ii iit roorkee seismic report

7/31/2019 II IIT Roorkee Seismic Report

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EARTHQUAKE ENGINEERING STUDIES

EQ : 2009- 39

SITE SPECIFIC DESIGN EARTHQUAKE PARAMETERS FOR

NYAMJANG CHHU H. E. PROJECT SITE, ARUNACHAL PRADESH

DEPARTMENT OF EARTHQUAKE ENGINEERING

INDIAN INSTITUTE OF TECHNOLOGY ROORKEE

ROORKEE - 247667INDIA


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NYAMJANG CHHU H. E. PROJECT SITE, ARUNACHAL PRADESH

Project No.EQD- 3017/ 09-10

Oct 2009

FOR OFFICIAL USE ONLY

DEPARTMENT OF EARTHQUAKE ENGINEERING

INDIAN INSTITUTE OF TECHNOLOGY ROORKEE

ROORKEE - 247667

INDIA.


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i

PREFACE

Bhilwara Energy Ltd., (BEL) has been entrusted with execution of Nyamjang Chhu H.E.

Project in Arunachal Pradesh. The project is located (Latitude 270

4306 N and Longitude

910 4337 E) in Tawang district of Arunachal Pradeshon Nyamjang Chhu. BEL referred

the study for Site-Specific Design Earthquake Parameters to the Department of Earthquake

Engineering, Indian Institute of Technology Roorkee. Accordingly the studies related to Site

Specific Design Earthquake Parameters were taken up.

This is the final report containing recommendations for the site dependent spectra and time

history of ground motion for seismic analysis of structures.Useful discussions held with BEL

officials regarding the site specific studies are gratefully acknowledged. This study has been

carried out by Prof. Ashwani Kumar, Prof. M. L. Sharma, Dr. H. R Wason, Dr. S. Mukerjee, Dr.M. Shrikhande, Dr. B. K. Maheshwari, Dr. J. Das and Dr. R. N Dubey.

Roorkee (Ashwani Kumar)Oct 2009 Prof. and Head


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CONTENTS

Preface ............................................................................................................................ i

Contents .......................................................................................................................... ii

List of Tables, Figures & Appendices ............................................................................ iiiExecutive Summary ..................................................................................................... iv

1.0 Introduction ............................................................................................................ 1

2.0 Regional geology and tectonics of the region ......................................................... 2

3.0 Site Geology ........................................................................................................... 9

4.0 Earthquake occurrences .......................................................................................... 12

5.0 Parameters for earthquake resistant design ............................................................. 14

5.1 Definitions...14

5.1.1 Maximum Considered Earthquake (MCE) ............................ 14

5.1.2 Design Basis Earthquake (DBE) .................................14

5.2 Seismogenic Sources around the Site....14

5.3 Estimation of Maximum Considered Earthquake ..................................... 17

5.3.1 Earthquake Parameters..................................................17

5.3.2 Ground Motion Characteristics .....................................19

5.3.3 Acceleration Response Spectra .....................................21

5.3.4 Vertical Acceleration ....................................................22

5.3.5 Safety Criteria ...............................................................22

5.4 Estimation of Design Basis Earthquake ..................................................... 22

5.4.1 Earthquake Parameters..................................................22

5.4.2 Ground Motion Characteristics .....................................22

5.4.3 Acceleration Response Spectra .....................................22

5.4.4 Vertical Acceleration ....................................................23

5.4.5 Safety Criteria236.0 Recommendations ................................................................................................... 25

References.....26


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List of Tables, Figures and Appendices

Caption Page No.

Table I Peak ground horizontal acceleration from various sources

around Nyamjang Chhu HE Project site, Arunachal

Pradesh.

16

Table II Values of various parameter for response spectra forvarious values of percentage of damping for Nyamjang

Chhu HE Project site, Arunachal Pradesh.

21

Fig. 1. Seismotectonic setup around the Nyamjang Chhu HE

Project site, Arunachal Pradesh (Modified after

Seismotectonic Atlas of India, Geological Survey of India,

2000)

11

Fig. 2. Seismicity map of the region around Nyamjang Chhu HE

Project site showing the line AB considered to plot thedepth section as given in Fig. 3.

20

Fig. 3. Depth section across the seismogenic features around theNyamjang Chhu HE project site for line AB as given in

Fig. 2.

20

Fig. 4. Time history of horizontal ground motion for NyamjangChhu HE Project site, Arunachal Pradesh (Normalised to

1g).

24

Fig. 5. Normalised horizontal acceleration spectra for variousconditions Nyamjang Chhu HE site, Arunachal Pradesh.

24

Annexure I Occurrence of Earthquakes around the Nyamjang ChhuHE Project site, Arunachal Pradesh.

29

Annexure II Ground motion acceleration time history for Nyamjang

Chhu HE Project site, Arunachal Pradesh (normalised to1g) at 0.01 sec interval.

46


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iv

EXECUTIVE SUMMARY

Bhilwara Energy Ltd., (BEL) has been entrusted with execution of Nyamjang Chhu H.E.

Project in Tawangdistrict of Arunachal Pradesh. The project is located (Latitude 2704306 N

and Longitude 910 4337 E) on the river Nyamjang Chhu. BEL referred the study for site-specific earthquake parameters to the Department of Earthquake Engineering, Indian Institute

of Technology Roorkee.

TheNyamjang Chhu HE Project site lies in seismic Zone V as per the seismic zoning map ofIndia incorporated in Indian Standard Criteria for Earthquake Resistant Design of Structures (IS

: 1893 (Part 1): 2002). The recommendations for the site specific earthquake design parameters

for the site are based on the studies carried out related to the tectonics, regional geology, local

geology around the site, earthquake occurrences (Annexure I) in the region around the site and

the seismotectonic setup of the area (Fig. 1).

The site specific design earthquake parameter for MCE condition is estimated to Ms=8.0

magnitude earthquake occurring at MCT. The PGA values for MCE and DBE conditions and

estimated to 0.36g and 0.18g respectively.

Data for time history of earthquake ground motion for the dynamic analysis of the barrage are

given in Annexure-II normalised to peak ground accelerations of 1.0 g. For MCE and DBE

time history analysis ground motion data as given in Annexure-II will have to be multiplied by

0.36g and 0.18g respectively. The corresponding response spectra are given in Fig. 5 and Table

II. Vertical spectral acceleration values may be taken as two third of the corresponding

horizontal values. Similarly acceleration ordinates for the time history of vertical ground

motion may be assumed as two third of the corresponding horizontal value.

The site specific design acceleration spectra shall be used in place of the design response

spectra, given in IS: 1893 (Part 1). The horizontal design seismic coefficient for preliminary

design of Dam (primary structure) is evaluated asg

Zh

aS.

2.

3

1= where, Z is taken as the

estimated PGA coefficient for MCE (0.36 in this case) andg

aSvalue is obtained from Fig. 5

(normalized horizontal acceleration spectra) corresponding to the fundamental time period of

the dam T. For other (secondary structures), appropriate Reduction Factor R, as specified in

IS: 1893 may be used along with Importance factor I=1. for calculating the horizontal seismic

design coefficient as:R

I

g

ZAh .

S.

2

a=


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NYAMJANG CHHU H.E PROJECT, ARUNACHAL PRADESH

1.0 INTRODUCTION

1.1 Bhilwara Energy Ltd., (BEL) has been entrusted with execution of Nyamjang

Chhu H.E. Project in Arunachal Pradesh. The project is located (Latitude 270

4306 N

and Longitude 910

4337 E) in Tawang district of Arunachal Pradeshon river Nyamjang

Chhu. BEL referred the study for site-specific earthquake parameters to the Department of

Earthquake Engineering, Indian Institute of Technology Roorkee. Accordingly the studies

related to site specific design earthquake parameters was taken up.

1.2 The proposed dam site lies in seismic zone V as per the seismic zoning map of

India as incorporated in Indian Standard Criteria for Earthquake Resistant Design of

Structures IS:1893-(Part I) 2002 : General Provisions and Buildings. It is usually

presumed that in design of normal structures adequate safety would be attained if

structures were designed as per Codal recommendations. The probable intensity of

earthquake in seismic zone V corresponds to Intensity IX on comprehensive intensity

scale (MSK64). The structures designed as per recommended design parameters for this

zone would generally prevent loss of human life and only repairable damage could occur.

However, the recommended design parameters in IS: 1893 are for preliminary design of

important structures and it is desirable to carry out dynamic analysis for final design of

important hydraulic structures in order to estimate stresses and deformations in probable

future earthquakes. IS code, therefore, recommends that for such structures detailed site

specific investigations be carried out for estimating the design earthquake parameters.

1.3 The site specific studies related to the local and regional geological conditions,

earthquake occurrences and seismotectonic set up of the region were carried out. The

earthquake catalogue containing the location, time of occurrence and the size of

earthquakes (provided by India Meteorological Department to the BEL project authorities)

was made available to DEQ by the BEL and the same has been used for this study.

Maximum Considered Earthquake (MCE) has been evaluated on the basis of above studies


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using deterministic approach and the same is recommended for consideration in the design

of structures.

1.4 Recommendations have been given in the form of smoothed design acceleration

response spectra for different values of damping. A time history of strong ground motion

and the acceleration spectra along with recommendations for consideration of vertical

component of earthquake motion/spectra are also included.

2.0 REGIONAL GEOLOGY AND TECTONIC SETUP

2.1 The Nyamjang Chhu H.E. Project site on the Nyamjang Chhu river is located in

the Lesser Himalayan region of Arunachal Pradesh and located 50 km north from the

surface trace of MCT. Geologically, the project area is represented mainly by the

quartzite-biotite gneiss rocks. Numerous tectonic features are present around the site and a

6 X 6 degree area bounded by latitudes 24.75N and 30.75N and longitudes 88.75E

and 94.75E around the site (Fig. 1) has been considered for the study of regional

geotectonic set up of the region.

2.2 The northern part of the study area is occupied by the Himalayas followed

southward by the narrow Brahmaputra River basin/ Assam basin, covered by alluvial fill,

and then by the Shield area i.e. Shillong Plateau. Whereas, the southeastern part of the area

is occupied by the part of Indo-Burman fold belt. Small part of the Mishmi geotectonic

unit occurs in the northeastern side of the study area. The Shillong Plateau is mainly

represented by oldest Archean landmass with Precambrian deposits. The Extra Peninsular

belt is mainly occupied by low grade complexes of the Lesser Himalaya tectonically

reworked during the Himalayan Orogeny. The foothills Himalaya, south of the MBT

exposes cover sequence of the frontal belt (Siwalik) affected by the terminal phase of

Himalayan Orogeny.

