCE 1) Teleseismic Earthquake > 1000 km 2) Regional Earthquake > 500 km 3) Local Earthquake < 500 km
EARTHQUAKE MAGNITUDE Richter Magnitude ML (Local Magnitude) ML = log A - log Ao ( ) Body-wave Magnitude (mb) mb = log (A/T) - f ( , h) Surface-wave Magnitude (Ms) Ms= log AHmax - log Ao ( o) MS = log (A/T)max + 1. 66 log + 3. 3 Moment Magnitude (Mw) Mw = 2/3 log Mo - 10. 7 Mo = A u Duration Magnitude (MD) MD = - 0. 87 + 2. 00 log + 0. 0035 Macroseismic Magnitude (Mms) Mms = 0. 5 Io + log h + 0. 35
Richter Magnitude Scale Distance km S–P sec Magnitude ML Amplitude mm
EARTHQUAKE INTENSITY Ø Rossi-Forel Intensity Scale (I – X) Ø Modified Mercalli (MM) Intensity Scale (1956 version), (I – XII) Ø Medvedev-Sponheuer-Karnik (MSK) Intensity Scale (1992 Version), (I – XII) Isoseismals are the curved lines joining the localities of same intensity.
EARTHQUAKE ENERGY log E = 12 + 1. 8 ML log E = 5. 8 + 2. 4 mb log E = 11. 4 + 1. 5 Ms Magnitude versus ground motion and energy Magnitude Ground Motion 1. 0 0. 5 0. 3 0. 1 10. 0 times 3. 2 times 2. 0 times 1. 3 times Energy about 32 times about 5. 5 times about 3 times about 1. 4 times
POWER LAW RELATIONS Frequency- magnitude Relation Log 10 N = a – b. M Aftershock Attenuation (p-value) N(t) t -p Fractal Dimension
b - VALUE ESTIMATION The Least-Square Fit Method: The log values of the cumulative number of earthquakes (N) are plotted against magnitude (M). The Maximum Likelihood Method : The maximum likelihood estimate of b-value is given by Aki ( 1965) : b =log 10 e/M-M 0
b-value: Log N b = 0. 77 Magnitude An example showing frequency-magnitude relation in NE India
SOURCE MECHANISM (fault-plane solution) Classification of Faults Dynamics of Faulting Elastic Rebound Theory v v v Thrust Fault Normal Fault Strike-slip Fault v v Single Couple Double Couple
Normal fault Regime Thrust fault Regime Strike-slip fault Regime
Fault Dimension
Different Types of Faulting
Graben & Horst in Fault System
Dynamics of Faulting
Elastic Rebound Theory Reid, 1910
Plotting of P-wave First-motion (Equal Area Projection)
Equal Area Plot of a Plane and its Pole
P-wave first-motion plot and fault plane solution Kayal, 1984
Source mechanisms of earthquakes at spreading centre
Source mechanisms of earthquakes at the subduction zone, Indo-Burma ranges Rao & Kalpana, 2005
- Earthquake magnitude classification
- What is the richter scale
- San francisco earthquake 1906 magnitude
- Earthquake intensity depends primarily on the height of
- Parsec distance
- Magnitude intensity
- Newton's first law and second law and third law
- Newton's first law
- Employee relations in public relations
- Triangle of power
- Mercalli scale
- When an earthquake occurs energy radiates in all directions
- Energy energy transfer and general energy analysis
- Energy energy transfer and general energy analysis
- R in coulomb's law
- Lattice energy trends
- Increasing lattice energy trend
- Boyle's law charles law avogadro's law
- Constant in avogadro's law
- Lambert beer law
- Balance of power in international relations
- Balance of power in international relations
- Puget sound energy investor relations
- Power-law (gamma) transformations
- Focus and epicenter of an earthquake