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A GEOSEISMOLOGICAL REPORT ON 8THOCTOBER 2005KASHMIR EARTHQUAKE

By

Prabhas Pande, D.D. Joshi, G.C. Kandpal, K.C. Joshi, R. J. Singh, B.K. Singh,Jaya Singh, Biju John, *Rajendra Sanwal, **Sagina Ram and ** S.P. Chaube

Earthquake Geology Division, *Project Landslide Hazard Studies Division andGeophysics Division, Lucknow

K.S. Jamwal, Raghubir Singh, Joginder Singh, V.K. Sharma and Ajay KumarOperation Jammu & Kashmir, Jammu

A.K. Sinha, S. Chopra, A.K. Relhan, A.K. Gupta and J. BagchiOperation Punjab, Haryana & Himachal Pradesh, Faridabad

Jognider Singh, A.K. Jain, Sanjiv Kumar, Pradeep Singh, Manoj Kumar,Sajin Kumar and M.K. Kaistha

Operation Punjab, Haryana & Himachal Pradesh, Chandigarh

Geological Survey of IndiaNorthern Region

Lucknow

June 2006

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CONTENTS

Abstract Pages

I. Introduction 2-4

II. Geotectonic Setting and Seismicity 5-8

III. Macroseismic Survey 9-25

IV. Effects of Kashmir Earthquake in Pakistan and 26-28

Pak Occupied Kashmir

V. Isoseismal Map and Isoseist Characteristics 29-32

VI. Aftershock Monitoring 33-34

VII. Conclusions 35-37

References 38-40

Annexure I: Locality Index

Annexure II: Medvedev-Sponheuer-Karnik (MSK-64) Intensity Scale

Annexure III: Newspaper Reports

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A GEOSEISMOLOGICAL REPORT ON 8THOCTOBER 2005

KASHMIR EARTHQUAKE

Abstract

A devastating earthquake of Mw7.6 occurred in the Kashmir Himalayan on the morning

of 8th October 2005. The tremors were felt in a radius of over 1000 km with damage

taking place in an area of 36000 sq km. The meizoseismal zone was located in Pakistan

and Pak Occupied Kashmir (PoK) in the Kunhar and Neelam (Kishanganga) valleys

where the death and destruction was unprecedented. On the Indian side heavy damagewas restricted to Uri Tehsil of Baramula District and Karna (Tangdhar) Tehsil of

Kupwara District.

The epicentre of the earthquake is located in the Jhelum reentrant, which is thereflection of Western Himalayan Syntaxis in the Frontal Belt. The area lies south of the

seismically hyperactive Kohistan Arc and is flanked on either side by Peshawar and

Kashmir basins that are locales of dispersed seismicity.

The Geological Survey of India took up the macroseismic survey of the earthquake and

aftershock monitoring on the Indian part. About 100 localities were visited to document

the effects of the earthquake and to constrain the isoseismals. The data pertaining to

Pakistan and PoK were collected from different sources, including Press and Electronic

Media reports and various scientific papers posted in the websites.

The epicentral tract of the earthquake experienced an intensity of X on MSK-64 scale.

This zone encompassed Balakot town in NWFP and Muzaffarabad city in PoK. In this

and adjoining sectors the event generated a very large number of landslides, which

showed concentration along a 65 km long belt trending in N35W-S35E direction and

extending between Balakot and Bagh. In this segment coseismic rupturing of

Muzaffarabad and Tanda faults was observed. Uri Tehsil experienced an intensity of IX

whereas Srinagar was subjected to intensity VII.

The Geological Survey of India carried out 24-day aftershock monitoring byestablishing an array of 5 digital MEQ instruments in the Kashmir Division. In this

period over 1000 events were recorded of which one was of M > 6 and one of M > 5.

The fault plane solution of the main event given by USGS identifies the strike of thenodal planes as N27W-S27E and N64W-S64E with dips of 39 and 57, respectively.

The isoseismal geometry gives the depth of focus of about 12 km. On the basis of source

mechanism studies, aftershock distribution and isoseismal pattern, a dominant NNW-

SSE trending basement fracture zone has been inferred to be involved in causing the

earthquake.

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I. Introduction

A devastating earthquake shook the entire western Himalaya and adjoining

regions on the morning of 8th October 2005, inflicting very heavy casualties in a large

area, particularly belonging to Pakistan and Pak Occupied Kashmir (PoK). Thisdeadliest of the Himalayan earthquakes, recording a magnitude of 7.6, took a toll of

thousands of human lives and rendered millions homeless. The human death figure on

account of the earthquake on the Indian side of the Line of Control (LoC) was 1209

whereas in Pakistan and PoK it was reported that more than 87,000 people perished in

the catastrophe. The USGS located the epicentre of 8th October 2005 main shock 125

km WNW of Srinagar in the Neelam (Kishanganga) valley in POK. The Harvard

Moment Tensor Solution by USGS, Denver gave the following parameters.

i) Centroid Location

a) Origin Time: 03:50:52.2 (UTC) : 09:20:20:52.2 (IST)b) Lat. 34.37N: Long. 73.47E

c) Magnitude Mw: 7.6

d) Dep. 12.0 km

ii) Principal Axes

a) (T) VAL = 3.16, PLG = 69; AZM: 338

b) (N) VAL = -0.44; PLG = 19; AZM: 128

c) (P) VAL = -2.71; PLG = 10 AZM: 222

iii) Best Double Couple Mo = 2.9 x 1027dyne cm

iv) Nodal Planes

a) NP1: Strike 333; Dip. 39; Slip 121

b) NP2: Strike 116. Dip 57, Slip 68

The India Meteorological Department (IMD) also recorded the following

attributes of the 8thOctober 2005 earthquake

a) Origin Time: 03 hrs. 50 min. 35.8 sec

b) Epicentre: 34.6N: 73.474E

c) Magnitude: 7.4

The Broadband Seismological Observatory of GSI at Jabalpur recorded the

origin time of the earthquake as 03 hrs 50 min 56 sec.

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The short period MEQ digital recorders stationed at GSI Office, Chandigarh for

purpose of microzonation of the Urban Complex picked up the following parameters of

the earthquake.

a) Arrival time of P-wave: 03:51:51.27 (UTC)

b) Time Gap (S-P): 55.00 sec.

c) Signal duration: 15 min.

d) Epicentral distance: 496 km (approximately from Chandigarh)

On the Indian side the maximum impact of the earthquake was in the Kashmir

Division where a total of 92,608 houses were fully or partially damaged, 1199 people

killed, 6149 injured and, in all, 4,50,000 people affected (Table 1).

Table 1

Effects of Earthquake in Kashmir Division

S. No. District Personskilled

Personinjured ormissing

Propertyfully

damaged

Propertypartly

damaged

Total No.houses

damaged

1.

2.

3.

4.

5.6.

Srinagar

Baramula

Kupwara

Anantnag

PulwamaBadgam

02

845

267

Nil

Nil01

237

4499

1369

13

2110

16

15663

11696

22

2080

4256

24597

25905

390

6419322

4272

40260

37601

412

6619402

Total 1199 6149 27497 65111 92608

Poonch District, J&K was the other region, which was affected by the

earthquake to a considerable extent. Here, the strong tremors impacted 136 villages and

59000 people. A total of 1524 houses were fully and 627 houses partially damaged in

which 10 people and 78 cattle got killed, and 73 people injured.

The earthquake, apart from damaging the civil structures, induced numerous

landslides and slope failures, which disrupted the road communication, affected human

settlements and killed some people and cattle in Uri Tehsil of Baramula Distict and

Karna (Tangdhar) Tehsil of Kupwara District. However, the well-engineered structures

with aseismic designs like the Uri Hydel Scheme, escaped without any damage to its

various appurtenant structures.

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The Geological Survey of India, Northern Region carried out the macroseismic

survey and aftershock monitoring of the 8th

October 2005 Kashmir earthquake. Officers

from Operations J&K, PH & HP and UP & Uttaranchal apart from Earthquake Geology

Division and Project Landslide Hazard Studies Division, Northern Region, were

deployed to collect data on the effects of the earthquake at different places in the States

of Jammu & Kashmir, Himachal Pradesh, Punjab, Haryana, Delhi, Uttaranchal and

Uttar Pradesh. An array of five MEQ Digital Recorders remained in operation in the

Kashmir Division between 23rd

October 2005 and 17th

November 2005 to record the

aftershock activity, which was prolific during the first few weeks of the main shock. A

preliminary report on the earthquake investigation was posted in GSI website on 18th

October 2005 (Pande, 2005).

The Department also took up the investigation of slope instability affected

villages in Uri Tehsil, Baramula District and Karna (Tangdhar) Tehsil, Kupwara

District, J&K at the instance of the Divisional Commissioner, Srinagar, for which the

field studies were carried out between 8th

and 14th December, 2005. A separate report in

this regard was submitted to the J&K State Government in December 2005 (Pande et

al., 2005).

Acknowledgements

The authors are grateful to the Director General, Geological Survey of India

under whose supervision this work has been pursued. The overall support and guidance

provided by Shri U.K. Bassi, D.D.G. (Retd.) and Dr. P.N. Razdan, D.D.G., NR, GSI are

thankfully acknowledged. The authors express their sincere gratitude to Shri Kuldeep

Singh, DDG, Op. J&K, Shri R.K. Singh, DDG, Op. UP & Uttaranchal and Dr. R.P.S.

