Muhammad Basharat

Evaluation of excess life time cancer risk from gamma dose rates in Jhelum valley

Abstract Human beings are continuously exposed to the radiations coming from outside and inside their bodies. Outside and inside radiations are coming from ground, building materials, food, air, the universe and even elements within human own bodies. According to UNSCEAR 2000 report, background radiations deliver an average effective dose of 2.4mSv per person worldwide. Sustained exposure from high background radiation levels may pose substantial health threats to general public. In the current study we are presenting the results of ambient outdoor gamma dose rates measured for Jhelum valley of the state of Azad Kashmir. This study has been carried out by using Ludlum micrometer-19 which is an active and portable detector. Effects of different parameters of interest on the measured values of gamma dose rates have been investigated. For the region under investigation, minimum and maximum indoor gamma dose rates were found as 610±4.05μGy·y−1 and 1372±2.7μGy·y−1, respectively, whilst minimum and maximum outdoor gamma dose rates were found as 495±4.49μGy·y−1 and 1296±2.78μGy·y−1, respectively. Overall arithmetic mean (A.M) and geometric mean (G.M) values of gamma dose rates for indoor and outdoor measurements were found as 940±3.26μGy·y−1, 892±3.35μGy·y−1 and 928±3.28μGy·y−1, 880±3.37μGy·y−1 respectively. Excess life time cancer risk (ELCR) for indoor exposure ranges from 1.057×10−3 to 2.377×10−3 with an average value of 1.629×10−3. For outdoor exposure, ELCR varies from 0.352×10−3 to 0.792×10−3 with mean value of 0.543×10−3. Average values of indoor gamma doses were found to be greater than the world population-weighted average for indoor gamma dose rates (780μGy·y−1 or 89nGy h−1).

Lithological and Structural Control of Hattian Bala Rock Avalanche Triggered by the Kashmir Earthquake 2005, Sub-Himalayas, Northern Pakistan

The Kashmir earthquake 2005 (magnitude MW 7.6) triggered thousands of mass movements in northern Pakistan. These mass movements were mainly rock falls, debris falls, rockslides and rock avalanches. The mass movements vary in size from a few hundred cubic meters up to about 100 million cubic meters estimated for the Hattian Bala rock avalanche, the biggest one associated with this earthquake. This mass movement, which moved in southeastern direction, created two natural dams on the valley bottom and blocked the water ways of the Karli and Tung tributaries of the Jhelum River. Topographic, lithologic and structural information were used to investigate the Hattian Bala rock avalanche. Geotechnical and structural maps were prepared to understand relationship between geology and structure of Hattian Bala rock avalanche. The geometry and failure mode of this rock avalanche are controlled by southeast plunging synclinal structures, lithology, a bedding parallel slip surface and a pre-existing old rockslide. The structural map shows that the mass movement failure was due to Danna and Dandbeh synclinal structures plunging southeast on the hanging wall block of the reactivated Muzaffarabad fault. The slip surface of the mass movement followed the bedding planes along mudstone, claystone and sandstone surfaces. The mass movement perfectly followed the pre-existing synclinal morphology of the Danna and Dandbeh synclines.

Tectonic study of the Sub-Himalayas based on geophysical data in Azad Jammu and Kashmir and northern Pakistan

The tectonic study based on geophysical data has been carried out in Sub-Himalayas in Azad Jammu and Kashmir and northern Pakistan. A series of thin skinned and thick skinned faults have been delineated in the investigated area on the basis of present study. In the study area compressional stresses caused by the collisional of Indian and Eurasian plates developed the northwestsoutheast trending faults which are Shaheed Gala thrust, Bagh basement fault, Kashmir boundary thrust and Kawai fault or Indus Kohistan seismic zone. The crustal thickness increases towards north due to the stacking of the thrust sheets along these faults. The Murree Formation thrusts over the Siwaliks molasse along the Shaheed Gala thrust. This fault dips at an angle of 43º northeast and joins the thick skinned Bagh basement fault in subsurface which are penetrated up to Moho depth. In the northeast of Bagh basement fault the northwest-southeast trending Kashmir boundary thrust has been delineated in the sedimentary-metasedimentary wedge which joins the Indus Kohistan seismic zone in the subsurface. The present study suggested that the Kawai fault which is running within Murree Formation cuts 16 km thick sedimentary-metasedimentary wedge and also joins the Indus Kohistan seismic zone in the subsurface.

Petrology and geochemistry of Jura granite and granite gneiss in the Neelum Valley, Lesser Himalayas (Kashmir, Pakistan)

Late Proterozoic rocks of Tanol Formation in the Lesser Himalayas of Neelum Valley area are largely green schist to amphibolite facies rocks intruded by early Cambrian Jura granite gneiss and Jura granite representing Pan-African orogeny event in the area. These rocks are further intruded by pegmatites of acidic composition, aplites, and dolerite dykes. Based on field observations, texture, and petrographic character, three different categories of granite gneiss (i.e., highly porphyritic, coarse-grained two micas granite gneiss, medium-grained two micas granite gneiss, and leucocratic tourmaline-bearing muscovite granite gneiss), and granites (i.e., highly porphyritic coarse-grained two micas granite, medium-grained two micas granite, and leucocratic tourmaline-bearing coarse-grained muscovite granite) were classified. Thin section studies show that granite gneiss and granite are formed due to fractional crystallization, as revealed by zoning in plagioclase. The Al saturation index indicates that granite gneiss and granite are strongly peraluminous and S-type. Geochemical analysis shows that all granite gneisses are magnesian except one which is ferroan whereas all granites are ferroan except one which is magnesian. The CaO/Na2O ratio (>0.3) indicates that granitic melt of Jura granite gneiss and granite is pelite-psammite derived peraluminous granitic melt formed due to partial melting of Tanol Formation. The rare earth element (REE) patterns of the Jura granite and Jura granite gneiss indicate that granitic magma of Jura granite and Jura granite gneiss is formed due to partial melting of rocks that are similar in composition to that of upper continental crust.

