Global seismic network in operation for 40 years

• Global seismic network in operation for ~40 years provides a huge database of information on earthquakes: • Location, Depth • Magnitude, Frequency • Total Energy released • Type of Faulting and orientation of fault planes • State of stress in brittle material

Subduction (Indonesia)

Terminology

• A typical seismogram and determination of range

Earthquake Locations • Accuracy ~ 10 km, slightly larger error in depth. • Geographic distribution: Pattern of plate boundaries

Energy and Polarity of “First Motions”

Earthquake on a vertical plane

Determination of nodal planes

Spreading of the seismic wave

Data on the surface, interpreted as a section

Azimuth (f) and take-off angle

In General have we seismic data from faults with any orientations – plot a stereogram

Fault types and “Beach Ball” plots

Example Focal mechanism diagrams on the Azores. Gibraltar fracture zone

Seismic Focal Mechanisms: Summary &Applications • Detection at a distance via the world network Energy and Polarity of “First Motions” • Plot polarity against azimuth and “take-off angle” • Determine orientation of Fault-plane • [explosions v. earthquakes]

Brief Facts About: By Dr. Qamar-uz-Zaman Chaudhary Director General Pakistan Meteorological Department pmd@pakmet. com. pk

Pakistan Meteorological Department

Seismogram

PAST SEISMIC HISTORY OF PAKISTAN

Earthquake in Quetta: 1935 7. 7 35, 000 Railway Station

Earthquake in Quetta: 1935 7. 7 35, 000 Lytton Road

Earthquake in Pakistan: 1892 6. 8 Chaman: Balochistan

Earthquake in Kangra: 1905 7. 8 Himachal Pradesh 19, 727 Town Hall Lahore Before After

M 7. 5 KASHMIR EARTHQUAKE ON OCTOBER 8, 2005

PAKISTAN METEOROLOGICAL DEPARTMENT M 7. 5 EARTHQUAKE OF 8 TH OCTOBER 2005 IN NORTHERN PAKISTAN EPICENTRE: 34. 4°N, 73. 5°E DEPTH: 10 KM

Shake. Map OF OCTOBER 8, 2005 EARTHQUAKE

KNOW THE RISK FOR FUTURE MITIGATION

Up-gradation of National Seismic Network for Pakistan (Approved June, 2005) National Seismic Control Room Peshawar National Geophysical Centre Quetta Chitral Mansehra Zhob Khuzdar Turbat National Tsunami Early Warning Centre (TWC), Karachi Muzaffarabad

Establishment of Tsunami Warning Center in Pakistan Backup Tsunami Warning Centers Information to Regional / Global Mitigation Centers Linkage with other Regional /Global TWS National Tsunami Early Warning Centre (TWC), Karachi

Thank You All