2.3 The Himalayan mobile belt forms the main and prominent geotectonic block of the

study area. The regional structural trend of the Eastern Himalayas is mostly E-W to ENE-

WSW from Bhutan to the northeastern Arunachal Pradesh, which changes gradually to


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NE-SW near the Siang valley and terminates against the Siang fracture (Nandy, 1976).

This block is bordered by the Central Burmese Plate towards east. The prominent tectonic

feature Indus-Tsangpo Suture Zone (ITSZ) separating the mobile belt from the Indus-

Shyok Belt of the Tibetan Plateau defines its northern limit. Along ITSZ, the river

Tsangpo (Brahmaputra) flows remarkably in an E-W rectilinear valley. The ITSZ marks

the collision boundary of the Indian and Tibetan Plates. The Main Central Thrust (MCT)

separates the rock units south of ITSZ, the highest-grade metamorphites and gneisses of

the axial belt, from Precambrian sedimentary sequence and its equivalents. The Main

Boundary Thrust (MBT) separates the Siwalik rocks from the pre-Tertiary rocks. Beyond

MBT, different stratigraphic units are disposed in intricate thrust slices. Since the rocks of

this segment range in age from Proterozoic to Cenozoic, it has undergone different stages

of crustal evolution and has been subjected to orogenic movements of varying intensity

from time to time, the imprints of which are identifiable in different deformational

structures, major unconformities or discontinuities (Kumar, 1997).

2.4 The northernmost tectonic feature of the study area is Indus Suture Zone (ISZ)

trending E-W and marks the boundary between the Indian and Tibetan plates and south of

this, litho-units of the main Himalayan belt are exposed. This zone is represented by the

obducted materials of the Neotethyan oceanic crust together with deep marine Triassic to

Eocene sediments. Main Central Thrust (MCT) is a regional tectonic feature that traverses

the whole length of Himalayas has developed in response to intensive and extensive

operative compressional tectonics. This feature is a north dipping thrust fault with initial

steepness and marks the tectonic boundary between the high-grade metamorphites of the

Se La Group and low to medium-grade metasediments of the Dirang Formation in the

Diggin Valley, in upper reaches of the Kamla river and near Taliha in the Subansiri river

section (Kumar,1997). Further in east, the Dirang Formation apears to get eliminated and

it marks the tectonic boundary with the Bomdila Group. The MCT has been traced to

Arunachal Pradesh through Nepal, Darjeeling-Sikkim and Bhutan (Ravi Shanker et al.,1989), which abuts against the Tidding Suture in the Siang Valley.

2.5 Main Boundary Thrust (MBT) is another regional tectonic feature of the

Himalayas, which demarcates the tectonic boundary between the Main Himalayan Belt


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and the Frontal Folded Belt forming the Sub-Himalayas. It is also a north dipping thrust

fault with ENE-WSW trend from the border with Bhutan in the west to Roing in the

Dibang valley and does not continue southeast to join the Mishmi Thrust as visualized by

Ranga Rao (1983). According to Sinha Roy (1976) the MBT flattens at depth, as indicated

by the absence of Gondwana rocks in southern Bhutan and in the west-central Arunachal

Pradesh. This is possibly due to the fact that the MBT merges at depth with some

dislocation zones in the inner belt.

2.6 In the region of foothills of the Arunachal Himalayas, south of MBT, a thick pile

of molassic sub-greywacke representing the Siwaliks are exposed. This belt is continuous

all along the Himalayan foothills from Kashmir to Arunachal Pradesh. The Siwalik

sequence was deposited during the Mio-Pliocene in an unstable sinking basin, developed

on the downward bending plate north of the Shillong Plateau and south of rising

Himalayas. The Siwaliks, are folded and thrust over by the older rocks from the north

along the MBT. The lithological assemblages of the Siwaliks were also controlled by the

vigour of tectonism in the source area of the rising Himalaya. The Main Frontal Thrust

(MFT) marks the southern fringe of the Siwalik belt, bordering the Brahmaputra basin.

2.7 Towards northeastern part of the study area the geotectonic block is represented by

the Mishmi Hills which does not belong to the Indian plate and considered to be part of the

Central Burmese Plate. This block comprises of metasediments, which had undergone four

phases of deformation and had been intruded by granites/granodiorites and abuts against

the Indian Plate along the Tidding Suture. The Mishmi Hills massif is comprised of

diorite-granodiorite crystalline complex (Nandy, 1976) and the southwestern boundary of

this is marked by high angle NW-SE trending Mishmi Thrust (MT) along which this block

is thrust on the adjoining rocks. In this region, the NW-SE trending metamorphic belt is in

direct contact with the Brahmaputra alluvium. This massif acts as a linkage between the

Himalayan and Indo-Burman structural and stratigraphical trends in north and eastrespectively.

2.8 The region south and southwest of the above geotectonic blocks is occupied by the

Brahmaputra River basin that has formed over the basement revealing some structural


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features through geophysical surveys. The basement rocks are exposed to the west of the

basin and the basement has northeastward slope which reaches up to a depth of 7 km near

Mishmi foothills (GSI, 2000) as indicated by basement configuration. Whereas, near

Guwahati the alluvial cover is only of the order of 0.34 km (Barooah and Bhattacharya,

1981) where the gneissic rocks of Shillong massif are exposed on surface as hills and

ridges in the river channel and on both banks of the river. Similar hills and ridges are also

exposed at the western most side of the Assam basin. In this part of the Assam basin the

basement lays at shallower depth due to undersurface extension of the Shillong massif

rocks. Here, the basement has been affected by various faults, highs and lows, upwarps

and downwarps as revealed by seismic survey in the upper Assam (Barooah and

Bhattacharya, 1981). Most of these basement faults trend NE-SW but some are having E-

W trends. The most striking fault of the Brahmaputra river basin is the NW-SE trending

Dhansiri-Kopili fault which runs between the Shillong and Mikir Hills Massifs in the

Kopili Gap and extends across the Brahmaputra River. In this region the morphology of

the basement is represented by bowl shaped basin with thickest sediments in the area north

of Nowgang (Nandy, 2001).

2.9 This Brahmaputra Basin is bordered by the Archean landmass, the Shillong Plateau

towards south. It is interesting to note that the Shillong Plateau has witnessed prolonged

crustal deformation since Archean time. The E-W trending Dauki Fault (DF) forming

steep scarps is a very prominent linear feature marking the southern edge of the Shillong

Massif. The basement rocks of the Shillong Plateau had faulted downward along the DF

for around 13 km. In Bangladesh, the basement rock is overlain by thick sediments. This

neighbouring part of Bangladesh also has suffered intense earth movements.

2.10 The Shillong Plateau is comprised of the Shillong Massif (SM) and Mikir Hills

Massif (MHM). The MHM is separated from the SM by an alluvial tract, which is located

in the central part of Northeast India. A large part of the shield area of Northeast India

exposes Archean folds. These zones show schistose tracts grading into vast stretches of

granitic gneisses incorporating metasedimentary and metavolcanic rocks within the

gneissic complex. A major part of this complex has apparently been formed by


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metasomatism of these sediments and volcanics. Intrusive augen gneisses occur within the

Archean and these could possibly mark late-tectonic magmatic episodes of older orogenies

(Mazumdar, 1978).

2.11 The Archean rocks of the Shillong plateau have been subjected to polycyclic

folding and metamorphism. The Shillong Group was deposited in central parts of the

plateau, as this area developed into a trough. The post-Precambrian landmass experienced

peneplanation till Jurassic, resulting into the formation of a flat-leveled surface, which is

preserved over the plateau till today (G.S.I., 1974). The MHM, with an average elevation

of 1,000 m, represents a peneplaned surface of predominantly gneissic rocks. The

sedimentary rocks are exposed along the southern and eastern flanks.

2.12 By the end of Jurassic, the southern margin of the Shillong Plateau experienced

eruption of Sylhet Traps through E-W trending fissures (Murthy, 1970; G.S.I., 1974).

Around 150 Ma, carbonatite complex was emplaced along an N-S trending fault in the

eastern part of the Shillong massif (Sarkar et al., 1992). The Cretaceous sediments got

deposited along the subsiding southern block. Towards the Paleocene-Eocene, the plateau

attained a stable shelf condition due to lower subsidence rate. The eastern and western

parts of the Shillong massif remained landmass till mid-Eocene and experiencedprogressive down-sinking which initiated the deposition of coal-bearing sandstone

(G.S.I., 1974).

2.13 Shillong Plateau represents a unique structural unit in the area, as it is block-

uplifted to its present height (Murthy, 1970; G.S.I., 1974). The southern margin of

Shillong Plateau is marked by the remarkably linear E-W trending Dauki Fault. Evans

(1964) gave detailed geological and tectonic set up along the Dauki Fault Zone and

suggested that this zone is essentially a tear-fault with a lateral movement of over 200 km.

Even though presence of slickensides on a fault surface shows horizontal E-W movement,

extent of movement was not possible to be estimated. Similarly, due to lack of evidences

on the extension of this zone below the alluvial gap between Shillong Plateau and


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turbiditic Cretaceous to upper Eocene shales and sandstones (Brunnschweiler, 1966). This

belt has been folded more intricately in Nagaland and the NE-SW trending Naga Thrust

traverses the whole of Nagaland and then verges with the Dauki Fault after taking a swing

towards southwest to west near Haflong. The anticlines, close to the Naga Thrust, show

reversal in topography with anticlines forming sites of valleys and synclinal hills (Nandy,

2001). These anticlines appear like upwarps on the edge of the moving Naga slice with

gently eastern limbs and steep, much sheared western limbs. Remarkably, most of the

thrusts in the region of Belt of Schuppen diverge from northwest and then unite with the

Naga Thrust. Thrust shows successive increase in magnitude of overriding movement

towards north. This zone has undergone large dislocation, as is indicated by enormous

variation in lithotectonic associations and attributes on either side of the Naga Thrust.