Pahuja, DDG, Op. PH & HP, GSI, NR for their constant encouragement in carrying out

the work. The authors thank Dr. P.C. Nawani for conveying the information regarding

the earthquake effects in the Garhwal Himalaya. The authors are thankful to Dr. G.M.

Dar, Disaster Management Institute, J&K Government for the help in carrying out the

field survey in Kashmir Division.

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II. Geotectonic Setting and Seismicity

The area of study comprises a highly diversified and complex domain that was

involved in different orogenic episodes and tectonic phases since Precambrian times.

The northern most tectonic unit incorporates the Trans-Himalayan tectogen. This isfollowed towards south by the accretionary complex, late to post tectonic granitoids,

accreted arc with sediments and ophiolite of the Kohistan Arc (Fig.1). Further south in

the Kashmir basin, basic volcanics, high and low grade metamorphic complexes, poorly

metamorphosed assemblages, granitoids and alluvial fill in superposed basins are

recorded. In the adjoining Potwar basin all other packets are present except basic

volcanics and high-grade crystallines. The Frontal Belt exposes cover rocks affected by

the terminal phase of the Himalayan orogeny followed by alluvial fill in the superposed

basins towards south (Narula et al., 2000)

The most spectacular feature of the Himalayan orogen is the Western Himalayan

Syntaxis. In the Frontal Belt this orogenic bend is reflected as the Jhelum reentrant,

which is flanked on either side by the Kashmir and Peshawar basins. The northern most

tectonic discontinuity of the area is the Main Karakoram Thrust (MKT), which

separates the Hindukush-Karakoram belt from the island arc of Kohistan. Towards

south, the Main Mantle Thrust separates the latter from Peshawar and Kashmir basins.

Southern most is the Main Boundary Thrust (MBT), which separates the main

Himalayan package from the sedimentary sequence of the Frontal Fold Belt (FFB).

The FFB along with the MBT and the Panjal Thrust (PT), a close sub parallel

discontinuity north of it, is involved in the Kashmir-Hazara Syntaxis, which according

to Powell (1979) was formed due to the interaction of three independently moving

tectonic elements - the Himalayas, the Indo-Pakistan Shield and the Salt Range.

Structurally, the earthquake-affected part of the Western Himalaya broadly has a

concave southward disposition. Within this curvature of the tectonic framework, two

conspicuous structural features interrupt the regional trend: the northwesterly oriented

Kashmir-Hazara Syntaxis and the northeasterly trending Nanga Parbat Syntaxis, the

former bordered by the MBT and the latter by the Main Mantle Thrust (MMT) (Bender,

1995)

One of the important discontinuities in this region is the MMT. This and the

Main Karakoram Thrust (MKT) are believed to represent the earliest suturing ofKohistan Island Arc with the rocks of Indo-Pakistan Plate in the south and Hindukush-

Karakoram belt in the north during the collision of the Indo-Pakistan and Eurasian

Plates (Tahirkheli et al., 1979; Coward et al., 1982; Searle et al., 1987; Bender, 1995).

The other important tectonic feature is the MBT, along which neotectonic

activity has been reported at different locales. According to Armbruster et al. (1978),

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recent seismicity of the Himalaya is associated with the frontal zone of deformation.

This zone parallels the Kashmir-Hazara Syntaxis and should correspond with the MBT

that became active after the cessation of motion along the Main Central Thrust (MCT)

(Le Forte, 1975; Mattauer, 1986; Ni and Barazangi, 1984).

The MBT and the Panjal Thrust, which east of the syntaxis adopt gradually,

curving trends of NS to NW-SE, bend backwards on the western side to follow a N-S

attitude, and further south, assume NE-SW and ENE-WSW trends. Interestingly, west

of the syntaxis or Jhelum re-entrant, these thrusts split into a number of planes.

Southwards, partly underneath the alluvial plain of Northern Punjab in Pakistan, the

sedimentary sequences, associated with a number of additional thrusts, which broadly

follow the configuration of the MBT including the Hazara Syntaxis, are strongly

deformed as well (Bender, 1995).

East of Jhelum Re-entrant within the Tertiaries and following the MBT is

another thrust known as Riasi Thrust. This tectonic plane, in fact, is a continuation of

Jwalamukhi thrust one of the important tectonic elements in the Himalayan Foot Hills

(Karunakaran and Rao, 1979), which can be traced for over 200 km from Riasi to

northwest of Kalka. For most of its length, the thrust brings the Lower Siwalik to rest

over Middle or Upper Siwaliks. West of Ravi river, this thrust continues as Kishanpur-

Mandli Thrust upto Riasi inlier and has brought the Upper Murrees in juxtaposition with

the Upper and Middle Siwaliks of Surien-Mastgarh anticline. The Riasi thrust has

surface manifestation for about 125 km northwest of Riasi town, beyond which it seems

to be dying out in an anticlinal fold (Karunakaran & Rao 1979). North of Riasi thrust

lies Tanhal thrust, which brings Murrees over Siwaliks. Interestingly, a number of blind

faults have been reported from the Himalaya, particularly the Sub-Himalaya. Suchsubsurface faults are manifested on the surface as folds. However, most of the regional

thrusts of the Lesser and Sub Himalaya downwards are believed to merge with a gently

sloping detachment/decollment, which represents the upper surface of the Indian Plate

(Seeber et al., 1981; Ni and Barazangi, 1974; Srinivasan and Khar, 1996).

Among the neotectonic discontinuities, the Jhelum fault is regionally the most

extensive. It is a N-S trending left lateral wrench fault, which separates the Peshawar

Basin from the Kashmir Basin. According to Tapponnier, et al., (2006) the motion on

the Jhelum fault is responsible for offsetting and folding the MBT, thus accounting for

its 180 bend northwest of Pir Panjal. Its conjugate set is the Mangla fault, which is aright lateral wrench fault. Subparallel to the Jhelum fault are the Tarbela and Shinkiari

faults. The former is located well within the Peshawar Basin, while the latter has

developed along the eastern margin of this basin. Both these fault zones cut across the

alluvium and offset streams, and therefore, can be classified as active. A few smaller

faults of the area also show neotectonic activity.

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In the Hazara-Kashmir syntaxis, Nakata, et al., (1991) have established that the

Muzaffarabad and Tanda faults are active. The former was initially reported as a N-S

trending 8 km long fault from clear eastward facing reverse scarplets that cut

Pleistocene river terraces of the Jhelum river south of Muzaffarabad town. Tanda fault

was mapped as a NW-SE trending, 16 km long active fault that dislocated Pleistocene

alluvial fan surfaces on the eastern bank of Jhelum River. The post 8th

October 2005

earthquake CORONA satellite images indicate that these faults extend further to

northwest and southeast (Nakata and Kumahara, 2006). Hussain and Yeats (2006)

recognise presence of Balakot- Bagh fault in the Jhelum reentrant as an offshoot of the

MBT. This fault reactivated/ ruptured in a length of 65 km between Balakot and Bagh,

in a NW-SE extension consequent to the 8thOctober 2005 earthquake.

Seeber, et al., (2005) have used microseismic data from the Tarbela and Chasma

seismological networks to develop a tectonic model for the Kashmir-Hazara Syntaxis

region in Pakistan. According to them, like in Indian part of the Himalaya, here too

exists a subhorizontal decollement as an interface between the

sedimentary/metasedimentary wedge and the basement. However, they have also

discerned two parallel clusters of epicentres associated with the basement faults,

extending towards northwest from the Hazara Syntaxis, which they interpreted as the

deeper level northwestern extensions of the structural trends in the Kashmir Himalaya,

east of the Syntaxis. Out of the two zones/clusters the northeast one, which they

preferred to call Indus Kohistan Seismic Zone (IKSZ), is currently more active and

indicates predominantly thrust type movement. The other zone towards southeast,

named as Hazara Lower Seismic Zone (HLSZ,) indicates basement faults with

predominantly strike slip right lateral movement.

The epicentre of the 8th

October 2005 Kashmir earthquake lies within the Jhelum

Reentrant (Fig.1). The last hundred-year database shows occurrence of a large number

of earthquakes in this tectonically highly diversified domain. The maximum clustering

of seismic events is in the Kohistan Arc, considered to be part of the Indus-Kohistan

Seismic Zone. Majority of the seismic events here lie between 40-70 km depth range.

The fault plane solutions of three seismic events of this domain, which occurred on 3rd

September 1972, 4th

September 1972 and 28th

December 1974 show predominantly

thrust type mechanism with the nodal planes aligned broadly in NW-SE direction. In

one event of 29th January 1965, the mechanism is given as predominantly normal type

(Chandra, 1978). North of MKT, some of the events have foci deeper than 150 km.

South of MMT, the seismic events are fairly well dispersed with majority

showing shallow foci. In this domain the 2nd

September 1963 Badgam earthquake gave

a thrust type solution with the nodal planes trending NW-SE. The 14th February 1977

Nilore earthquake located east of Rawalpindi deciphers a left lateral strike slip mode of

rupture.

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There is mention of two powerful historical earthquakes in the Catalogue of

Indian Earthquakes (Oldham, 1883) that had their profound influence in the region. On

6th July 1505 an immense earthquake occurred in the confines of Kabul. The description

in the Catalogue reads, Since the creation of the world there never was so dreadful an

earthquake. It mentions that the ground was elevated and depressed to the height of an

elephant and in many places so split that a person might have hid himself in the gaps.