Effects of volume on travel distance of mass movements triggered by the 2005 Kashmir earthquake, in the Northeast Himalayas of Pakistan

Abstract The 2005 Kashmir earthquake (Mw 7.6) generated widespread mass movements in the Northeast Himalayas of Pakistan. The mass movements were mainly catastrophic rock avalanches, rockslides, rockfalls and debris falls, ranging in volume from a few hundred cubic meters to hundreds of million cubic meters. Data of 103 mass movement events were collected during field surveys to characterize each event. The mass movements and their travel distances were analyzed, using empirical models, widely adopted in the literature. The empirical approaches were used to analyze the relationships between geometrical parameters like volume, Fahrböschung angle, fall height, surface area, travel path and travel distance. The mobility of mass movements was expressed as the ratio between the height of fall and travel distance as function of volume. The volume was estimated by multiplying the deposit area by average thickness. The Fahrböschung angle showed a decreasing tendency with increasing mass movement volume. In addition, the Fahrböschung angle of mass movements with small volumes was more variable. A strongly correlated linear trend exists between the height of fall and travel distance for all types of the mass movement. Moreover, a weak correlation was found between unconfined and partly confined travel path. The empirical results of the 2005 Kashmir earthquake data are consistent with the previously published data from other parts of the world.

Large scale mass movements triggered by the Kashmir earthquake 2005, Pakistan

The SPOT image analysis in Muzaffarabad Azad Kashmir, northwest Himalayas, Pakistan reveals that the Kashmir earthquake 2005 triggered a number of coseismic mass movements along the hanging wall block of the Muzaffarabad Fault. The Neelidandi and Langarpura rock falls have been identified as two major reactivated mass movements with an estimated volume of 3.1 × 106 m3 and 5.76 × 106 m3, respectively. The Neelidandi and Langarpura mass movements were initiated during earthquake in the direction of northwest-southeast extension and northeast-southwest directed thrusting, respectively. The Neelidandi rock fall occurred in sheared cherty dolomites and limestones of the Cambrian Muzaffarabad Formation, whereas the Langarpura rock fall occurred in alternating clays, shales, claystones, siltstones and sandstones of the Miocene Murree Formation. These rock units along the fault are highly fractured and jointed. The geotechnical maps and geological longitudinal profiles show the relationship between the geometrical characteristics and mechanism of these mass movements. Their characteristics were analyzed according to the role of topographic, seismic, geological and tectonic factors. The steep topography, sheared rocks, lithology, coseismic uplift and strong ground shaking of the hanging wall block along Muzaffarabad Fault facilitated the gravity collapse of these mass movements.

Effects of volume and topographic parameters on rockfall travel distance: a case study from NW Himalayas, Pakistan

This paper presents an analysis of rockfall travel distance for incidents along the roads of the Abbottabad and Mansehra Districts, Khyber Pakhtunkhwa, Pakistan. Data for 121 rockfall events ranging from 100 m3 to 10 000 m3 volume were gathered during field investigations and used to facilitate an assessment of parameters such as height of fall, travel angle, travel distance and rockfall volume. The relationship between the height of fall and travel distance was investigated using well-established empirical approaches published in the literature. This analysis showed that travel angle decreased with increase in the rockfall volume, but that there was a weak correlation between the volume of rockfall and travel distance. A strong positive relationship between the travel distance and the height of fall was also identified. Comparison of the rockfall events identified during this study and existing data published from other regions in the world shows that the characteristics of the rockfalls are largely consistent with those identified by previous investigations. The study findings provide a useful set of data for empirical analyses that may be used for hazard and risk assessment in the region.

Application of gravity and magnetic methods for the crustal study and delineating associated ores in the western limb of Hazara Kashmir Syntaxis, Northwest Himalayas, Pakistan

The present geophysical study deals with the ores and crustal demonstration of southeastern Hazara and its adjoining areas of Azad Jammu and Kashmir, Pakistan, on the basis of terrestrial gravity and magnetic data. Tectonically, the study area lies in the Lesser Himalayas as well as to an extent in the sub-Himalaya, more specifically in the western limb of Hazara Kashmir Syntaxis. In this study, 567 gravity and 508 magnetic stations have been measured with CG-5 gravimeter and proton precession magnetometer, respectively. The collected data have been processed by applying standard corrections and then different types of maps were prepared. The ores in the area have been delineated by the qualitative interpretation of residual Bouguer anomaly and reduction to pole total magnetic intensity maps, whereas regional structures are demarcated by the Bouguer anomaly and regional Bouguer anomaly maps. The positive contour closures on the residual Bouguer anomaly map indicate the iron ore and phosphate, whereas negative contour closures are the effects of low-density material which consists of gypsum and soapstone. The pole-reduced total intensity map also shows the negative and positive contour closures almost in the same localities and confirms the residual Bouguer anomaly map. The geological model computed on the basis of Bouguer anomaly demarcated a series of faults between different rock units in the study area. The Kashmir Boundary Thrust cuts the western limb of Hazara Kashmir Syntaxis near the apex in the north of Muzaffarabad and marks the boundary between Murree Formation and carbonates of Abbottabad Formation. The gravity model also suggests that the thickness of the crust increases towards the northeast.