2.17 The belt of Schuppen in the Naga hills is a narrow linear belt of imbricate thrust

slices adjacent to the Assam valley and runs for 350 km (Mathur and Evans, 1964). This

belt comprises eight or possibly more overthrusts along which Paleogene rocks of Indo-

Myanmar mobile belt have moved northwestward. These thrusts define various

lithotectonic blocks and the thrusts have monoclinal dip towards southeast. As a result of

large scale thrusting in the schuppen belt the total horizontal movement that occurred is

estimated to be over 200 km (Nandy, 2001).

2.18 Towards south in the state of Mizoram and Tripura, the folded belt is represented

by high anticlinal ridges and synclinal valleys of Surmas and Tipams (Miocene) having

major N-S trending strike faults. The Oligocene rocks (Barail) consist of a series of N-S

trending marginal to basin faults. The intensity of fold movements and amplitudes of

folded layers are higher in the eastern part than in the western part of the basin. In the

Tripura and adjacent Bangladesh area, the folds are characterized by compressed

anticlines alternating with broad, very gently depressed synclines which, becomes more

compressed towards east. The Plio-Pleistocene beds in Bangladesh plains just west ofTripura folded belt are also affected due to folding. Both anticlines and synclines are

traversed by sub-parallel and sub-vertical regional strike faults adjacent to the crestal

region of the folds. One of the significant tectonic features of this region however, is the

region of Barak-Surma valley which is bounded by hills on three sides with opening to the


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plains of Bangladesh through Sylhet. The valley appears to have affected by tearing and

the valley trend coincides with the well known Sylhet fault. The prominent Sylhet Fault

has long been recognized in this region which trends NE and truncates the N-S trending

fold belt of Bangaldesh and Tripura region. These fold ridges exhibit eastward dragging

affect along this fault, as these folds take eastward swing. This fault extends for about 140

km and the Kusiyara River flows along this lineament for 35 km. Study of a 1968

earthquake indicated thrust faulting along this feature (Tandon and Srivastava, 1975).

However, Dasgupta and Nandy (1982) suggested deep-seated high angle reverse fault,

having a dip of about 700 towards southeast along this lineament.

2.19 To the south of the Dauki Fault of the Shillong Plateau, the plains of Bangladesh

are covered by enormously thick alluvium. The Bengal Basin is bordered on its west by

the Precambrian basement complex of crystalline metamorphics of the Indian Shield and

to the east by the frontal folds of Tripura. The basement below the basin is marked by the

Hinge zone, a high and a trough. Differential thickening and subsidence of the overlying

Oligo-Miocene sections between the shelf on the northwest and deeper basin to the

southeast has occurred in the region of EHZ. The Bengal basin basement steeply plunges

from 4 to 10 km or even further across the EHZ (Mukhopadhyay and Dasgupta, 1988).

This extends for at least 500 km from the Dauki fault on the north and Kolkata on the

south with probable extension into the Bay of Bengal having varying width from 25 km inthe north to 110 km in the central part and 35 km in the south.

3.0 SITE GEOLOGY

3.1 The geology of the project site is represented by quartz-biotite gneiss (QBG)

belonging to Precambrian Sela Group towards upstream and an interbedded sequence of

quartzite (IQS) and schist of Precambrian Lumla/Rupa Group towards downstream. The

QBG is a fairly uniform, medium to coarse grained, well foliated rock. It shows gneissose

texture with alternate bands of mainly quartz feldspar and micas aong with accessories.

The IQS are 10m to over 40m thick and are associated with thin interbands of grey

quartzite. Occasionally, thin bands of carbonaceous schist and calcitic marble also occur.


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A limited occurrence of granitic gneiss is also found.

3.2 At the barrage site, the river is flat and very wide up to 200m. River bed exposes

black fine silty sand with high content of micaceous minerals. Boulders composed mostly

of quartzite and gneiss and ranging in size from a few centimeter to a few meters are seen

in the river bed area. Gneissic rocks are best exposed on the right bank. On the left bank,

gneisses are exposed only along the deeply incised nallas. River bed bore hole (98m deep)

information indicate presence of overburden consisting of boulders of biotite, gneisses

with quartz content and blackish medium to fine silty sand up to a depth of 7.5m and

followed by only sand without boulder up to a depth of 91.5m. Rocks consisting of biotite

gneisses with quartz content have been encountered after the depth of 91.5m. Whereas, in

the other bore hole in river bed rock were encountered at a depth of 49m overlain by

blackish medium to fine silty sand and then boulders.


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Fig.1 Seismotectonic around the Nyamjang Chhu HE project site.

ISZ-Indus Suture Zone, MCT- Main Central Thrust, MT-Mishmi Thrust, LT-Lohit

Thrust, BFT-Bame Tuting Fault, MBT-Main Boundary Thrust, MFT-Main

Frontal Thrust, AF-Atherkheit Fault, DF-Dhubri Fault, DKF-Dhansiri Kopili

Fault, KS-Kalyani Shear, BS-Barapani Shear, NT-Naga Thrust, DT-Disang

Thrust, EBT-Eastern Boundary Fault, DFZ-Dauki Fault.


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4.0 EARTHQUAKE OCCURRENCES

4.1 The Nyamjang Chhu H.E. Project site situated in Tawang district of ArunachalPradesh and lies in seismic zone V as per the seismic zoning map of India as incorporated

in Indian Standard Criteria for Earthquake Resistant Design of Structures IS:1893-(Part I)

2002: General Provisions and Buildings. Many earthquakes, having large to great size,

have occurred in this region as per historical and instrumental earthquake data (1834-

2007) provided India Meteorological Department (IMD) and given in Appendix-I. There

are 733 earthquakes that have occurred around the site in 6 x 6 area out of which there

are 55 earthquakes with unassigned magnitude. However, there are 16, 121, 378, 139, 6

and one earthquakes reported in the magnitude ranges 1.0-3.0, 3.1-4.0, 4.1-5.0, 5.1-6.0,

6.1-7.0, 7.1-8.0 and M > 8.0, respectively.

4.2 Figure 1 shows the epicentral map along with the tectonic features in the area. Theanalysis of epicentral map shows that the occurred earthquakes around the site are mostly

associated with the tectonic features such as the Main Central Thrust, Main Boundary

Thrust, Mishmi Thrust and the Shillong plateau region. Shillong plateau earthquake of

June 12, 1897 (M=8.7), Dhubri earthquake of July 3, 1930 (M=7.1) and Arunachal

Pradesh - China Border earthquake of August 15, 1950 (M=8.5) are the prominent

earthquakes experienced by this region.

4.3 The Shillong plateau earthquake of June 12, 1897 had its epicentral tract in and

around Shillong where there was considerable damage to lives and property, in addition

to other effects of very strong ground shaking. The maximum seismic intensity

experienced in the region due to the Shillong plateau earthquake of 1897 was estimated to

be X on MMI. According to an estimate it took a toll of 1542 human lives and almost

complete destruction of all brick and stone buildings in all the principal towns of

northeast Indian region including Shillong, Sylhet, Goalpara, Guwahati, Dhubri and Tura.The destruction spread over an area of 3,71,200 sq km and the shock was felt over an area

of 4.48 million sq km. The intensity of the shaking within the epicentral tract was so large

that visible waves were seen at a number of places viz. Shillong, Nalban, Magaldai. On

the slopes of the Khasi hills anumber of embedded rounded small blocks of granite were


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thrown out of their places, showing that at these places the vertical acceleration exceeded

that of gravity, at least momentarily. Landslides occurred on enormous scale in the hills

and soft ground was filled with fissures throughout the epicentral tract. The earthquake

caused visible movements along faults besides fracturing long stretches of rock. In a

number of places the streambeds were tilted resulting in changing their course. Even the

bed of the Brahamputra river was affected, resulting in unprecedented floods in the

second half of the year 1897. The earthquake was followed by a very large number of

aftershocks whose epicenters were apparently scattered over a large area.

4.4 The Arunachal Pradesh China Border earthquake of August 15, 1950 was the

largest earthquake to have occurred in the past five decades in India. The epicenter lay

close to the junction of the borders of India, Burma and Tibet. The level of river Lohit and

all the other streams had risen. Landslides on all the mountains enclosing the basin, has

been on a very extensive scale and wide belts had been ripped off their vegetation, which

fell into the valleys. Although the epicenter of the earthquake was located in the

unpopulated part, just outside the north east boundary of India, it caused great

destruction to property in northeastern Assam particularly in the sub-division of North

Lakhimpur, Dibrugarh, Jorhat, Sibsagar and Arunachal Pradesh. Road and rail

communications in the affected areas got completely disrupted, due to ground subsidence

and enormous fissures. The bed of the Brahmaputra rose giving rise to floods in the valley.

An area of nearly 46000 sq km in Assam suffered extensive heavy damage, The shock was

felt up to Lucknow, Allahabad, Rangoon and the total felt area therefore must have

exceeded 2.9 million sq km. Numerous aftershocks followed the main earthquake, their

epicenters scattered over a large area. The largest magnitude of the aftershock was 7.0.

4.5 An earthquake of moderate intensity (M=6.6) occurred on August 6, 1988 in

Manipur-Burma border region. This earthquake was widely felt in all the Northeastern

states including Arunachal Pradesh, Bangladesh, parts of North Western Burma andKathmandu (Nepal). Due to this earthquake, three people were killed, 12 injured and

considerable damage and landslides were noticed in the Guwahati - Sibsagar - Imphal

area. Subsidence of about 20 centimeters occurred in the Guwahati area. About 30 people

injured and some damage in Bangladesh was reported. Some damage in adjoining area of


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Burma was also reported. The earthquake was followed by a number of aftershocks.

5.0 PARAMETERS FOR EARTHQUAKE RESISTANT DESIGN

5.1 Definitions

5.1.1 Maximum Considered Earthquake (MCE)

The Maximum Considered Earthquake is defined as the earthquake that can cause the

most severe ground motion capable of being produced at the site under the currently

known seismotectonic framework. It is a rational and believable event, which can be

supported by all known geological and seismological data. It is determined by judgment

based on maximum earthquake that a tectonic region can produce considering the

geological evidence on past movement and the recorded seismic history of the area.

5.1.2 Design Basis Earthquake (DBE)

The Design Basis Earthquake is defined as that earthquake which can reasonably be

expected to occur during the economic life of the structure (say 100 years) and in the event

of exposure to earthquake hazards it will not cause loss of life and the structure will

undergo permissible deformations and repairable damage such that the structure,

equipment facilities and services will remain functional after the earthquake. As design

criteria the resulting ground accelerations at the site under DBE may be taken as a fraction

of MCE based on engineering judgment for adopted design methodology.