The second earthquake was that of Cashmir of 22nd

June 1669. It is mentioned that the

event was very violent, felt all over Cashmir (Kashmir) and lasted the whole night.

The India Meteorological Department (IMD) database lists occurrence of 13

earthquakes of M > 5.0 in the Kashmir Division of J&K State, including the Districts of

Kupwara, Baramula, Srinagar, Badgam, Pulwama and Anantnag. These are the events

of 1552 of M 7.5, 1662 of M 7.5, 1735 of M 7.5, 1778 of M 7.7, 1784 of M 7.3, 1828 of

M 6.0, 1863 of M 7.0, 1884 of M 7.3, 1885 of M 7.0 (Kashmir earthquake), 1963 of M

5.3 (Badgam earthquake), 1967 of M 5.5 (Anantnag earthquake), 1973 of M 5.1 and

1999 of M 5.3. In the adjoining territory of PoK earthquakes of 1554 of M 7.7 and 1885

of M 6.5 have been mentioned.

The largest earthquake of this domain of which a geological report is available is

that of 30th

May 1885 of M 7.0 (Jones, 1885). The epicentre of the event is located 19.5

km west of Srinagar. This earthquake killed about 3000 people and caused widespread

damage around Srinagar. The other significant earthquakes, which had considerable

effect in the area of present study, include that of 2nd

February 1929 Northwest

Himalaya of M 7.2, 14th May 1937 Hindukush of M 7.2 and 21

st November 1939 Great

Pamir of M 6.9. The isoseismals of the above-referred four seismic events are given inFig.2.

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III. Macroseismic Survey

The 8th October 2005 Kashmir earthquake proved to be the deadliest natural

calamity of the Himalaya where the death and damage figures far exceeded that of any

previously recorded ones in the region. The extent of the disaster was, however, muchless on the Indian side as compared with that of Pakistan and Pak Occupied Kashmir

though the felt area had a radius of almost 1000 km. `As the news of the earthquake

poured in from various sources, plans were drawn in the Geological Survey of India to

expeditiously take up the macroseismic survey in different parts of North India. Various

teams of GSI officers from Northern Region were formed to cover parts of North Indian

States. The officers from Operation Jammu & Kashmir were deployed in the J&K.

Geologists from Operation Punjab, Haryana & Himachal Pradesh covered parts of

Himachal Pradesh, Punjab, Haryana and Delhi, as well as the bordering Districts of

J&K. An expert group from Earthquake Geology Division moved to the meizoseist and

other parts of J&K. Officers from Landslide Hazard Studies and Earthquake Geology

Divisions covered parts of Uttaranchal and Uttar Pradesh. In all, about 100 localities

were visited during the course of the survey by different teams of 26 geologists

(Annexure I).

The damage to civil and engineered structures was restricted in J&K region

only. A rapid assessment of the damage pattern and other seismological effects were

carried out using Madvedev-Karnik-Sponheuer (MSK-64) Intensity scale (Annexure II).

The survey work could not be extended to several difficult localities of J&K because of

certain logistic constraints. At places other than in J&K, the assessment was based

mainly on human perceptions because of the lower intensity of ground motions. The

data from Pakistan and Pak Occupied Kashmir were gathered from press and electronic

media reports, and scientific papers and reports published in various Journals and posted

in different websites. The State -wise description of various localities visited during the

course of the survey is given as follows.

1. Jammu & Kashmir

Kashmir Division

In the Kashmir Division comprising six districts of Srinagar, Baramula,

Kupwara, Anantnag, Pulwana and Badgaun, a total of 1199 people got killed and 6149injured by the earthquake. In all, 92,608 houses were fully or partly damaged.

The survey work was conducted in different localities of Srinagar, Baramula and

Kupwara Districts. The District-wise description is given as follows.

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Srinagar District

In the district the effect of the earthquake was of moderate order where two

persons were killed and 237 injured. A total of 4272 houses received various grades of

damage. Srinagar city is located over Karewa and alluvial deposits with hillocks of

Panjal Volcanics dotting the landscape. In the urban agglomeration everybody felt very

strong tremors, accompanied by a whizzing sound. There was lot of panic all around,

and some, particularly women and children, remained traumatised for days. The

inhabitants narrated that at the time of the earthquake it was difficult to keep standing,

so people sat down, and some, to maintain balance, kneeled on the ground. During the

passage of strong ground motions, those driving two or four wheelers felt the tremble,

and on impulse, stopped their vehicles immediately, irrespective of where they were.

The damage to the buildings and other civil structures was not significant in

Srinagar. In Batmaloo locality, partial collapses of a few old and weak brick walls, was

noticed (Photo 1). In an old conventional type building constructed of unbaked bricks

with timber bracings, a staircase collapsed (Photo 2). In the Hazaratbal Shrine a few

marble face stones got peeled off from one of the burzis due to the strong shaking

(Photo 3). Cracks appeared in many old buildings in the downtown area and slight

distress in the form of Grade 1 damage could be documented even in well-constructed

structures. The ancient Shankaracharya Temple, located over a hilltop of Panjal

Volcanics, remained unscathed (Photo 4). The structure, repaired and renovated in parts

in recent times, is founded over solid bedrock and is constructed of large, tabular basalt

blocks having very good shear strength. It was perhaps the type of construction and

subsequent repairs that prevented any damage from taking place, where otherwise there

would have been intensity accentuation due to topographic effect. In Srinagar, most ofthe buildings are two storied and have used baked bricks with sand-cement mortar in the

walls and G.I. Sheets in roofing. The older buildings deploy timber bracings in the

walls. Such types of structures seem to behave quite efficiently under seismic loading

corresponding to intensity VII or even VIII.

Baramula District

The Baramula District faced the brunt of the earthquake calamity on the Indian

side with 845 people getting killed and 4499 suffering injuries. A total of 40,260 houses

were damaged to various grades.

The town of Baramula, like Srinagar, is located on the banks of Jhelum river

over Karewa and alluvial deposits. The tremors, accompanied by a sound resembling

that of a storm, were very distinct, instilling a deep sense of fear among the residents.

The tremors were described to be having a predominant E-W direction of vibration

under whose influence several of the civil structures came under distress. Some of the

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low strength compounds walls using stone masonry in mud mortar failed during the

earthquake. A few of such buildings, particularly old ones, suffered partial collapses. In

many buildings, cracks appeared on the walls and the plaster peeled off at places. In a

stray case, the newly constructed portion of a three storey brick structure, housing the

Show Room of Dayal Furnishing caved in and the ground floor walls developed gaping

diagonal shear cracks (Photo 5). It appears that the lean RBC/brick columns supporting

the rather heavy structure were not capable of withstanding the strong horizontal

seismic loading, and thus failed (Photo 6). The building was founded over silty soil

where groundwater occurred at a depth of 7.5 m. In an adjoining two-storey building

made of unbaked bricks and timber bracings, the eastern end gabble portion suffered

partial collapse and the other walls developed gaping shear cracks (Photo 7). This stray

case of intensity accentuation at Baramula could have been prompted by soil

characteristics.

Rampur-Uri Sector

As one proceeded on Baramula-Uri Highway, a perceptible increase in the

intensity of ground motions was witnessed. The masonry gate of Rampur Garrison was

found sheared with chunks of plaster peeling off at places. Further ahead, the ancient

temple of Buniyar, also known as Pandav temple constructed in the 12 thCentury AD by

the Rulers of Avantivarman Dynasty, suffered some conspicuous damage on account of

the earthquake. From its front portal, constructed of large interlocked tabular blocks of

granite, stone slabs slipped off and were seen strewn by the side of the road (Photo 8).

The sanctum sanctorum of the rather dilapidated temple developed gaping cracks.

The Datta Mandir near Mohura of a similar type as that of Buniyar temple butconstructed of large blocks of metavolcanics experienced partial collapse of stone

blocks from one corner (Photo 9). The pitched stones and boulders from the retaining

walls enclosing the temple complex also got dislodged, at places. The dwellings of

nearby hamlets were appreciably damaged forcing their inhabitants to shift in makeshift

tents pitched on flat ground adjoining the temple precinct.

Major failure of terrace slopes on the banks of Jhelum river were first spotted

near Mohura (Photo 10). At Bandi, a coseismic debris slide blocked the highway that

was being cleared up by the Border Road Organisation at the time of the visit.

At Uri, there was a clear accentuation in the intensity level, as from here

onwards most of the structures suffered damage of Grades 4 and 5 (Fig. 3, Photos 11 &

12). The entire Uri Tehsil was severely affected by the earthquake wherein of the total

95 villages, 65 were completely and 30 partially damaged. In this sector large-scale

collapse of dwellings and fairly intense coseismic slope failures were responsible for a

number of deaths and injuries. The sector wise description follows.

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Uri-Salamabad-Kamalkot Sector

The earthquake destroyed the village of Salamabad, situated about 6 km from

Uri along the Muzaffarabad Highway. Here, most of the structures, constructed of stone

masonry packed in mud or weak sand-cement mortar with sloping GI sheet roofing

suffered total collapse corresponding to Grade 5 of the MSK-64 scale (Photos 13a, b, c

& d). The bunkers (low mud-stone masonry structures) and the abutments of

bridges/culverts came under high distress in this sector (Photo 14). In the region

comprising shale and sandstone bands of Murree Group a number of coseismic

landslides developed, which blocked the Highway and the roads at several places or left

distinct scars on the banks of Jhelum river and its tributaries (Photo 15). On the day of

the visit on 12th

October 2005, the Muzaffarabad Highway was still blocked by a series

of huge landslides a little ahead of Salamabad (Photo 16). It was reported that a number

of persons were killed or injured by the triggered landslides in the Tehsil.

