Pakistan Earthquake 2005Pakistan Earthquake 2005

Peter Parsons and Geraint Roberts

LocationLocation

• 8:50:39 am on the 8th October 2005

• Measured 7.6 on the Richter scale

• Epicenter was 19km northwest of Muzaffarbad and 95km north-northeast of Islamabad, in Kashmir region of Pakistan

• Caused by faulting under the stress field due to the collision of Indian and Eurasion plates

• High density of active faults on eastern side of the colliding plates

• 2 responsible faults – Muzaffarabad and Tanda Faults located in the Hazara Kashmir Syntaxis, in the northwestern end of the Himalayan front

ConsequencesConsequences

• Reactivation of the Indus Kohistan Seismic zone and the right-lateral Chail Sar Thrust in the northwest

• Rupture zone passes through Balakot, Muzaffarbad, Kardalla, Bandi Karim Haideshah, Sarain, Chikar and Sudangali. 120 km in length

• Active rupture resulted in 2.5 m reverse slip and a 2 m right lateral slip

• Landslides formed from ground shaking, gravity collapse and induced tectonic activity

• Largest landslides recorded in Bagh causing interruption to the main highway between Islamabad and Muzaffarabad

ConsequencesConsequences

• Earthquake felt in NE Pakistan, North India and SE Afghanistan

• Main aftershocks felt at the Northwestern end of the fault trend

• 47 aftershocks within 30 days of initial quake of magnitudes of 5.0 or greater on the Richter scale

• Caused severe surface co-seismic rupture in the epicenter region damaging roads and leading to difficulty in relief effort

GeologyGeology

• Main rock types in epicenter area– Schists– Sandstone– shale– Dolomitic limestone

• Limestone is particularly susceptible to intense shearing resulted in most failures in the region

• Rock falls occurred mainly in sandstone slopes

Cause of Destruction Cause of Destruction

• The ground shaking• Slope failure• Structural collapse• Basement failure• Liquefaction• Old building material• Structural design

Resulting in the death of over 80,000 lives and leaving 3.3m people homeless

Improvements to InfrastructureImprovements to Infrastructure

• 75% of worldwide earthquake fatalities caused from collapse of buildings

• Building materials primarily weak un-reinforced masonry – Adobe, Rubble stone, Rammed Earth

• Concrete Lacing and Reinforcement• Drainage• Mortar quality

• Quality control

Slope StabilitySlope Stability

• Housing and road access

• Solutions– Retaining Walls– Rock bolting– Gabions– Drainage– Anchorage– Rock Shade

Current SituationCurrent Situation

• Only $1b of the $6.5b pledged has been received by the Pakistani government

• A large proportion of people still remain in refugee camps

• Reconstruction work is slow, exacerbated by rugged terrain and could take over 3 years to complete