5.2 Seismogenic Sources around the Site

5.2.1 This project site falls in the easternmost part of the Himalayan orogenic belt close to

the regional tectonic feature MCT. In order to evaluate earthquake hazard for the

Nyamjang Chhu H.E. project site, various important earthquake sources around the site

have been considered. To explain the cause of occurrence of earthquakes and to

understand the seismotectonics of the Himalayan collision zone, various models have been

proposed for the evolution of the Himalaya. Of these, two models namely, Steady State

Model and the Evolutionary model have gained considerable importance.


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5.2.2 Steady state model (Seeber et al., 1981) postulates that the active low angle

contemporary thrusts i.e. MCT and MBT converge with the plane of detachment, which

marks the interface between the subducting Indian slab and overlying sedimentary wedge.

Whereas, the basement thrust in this model represents that part of shallow dipping

detachment surface where the MCT merges and hence spatially the basement thrust is

located just north of MCT. According to this model the great Himalayan earthquakes are

related to the detachment surface. The evolutionary model (Ni and Barazangi 1984)

postulates that zone of plate convergence has progressively shifted south by formation of

intra crustal thrusts and hypothesizes that the MBT is the most active tectonic surface and

that the seismicity is concentrated in a 50 km wide zone between the map trace of MBT

and MCT. This model suggests that the rupture of Great Himalayan earthquakes may have

started in the interplate thrust zone, which propagated south along the detachment to the

MBT and further south to the subsidiary blind thrusts making MBT the most active thrust

rooted in the detachment. Both these models suggest that the contemporary deformation

styles in the Himalayas are guided by the under thrusting of the Indian thrust along the

detachment surface.

5.2.3 Nearest seismogenic sources to the site are Main Central Thrust and Main

Boundary Thrust. The project area is seismically active as several earthquakes are reported

from this region.

5.2.4 The NE-SW trending Main Central Thrust (MCT) in this part of the Himalayas is a

north dipping thrust with initial steepness and marks the tectonic boundary between the

high-grade metamorphites of the Se La Group and low to medium-grade metasediments of

the Dirang Formation in the Diggin Valley, in upper reaches of the Kamla river and near

Taliha in the Subansiri river section. Further in east, the Dirang Formation appears to get

eliminated and it marks the tectonic boundary with the Bomdila Group. The MCT has

been traced to Arunachal Pradesh through Nepal, Darjeeling-Sikkim and Bhutan (RaviShanker et al., 1989), which abuts against the Tidding Suture in the Siang Valley. A

magnitude 8.0 has been assigned to this regional feature for the assessment of seismic

hazard using deterministic approach.


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5.2.5 The Main Boundary Thrust (MBT) and other north trending thrusts dip towards the

project site and hence the thrust plane lies beneath the project site. MBT demarcates the

tectonic boundary between the Main Himalayan Belt and the Frontal Folded Belt forming

the Sub-Himalayas. The Lesser Himalayan meta-sedimentaries have been brought over the

Sub Himalayan successions through large-scale movement that took place along the MBT.

The MBT is not a single tectonic plane instead is represented by several thrust slices. It is

also a north dipping thrust fault with ENE-WSW trend from the border with Bhutan in the

west to Roing in the Dibang valley and does not continue southeast to join the Mishmi

Thrust as visualized by Ranga Rao (1983). According to Sinha Roy (1976) the MBT

flattens at depth, as indicated by the absence of Gondwana rocks in southern Bhutan and

in the west-central Arunachal Pradesh. This is possibly due to the fact that the MBT

merges at depth with some dislocation zones in the inner belt. To the seismogenic source

earthquake of magnitude 7.5 has been assigned.

Table I - Peak ground horizontal acceleration from various sources around Hutong-

II H.E Project Site

Sl.

No.

Sources Magnitude Distance to

zone of

energy

release(Km)

Max.

Accl.

(g)

1. Main Central Thrust 8.0 15 0.36

2. Main Boundary Thrust 7.5 15 0.31

3. Lineament L1 6.5 18 0.15

4. Indus Suture Zone 7.0 131 0.03

5. Atherkheit Fault 6.5 107 0.03

6. Dhansiri Kopili Fault 7.0 116 0.04

7. Barapani Shear 6.5 209 0.02

8. Dhubri Fault 7.5 241 0.02

9. Dauki Fault Zone 7.5 283 0.02

10. Naga / Disang Thrust 6.5 280 0.02

11. Shillong Plateau Earthquake Source 8.7 218 0.05


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5.3 Estimation of Maximum Considered Earthquake (MCE)

5.3.1 Earthquake Parameters

5.3.1.1 Based on the regional geology along with the seismotectonics as described in

sections 2.0 to 4.0 the parameters for maximum probable earthquakes which can be

generated from the potential seismogenic sources around the site are given in Table I,

wherein eleven such sources have been considered for deterministic analysis. The peak

ground horizontal acceleration estimates are made using empirical formulae worked out

by some of the research workers for various tectonic environment. Attenuation

relationships are derived by regression analysis using different distance measures and

magnitude measures. Thus different relationships provide different estimates of probable

ground acceleration and a judicious decision to estimate ground acceleration is therefore

required for adoption in any particular situation.

5.3.1.2 ICOLD Bulletin 72 (1989) recommends use of some empirical relationships like

that of Campbell (1981) and Joyner and Boore (1981). Subsequently, Abrahamson and

Litehiser (1989) using formulation similar to the above have made comprehensive

recommendations based on analysis of 585 records from 76 world wide earthquakes. For

the present study attenuation relationship proposed by Abrahamson and Litehiser (1989)

has been used. The regression used a two-step procedure that is hybrid of the Joyner and

Boore (1981) and Campbell (1981) regression methods. The horizontal acceleration

attenuation relation is as follows:

ErFM

erMa 0008.0132.0)284.0

log(982.0177.062.0)log( +++= -(1)

where, a is peak horizontal acceleration, r is the closest distance (in km) from site to the

zone of energy release, M is the magnitude ( LM < 6.0 and Ms > 6.0) following

Campbell (1981) where Ms is used if it is greater than or equal to 6., F is dummy

variable that is 1 for reverse or reverse oblique fault otherwise 0, and E is a dummy

variable that is 1 for inter-plate and 0 for intra-plate events. The rupture width is estimated

using Wells and Coppersmith, (1994) relationship

MRW 32.001.1)log( += -(2)


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where RW is the rupture width. In case the rupture width is less than the general focal

depths of the region ( FD ) then the depth to the zone of energy release is estimated as

)sin2

( RW

FDNSDDz += -(3)

where NSD is non seismogenic depth and is the dip angle. When the rupture width is

more than FD the depth to the zone of energy release is estimated as

sin2

RWNSDDz += -(4)

The distance to the zone of energy release De is estimated using the depth to the zone ofenergy release Dz and the epicentral distanceEp as

22DzEpDe += -(5)

If the site is on hanging wall of the thrust type of seismogenic feature, the epicentral

distance is considered as zero and the distance to the zone of energy release is taken as

depth to the zone of energy release i.e.,Dz . The angle is taken as 15 for the thrust type

of seismogenic features which are necessarily the low angle reverse faults. In case of

normal/strike slip the angle

is taken as 90.

The estimation of the general depth of focus in this region is made using the cross section

of the line AB across the main seismogenic features such as the trends of MCT and MBT.

The line on which the earthquakes are projected is given in Fig. 2. The depth section is

shown in Fig. 3. The depth section reveals the general depth around 15 km. The trend of

the data could not be interpreted in terms of the detachment surface present in the region

due to lesser number of data available and the errors in the depths of the located events as

given in section 5.2 of the report. Conservatively, the models as proposed for the orogeny

of these seismogenic features (as reported in section 5.2) have been considered and a depth

of 15 km is assigned for general focal depth in the area as per the models.

The relationship given by Wells and Coppersmith (1994) uses the moment magnitude

which is approximately equal to surface wave magnitude in the range of 5.0-7.5

(Kanamori, 1983). Therefore, the same magnitudes are used to compute the rupture width.


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The magnitudes are assigned to the seismic sources based on the past seismicity associated

with the individual seismogenic features. The maximum value estimated for horizontal

peak ground acceleration (PGA) is 0.42g (Table I). The surface wave magnitude Ms is

used for the estimation of PGA values.

5.3.2 Ground Motion Characteristics

Time history of ground motion is worked out from the shape of target acceleration

response spectra, which in turn depends on the parameters of the earthquake, the

predominant period of the ground motion, and the amplification of spectral acceleration at

various periods. Shape of design response spectrum is based on subjective judgment of

local geology and bed rock conditions. For the present situation the maximum

amplification is taken as 3.200 corresponding to 5% damping. This amplification

corresponds to the mean level. The history of ground motion (accelerogram) has been

generated for these parameters. Figure 4 shows the accelerogram with normalised peak

ground acceleration of 1.0 g. Appendix-II gives listing of acceleration ordinates at

intervals of 0.01 sec. corresponding to ground acceleration time history (normalised to 1.0

g) in horizontal direction. The ordinates of Fig. 4 and acceleration ordinates in Appendix-

II will have to be multiplied by 0.42 g to obtain MCE time history.


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Fig. 2 Seismicity map of the region around Nyamjang Chhu HE project showing the line

AB considered to plot the depth section as given in Fig. 3.

Fig.3 Depth section across the seismogenic features around Nyamjang Chhu HE project

site for line AB as given in Fig. 2.


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5.3.3 Acceleration Response Spectra

The smoothed acceleration spectra normalised to 1.0 g ZPA are given in Fig. 5 with

suitable multiplying factors (0.36 and 0.18) for MCE and DBE respectively. Table II

gives the functional representation for normalised spectral shapes for 1, 2, 5, 7, and 10%

damping. The equation (6) can be used to calculate the digital values of normalized

acceleration spectral values. Various parameters used in the equation for different

damping values are given in Table II. Accordingly these normalized spectra are to be

multiplied by 0.36 to obtain MCE spectral acceleration coefficient values. These spectra

already include the seismic environment of the site as well as the importance and response

reduction factors related to structure. Hence these spectra do not require any further

consideration of the Clause 6.4, IS: 1893 - ( Part I 2002 ) General Provisions and

Buildings ( Indian Standard Criteria for Earthquake Resistant Design of Structures) related

to design spectrum.