In Lachi and Sultan Dhakki villages, the damage was near total with heavy loss

of life in most of the settlements (Photo 17).

The damage was equally severe in the village of Kamalkot and the surrounding

hamlets situated at the foot of a high mountain range, about 15 km from Uri (Fig.4). The

inhabitants who were interviewed narrated that an explosion like sound accompanied

the powerful shocks the type of which were never experienced before. They further

stated that there was dust all around and on regaining composure realized that their

world was lost. There were several who were killed instantly and many buried under

tons of debris. In all these settlements the dwellings were constructed in the typical stylewith heavy stone masonry walls of low shear strength and slopping GI sheet roofing.

Nearly all such structures were reduced to heaps of rubble (Photos 18a, b & c). From a

distance the dwellings appeared like canopies of glimmering sheets placed over the

ground (Photo 19a). The debris slopes also failed at a number of places (Photo 19b).

In two of the rivulets of the area, the discharge increased several folds as a few

new springs opened up (Photo 20). In one of the nalas that cut across the Kamalkot

road, the water discharge turned blackish in colour and was depositing the fines on its

sides at the break in slopes. The nala originated from a pulverised carbonaceous shale

bed representing the contact of the Main Boundary Thrust (MBT). It appears that due tothe earthquake a new spring opened up in the zone, which was eroding away the weak

mass of the fault zone and carrying the sediments along with the swift flow. Whether

this phenomenon was related with some coseismic tectonic movement along the MBT,

is to be established.

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Dardkot Village

The village is located on the right bank of Dardkot nala, a tributary of Nawa

Rundan stream, 12 km southwest of Uri and is approachable by a fair weather road from

Lal Bridge. The village dwellings are located over a sprawling terrace, which lies at the

foot of a moderately slopping hill composed of Murree Group of rocks. Like rest of the

villages of Uri Tehsil, Dardkot also suffered heavily on account of the earthquake.

Isham Village

Isham village, located 1 km east of Chakra on the left bank of Jhelum river, is

approachable from Lal Bridge by a motorable road. In this locality 7 people were killed

and 15 injured in house collapses, which were constructed on Jhelum terrace deposits

(Photo 26).

Kupwara District

Kupwara was the other district in which the effect of the earthquake was very

pronounced. In the Karna (Tangdhar) Tehsil, 267 people perished and 1369 injured with

37601 houses suffering various grades of damage.

In the Kupwara town, low order damage was witnessed in many of the

structures. A similar order of effect was witnessed in Sopore. Along the Kupwara-

Tangdhar road, the seismic intensity was observed to be of a higher order at places like

Tregaon, Karalgaon and Chowkibal. Partial collapses of a larger number of structures

could be noticed in these localities. In Tangdhar town partial collapses in many of theconventional Type A structures were witnessed (Photos 27 & 28). A single storey

structure with symmetrical dispositon showed gaping shear cracks (Photo 29). The

newly constructed single storey Police Station building, made of stone masonry

(dressed stones) in sand-cement mortar with GI sheet roofing, surprisingly suffered total

collapse (Photo 30). The building is located over the Quaternary deposits of Sulaiman

rivulet. There was no loss of life in Tangdhar town.

In villages like Badarkot, Ibekot, Dringla, Dundishtsh, Haridal and Prada,

located west of Tangdhar, the damage was reported to be higher, reaching Grade 5 of

the MSK-64 scale.

Jammu Division

In the Jammu Division the survey was conducted in localities belonging to

Poonch, Jammu, Udhampur, Doda, Rajauri and Kathua Districts. The District-wise

description follows.

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Poonch District

In the Poonch District the effect of the earthquake was very pronounced. The

State Government records reveal that 10 persons were killed, 73 injured and 78 cattle

heads perished in the earthquake. In all, 50,000 people residing in 136 villages were

affected. A total of 1524 houses got fully and 6272 partly damaged. The worst affected

localities from where deaths were reported include Ajote, Karmara, Khari, Gulpur,

Baila, Mandi, Ghani, Mendhar and Poonch town. The persons who were injured

belonged to Jandrolla, Qasba, Salotri, Azamabad, Gulpur, Loran, Khori, W.No.15 and

Poonch town.

The Poonch town is located at the confluence of Poonch and Betar rivers over

different terrace levels, 25 km south of Uri and 95 km southeast of the USGS epicentre

of the earthquake (Figs.1&5). The area comprises an alternate sequence of sandstone-

shale belonging to Murree Group of rocks and Quaternary deposits. The inhabitants,

who were deeply frightened at the time of passage of seismic waves, heard an explosion

like sound followed by intense ground vibrations.

The tremors induced partial collapse of walls of many poorly constructed

structures of random rubble masonry in mud mortar The Deputy Commissioners Office

Complex comprising a number of individual structures showed various grades of

damage. Whereas a few were raised to the ground, some suffered partial collapses

(Photos 31, 32 & 33). The Deputy Commissioners residence, a two storey well

constructed masonry structure, showed failure of both ground and first floor outer walls

(Photos 34a & b). The Sheesh Mahal, an old conventional type double storey structurebuilt around 1852 by Raja Jagdeo Singh, presently housing the Girls Higher Secondary

School, suffered partial collapse, in the upper floor (Photo 35). The Geeta Bhawan, a

three storey old structure of the town also received considerable damage.

The newly constructed mosque in the town, using brickwork, sand-cement

mortar and a modern architecture, displayed the most prominent damage. The

ornamental arches, minarets and columns developed shear cracks, the burjis tilted and

the central dome totally sheared off from its base consequent to the strong motions

(Photos 36a & b and 37).

A number of single storey Type A structures in the residential colony located on

the higher-level terrace suffered Grade 4 damage in the form of collapse of partition and

load bearing walls. A three-storey bungalow, a relatively strong structure consisting of

brick masonry reinforced by columns and beams belonging to Dr. Tej Bahadur Sharma

became uninhabitable, as most of the walls, especially of the upper floors, were severely

damaged.

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The Poonch Fort walls also received considerable damage. The western (back)

portion of the Fort wall built of stone masonry in a mortar of lime and surkhi failed

under the influence of strong motions. Skirting the courtyard on the three sides viz., the

northern, western and southern were built double storey structures. On the eastern side a

three-storey building was present. The earthquake caused collapse of the entire upper

storey on the western side building, housing the G.P. Fund Office of the J&K

Government Finance Department (Photo 38).

Moti Mahal, an old palace built by Sukhdeo Singh, presently being maintained

by the Indian Army, also became uninhabitable as a number of rooms on the first floor

of this stone masonry building suffered Grades 3 & 4 damage (Photo 39).

The Vishnu Temple located within the Fort Complex also had telltale imprints

of the earthquake. The black stone idol of Lord Narada, which was earlier placed over a

20 cm high wooden pedestal, was found lying on the floor, broken into three pieces

(Photo 40). The idol was thrown towards S80E direction. Another idol of Lord

Hanuman apparently fell down from its concrete pedestal towards S80E direction.

Khari village, located northwest of Poonch town on terrace deposits and slope

debris received considerable damage in which one person was killed and another

injured. Masonry walls of a single storey house were heavily sheared and dislodged by

the strong motions (Photo 41). The poor type structures suffered total collapse in the

area (Photo 42). The influence of topography was clearly discernible in the damage

pattern, which was more pronounced on structures located over the higher-level terraces

as compared with the lower ones.

In Ajote village, located on a terrace deposit on the western bank of Betar river

about 2 km northwest of Poonch town, Type A structures composed of random rubble

masonry showed considerable damage. A person was killed in a house collapse in the

village. Some Type B structures also suffered Grade 3 damage in the form of gaping

shear cracks in the walls. The villagers heard a sound resembling that of gushing wind

followed by thundering at the time of the earthquake. The tremors were very strong

under whose influence people lost balance.

In village Dalan, located 5 km north of Poonch town over steep rocky slopes onthe left bank of Betar river, the intensity of ground motions appears to be less than at

Poonch. Here, Type A structures made of random rubble masonry in mud mortar with

thatched roofs suffered maximum damage in the form of partial collapses. The Middle

School building of Bagyal Dar hamlet adjacent to the Dalan village showed damage in

the form of collapse of one of the walls. There was no case of total collapse of any

structure in the locality. It was observed that the Bagyal nala, which remained dry in

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this part of the year, started discharging water consequent to the earthquake. It is likely

that some of the springs opened up feeding the drainage of the village.

Jammu District

The district comprises a hilly terrain belonging to Siwalik Group of rocks and

vast alluvial plains in the southern part with Tawi river providing the principal drainage.

In this area, the tremors were felt strongly by almost everybody. Accept for stray cases,

no significant damage other than widening of preexisting cracks and opening up of

construction joints was witnessed in and around Jammu town. Prominent cracks in taller

structures like Jammu Medical College building, Tehsil Office of Wazarat road, etc.

were reported. In a 19th

Century structure known as Mubarak Mandi, a dilapidated wall

constructed of lakhori bricks in lime mortar collapsed (Photo 43). Cracks appeared in

some walls and parapets in the city area.

