This paper is about short review of earthquake statistics and efforts for earthquake mitigation, hazard and risk assessment studies in Pakistan. Pakistan and adjoining region lying between longitude 60°E to 78°E and latitude 20°N to 45°N are selected for the study as this region has a history of many large earthquakes because of its location in the region of intersection of three plates namely Indian, Eurasian and Arabian Sea plate. This paper is based on the study of both seismological history of the region which includes recent and historical seismicity based on earthquake catalogue as well as geological knowledge supplemented with available fault system information. In this study, Pakistan and adjoining regions are divided into 14 seismogenic zones. Seismicity of each zone is studied considering also the major cities in the respective zone and type of infrastructure which is mainly responsible for earthquake disaster rather than earthquake itself.
Pakistan has a history of many large earthquakes and its various regions are at high seismic risk due to presence of numerous active faults as the area under consideration is situated on a known high seismic belt bordering various active plates and it has been shown in [
In this paper, both the seismological and geological history of the region has been taken into account, which is based on earthquake catalogue and associated fault system in the region. Geologically Pakistan overlaps two tectonic plates, Eurasian plate and Indian plate. On the north-western edge of Indian plate lies Punjab and Sindh, the Khyber-Pakhtunkhwa and Balochistan lie within the Eurasian plate whereas Azad Kashmir and Northern Areas are prone to strong earthquakes as they lie where two tectonic plates collide. Unfortunately not much attention is being paid to earthquake studies and research work in Pakistan. It was only after 2005 Muzaffarabad earthquake that the government realized the importance of earthquake studies but unfortunately for a short time period. The more recent Ziarat earthquake on 28 October 2008 of M 6.4, Awaran district Balochistan earthquake on September 24, 2013 of M 7.8 and Awaran district Balochistan earthquake on September 28, 2013, M 6.8 and on 26 Oct 2015 of magnitude 7.6 struck northern areas, and all these earthquakes all over the country had created a threat to the human society.
Earthquake Prediction studies is not getting much attention and hence is not an active research field in Pakistan as in other countries prone to earthquake, this is because most of the seismologists in Pakistan take earthquake prediction as fool’s paradise and focus only on the earthquake hazard studies and therefore in the past, few hazard maps based on probabilistic approach which is defined as the likelihood for a specified Peak Ground Acceleration (PGA) value to be exceeded within a certain time interval are available for the region but unfortunately the drawback of this approach is that catalogue completeness is very essential parameter in this technique and we may be underestimating the seismicity in those seismogenic zones where the strongest occurring event is not reported in the catalogue, in addition to this, other aspects largely overlooked in this approach are that the effects of crustal properties on attenuation are neglected and the ground motion parameters are derived from overly simplified attenuation functions, and a partisan solution to this problem is field studies aimed at the recognition of the seismogenic potential of major active faults. As shown in this paper, it is required that reasons for main destruction due to these earthquakes may be addressed properly like implementation of building code especially in areas lying on the active faults as many thickly populated major cities of Pakistan like Islamabad, Quetta, Muzaffarabad etc. lie on active faults that are source of many destructive earthquakes in the past. It is also immediate need that individual as well as Government supported Earthquake safety and preparedness training programs should be organized in order to save lives and properties.
Pakistan is the most seismically active regions of Asia because of the presence of a number of active faults. For thorough study of seismicity and hazard investigation, earthquake catalogues plays a vital and significant role as it provides a systematic record of recent and historical seismicity therefore it is prerequisite to examine the completeness and uniformity of the catalogue. The earthquake catalogue has been analyzed for the studied region by Farhana et al. in [
・ The level of seismicity
・ Tectonic behavior
・ Stress dominance
We have shown in our studies that the advantage of this zoning is that the cities lying on the active faults can be prevented from destruction from future disaster by proper planning of infrastructure and by growing knowledge and awareness in common man to take safety precautions. The seismogenic zones are very dense along the collision plate boundary, i.e. along the Kirthar Suleiman Hindu Kush, Himalaya [
A number of active faults have been identified in Pakistan [
Pakistan appear to be seismically quiet except at the times of large earthquakes [
We locate the faults present in zone-1 are Reshun fault, Panggong-Nuchang fault, Altayan-Tagh fault systems.