-(6)

The values of, T1, A, T2, V, T3, D are given in the following Table

Table II Values of various parameters for response spectra (Normalised To 1 g) for

various values of percentage of damping for Nyamjang Chhu H.E project

(Refer Eq(6))

Damping

%

1

(s)

A2

(s)

V

(s)

3

(s)

D

)(s2

1.0 1.223 0.144 6.810 0.540 3.745 3.300 12.735

2.0 1.014 0.150 5.110 0.550 2.811 3.400 9.556

5.0 0.723 0.150 3.200 0.600 1.920 4.000 7.680

7.0 0.619 0.150 2.710 0.600 1.626 4.100 6.829

10.0 0.509 0.150 2.270 0.600 1.362 4.150 5.720


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5.3.4 Vertical Acceleration

Vertical spectral acceleration values may be taken as two third of the corresponding


motion may be assumed as two third of the corresponding horizontal value.

5.3.5 Safety Criteria

Where the structure is checked for MCE either the response spectra or time history

analysis of the structure could be carried out.

5.3.5.1 Factor of safety against sliding and overturning for MCE condition should not be

less than 1.0.

5.3.5.2 For concrete barrage the maximum tension under MCE may be allowed to exceed

50% more than those specified for DBE.

5.4 Estimation of Design Basis Earthquake

5.4.1 Earthquake Parameters

Having obtained spectra and time history for Maximum Considered Earthquake conditions

the Design Basis Spectra is evaluated by using appropriate reduction factors. A scaling

factor of 2 with respect to MCE values is recommended for obtaining Design Basis

Earthquake (DBE) values.

5.4.2 Ground Motion Characteristics

The horizontal ground acceleration values for this condition shall be derived by

multiplying the values as given in Annexure-II by a factor of 0.18g.

5.4.3 Acceleration Response Spectra

The normalised smoothed acceleration spectra are given in Table II and Fig. 5.


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Accordingly, these are to be multiplied by 0.18 to obtain DBE spectral acceleration values.

For estimating the design seismic coefficient, h for the preliminary design of barrage

(primary structure) is obtained as:

g

Zh

aS

.2.3

1=

where, Z is the estimated PGA coefficient for MCE (0.36 in this case). For other

(secondary structure), appropriate Response Reduction Factor R, as specified in IS: 1893

may be used along with I=1 for calculating horizontal seismic design coefficient as:

R

I

g

ZAh .

S.

2

a=

5.4.4 Vertical Acceleration

Vertical spectral acceleration values may be taken as two third of the corresponding


motion may be assumed as two thirds of the corresponding horizontal values.

5.4.5 Safety Criteria

5.4.5.1 Factor of safety against sliding for DBE condition should not be less than 1.5.

Factor of safety against overturning should not be less than 1.5.

5.4.5.2 For concrete/masonry barrage the maximum tension under DBE may be allowed

to exceed upto 12.5% of the ultimate compressive strength.

5.5 For design of other relatively less important and less hazardous structures/systems

the value of acceleration history/spectra could be further reduced by 50% with respect to

DBE values. Forces obtained in this manner are to be considered as working seismic loads

and may be combined with other loads as specified in the relevant codes along with

permissible stresses.

5.5.1 The reduced spectra concept mentioned in 5.4 above is based on assumption of

ductile behaviour of structures. Hence structures must be appropriately detailed for

achieving such ductility. In case of reinforced concrete structures such details are included

in IS: 13920-1993.


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Fig. 4 Time history of ground motion for Nyamjang Chhu H.E. Project site

Fig. 5 Normalised horizontal spectral acceleration for various conditions for

Nyamjang Chhu HE project site.


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6.0 RECOMMENDATIONS

6.1 The site specific design earthquake parameter for MCE condition is estimated to be

magnitude 8.0 earthquake occurring at MCT.

6.2 The PGA values for MCE and DBE conditions and estimated to 0.36g and 0.18g

respectively.

6.3 The design acceleration response spectra is obtained by multiplying the normalized

horizontal acceleration spectra as given in Fig. 5 by the corresponding PGA values.

6.4 Vertical acceleration spectral values shall be taken as 2/3 of the corresponding to

horizontal values.

6.5 Data for time history of earthquake ground motion for the dynamic analysis of the

barrage are given in Annexure-II normalised to peak ground accelerations of 1.0 g.

For MCE and DBE time history analysis ground motion data as given in

Annexure-II will have to be multiplied by 0.36g and 0.18g respectively. The

corresponding response spectra are given in Fig. 5 and Table II.

6.6 Safety criteria as indicated in Sections 5.3.5 and 5.4.5 as applicable may be

followed in design of the Barrage.


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REFERECES

1. Abrahamson N. A. and J. J. Litehiser (1989) Attenuation of vertical peakaccelerations Bull. Seis. Soc. Am. 79 549-580.

2. Barooah BC, Bhattacharya SK. 1981. A review of basement tectonics of theBrahmaputra valley, Assam. Geological Survey of India, Miscellaneous

Publication No. 46: 123-128.

3. Brunnschweiler, R. O. (1966). On the geology of the Indoburman ranges. J. Geol.Soc. Aust., 13, 137-194.

4. Campbell K. W. (1997) Empirical near source attenuation relationships forhorizontal and vertical components of peak ground acceleration, peak ground

velocity and Pseudo-Absolute acceleration response spectra, Seis. Res. Let. Vol.

68, 154-179

5. Campbell, K. W. (1981), Near source attenuation of peak horizontal acceleration,Bull. Seis. Soc. Am., 71, 2039-2070.

6. Desikachar, S. V. (1974). A review of the tectonic and geological history of easternIndia in terms of plate tectonic theory. J. Geol. Soc. India, 15, 137-149.

7. Evans, P. (1964). The tectonic framework of Assam.J. Geol. Soc. India, 5, 80-96.8. G. S. I. (1974). Geology and mineral resources of the states of India, Part IV,

Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura.

Geol. Surv. India, Misc. Publ., 30, 124 pp.

9. GSI (2000) Seismotectonic Atlas of India and its environs, Geological Survey ofIndia.

10.ICOLD Bulletin (1989), Selecting seismic parameters for large dams, Guidelines,Bulletin 72, International Commission on Large Dams

11.IS : 1893 (Part-1) - 2002, Criteria for Earthquake Resistant Design of Structures;General Provisions & Buildings, Bureau of Indian Standards, New Delhi

12.IS:13920-1993, Ductile detailing of reinforced concrete structures subjected toseismic forces - Code of Practice, Bureau of Indian Standards, New Delhi.

13.Joyner, W. B. and D. M. Boore (1981), Peak horizontal acceleration and velocityfrom strong motion records including records from the 1979 Imperial Valley,California earthquake, Bull. Seis. Soc. Am., 71, 2011-2038.

14.Kanamori, H (1983) Magnitude scale and quantification of earthquakes,Tectonophysics 93, 185-199.

15.Kumar, G. (1997) Geology of Arunachal Pradesh. Geological Society of India,


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Bangalore, 217pp.

16.Mathur, L.P. and Evans, P. (1964). Oil in India. 22nd Int. Geol. Congress, India,New Delhi, 85pp.

17.Mazumdar, S. K. (1978). Morphotectonic evolution of the Khasi hills, Meghalaya,India. Geol. Surv. India, Misc. Publ., No. 34, 208-213.

18.Murthy, M. V. N. (1970). Tectonic and mafic igneous activity in Northeast India inrelation to upper mantle. Proc. Symp. Upper Mantle Project, Hyderabad, 287

19.Murthy, M. V. N., Mazumdar, S. K. and Bhaumik, N. (1976). Significance oftectonic trends in the geological evolution of the Meghalaya uplands since the

Precambrian. Geol. Surv. India, Misc. Publ, 23, 471-484.

20.Nandy, D. R. (1976). Geological set up of the Eastern Himalaya and the Patkoi-Naga-Arakan-Yoma (Indo-Burman) Hill Ranges in relation to the Indian Plate

movement. Geol. Surv. India, Misc. Publ., 41, 205-213.

21.Nandy, D.R. (2001) Geodynamics of Northeastern India and the adjoining region.ACB publication, Kolkata, p209.

22.Ni, J. and Barazangi, M. (1984) Seismotectonics of the Himalayan collision zone:geometry of the underthrusting Indian Plate beneath the Himalaya. J. Geophys.

Res., 89, 1147-1163.

23.Ranga Rao, A. (1983). Geology and hydrocarbon potential of a part of Assam-Arakan Basin and its adjacent regions. Petroleum Asia Jour., 6(4), 127-158.

24.Sarkar, A., Datta, A.K., Poddar, B.C., Kollapuri, V.K., Bhattacharyya, B.K. andSanwal, R. (1992). Geochronological studies on early Cretaceous effusive and

intrusive rocks from Northeast India. (Abstract). Symp. on Mesozoic Magmatism

of the Eastern Margin of India, Patna University, 28-29.

25.Seeber, L. and Armbruster, J. G. (1981). Great detachment earthquakes along theHimalayan arc and long term forecasting. In: Earthquake Prediction (edited by

D.W. Simpson and P.G. Richards), Am. Geophys. Un., 259-277.

26.Shanker, R., Kumar, G. and Saxena, S.P. (1989). Stratigraphy and sedimentation inHimalaya: A reappraisal. In: Geology and Tectonics of Himalaya. Geol. Surv. Ind.

Spl. Pub. No. 26, pp. 1-60.

27.Sinha Roy, S. (1976). Tectonic elements in the eastern Himalaya and geodynamicmodel of evolution of the Himalaya. Geol. Surv. India, Misc. Publ., 34, 57-74.


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28.Tandon, A. N. and Srivastava, H. N. (1975). Focal mechanism of some recentHimalayan earthquakes and regional plate tectonics. Bull. Seism. Soc. Am., 65,

963-969.

29.Wells, D. L. and Coppersmith, K. J. (1994), New empirical relationships amongmagnitude, rupture length, rupture width, rupture area, and surface displacement,Bull. Seis. Soc. Am., Vol. 84, No. 4, 974-1002.


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Appendix I

29

Occurrence of earthquakes around Nyamjang Chhu H.E Project Site, Arunachal

Pradesh from historical times to 2007 between latitude 25.00 - 31.00 N and longitude

88.00 - 94.00 E (Source IMD, New Delhi).