In Kotli-Shah-Daulla area located along Jammu-Suchetgarh road the corner

burzis of a Gurudwara, a three-storey brick building, got displaced during the

accentuated vibrations and thrown down (Photo 44). In an adjoining newly constructed

temple structure fine horizontal cracks appeared in the walls (Photo 45). In some other

structures in this area fine cracks and opening of construction joints were recorded. In

Saror area located about 20 km from Jammu town along Jammu-Pathankot Highway,

chimneys of some of the brick Kilns either developed shear cracks or got sheared off

from the top part (Photo 46). One of the walls of the Jammu Old Fort also caved in

during the earthquake (Photo 47). An open fissure, traced for a length of 100 m

appeared along a bund structure near Simbal Camp, 15 km south of Jammu (Photo 48).

Udhampur District

The District, comprising mainly a hilly terrain with longitudinal valleys, is

represented by rocks belonging to Murree and Siwalik Groups and Sirban Formation.

The tremors were strongly felt by everybody though damage to civil structures was, by

and large, absent. In a stray case, a hotel building located 7 km from Udhampur town

suffered Grade 1 damage. The owner described that the GI sheet roofing clattered as if

monkeys were jumping over it. A hot spring appeared in the lawn of Triyath High

School, located at the border of Udhampur and Rajouri Districts.

There was evidence of somewhat stronger seismic intensity towards southeast of

Rajauri in Triyath, Paoni and Riasi area. At Triyath, partial collapses in a few houses

constructed of random rubble masonry and cracks in brick structures were recorded.

New hot springs giving sulphurous odour spouted at places from Sirban Formation. At

Damar village, the inhabitants found it difficult to stand. Partial collapse in a few poor

type structures was reported from the locality. At Kheral village, located 6 km west of

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Riasi towards Pauni, collapse of mud walls of a thatch-roofed structure was noticed

(Photo 49). Here, two inhabitants were injured. The walls of the old Riasi Fort suffered

partial collapse. Southeast of Riasi the seismic intensity showed a diminishing trend.

At Katra there was no significant damage though the inhabitants experienced

strong tremors and came out of their dwellings in panic. At Chiara, located a few

kilometers east of Katra, a few collapses from poor quality constructions were reported.

Doda District

The mountainous terrain of the District with Chenab river forming the principal

drainage was shaken by the tremors of 8th October earthquake. However, there was no

report of damage in this region.

Rajauri District

The intensity of ground motions in the District was similar to that at Jammu

though no significant damage to civil structures was observed or reported from the area.

However, the famous hot spring of Tatta Pani in the district located near Kalakot

Eocene Coal deposits with temperatures of 45C dried up consequent to the earthquake.

It is reported by the local people that immediately after the main shock water gushed out

from the spring for some time before gradually drying up.

Change of flow in springs was reported from Bimbergali, located 25 km west of

Rajauri. South of Rajauri towards Akhnoor the seismic intensity distinctly diminished.

In this area, most people felt the tremors and ran outdoors. The tremors were, however,not strong enough to destabilize even small objects kept in shelves. Cracks in poor

quality mud masonry structures were reported as the maximum damage. At Surankot, it

was reported that half litre cold drink bottles kept over the top of a refrigerator fell down

whereas 2 litre bottles remained untoppled.

Kathua District

The effect of the earthquake was very conspicuous in this District, whose

western margin forms the International border with Pakistan and the southern and

southeastern with the States of Punjab and Himachal Pradesh, respectively. Drained byRavi river and its various tributaries, the region is an assemblage of hilly terrain

composed of Murree and Siwalik Group of rocks and a dissected alluvial plain. The

distinct tremors observed for a considerable duration infused a sense of panic among the

residents. At Basantpur, located on the right bank of river Ravi over terrace deposits,

water spilled out from the containers. However, no report of damage was received from

this locality. In Bilawar Tehsil utensils and other objects kept over racks and tables

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started clattering and water spilled out from buckets. In localities between Ramkot and

Udhampur, people reported that even deep bore well water (80 m depth) turned turbid.

This turbidity was evident for about 12 hours following the main shock of 8th October

2005. At Rampur, water in a lake turned muddy. At Manawal and Kuthed, the shutters

of the shops and GI sheet roofing clattered violently during the passage of the seismic

waves. Cracks appeared in a few Type B structures of the locality. Grade 1 damage was

also reported from a few Type A structures. It was also reported that 85% of the hand

pumps started giving muddy water after the quake. There was vigorous shaking of the

trees.

The Navodaya Vidhyalaya building at Nad (located between Mansar and

Samba) received Grade 1 damage in the form of cracks. Water supplied through

pipelines turned muddy and remained so for about 30 minutes after the earthquake. The

furniture got displaced and books kept in the racks fell down. In Hira Nagar and

Lakhanpur the water in a few hand pumps became reddish brown in colour. In the RTO

Office at Lakhanpur a joint in the stone slab floor opened by about 2 mm due to the

shaking. Here, a farmer reported that the tremors were so strong that it became difficult

to maintain balance, doors rattled, utensils kept on the racks fell down and hair line

cracks appeared in the walls and roof.

In Kathua town, it was noticed that the ground oscillated in E-W direction. The

shutters vibrated vigorously. In the house of Diwan Chand, a wall-floor joint opened by

3-4 mm. Many hand pumps discharged muddy water. Hairline cracks developed in a

School boundary wall. Firozuddin, a farmer from the outskirts of Kathua, reported

appearance of cracks in roof and walls of his house and falling down of utensils in the

kitchen. Many hand pumps started discharging muddy water.

Harnam Singh, the Patwari of Padyari and Phalote villages reported that in his

locality 20%-30% Type B houses developed hairline cracks mostly in N-S trending

walls. He also reported that all hand pumps and even deeper tube wells discharged

muddy water throughout the day following the earthquake. A few people lost balance

and fell down. In the house of Dilbagh Singh, a farmer, cracks, disposed vertically and

horizontally, developed in the walls of all the rooms of his village house. Water spilled

from tanks, objects kept in the almirah fell down, some lost balance and fell down and

water remained turbid for 6-7 hours.

Other Seismological Effects in Jammu & Kashmir

The earthquake induced various other seismological effects, particularly in the

Uri and Karna (Tangdhar) Tehsils, of which conditions of slope failures were the most

conspicuous. The highly tectonised rocks of Murree Group, represented by alternate

bands of shale and sandstone are even otherwise highly susceptible to slope failures.

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The strong ground motions therefore induced numerous slope failures some of which

adversely affected the road sectors, endangered the settlements and cultivated fields and

became responsible for some casualties of people and cattle. The Jhelum valley south of

Uri and Kishanganga valley in Tithwal area were marked by numerous coseismic slope

failures.

The hydrological effects like changes in flow of springs, and opening of new

and closing of old springs were common in the higher intensity zones. Several such

cases have come to notice from areas surrounding Kamalkot village (Photo 20). The

discharge from Tatta Pani thermal spring stopped consequent to the earthquake.

Groundwater fluctuations were common in many parts of Kathua and Jammu Districts.

A case of liquefaction was documented from Simbal Camp area, located 15 km

south of Jammu town. On the left bank of Balawal nala, ground fissures extending

interruptedly in a length of about 1 km and trending in N40 -70E -S40-70W

directions were seen arranged in en echelon patterns (Fig. 6). At many places, fine sand-

water mixture spouted for some time through these fissures and vents consequent to the

8th October 2005 earthquake and rose to a height of 0.6 m. The sand deposits on the

sides of the fissures attained a maximum height and width of 12 cm and 3.0 m,

respectively (Photos 50a & b). The opening of the fissures varied from 15 cm to almost

50 cm. Trenches excavated across the ground fissures at two places showed presence of

5.5 to 2.5 cm thick liquefaction induced sand dykes cutting through silty clay deposits

(Photos 51a & b). In this area the ground water was very shallow, of the order of 1 to

1.2 m only and the strata comprised sand-silt of newer alluvium. It is interesting to note

that the villagers who were interviewed told that they heard a sound accompanying thetremors though the place is located some 250 km away from the epicentre.

In the Uri Sector the most important tectonic feature is the Main Boundary

Thrust (MBT), along which the Pre-Tertiary Formations represented by rock sequence

of limestone and carbonaceous shale override the Murree Group of rocks. The thrust

zone is demarcated by highly pulverised carbonaceous material. In the Jhelum valley

south of Salamabad the MBT appears to be off set by a cross fault. Near the junction of

these two structural discontinuities some fresh rupturing along the MBT is discernible,

which may be coseismic in nature (Photo 52). From the northward displaced part of the

MBT a few new springs opened up. On 12th October 2005, it was witnessed that one ofthe new springs originating in the MBT was bringing lot of carbonaceous material along

a gully and depositing part of the debris on the Kamalkot road.

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2. Punjab

Amritsar-Beas-Batala-Gurdaspur-Jalandhar Sector

In this sector the tremors were strong enough to be felt by all and infuse a senseof fear among the residents. Some people reported giddiness consequent to the

earthquake. At Batala, Kalanaur and Amritsar oscillations were noticed in water bodies.

Fine cracks developed in walls of buildings at Batala, Kalanaur, Dera Baba Nanak,

Amritsar and Gurdaspur. A few cases of widening of old cracks in monumental

buildings came to notice at Batala and Amritsar. In the building of Guru Nanak Dera

Sahib at Bata, a historical palace, a casualty was reported because of collapse of a

portion of an old wall.