The Reshun faults [
We locate the faults present in zone-2 are Upper Hunza fault, Main Mantle Trust (MMT), and Tirich Mir. The Hindu Kush and Pamir are amongst the most active seismic regions of the world [
We find that the Reshun, Main Karakoram Thrust (MKT), Hamran, Raikot-Sassi, Harban faults are present in zone-3. Main Karakoram Thrust (MKT) is a source of high seismic activity with a large number of earthquakes. Harman fault runs along the Harman valley and there is satisfactory information that this fault and Raikot Sassi fault is active [
We have identified that zone-4 is seismically the most active zone of Pakistan because it consist of most active faults namely the Resbun fault, Main Karakoram Thrust (MKT), Main Mantle Thrust (MMT), Sassi-Dassu, Jehlum fault, Terbela fault, Balakot-Bagh fault (BBF). A seismically active emergent thrust fault system extends stepwise from the Balakot-Bagh fault [
The zone-5 comprises Kangra Valley fault (KVF) India, which is a newly identified right lateral strike-slip active fault [
The fault system in zone-6 is Indus (Darband) fault, Nowshera fault, Attock (khairabad) fault, Main Boundary Thrust (MBT) (Parachinar-Hissartang-Cambellpur-Murree F.) and Jhelum fault. We have identified that this zone is a region of moderate to high seismicity having many active faults. The two active faults Attock and Nowshera faults have been mapped in [
We locate the faults in zone-7 are Uchchali fault, Salt Range thrust, Kalabagh fault, Surghar thrust, Bannu basin. The Kalabagh is right lateral strike slip active fault as shown in [
We have located zone 8 in our studies in Rajasthan India and we establish that this zone comes is the least active seismic zone. It is seen that except a few places close to Sindh of Pakistan are safe from earthquakes.
We find that the fault system in this zone are Sora-Rogha fault, Mandana-Kach fault, Domanda fault, Takht-e- Sulaiman, Moghalkot, Manikhawa, Kingri, Kakar-Khorasan, Chaudhan-Manda, Mekhtar and Kohlu faults. We show that two left-lateral wrench faults have been identified in the eastern and western margin of the Sulaimanrange and further on the eastern side, two faults constitute a left-lateral fault system having Chaudhan fault and Domanda fault and on the western side also there is left-lateral fault system constituting Thakht-e-Sulaiman fault, Manikhawa fault and Moghulkot fault. Kingri fault is a regional north northwest-south southeast trending strike slip fault cutting the Tertiary and Mesozoic section in the Sulaiman fold and thrust belt. The main cities in this zone are Dera Ismail Khan, Zhob, Dera Ghazi Khan and Multan with moderate seismicity.