Origin Time Location SizeYear Month Day Hour Min Sec Lat Long Depth Mag

1834 7 8 0 0 0 25.8 89.4 0 6.3

1834 7 21 0 0 0 25.8 89.4 0 6

1842 11 11 0 0 0 25 90 0 6.5

1843 8 10 0 0 0 27 88.3 0 5.5

1846 12 10 0 0 0 27 94 0 6

1849 2 27 0 0 0 27 88.3 0 6

1852 5 0 0 0 0 27 88 0 6.5

1897 6 12 11 6 0 25.9 91 0 8.7

1899 9 25 0 0 0 27 88.3 0 6

1915 2 3 2 39 19 29.5 91.5 0 7.1

1915 11 14 0 0 0 26 92 0 5

1915 12 5 0 0 0 26 92 0 5

1923 9 9 22 3 42 25.3 91 0 7.1

1924 1 30 0 5 24 25 93 0 6

1924 8 13 23 57 42 29.5 91.5 0 5

1924 10 8 20 32 52 30.5 91 0 6.5

1926 10 23 14 30 18 25 93 0 5.5

1927 2 13 3 33 20 25.5 93.5 0 0

1930 7 2 21 3 34 25.8 90.2 0 7.1

1930 7 3 0 19 5 25.8 90.2 0 5.5

1930 7 4 18 54 44 25.8 90.2 0 5.5

1930 7 4 21 34 0 25.8 90.8 0 5.5

1930 7 8 4 32 24 25.8 90.8 0 5.5

1930 7 8 9 43 0 25.8 90.8 0 5.5

1930 7 11 7 6 34 25 93.5 0 5.5

1930 7 13 14 0 12 25.8 90.8 0 5.5

1930 9 22 14 19 14 25.3 93.8 0 6

1932 3 6 0 18 4 25.5 92.5 0 5

1932 3 24 16 8 44 25.8 90.2 0 5.5

1932 3 25 4 29 32 30 89.2 0 5.5

1932 3 27 8 44 45 25.5 92.5 0 5.5

1932 11 9 18 30 16 26.5 92 0 5.5

1933 3 6 13 5 38 25.7 90.5 0 5.8

1934 7 21 0 0 0 25.8 89.4 0 5.5

1934 12 18 11 22 24 30.9 89.1 0 5.7

1935 1 3 1 50 14 30.8 88 0 6.3

1935 5 21 4 22 31 28.8 89.3 140 6.3

1936 2 18 14 30 39 30.9 89.1 0 5.7

1936 5 30 7 8 38 25.7 90.5 0 5.3


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Appendix I

30

Origin Time Location Size

Year Month Day Hour Min Sec Lat Long Depth Mag

1936 6 18 14 56 27 26.6 90.3 0 5.8

1937 3 9 20 19 14 27 92 0 5.7

1937 3 21 16 12 2 25.5 94 0 5.9

1937 8 15 11 36 48 30 90 0 5.81938 2 26 12 10 43 28 90.5 0 5.7

1938 4 13 1 10 17 26 91 0 5.2

1940 2 13 11 46 28 27 92 0 5.7

1940 8 2 3 3 59 28 90.5 0 5.2

1940 9 3 14 40 33 30.5 91.5 0 6

1940 9 3 19 57 7 30.5 91.5 0 5.6

1940 10 4 4 35 51 30.5 91.5 0 6

1941 1 21 12 41 41 27.2 92 180 6.8

1941 1 27 2 30 4 27 92 0 6.5

1941 5 22 1 0 25 26.7 93.1 0 5.9

1941 9 6 3 17 47 27 92 0 5.81943 2 8 21 5 24 27 92 0 6

1943 10 23 17 23 17 26.8 94 0 7.2

1945 5 19 5 2 53 25.1 90.9 0 6.1

1946 3 16 14 15 8 26.4 92.6 0 5.6

1946 7 2 11 12 46 30 92 0 5.7

1947 7 29 13 43 20 28.8 93.7 0 7.7

1947 11 29 17 56 4 27.9 91.9 0 5.9

1948 3 1 16 50 5 26.8 94 0 5.5

1948 10 7 1 18 32 27.9 91.9 0 5.5

1948 11 28 21 43 7 26.8 94 0 6

1949 8 11 20 59 5 31 89 0 5.51949 12 10 19 37 14 26 89 0 6

1950 2 26 3 35 48 28 90.5 0 6

1950 8 15 21 42 14 25 93 0 6

1950 8 16 12 38 27 27.9 91.9 0 5.5

1950 8 16 17 51 37 27.9 91.9 0 6.7

1950 8 17 23 56 34 27.9 91.9 0 6

1950 8 21 22 55 40 28.8 93.7 0 6

1950 9 5 20 18 14 29.3 92 0 5.5

1951 4 7 20 29 12 25.9 90.5 0 6.8

1951 4 14 23 40 52 28.1 93.7 0 6.4

1951 10 18 5 2 41 28.8 93.7 0 6

1951 11 17 4 45 58 31 91.6 0 6.3

1951 11 18 9 26 32 30.5 91.5 0 6

1951 11 18 11 22 56 30.5 91.5 0 5.5

1951 11 18 12 6 57 30.5 91.5 0 6

1951 11 18 17 46 35 30.5 91.5 0 5.5

1951 11 18 18 41 26 30.5 91.5 0 6

1951 11 19 0 26 43 31 91.6 0 5.5


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1951 11 22 19 35 37 30.5 91.5 0 5.5

1951 11 23 4 11 46 30.5 91.5 0 5.5

1951 11 25 14 2 32 31 91.6 0 5.5

1951 12 3 6 57 32 30 92 0 5.51951 12 7 20 52 50 31 90.5 0 5.5

1951 12 26 10 6 56 31 90.5 0 6.3

1952 3 6 9 11 23 29.6 90.8 0 5.5

1952 3 14 18 19 48 30 92 0 5.5

1952 4 30 0 53 45 31 91.6 0 5.5

1952 6 2 10 8 23 30.5 91.5 0 6

1952 6 2 10 33 34 30.5 91.5 0 5.5

1952 8 17 16 2 7 30.5 91.5 0 7.5

1952 8 25 1 44 48 28 94 0 6

1952 9 15 17 59 22 30 92 0 5.5

1952 11 7 4 33 57 25.5 94 0 61954 2 23 6 40 32 27.8 91.7 0 6.5

1955 3 27 14 38 43 29.9 90.2 0 6.3

1955 12 29 8 25 31 30.1 90.3 0 6

1958 1 4 0 0 0 27 92 0 5

1958 2 13 0 11 37 27.62 92.53 0 5.5

1959 2 22 3 30 38 28.5 91.5 0 5.7

1959 6 10 4 25 15 30 91 0 5.7

1959 11 2 5 9 42 28 93 0 5

1960 5 26 20 5 7 27 93 160 5

1960 7 29 10 42 44.6 26.9 90.3 11 6.5

1960 8 21 3 29 4.9 27 88.5 29 5.51961 11 6 7 59 4.1 26.7 91.9 67 5

1961 12 25 11 19 10 27 90 0 5.5

1962 10 30 16 13 25.6 26.6 93.3 33 5.5

1963 6 21 15 26 30 25.13 92.09 47 4.9

1964 2 18 3 48 34.4 27.4 91.18 22 5.3

1964 3 27 23 3 41.1 27.13 89.36 29 5

1964 4 13 3 19 57.3 27.52 90.17 1 5.2

1964 8 30 2 35 7.3 27.36 88.21 21 5.1

1964 9 1 13 22 37.3 27.12 92.26 33 5.5

1964 10 21 23 9 19 28.04 93.75 37 5.9

1965 4 11 22 33 6.6 26.82 92.33 70 4.9

1965 12 9 20 26 1.4 27.43 92.51 4 5.2

1965 12 9 20 26 17 26.7 92.5 8 5

1966 2 24 0 16 40.8 26.35 91.44 47 4.7

1966 6 26 10 56 11 26.14 92.84 74 4.8

1966 7 5 10 1 18.1 27.84 92.6 33 4.8

1966 8 10 3 21 52.4 31 91.7 33 4.6

1966 9 26 5 10 56.2 27.49 92.61 20 5.4


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1967 2 25 11 56 10.9 27.38 92.52 33 4.7

1967 7 7 22 56 30.9 27.87 92.14 33 4.8

1967 9 15 10 32 44.2 27.42 91.86 19 5.8

1967 11 10 6 4 7 25.46 91.75 44 4.71968 1 31 11 45 18 29.8 92.2 25 5.1

1968 5 2 0 26 2.2 26.23 92.28 51 4.6

1968 8 18 14 18 58 26.42 90.62 22 5.1

1968 11 18 8 49 3.4 26.9 92.9 51 4.3

1969 2 22 20 37 5.4 26.54 92.36 38 4.6

1969 2 22 20 37 5.4 26.54 92.36 38 4.6

1969 11 5 20 25 13.7 27.66 90.24 13 5

1970 2 19 7 10 1.5 27.4 93.96 12 5.4

1970 7 25 1 35 26 25.72 88.58 32 5.1

1971 7 17 15 0 55.8 26.41 93.15 52 5.4

1971 10 31 15 54 48.2 26.18 90.65 33 4.71972 3 26 6 10 40.4 25.79 93.55 88 4.4

1972 6 8 23 10 14 29.59 92.44 73 4.6

1972 8 21 14 4 34.2 27.33 88.01 33 4.5

1972 11 6 10 56 13.5 26.88 88.43 59 4.4

1973 7 4 16 44 13.5 27.49 92.6 30 4.9

1973 8 1 14 5 15.5 29.59 89.17 63 4.9

1973 9 11 15 56 0.3 27.08 92.61 54 4.8

1973 10 9 4 1 46.8 27.69 93.55 33 4.9

1973 10 31 12 6 47.6 25.21 92.45 33 4.3

1973 11 2 12 9 55.4 25.72 91.7 21 4.6

1974 5 15 3 51 21.8 25.66 91.91 34 4.51974 6 22 18 10 53.2 25.79 93.54 50 4.7

1974 7 9 7 17 12.9 27.34 92.32 53 4.6

1974 9 21 6 27 41.8 25.63 91.04 27 4.7

1975 1 23 1 37 42.6 27.44 88.37 33 4.5

1976 3 11 0 32 41.2 26.55 92.09 68 4.7

1976 8 5 10 24 13 28.06 92.4 55 4.8

1976 9 14 6 43 51.6 29.81 89.57 75 5.4

1977 6 5 19 21 37.4 26.07 88.43 0 4.7

1977 11 13 21 2 31.7 26.51 93 52 5.1

1978 4 19 17 1 45.5 27.67 92.68 51 4.9

1978 11 18 13 24 31 26.55 92.59 55 4.4

1979 1 13 3 27 15.4 27.39 91.89 33 4.4

1979 2 26 6 54 56 25.98 91.23 53 4.3

1979 4 2 1 16 46.5 26.46 90.68 33 4.4

1979 4 11 16 8 12.6 25.98 88.84 33 4.7

1979 11 16 19 17 27.4 27.95 88.69 39 4.6

1980 2 22 3 2 44.8 30.55 88.64 14 5.7

1980 2 22 3 20 56 30.62 88.68 39 4.8


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Appendix I

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1980 2 22 4 16 50.9 30.64 88.74 37 4.7