At Shahpur Jajhan located near Dera Baba Nanak, a 7-year-old boy got killed

due to collapse of a mud wall. Fall of minor nature were noticed from projections of old

buildings at Gurdaspur. The reported direction of vibrations was N-S. In and around

Jallandhar, all felt the vibrations and people got frightened, but there was no report of

damage to any structure. At village Madhar in Jalandhar district the groundwater level

remained raised so much that for almost 10 days the hand pumps started overflowing.

At Kaporthala a few fell dizzy.

Beas-Hoshiarpur Sector

The earthquake was strongly felt in the region, frightening the people

everywhere. In Hoshiarpur cases of minor dislodgements of projections in old buildings

were reported. In Una, a Chunk of alluvium from a road cut bluff fell down.

Mamoon-Shahpur-Madhopur-Ranjit Sagar Dam Sector

At Mamoon Cantonment near Pathankot most of the people felt giddy though

there was no damage in the area. At Shahpur Kandi there was general panic, pictures on

the walls swung, water spilled from buckets, shutters rattled and a sound resembling

that of a passing train was heard. But there was no structural damage though hairline

cracks were reported from buildings. At Madhopur it was reported that the shutters of

shops rattled vigorously, trees and parked trucks swayed and electric wires swung but

the buildings escaped any damage.

In the Ranjit Sagar (Thein) dam project area, a landslide activity occurred for

about 30 minutes downstream of the dam structure. The workers who were inside the

dam galleries felt three distinct shocks and were terribly frightened. Some lost their

balance. The discharges in Transverse gallery at EL.432 m (hole No.22), Longitudinal

gallery (hole No.2), Crest gallery (hole No.7) and L/S gallery EL. 400 m (hole No. 2, 6

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and 11) increased. Some of the casegrande piezometers, which were initially in dry

condition, started overflowing and the pore potential in some other holes increased by

about 1m after the quake. As such, there was no damage at Ranjit Sagar Dam project

and the powerhouse remained fully operational, uninterruptedly.

Ropar and Patiala Districts

At Mohali and Kurali everybody felt the tremors with some complaining of

giddiness. Many ran outdoors out of fear. In stray cases cracks of minor nature appeared

in wall plaster. Splashing of water from tanks, swaying of trees and parked vehicles, etc.

were reported from Kwali. People witnessed perceptible swaying of the 120 and 140 m

high chimneys of the Super Thermal Power Plant. It is reported that during the tremors

the speed of the turbine crossed its optimum limit and got tripped. At Zirakpur stray

cases of plaster cracks were reported from upper floors of buildings.

3. Himachal Pradesh

Chamba-Bathri-Nanikhad-Jandrah Sector

The earthquake was strongly felt in the region. In Chamba town, the ground

motions were in E-W direction and resembled that of a rocking boat. Minor cracks were

reported to have developed in some buildings in Chamba town, Holi and Bharmour area

of Chamba District. Hanging objects swung violently at all the places. No incidence of

co-seismic landslides was recorded.

Nurpur-Kotla-Draman-Shahpur-Gagal-Kangra-Palampur Sector

All who were indoors or outdoors felt the tremors but those who were moving in

vehicles could not feel them. Trees, buildings and parked vehicles were found swaying.

A very small percentage of people in Palampur town did not feel the tremors at all. In

general, there was no damage in the area from the earthquake.

Chamba-Koti-Sundla-Salooni-Langera Sector

This sector, located close to the J&K border, had a similar seismic intensity as at

Chamba town, where stray cases of non-structural damage occurred. At Langera loose

objects fell down, a trishul (trident) embedded vertically shook vigorously but bells intemples did not ring. In a poor structure Grade 1 damage was witnessed. Along the road

cut, minor dislodgement of rock blocks was noticed. The springs momentarily turned

muddy after the quake. The quantity of water in natural springs reduced by as much as

50%.

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Sundarnagar-Mandi-Simla Sector

All in the region distinctly felt the shocks and people came out in the open.

Some had a feeling of nausea due to the rocking motions. In Sanskrit College building,

Sundernagar constructed in 1980, a crack developed in one of the walls. Accept for

some poor type constructions where minor damage occurred, rest of the buildings in the

locally escaped without any damage. In PWD Colony, Kusumli, Simla a wall of a Type-

III Quarter suffered a partial collapse. It was reported that the structure was in quite a

dilapidated condition. A crack in the wall of Dental College building was also reported.

Kulu- Manali Sector

In this sector, almost everybody rushed out of their buildings on perceiving the

strong tremors. Accept for stray cases the structures escaped without any damage. In an

isolated case, a two-storey old and poor quality house in Chong village in the Parbati

valley suffered partial collapse. It was noticed that persons working in the underground

structures of Larji project, like power house cavern, surge gallery, tail race tunnel, draft

tube gate gallery, etc., did not feel the tremors at all whereas those in the open felt them

distinctly. It was reported that in remote areas of Lahaul and Spiti as well most of the

people felt the tremors, which were of frightening proportions.

4. Chandigarh

All felt the tremors, which lasted for a minute. Those residing in the upper floors

of the buildings were frightened and rushed out of their houses. Some felt giddy and

were reported to have lost balance. The hanging objects swung to moderate extent.

Objects like trees and poles swayed considerably and water in containers splashed in

some cases. Perceptible waves were generated in the Sukhana lake. The tremors were

not perceptible to those who were moving in vehicles.

5. Haryana

Panchkula

The effect of the earthquake at Panchkula was similar to that at Chandigarh. In

the Jalvayu Vihar, an eight storey residential complex, small unstable objects gottoppled. A pendulum clock in a 6th floor apartment stopped due to the vibrations. Stray

cases of plaster cracks occurred in some high-rise buildings in Sector 20. Dogs started

barking and birds chirped and flew away.

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Faridabad-Gurgaon

All felt a total of three shocks lasting for duration of 50-60 seconds. Some felt

giddy by the swaying motions. Those residing in upper floors felt the tremors more

strongly and therefore moved out of the buildings. Rattling of doors and windows and

swinging of hanging objects were the common observations.

In stray cases minor damage in buildings was noticed. In Kali Bari Society,

Sector 21D, Faridabad, cracks developed in one of the ground floor toilet floors. In the

5th Floor of flat No. C-52, Ringwood Apartments in DLF Phase IV, Gurgaon, about 2 m

long and 2-3 mm wide cracks developed. Minor cracks in plaster and Plaster of Paris of

8th floor flat No. 308 B of Hamilton Court Apartment at Gurgaon were noticed. A tile

got separated out in the BSF Apartment located along Faridabad-Gurgaon road.

Bahadurgarh-Rohtak-Meham-Sorkhi-Hansi-Hissar

The tremors lasting for about 50 seconds were of mild intensity and could be felt

by all the people. Not much of fright was associated. In the 80-year-old Chaupal

building at Sorkhi, cracks appeared in the arches. An adjoining old structure also

suffered some damage in the form of widening of old cracks/development of minor new

cracks. Some people reported giddiness.

Fatehabad-Ratia-Moonak-Narwana-Jind-Safidon-Panipat-Ballabhgarh

Three distinct shocks in E-W direction, lasting for duration of 40-50 seconds

were observed in this part of Haryana. Some reported giddiness. No damage was

reported. However, at Safidon a preexisting crack in an old Type B structure widened.

6. Delhi

Four localities in Delhi were surveyed to get an idea of seismic intensity in the

capital region. The localities were Mayur Vihar, Adarsh Nagar, Peetam Pura and Delhi

Secretariat. Almost all who were indoors and many who were outdoors felt the

earthquake. Those residing in upper floors felt much stronger vibrations and therefore

attempted to come out of their buildings. The furniture shook and the hanging objects

swung. No case of damage to buildings was reported except from Delhi Secretariat

complex where hairline plaster cracks appeared in some walls.

7. Uttaranchal

Traverses were taken in different parts of Garhwal and Kumaon regions to

observe the effect of the 8th

October 2005 earthquake. Special care was taken to

investigate any distress in major river valley projects like Tehri dam, Koteshwar dam

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and Maneri Bhali Hydel Scheme Stage-II. Tremors of feeble to moderate intensity were

felt in different parts of the State. There was no report of any damage to structures in

Uttaranchal due to the earthquake.

8. Uttar Pradesh

A large number of localities in Central and Western parts of the State were

reconnoitered to gather information on the effects of the earthquake. At Lucknow only

those residing in G+4 or above floors perceived feeble tremors. At Bareilly the intensity

was higher than at Lucknow. At Meerut the tremors were distinctly felt by almost

everybody.

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IV. Effects of Kashmir Earthquake in Pakistan and Pak Occupied

Kashmir

The earthquake had a devastating effect in a large part of North Pakistan and

Pak Occupied Kashmir, where, as per Government reports of November 2005, 87,350people perished, 1,38,000 injured and over 3.5 million rendered homeless. Of the dead,

19000 included children. The earthquake affected more than 5,00,000 families. Over

7,80,000 buildings were either destroyed or damaged beyond repair. Approximately

17,000 School and Hospital buildings in and around the epicentre were totally damaged.

The entire road network in the affected region became dysfunctional due to massive

landslide activity triggered by the strong motions. Several areas were unapproachable

by road even after three months of the main shock. Power-water supply and

telecommunication links remained disrupted for varying lengths of time in different

sectors.

