Calibration of local magnitude scale for Hindukush continental subduction zone          下载免费PDF全文

Muhammad N.Mushtaq  Muhammd Tahir  Muhammd T.Iqbal  Muhammd A.Shah  Saleem Iqbal  Talat Iqbal 《地震科学（英文版）》2021,34(2):114-122

Hindukush is an active subduction zone where at least one earthquake occurs on daily basis. For seismic hazard studies, it is important to develop a local magnitude scale using the data of local seismic network. We have computed local magnitude scale for Hindukush earthquakes using data from local network belonging to Center for Earthquake Studies (CES) for a period of three years, i.e. 2015–2017. A total of 26,365 seismic records pertaining to 2,683 earthquakes with magnitude 2.0 and greater, was used with hypocentral distance less than 600 km. Magnitude scale developed by using this data comes to be M_L = logA + 0.929logr + 0.00298r – 1.84. The magnitude determined through formulated relation was compared with that of standard relation for Southern California and relation developed by the same authors for local network for Northern Punjab. It was observed that Hindukush region has high attenuation as compared to that of Southern California and Northern Punjab which implies that Hindukush is tectonically more disturbed as compared to the said regions, hence, seismically more active as well. We have calculated station correction factors for our network. Station correction factors do not show any pattern which probably owes to the geological and tectonic complexity of this structure. Standard deviation and variance of magnitude residuals for CES network determined using Hutton and Boore scale and scale developed in this study were compared, it showed that a variance reduction of 44.1% was achieved. Average of magnitude residuals for different distance ranges was almost zero which showed that our magnitude scale was stable for all distances up to 600 km. Newly developed magnitude scale will help in homogenization of earthquake catalog. It has been observed that b-value of CES catalog decreases when magnitude is calculated by using newly developed magnitude scale.  相似文献   

Aspects of petrochemical pollution in coastal Louisiana, USA     

Iqbal J  Portier RJ  Gisclair D 《Marine pollution bulletin》2007,54(6):792-797

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Inorganic and organic contaminants in intertidal sediments of the Clyde: Preliminary observations of historical trends?     

Andrew S. Hursthouse  Monika Adamczyk  Leslaw Adamczyk  Frank J. Smith  Parveen Iqbal 《Marine pollution bulletin》1994,28(12):765-767

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Soil studies for highway construction in arid zones     

Iqbal H. Khan 《Engineering Geology》1982,19(1):47-62

An appreciation of the special features of the desert environment is necessary for proper construction and subsequent maintenance of highways in arid zones. Geotechnical tests and chemical analyses were carried out on a large number of samples of dune sand collected from four different sites in the Sahara desert. It is concluded that greater use can be made of local materials and that cement-stabilized sand should prove an adequate base for highways. Some useful suggestions are given for engineers operating in the hot deserts.  相似文献   

Transport of Bromide and Other Inorganic Ions by Infiltrating Storm Water Beneath a Farmland Plot     

Mohammad Z. Iqbal  Noel C. Krothe 《Ground water》1996,34(6):972-978

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SIMULATION OF POLLUTANTS IN RIVER SYSTEMS USING FINITE DIFFERENCE METHOD     

ZAHEER Iqbal  CUI Guang Bai Ph D candidate  College of Water Resources  Environment  Hohai University  Nanjing  China E-mail: zaheeriqbal@hotmail.com Prof. College of Water Resources  Environment  Hohai University  Nanjing  China 《国际泥沙研究》2002,17(2)

1 INTRODUCTION Numerical computation provides an easily extended and user-friendly environment with computer aided programming for the simulation of pollutants in river systems. In the most of water quality assessment and monitoring problems during water pollution control and environmental impact assessment studies of river systems, mathematical modeling has been playing a key role for the last two decades. The majority of existing water quality models are the mechanistic and are based o…  相似文献   

Local perceptions of and adaptation to climate variability and change: the case of shrimp farming communities in the coastal region of Bangladesh     

Masud Iqbal Md Shameem  Salim Momtaz  Anthony S. Kiem 《Climatic change》2015,133(2):253-266

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Structural model of the Balkassar area,Potwar Plateau,Pakistan     

Shahid Iqbal  Gulraiz Akhter  Sehrish Bibi 《International Journal of Earth Sciences》2015,104(8):2253-2272

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Long-term activity of earthquake-induced landslides: A case study from Qionghai Lake Basin,Southwest of China   总被引：2，自引：0，他引：2  

Xue-li Wei  Ning-sheng Chen  Qian-gong Cheng  Na He  Ming-feng Deng  Javed Iqbal Tanoli 《山地科学学报》2014,11(3):607-624

Earthquake-triggered landslides are a major geological hazard in the eastern Tibetan Plateau, and have prolonged impact on earth surface processes and fluvial system. To determine how long co-seismic landslides affect basins, a massive number of landslides existing in Qionghai Lake Basin were investigated for landslide distribution characteristics and geomorphological evidences, with further comparison and analysis using historic seismic analog method. The landslides found in Qionghai Lake Basin showed clear features of seismic triggering with strongly controlled by Zemuhe fault. These landslides are still active at present. Some new slides generally occur in ancient slope failure zones causing serious secondary hazards in recent years. In this study we strengthen the idea that the landslides triggered by the 185o Xichang earthquake （Ms7.5） have long term activity and prolonged impact on the mountain disasters with a period of more than 16o years. Our results support growing evidence that coseismic landslides have a prolonged effect on secondary disasters in a basin, and invite more careful consideration of the relationship between current basin condition and landslide history for a longer period.  相似文献   

Measuring temperature variability of five major cities of Pakistan     

M Jawed Iqbal  J Quamar 《Arabian Journal of Geosciences》2011,4(3-4):595-606

Changes in surface air temperature during the last century are widely discussed among researches in the field of climate change. This paper measures the variability of annual surface air temperature of five major cities of Pakistan (Lahore, Peshawar, Quetta, Hyderabad and Karachi) for the period from 1882 to 2003. We perform an exploratory analysis which shows that the annual landmass air temperature series of five relatively more important climate stations of Pakistan obey the normal distribution. A subsequent trend analysis shows that the temperature has been increasing in the twentieth century for the five (major) cities of Pakistan, the increase being 0.3°C to 1.0°C. We computations based on Bayesian analysis for two samples (e.g., for Lahore, we use data for the period from 1882 to 1960 and 1961–2000 for first sample and second sample, respectively) of temperature data of five cites shows that the average of annual mean temperature for the second period is higher than the average of first period. Thus, Bayesian inferencing shows that the general pattern of evolution of temperature over Pakistan is pretty similar to the current global warming configuration.  相似文献