1980 2 22 7 5 44.9 30.55 88.68 40 4.6

1980 2 22 11 7 22.2 30.61 88.78 21 4.4

1980 2 22 11 58 38 30.67 88.74 6 4.71980 2 28 11 36 41.4 30.54 88.71 33 4.3

1980 3 4 7 16 49.3 30.54 88.68 48 4.7

1980 6 3 20 32 9.2 30.75 88.65 0 4.8

1980 6 10 7 48 40.6 30.42 88.57 64 4.6

1980 6 11 5 25 15.4 25.79 90.31 68 4.9

1980 6 25 21 32 49.3 30.57 88.84 33 4.4

1980 11 19 19 0 44.5 27.4 88.8 1 6

1980 12 22 4 36 8 26.67 89.59 33 4.4

1980 12 26 5 19 44.9 29.08 88.88 66 4.5

1981 2 9 15 49 21.6 27.2 89.76 16 4.9

1981 2 28 1 58 21.5 26.03 93.66 40 4.81981 11 21 4 25 5.6 29.52 89.12 50 4.8

1981 12 9 10 52 57.5 27.5 92.51 33 4.5

1982 1 22 4 29 55.9 30.89 89.87 2 5.3

1982 1 28 7 18 7.6 25.47 90.89 33 4.4

1982 2 26 0 5 47.5 25.79 90.62 48 4.6

1982 2 26 8 14 0.7 26.3 92.29 33 4.6

1982 3 24 23 17 51.4 30.55 88.7 33 4.6

1982 4 5 2 19 41.1 27.38 88.84 9 5

1982 4 24 2 4 43.7 28.31 92.92 52 4.8

1982 6 20 15 29 19.8 26.24 89.97 33 4.5

1982 7 6 6 13 32 25.88 90.31 8 51982 8 18 18 1 7.6 27.04 89.26 51 4.6

1982 8 21 4 26 25.4 25.16 92.23 50 4.6

1982 8 31 10 42 45.4 25.38 91.46 32 5

1982 9 21 12 38 27.9 25.15 91.27 43 4.9

1982 11 18 6 2 26.5 26.38 91.75 0 4.8

1982 12 30 8 37 16 26.01 91.69 61 4.9

1982 12 30 12 29 27.5 26.25 91.65 33 4.6

1983 1 19 12 9 33.2 25.46 91.36 10 4.8

1983 2 2 20 44 6.7 26.9 92.87 42 5.2

1983 5 1 0 19 28.5 25.09 92.24 0 4.3

1983 7 23 7 28 34.4 25.37 91.25 58 4.7

1983 10 2 21 3 24.1 28.05 92.52 38 5

1983 10 16 22 3 14.5 29.51 90.31 33 4.5

1983 11 17 21 20 12.8 25.15 91.73 41 4.4

1984 3 21 23 6 24.4 26.75 93.29 15 5

1984 6 9 23 7 49.7 26.91 92.61 72 4.5

1984 7 4 13 29 23.8 25.8 92.74 33 4.6

1984 9 7 22 23 5.3 30.43 91.08 86 4.1


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Appendix I

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1984 9 22 9 10 29.8 26.49 92.15 28 5.2

1984 9 30 21 35 25.3 25.44 91.51 34 5

1984 10 3 21 46 0.5 25.37 93.44 59 4.6

1984 11 15 21 9 3.6 26.72 92.72 83 4.61985 1 7 16 13 5.4 27.14 91.96 12 5.4

1985 1 7 20 14 44.8 27.2 91.77 33 4.6

1985 1 11 20 39 28.4 27.13 91.9 33 4.6

1985 5 25 0 28 18.7 27.6 88.48 33 4.6

1985 6 7 18 23 59 26.87 90.21 33 4.8

1985 6 17 21 52 49 25.65 90.2 22 4.6

1985 7 28 14 45 42 30.2 88.61 66 4.4

1985 10 2 16 33 50.3 27.19 89.73 45 4.4

1985 10 12 18 22 37 27.1 92.52 14 5.3

1985 10 12 19 35 6.5 27.19 92.62 10 4.6

1985 10 25 19 59 3.1 27.2 92.48 33 4.91985 10 31 15 26 8.4 27.1 92.51 18 4.8

1985 12 8 21 49 16 30.97 88.8 33 4.4

1985 12 26 18 4 26 27.09 92.07 11 4.8

1986 1 7 20 20 0.4 27.4 88.43 41 4.7

1986 2 19 17 34 23 25.1 91.13 7 5.2

1986 4 4 7 58 39 30.81 88.2 44 4.5

1986 7 16 6 37 49.1 27.6 91.6 33 4.5

1986 9 10 7 50 26.4 25.38 92.14 47 5.3

1986 10 14 14 3 2.1 25.03 91.97 33 4.6

1986 10 25 21 25 30.4 26.12 88.26 33 0

1986 11 8 18 24 33.2 27.17 92.21 48 4.31986 12 31 15 49 52.8 26.47 92.91 46 5.1

1987 1 24 10 34 25.9 27.63 92.69 24 5

1987 4 25 22 13 47 25.3 88.46 10 0

1987 6 11 17 29 26.8 26.15 93.59 62 4.4

1987 7 17 21 12 31 27.76 92.68 9 4.7

1987 9 6 23 38 54.1 26.64 93.41 58 5.2

1987 9 13 21 4 51 27.3 92.8 33 4.4

1987 9 25 23 16 29 29.84 90.37 19 5.1

1987 9 26 1 3 3 29.82 90.45 33 4.4

1987 9 29 17 30 28.3 29.91 90.41 33 4.6

1987 9 29 21 12 30 29.7 90.41 46 4.5

1987 10 6 22 18 17.2 29.9 90.42 10 4.7

1987 10 15 16 22 48 27.38 92.76 27 4.9

1987 10 22 21 23 56 27.07 89.06 19 4.2

1987 11 15 15 13 23 26.52 93.38 53 4.3

1987 12 1 8 50 41.4 26.33 93.22 59 4.9

1987 12 6 23 29 44 27 88.52 42 0

1987 12 11 6 39 40 26.04 90.92 57 4.6


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Appendix I

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1987 12 12 5 49 0 29.8 90.4 45 4.8

1988 1 10 6 18 35 29.75 90.29 50 4.7

1988 1 10 6 31 42.7 29.89 90.44 10 4.7

1988 1 19 11 23 51 27.8 88.8 33 4.31988 2 12 5 51 38.3 25.1 93.9 33 4.4

1988 2 17 1 1 57 26.73 92.99 46 4.5

1988 2 17 6 30 8 27.11 92.11 2 4.8

1988 3 24 18 45 38 30.9 89.4 33 0

1988 3 27 5 56 30 27.1 88.42 70 4.1

1988 4 6 11 28 35 28.27 92.47 33 4.1

1988 4 30 3 27 51 25.9 91.6 33 4.2

1988 5 10 7 16 16.1 25.32 90.88 33 4.4

1988 5 26 16 30 5.5 27.45 88.61 42 4.7

1988 5 28 23 13 12 28 89.7 33 0

1988 7 5 7 36 27.4 28.11 91.24 66 4.81988 9 4 8 1 58 26.3 91.75 7 4.4

1988 9 27 19 10 10 27.19 88.37 28 5

1988 12 20 9 45 44.4 27.66 91.12 39 4.9

1988 12 24 13 32 22 26.9 88 41 4.4

1989 1 6 13 31 58 25.1 91.61 10 0

1989 2 3 17 50 0 30.19 89.94 19 5.4

1989 2 3 22 10 1.5 30.27 89.97 10 4.4

1989 2 4 1 55 6 30.2 90.1 33 0

1989 2 4 7 15 56.4 30.25 90.05 10 4.2

1989 2 4 13 46 8.2 30.19 90.09 10 0

1989 2 5 10 43 35.9 30.12 90.07 10 4.11989 2 6 13 9 6 30.08 90.11 14 0

1989 2 6 14 35 29 30.4 90.2 10 0

1989 2 7 4 27 27 30.5 90.2 33 4.2

1989 2 12 23 44 57 30 89.86 53 0

1989 2 28 0 26 41.1 27.1 92.64 42 4.7

1989 3 8 20 2 6.7 26.93 92.77 59 5.1

1989 4 9 2 31 36.3 29.11 90.02 10 5.1

1989 4 16 0 2 33 29.2 89.7 33 0

1989 4 19 16 40 29 30.16 89.96 39 4.4

1989 4 29 12 55 17 25.6 91.58 33 4.3

1989 6 11 13 42 45.7 26.39 90.7 50 4.5

1989 7 30 21 4 44 30 90.5 33 0

1989 8 3 11 10 10 26.9 92.7 33 4.4

1989 9 19 17 7 42 26.88 92.65 25 4.6

1989 11 19 22 11 34 29 89.7 33 4.4

1990 1 9 2 29 21.8 28.15 88.11 35 5.7

1990 2 8 20 28 8 30.1 90.6 10 0

1990 2 9 20 11 41.6 30.1 90.23 33 0


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Appendix I

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1990 2 18 18 12 48.3 29.39 89.95 10 4.5