The death and damage figures in North West Frontier Province, Pakistan and

Pak Occupied Kashmir are given in Table 2.

Table 2

Death and Damage Figures

(Source: MEA Report 05-04, 2006)

Sl.

No.

District

North West Frontier Province (NWFP)

Dead Injured Buildings Damaged

Fully Partially

1.

2.

3.

4.

5.

Shangla

Manshera (Balakot)

Kohistan

Abbottabad

Batagram

423

24511

661

515

3232

957

30585

639

1730

3279

15880

32293

4504

7267

29015

11087

43925

18737

27813

8841

Pak Occupied Kashmir (PoK)

1.

2.

3.

4.

5.

6.

Neelum

Muzaffarabad

Bagh

Rawalakot

Sudhmoti

Mirpur

447

33724

8157

1025

4

6

1013

21374

6644

1909

16

11

3692

115211

48365

15362

430

0

8991

17209

18736

25770

1777

0

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As per reports gathered from various sources, the maximum damage occurred in

an area of about 458 sq km between Balakot and Muzaffarabad. It has been estimated

that 30%-35% buildings in Muzaffarabad, located on the banks of Kishanganga

(Neelam) and Jhelum rivers were either destroyed or badly damaged (Fig.7). Major

damage concentrations were in areas of deeper alluvial deposits (EERI, 2006). An

assessment of damaged buildings in Muzaffarabad and the surrounding areas carried out

by the Earthquake Engineering Center of the University of Engineering and

Technology, Peshawar showed that about 60% of the urban structures were

unreinforced solid concrete block masonry buildings and it was the collapse of more

than 60% of them that became responsible for majority of the deaths and injuries (Photo

53a). The Combined Military Hospital, a well designed and well constructed structure

with a soft storey suffered major damage due to the strong and prolonged shaking

(Photo 53b).

The town of Balakot, situated on the banks of Kunhar river, a tributary of

Jhelum, was the worst affected where majority of the buildings suffered high-grade

damage (Fig. 8). The RCC deck of Balakot bridge over Kunhar river having two central

piers got displaced by about a metre from its support bearings due to the strong motions

(Photo 54). It has been analysed that lack of lateral resistance allowed sliding of the

bridge where vertical motions might have played a significant role in reducing the

vertical force on the bearings, leading to the large observed lateral displacement (MEA

Report no. 05-04, 2006). The effect of topography was also significant in accentuating

the damage intensity at Balakot.

The masonry abutment of one of the bridges sheared off along a subhorizontal

fracture plane (Photo 55). One of the suspension bridges between Balakot andMuzaffarabad snapped off (Photo 56). High order damage was also recorded in places

like Garhi Habi Bullah, Bagh, Manshera, Abbottabad, Rawalakot, Batgran, etc. Peak

Horizontal Ground Acceleration (PHGA) of 0.231g was recorded at Abbottabad by the

strong motion recorders (EERI, 2006). At Tarbela dam, located about 78 km from the

epicentre, the PGA was 0.16g at the crest and 0.1g at the base of the structure (EERI,

2006).

According to the Associated Press hundreds of people were affected in the

collapse of a nineteen storey building in Islamabad, known as Margalla Towers (Photo

57). This was a stray case of major damage to a well-constructed building in the citylocated 95 km away from the epicentre. In Rawalpindi also damage to many buildings

was recorded.

The earthquake induced profuse landslide activity in a very large area. Sato et

al., (2006), identified presence of over 100 coseismic landslides on the basis of

IKONOS imagery in the isoseist and surrounding areas of 8th

October event (Photos 58a

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& b). They confirmed that most of the landslides occurred along the uplifted northeast

side of Muzaffarabad and Tanda faults.

One of the rare earthquake phenomena witnessed in the epicentral and

surrounding regions was rupturing/displacements along faults. The thrust referred to as

Jhelum thrust that slipped during the 8th

October 2005 earthquake stood out clearly in

the geomorphic landscape of the Jhelum valley in the form of triangular facets

(Tapponnier, et al., 2006). Just north of Muzaffarabad the thrust stepped leftwards

across the Neelam valley, continuing into the Kunhar valley along high faceted spurs.

Hussain & Yeats (2006) found reactivation of the primary surface trace of MBT

between Balakot and Muzaffarabad. Southward, it diverged from the MBT and

followed the northern bank of Jhelum river passing near the villages of Garhi Dupatta,

Chakar, Sudangalli and Bagh where its surface trace ended. The fault appeared to have

broken along its entire 65 km trace and new springs opened up at places. Between

Balakot and Muzaffarabad the fault separated Precambrian dolomitic limestone and

carbonaceous shale from Miocene Murree Formation. Further south, the fault remained

restricted within Murrees.

Nakata and Kumahara (2006) observed reactivation of Muzaffarabad and Tanda

faults in a total 60 km long segment. The sense of movement was identified as right

lateral together with westward thrusting component on the basis of off setting of

streams. The high order of damage followed the trace of the rupture zone.

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V. Isosleismal Map and Isoseist Characteristics

The shock waves generated by the Mw 7.6 Kashmir Earthquake of 8th October

2005 could be perceived throughout the northern part of India for hundreds of

kilometres from the epicentre, including the States of Uttar Pradesh, Uttaranchal,Punjab, Haryana, Delhi, Himachal Pradesh, Rajasthan and Gujarat. Jammu & Kashmir,

being closest to the rupture zone, was shaken to the maximum extent, resulting in low to

high order seismic effects in different parts of the Himalayan State. The Geological

Survey of India mobilised several teams of scientists to record and document the effects

of the earthquake in various places with the main objective of preparing the isoseismal

map. To assess the intensity levels, Medvedev-Sponheuer-Karnik (MSK-64) intensity

scale was used (Annxure II). The grades of damage to different types of structures and

damage patterns were evaluated, human perceptions recorded and the coseismic

secondary effects documented. The intensity levels were assigned after carefully

collating and analysing the evidences collected from different sources (Figs.1& 9). The

seismic intensity distribution in the adjoining territory of Pak Occupied Kashmir and

Pakistan was assessed by going through the press and electronic media reports

(Annexure III) and various scientific reports posted in the websites and presentations

made in the Seminars (Zare, 2005).

The epicentral tract of 8th

October 2005 Kashmir Earthquake encloses an area of

458 sq km and includes localities like Muzaffarabad, Balakot, Ghori Habibulla, etc.

belonging to NWFP and PoK. As per reports gathered from various sources, the city of

Balakot was almost totally destroyed with most of the structures suffering Grade 5

damage. In this District a total of 24511 deaths and 30585 injuries, apart from damage of

over 76000 buildings were reported (MEA Report no. 05-04. 2006). The old type stone

masonry structures, the mixed type structures using RCC columns and beams with

brick/stone partition walls, well constructed RCC framed structures and RCC buildings

with soft stories all suffered heavily, including total to near total collapse.

The intensity of ground shaking appears to be equally strong in Muzaffarabad

were over one lakh buildings were destroyed. Huge landslides were generated and

coseismic rupturing took place along Muzaffarabad and Tanda Faults within the

epicentral tract. Judging from the damage pattern and other seismological effects, the

epicentral tract has been assigned an intensity of X on MSK-64 Scale (Fig.1&9).

Isoseismal IX encloses part of NWFP, PoK and the western sectors of Baramula

and Kupwara Districts in Kashmir Division. The isoseist occupies an area of 3867 sq km

and is highly elongated in N36W-S36E direction with long-short axes ratio of 2.5:1.

The major localities within this isoseist include Uri, Tithwal on the Indian side of LoC

and Bagh (PoK), Shinkiari and Deoli (NWFP). In this intensity zone the people heard an

explosion like sound accompanying very powerful shocks that were never felt before.

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The typical Type A structures of the area consisting of walls using large stone masonry

packed in mud or sand- cement mortar and GI sheet roofing over timber support, failed

in this intensity, showing Grades 5 and 4 damage. A number of new springs opened up

and numerous landslides generated from the rock and debris slopes. Casualties in this

isoseist were also quite high.

The isoseismal VIII is also elongated in N35W-S35E direction with the long-

short axes ratio of 1.8:1. The isoseist, occupying an area of 9142 sq km, encompasses a

considerable part of the Indian Territory. The important localities in India include

Poonch, Rampur, Mahura, Tangdhar, Tregaon, etc. The localities in Pakistan and PoK

are Abbottabad, Rawalakot, Manshera, Batagram, etc. In this intensity tremors were

very strong. Partial collapse and development of cracks in Type A structures were

common. Many Type B structures also suffered damage of Grades 2-3. Low order

landslide activity occurred in this zone.

The egg shaped isoseismal VII occupies an area of 22673 sq km in the territory

of NWFP, PoK and Jammu and Kashmir. The Isoseist is distinctly elongated in N35W-

S35E direction with long-short axes ratio of 1.85:1 The important localities in this

isoseist include Srinagar, Baramula, Sopore, Kupwara, Mendhar, Murree, etc. In this

intensity strong tremors lasting for a considerable duration were experienced, instilling a

deep sense of anxiety and fear. There were reports of loss of balance and those driving

cars/two wheelers felt wobbling effect. In stray cases poorly constructed Type A

structures suffered partial collapse. In many such structures cracks appeared. Some well-

constructed buildings also developed fine cracks. Cases of appearance/ disappearance of

springs/thermal spring occurred in this intensity. An isolated intensity high of VII amid

intensity VI was observed around Riasi-Paoni area. In this more or less circular zonepartial collapse of weak structures was witnessed. This included walls of Riasi Fort.