We identify the faults in this zone are Ghazaband, Chiltan Takhatu, Quetta, Johan, Mach, Harnai, Chaman, and Barkan faults. We show that the main cities in this zone are Chaman, Pishin, Quetta, Ziarat, Much, Nushki, and Kalat. In 1935 on 30th May, an earthquake of magnitude 7.6 rocked Quetta city, the epicenter was in the Sulaiman Range in Pakistan along the fastest moving left-lateral, strike-slip Chaman fault. As indicated by ground deformation Chiltan range and Ghazaband fault zone are also responsible for the earthquake.It was one of the deadliest quakes ever in Southeast Asia. It begins in the west from Herat, Afghanistan and moves to the east and become source of seismic activities in Pakistan and from the west of Quetta it is connected to Kirthar range. The Chaman fault zone characterizes the western boundary of this wide deformation zone. While its northern part traverses Afghanistan, the central part goes into Pakistan northwest of Quetta before it continues southwards towards the Arabian Sea [
We find that this zone has Mashkichah fault, Ladgasht fault, Ahmadwal fault, Dalbandin fault, Chama, Panjgur fault, Hoshab fault, Awaran fault, Bazdar fault and Jhal-Jhao fault. We establish that the Hoshab fault is one of the major thrust faults which divide the Makran region into a number of thrust bound blocks. Hoshab fault is situated in the Makran convergence zone, which is an intensely deformed, east-west trending fold and thrust belt. This fault has an arc shape having east-west trending near the Nasirabad and Hoshab areas, however eastward it swings to the north-east until it runs parallel to Mashkairud. On 18 January 2011, a Mw 7.2 earthquake occurred in Southwestern Pakistan. The location of the earthquake was 28.732˚N, 63.928˚E. Its epicenter was located 50 km WSW of Dalbandin. At least three people died and several were injured. The depth of the earthquake was 84 km. The area is dominated by both strike slip and thrust faults [
We find that the zone-12 has Kirthar fault which is quite prominent north-south trending lineament on the satellite imagery and a number of earthquake epicenters are located in this region associated with this fault and with a relatively diffused seismicity as compared to that in the Suleiman range. In the latter, the seismicity falls on or near a distinct fault fragment which balance the range against the east-ward ranging Indus basin. On 27 August 1931 during the much earthquake the northern two thirds of the faults was ruptured [
We identify the faults in zone-13 are Ras Malan fault, Aghor fault, Nai-Rud fault, Ormara fault, Makran coast fault, Kulmir-Sunt fault, Surjan fault, Jhimpir fault, Hab fault, Somianni fault, Rann of Kutch and Ornarch fault.
Ornarch-Nal fault is the southeastern extension of the Chaman fault system, strike slip fault extending into the Arabian Sea in south. The southernmost segment of the Ornarch-Nal fault system starts 130 km due west of Karachi and extends northward for 200 km. Based on scaling relations [
We identify that this zone contains Herat fault. This fault is seismically inactive [
We have studied historical and recent seismic activities in Pakistan in our 14 seismogenic zones and we have found that the zones 3, 4, 6, 10 and 13 show high seismic activity and some of the major cities that are thickly populated lying in these zones like Islamabad, Karachi, Quetta, Peshawar, Gawadar, Pasni, Ziarat, and Kalat are at constant threat from future destruction. Pakistan is an earthquake prone developing nation and we need to explore more about the techniques which are supposed to be the best and rapid way to reduce or if possible, put an end to earthquake disasters in the country in future but unfortunately in a developing country like Pakistan we had to minimize our expectations and analyze why our research is not pinpointed on seismic instrumentation and monitoring, careful data analysis and catalogue production, the fundamentals of seismic hazard evaluation complementary micro-zonation studies, vulnerability, and risk assessment. We do not need a major research program but with the help of current knowledge, much can be done to reduce the potential loss of life and property from future earthquakes. In order to improve the required database for earthquake prediction research and applications, both quantitatively and qualitatively, large country-wide digital sensor networks comprising different types of monitor should be deployed. There is increasing need on long-term disaster preparedness and mitigation efforts based on improved seismic hazard assessment, micro-zonation, earthquake resistant construction, etc. Quite a few contributions to the probabilistic approach to seismic hazard assessment have been made in the Pakistan. Although earthquakes cannot be predicted but as all major cities of Pakistan are located on the fault line, we must take every step to ensure every possible measure to protect the country from future disaster. Now people are well aware of the fact that earthquakes are not the cause of killing the people, and the destruction is mainly due to collapsing of the buildings. This is certainly largely true for earthquakes in Pakistan where hardly some structures resistant to earthquake exist and mostly the buildings are highly vulnerable to earthquake. It is the pressing need of the time to develop new building codes and they should strictly be implemented.
Farhana Sarwar,Saleem Iqbal,Muhammad Qaisar,Abdul Rehman,Faiza Akhtar,Syed Mohsin Raza, (2016) Earthquake Statistics and Earthquake Research Studies in Pakistan. Open Journal of Earthquake Research,05,97-104. doi: 10.4236/ojer.2016.52007