Sri Lanka Earthquake Tsunami Warning Training Program Session

Sri 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 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 Program Handout pages 63, 75 -80

Sri Lanka Earthquake & Tsunami Warning Training Program Frequency distribution of earthquakes 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. 9 158 126 130 141 150 21 5. 0 to 5. 9 1345 1243 1218 1203 1515 1720 239 Log N = a - b. M Handout pages 101 -114

Sri 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 Program Elastic Rebound Theory Handout pages: 62, 95

Sri 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 Program Handout pages: 48 -60, 72

Forward Branch Shadow Zone P waves Forward Branch Backward Branch

Sri Lanka Earthquake & Tsunami Warning Training Program Ray paths Handout pages: 82 -94 . “Whole Earth Geophysics” by Robert J. Lillie

Sri 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 Program P S Rayleigh Waves vertical radial Love Waves Handout page 70 transverse

Sri 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 Program Types of Magnitude Scales Period Range ML Local magnitude (California) regional S and surface waves 0. 1 -1 sec Mj JMA (Japan Meteorol. Agency) regional S and surface waves 5 -10 sec mb Body wave magnitude teleseismic P waves 1 -5 sec Ms Surface wave magnitude 20 sec Mw Moment magnitude Mwp P-wave moment magnitude teleseismic surface waves teleseismic P waves Mm Mantle magnitude teleseismic surface waves > 200 sec 10 -60 sec > 200 sec

Sri 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 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 Program hypocentral locations Handout pages: 64, 115 -117 & Dr Kayal’s notes on the CD. “Whole Earth Geophysics” by Robert J. Lillie

Sri 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 Program. “Whole Earth Geophysics” by Robert J. Lillie Handout pages 73 -75, 98 -100, 122124

Sri 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 Program Vault of an observatory Handout pages: 127 -130

Sri Lanka Earthquake & Tsunami Warning Training Program Handout pages 131 -132