Isoseismal VI is highly elongated in N30W-S30E direction though it has been

constrained on the Indian side, its full trace in the territory of Pakistan and further north

in Afghanistan could not be closed due to lack of information. The prominent localities

falling in this isoseist are Anantnag, Rajauri, Batote, Udhampur, Kathua, Gurdaspur,

Pathankot, etc. Places such as Islamabad, Tarbela, Mirpur, Jhelum, Sialkot, etc. lie in

this isoseist in Pakistan. Here, the tremors were strong enough to be distinctly felt by

everybody, instilling a sense of panic amongst the residents. Fine cracks appeared in

some poor type structures. In stray cases a few old walls suffered partial collapse.Fluctuations in groundwater levels and its getting turbid was widely reported from many

localities falling in the alluvial tract.

Jammu city and surrounding areas form an isolated intensity high where the

intensity approached VII on MSK-64 scale. Partial collapse of some structures and brick

kiln chimneys has also been witnessed. In this zone near Ranbir Singh Pura,

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liquefaction occurred in the very shallow groundwater regime in the recent flood plane

deposits. It is interesting to note that in Jammu area the inhabitants heard a low

explosion like sound accompanying the tremors. The place is located about 240 km

away from the epicentre. It is unlikely to hear a seismic sound, which is produced by

passage of strong phase of P-waves into the air, at such a distance. It may be possible

that at Jammu a secondary rupture got triggered at a very shallow depth along another

inflamed zone under the influence of seismic perturbations. This is how the isolated

intensity high at a far off place can be explained.

Table 3

Isoseist Details of 8th

October 2005 Kashmir Earthquake

S.No. Isoseist Area(sq km)

CumulativeArea (sq km)

LongAxis(km)

ShortAxis(km)

RatioL: S

Radius(km)

1.

2.

3.

4.

X

IX

VIII

VII

458

3867

9142

22673

458

4325

13467

36140

36

120

177

286

18

48

98

155

2:1

2.5:1

1.8:1

1.85:1

12.071

37.094

65.459

107.233

For constraining isoseismal V some localities in Punjab and a few in Himachal

Pradesh were visited. Places such as Amritsar, Hoshiarpur, Jalandhar, Chandigarh,

Simla, and Chamba showed effects of intensity V. All felt the tremors and some reported

a feeling of giddiness, fear and anxiety. In some cases preexisting cracks got widened,

and in some, plaster cracks appeared. No structural damage took place in this intensity.

Places located in parts of Punjab Haryana, Uttaranchal, Delhi and NW Uttar

Pradesh showed characteristics of Intensity IV where the tremors were widely felt but

were not strong enough to cause any panic. The observations made at places like

Bareilly and Jaipur indicated effects of intensity III. At Lucknow, located more than

1000 km away from the epicentre, the tremors were felt only above G+4 floor levels in

the form of mild shaking. Those on the ground floor could not feel the tremors at all,

which puts the intensity at Lucknow as II (Fig.9).

The isoseists are highly elongated in N35W-S35E direction showing a stronggeological control. The focal depth of the main event of 8

th October 2005 has been

evaluated using the following empirical relationships.

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1. Gzovsky, 1962

Io=1.5 M - h/15 (where, Io is epicentral intensity, M magnitude and h focal

depth)

This gives h = 21.0 km for M 7.6 (USGS)

and 16.5 km for M 7.4 (IMD)

2. Shebalin, 1974

Io =1.5M 3.5log h + 3

This gives h = 18.07 km for M 7.6

and h = 14.83 km for M 7.4

3. Karnik

Io In = log Dn/h

Where, Io = Maximum Intensity

In = Intensity of the chosen Isoseismal

V = a constant (say 3)

Dn = r 2+h 2

r = Distance from maximum to chosen isoseismal

h = focal depth

According to this relationship h = 13 km for In = IX and h = 12 km for In =

VIII.

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VI. Aftershock Monitoring

The 8th October 2005 Kashmir earthquake was followed by an intense aftershock

activity. Reports indicated that in the first week over 575 seismic events occurred with

peak of the activity forming in the first two days. The India Meteorological Department(IMD) and USGS Permanent Seismological Observatories recorded numerous

aftershock events, a plot of which is shown in Figure 1. The Geophysics Division, GSI,

NR deployed an array of five digital MEQ recorders at Stations i) Srinagar, ii)

Baramula, iii) Bandipore, iv) Gulmarg and v) Gingal (Uri) with the objective of

recording the aftershock activity as accurately as possible (Fig.10, Table 4).

Table 4

Details of Temporary MEQ Network

S.No.

Station with code Latitude (E) Longitude (N) Period of operation

1

2

3

4

5

Srinagar (SGR)

Baramula (BML)

Gingle ( GNL)

Gulmarg (GLM)

Bandipore (BDP)

34.06

34.02

34.12

34.07

34.42

74.82

74.34

74.10

74.33

74.63

23rdOct- 17

thNov05

24thOct- 14

thNov05

25thOct- 14

thNov05

2nd

Nov- 15th

Nov05

9th

Nov-16thNov05

Each microearthquake station of the network was equipped with a digitalseismograph (K2-Altus, Kinemetrics Inc, USA) coupled to three numbers seismometers

(Ranger SS-1, Kinemetrics Inc, USA). The two sensors were aligned in north-south and

east-west directions and one placed vertically over the ground.

The monitoring was done for a total duration of 24 days from 23rd

October to

17th

November 2005. In this period about 1000 events, mostly aftershocks of 8th

October 2005 main shock, were recorded of which 20 were of magnitude > 5 and one of

magnitude > 6 on the Richter scale.

The P-phase, S-phase and coda duration of aftershocks were determined from

their digital waveform. These phased data of aftershocks were analysed and processed

on computer using SEISAN seismological software at Geophysics Division, Geological

Survey of India, Lucknow. The epicentral, hypocentral and other statistical parameters

of the aftershocks were computed and analysed in rela tion to the seismotectonic setup of

the area.

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The daily statistics of the aftershocks is shown in Fig.11. This is in accordance

with Omris law of aftershock distribution related to an earthquake. Even after 15 days

of the main shock the frequency of occurrence of aftershocks was as high as 30 events

per day, which came down to about 5-6 events per day by 17th

November 2005. This

indicates that the strain adjustment was fast occurring to attain normal values in the

Kashmir region.

Most of the aftershocks were generated in the epicentral zone, located about

120-150 km WNW of Srinagar. The cluster of epicentres suggests emergence of certain

trends, which are aligned along the surface traces of MBT and Jhelum fault in N35W to

NNW directions. However, their relation to these tectonic features would be clear after

a detailed analysis of the data is completed. The data analysis indicates generation of

maximum number of the aftershocks within 20 km depth.

The preliminary results of the study are listed as follows.

1. Approximately 1000 aftershocks were recorded during the period from 23rd October

to 17thNovember 2005.

2. A total of 20 aftershocks of Richter magnitude 5 and one of 6+ were recorded

during the 24 days of monitoring.

3. Daily statistics of aftershocks of Kashmir earthquake obeys Omris Law. By 17th

November 2005, it seems that the strain adjustment in Kashmir region reached near

normal values.

4. Maximum number of aftershocks originated within the epicentral zone, which wasabout 120-150 km WNW of Srinagar.

5. Aftershocks were aligned along MBT and Jhelum fault.

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VII. Concluding Remarks

1. The 8th October 2005 Kashmir earthquake has reiterated the high vulnerability of

the region to seismic hazard, included in Zones V and IV of the Seismic Zoning

Map of India. The colossal loss of life and property in this natural catastrophehas been of unprecedented scale in the entire Himalayan habitat.

2. The earthquake occurred in the Hazra-Kashmir Syntaxis represented by Jhelum

reentrant south of the Kohistan Arc. The dominant tectonic discontinuities of

this domain are the Main Boundary Thrust (MBT) and the left lateral Jhelum

tear fault. In the Tertiary Frontal Belt the surface trace of Balakot-Bagh offshoot

of the MBT got coseismically reactivated and ruptured in a length of 65 km. The

landslide activity was profuse along this surface and conspicuously high damage

also witnessed. It is likely that the reactivation of the MBT and its offshoots may

be sympathetic to the rupture along the hidden causative fault.

3. The fault plane solution of the 8th October 2005 earthquake of Mw 7.6 shows

that one of the nodal planes has strike of N27W-S27E with dip of 39 towards

NE. A net slip of 4.2 0.5 m and a maximum slip of about 5.0 have been

estimated for the event. The focal depth has been calculated ranging from 12 to

26 km in various solutions. The general elongation of the isoseismals is in

N30W-S30E direction. This trend matches well with the strike of the above-

referred nodal plane, which could be the trend of the causative fault.

4. The plot of M 5 aftershock sequence as given by USGS and IMD indicates

distinct clustering at two locales, one 50 km northwest of USGS epicentre of the

main shock and the other, less prominent one, 90 km NNW to it (Fig.1).

5. The inferred causative fault more or less assumes the surface trend of the MBT

in the area. The migration of the aftershock activity has also been in NNW

direction with respect to the