Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Session IV.3
Review of the Seismology component of the training course
April 6, 2006
Sri Lanka
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Handout pages 63, 75-80
Frequency distribution of earthquakes
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Number of Earthquakes Worldwide for 2000 - 2006 Located by the US Geological Survey National Earthquake
Information Center
Magnitude 2000 2001 2002 2003 2004 2005 2006
8.0 to 9.9 1 1 0 1 2 1 0
7.0 to 7.9 14 15 13 14 14 10 4
6.0 to 6.9 158 126 130 140 141 150 21
5.0 to 5.9 1345 1243 1218 1203 1515 1720 239
Log N = a - bM
Handout pages 101-114
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Elastic Rebound Theory
Handout pages: 62, 95
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Handout pages:48-60, 72
Forward Branch
Backward Branch
Forward Branch
Shadow Zone
P waves
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Ray paths
. “Whole Earth Geophysics” by Robert J. Lillie
Handout pages:82-94
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Love Waves
vertical
radial
transverse
Rayleigh Waves
P S
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Handout page 70
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
ML Local magnitude (California) regional S and 0.1-1 sec surface waves
Mj JMA (Japan Meteorol. Agency) regional S and 5-10 sec surface waves
mb Body wave magnitude teleseismic P waves 1-5 sec
Ms Surface wave magnitude teleseismic surface 20 sec wavesMw Moment magnitude teleseismic surface > 200 sec wavesMwp P-wave moment magnitude teleseismic P waves 10-60 sec
Mm Mantle magnitude teleseismic surface > 200 sec
waves
Types of Magnitude ScalesPeriod Range
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Relationship between different types of magnitudes
Handout pages:65-69, 118-121, 125-126
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
hypocentral locations
. “Whole Earth Geophysics” by Robert J. Lillie
Handout pages:64, 115-117 & Dr Kayal’s notes on the CD
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
. “Whole Earth Geophysics” by Robert J. Lillie
Handout pages 73-75, 98-100, 122-124
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
• Key topics covered in the seismology component of the course:– Global distribution and frequency of earthquakes.– Elastic rebound theory.– The particle motion and path through the Earth of
major seismic phases (P, S, Surface waves).– Identification of P, S and surface wave arrivals
on a seismogram.– Earthquake magnitude scales.– The principles of hypocentral location.– Focal mechanisms.– Recording station operations and seismic
networks
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Vault of an observatory
Handout pages:127-130
Sri Lanka Earthquake & Tsunami Warning Training ProgramSri Lanka Earthquake & Tsunami Warning Training Program
Handout pages 131-132