1990 2 22 13 33 16.6 29.14 90.02 54 4.9

1990 2 23 14 25 19.3 29.38 90.02 10 4.3

1990 3 1 18 47 28 28.7 88.4 33 4.21990 5 6 10 30 9 29.99 89.98 33 4.2

1990 5 19 2 18 57 25.4 90.93 33 0

1990 5 22 9 0 21.1 30.16 89.96 3 3.9

1990 8 29 2 41 34.3 27.18 92.74 25 4.9

1990 9 2 6 29 26.1 26.58 92.67 57 5.2

1990 10 29 11 32 54.7 26.47 92.44 37 4.8

1990 10 29 12 6 28 27.6 89.1 33 0

1990 11 28 14 37 8.8 25.9 93.02 33 0

1990 12 11 18 38 56 27.8 92.3 33 4.3

1990 12 29 19 24 12 26.68 92.59 27 4.9

1991 2 2 0 15 40 25.51 91.17 25 51991 2 3 13 22 10 25.5 91.67 19 4.1

1991 3 4 0 55 38 28.1 89.2 33 0

1991 4 9 22 59 9.9 26.4 92.96 50 4.5

1991 4 13 4 58 30.5 26.7 92.5 56 4.2

1991 5 1 7 47 41 30.5 90.3 33 3.9

1991 6 8 18 59 57.8 26.3 90.37 33 4

1991 6 23 10 4 1.7 26.59 93.19 46 5.4

1991 7 2 9 4 30.2 26.3 92.18 33 0

1991 8 7 11 36 29.1 25.27 88.66 10 4.7

1991 8 19 22 28 41 26.8 90.7 10 0

1991 8 22 3 53 44.3 25.29 91.18 45 4.71991 9 25 19 26 49.3 26.7 88.4 33 0

1991 9 27 11 56 40.8 29.9 90.4 33 0

1991 10 30 13 13 57 26 88.6 33 0

1991 11 11 13 42 46.1 26.14 92.86 33 4.3

1991 12 4 5 1 47.6 25.5 93.25 33 0

1991 12 15 15 59 34.3 30.03 93.88 33 4.3

1991 12 24 21 27 51 30.11 92.52 20 4.4

1992 1 8 17 41 41.5 30.1 92.5 33 4

1992 2 25 1 57 25.8 25.2 92.2 33 5

1992 3 7 22 41 50.8 29.4 89.4 113 4.3

1992 4 4 17 43 20.7 28.1 88 33 4.9

1992 4 20 18 50 28.3 27.3 92.1 33 4.6

1992 4 20 19 22 59.7 25.8 90.6 55 4.2

1992 6 14 11 12 37.5 27 92.7 33 3.6

1992 6 21 8 7 46.5 30.4 89.4 28 4.2

1992 7 24 6 24 17.6 29.3 90.2 33 4.8

1992 7 30 8 24 46.6 29.6 90.2 14 5.9

1992 7 30 9 7 39.1 29.9 90.3 33 4.2


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1992 7 30 9 14 24.2 26.5 92.2 33 4

1992 7 30 9 33 52.3 30.3 90.3 33 0

1992 7 30 13 36 42 29.8 90.3 33 4.4

1992 7 30 17 28 53.9 30 90.4 33 4.51992 7 30 19 6 13.3 29.8 90.2 33 4.3

1992 8 4 22 50 3 29.9 90.4 10 4.2

1992 8 8 12 7 48.7 25.4 91.9 50 4.3

1992 8 8 19 50 42.6 29.9 90.3 33 4.3

1992 8 16 20 16 40.2 30.1 92.1 33 5

1992 10 31 1 56 5.2 27.6 93.2 33 4.4

1992 11 11 5 27 31 27.6 92.9 68 4.5

1993 1 18 12 42 7.8 30.8 90.4 33 5.7

1993 1 18 13 28 6.6 30.8 90.4 33 4.2

1993 1 18 14 49 43.7 30.9 90.5 33 4.5

1993 2 15 8 45 50.5 30.8 90.4 33 4.61993 2 16 17 21 6.1 30.9 90 33 4.5

1993 2 17 23 27 41.4 26.3 92.8 28 4.2

1993 3 3 5 17 31 25.4 90.2 33 4.5

1993 5 28 14 20 28.6 26.8 93.3 33 4.6

1993 6 23 17 19 26.7 27.5 92.6 33 4.6

1993 7 31 19 29 21.7 27.9 91.9 33 4.4

1993 9 20 7 40 54.9 27.8 92.9 33 4.7

1993 12 12 23 54 18.4 27.2 92 33 5.1

1994 1 16 14 22 38.3 26.4 89.1 33 3.9

1994 1 20 23 30 41.8 25.2 93.5 33 4.7

1994 3 24 13 51 31.4 26.4 91.3 33 4.31994 4 15 14 28 48.7 25.9 90.5 33 4.2

1994 4 18 14 40 56.3 26.3 92.9 33 4.4

1994 5 6 17 52 39.6 26.4 93.6 33 4.3

1994 7 24 23 39 6.6 25 92.7 33 4.7

1994 8 5 11 19 10.2 26.7 92.5 33 4.7

1994 10 11 5 32 48.2 30.1 91.9 33 4.8

1994 10 24 16 6 37.3 27.1 92.3 33 4.2

1994 10 25 7 29 6 27.2 92.4 33 4.9

1995 1 12 23 39 51 29.4 88.2 33 4.9

1995 2 17 2 44 24.4 27.6 92.3 33 5.2

1995 3 26 18 22 36.2 28.1 92.5 33 4.7

1995 4 3 1 59 12 26.3 91.3 33 4.2

1995 4 24 4 29 2.4 30.1 88.1 33 4.7

1995 7 3 0 59 48.5 27.5 92.3 33 4.7

1995 7 30 7 4 1.1 30.3 88.3 33 4.9

1995 7 30 12 54 10.1 26.9 92.6 33 4.3

1995 8 8 16 52 48.8 26.4 90.4 33 4.4

1995 12 1 20 9 23 26.2 91.6 33 4.5


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Appendix I

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1995 12 4 17 54 46 27.6 92 33 4.2

1995 12 6 0 50 33 25.2 91 33 4.5

1996 1 26 2 21 11.2 30.9 91.5 33 5.1

1996 3 5 9 27 39 26.9 93.2 33 41996 3 21 15 0 30.8 30.3 88.4 33 3.9

1996 3 23 16 7 34.2 27.2 88.3 33 4

1996 5 10 9 7 1.8 30 88.1 0 4.8

1996 5 10 9 10 13.3 30.1 88.3 0 4.1

1996 5 10 21 34 57.6 30.1 88.3 0 4

1996 5 11 3 58 50.2 29.9 88.1 0 4.8

1996 5 11 4 48 32.2 30.2 88.1 0 4.3

1995 5 11 7 27 11.2 29.9 88.1 0 4.3

1996 5 14 19 5 26.5 25.9 92.4 0 4.6

1996 5 17 17 3 48.2 30.2 88.2 0 4.3

1996 5 17 17 4 39.8 30.1 88.1 0 4.61996 5 17 17 5 39.7 30.2 88.2 0 4.3

1996 5 21 0 35 44.4 29.2 91.99 0 4.1

1996 6 3 4 17 1.3 27.9 93.8 0 4.1

1996 6 9 23 15 18.5 28.3 92.2 0 5.1

1996 6 27 16 21 21.8 27.05 92.2 0 4.2

1996 7 3 6 44 46 30.1 88.2 0 5.6

1996 7 3 7 0 28.9 29.9 88.1 0 4.1

1996 7 3 7 10 16 30.5 88.2 0 4.1

1996 7 3 10 10 33.8 29.9 88.2 0 5

1996 7 3 10 19 42.9 30 88.2 0 4.3

1996 7 3 12 59 7 30.1 88.1 0 3.81996 7 4 3 38 23.6 30.1 88.2 0 4.3

1996 7 4 18 11 4.6 30 88.1 0 4.9

1996 7 5 13 9 56.1 30.1 88.1 0 4.2

1996 7 8 0 18 36.2 30.1 88.2 0 4.5

1996 7 8 23 28 30 30.4 88.2 0 4.1

1996 7 10 0 27 55 30.3 88.2 0 4

1996 7 12 2 51 48.2 30.1 88.3 0 3.9

1996 7 12 11 54 37.5 30.1 88.1 0 4.2

1996 7 12 12 38 38.2 27 92.1 0 4.5

1996 7 13 8 29 4 29.9 88.1 0 4.3

1996 7 13 13 19 44.1 30.1 88.2 0 4.1

1996 7 17 5 23 47.6 26 91.9 0 4.3

1996 7 18 10 25 2.4 30.4 88.1 0 4.6

1996 7 22 15 54 7 30 88 0 4.5

1996 7 31 8 0 27 30.1 88.1 0 5.1

1996 7 31 8 2 52 30.1 88.1 0 5.1

1996 8 3 7 12 6 30 88.2 0 4.1

1996 8 7 8 3 44 30.1 88 0 3.9


45/70

Appendix I

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1996 8 18 2 48 0 25.8 90.1 0 4.4

1996 8 29 8 38 25.1 30.1 88.2 33 4.7

1996 9 11 23 14 14.9 27.5 92.6 33 4.6

1996 9 12 18 4 47.7 27 92.5 33 4.61996 9 13 3 41 8.6 27 88.2 33 4.5

1996 9 14 2 9 19.1 27.6 92.6 33 4.7

1996 9 25 17 41 17.2 27.4 88.5 33 5

1996 10 14 14 49 12.7 29.9 88.2 33 4.4

1996 10 25 19 31 26.3 25.4 91.8 61 3.8

1996 11 11 20 13 48.9 28.9 91.8 33 3.9

1996 11 24 0 52 8 26.72 92.57 33 4.5

1996 12 23 9 39 31 26.8 92.5 33 4.5

1996 12 24 0 52 8.5 26.7 92.5 33 4.5

1997 1 8 19 56 12.5 30.3 88 33 3.6

1997 1 22 11 12 4.4 25.6 90.3 33 01997 1 25 20 8 28.7 30 88 33 4.4

1997 3 5 15 13 17.1 30.74 90.27 33 4.7

1997 3 10 17 50 36.9 27.38 92.71 33 4.4

1997 3 10 17 55 14.4 27.21 92.41 33 4.5

1997 3 22 21 16 4.8 29.89 88.15 33 4.4

1997 4 4 10 8 41 25.5 90.8 33 3.8

1997 4 4 18 5 9.2 27.3 92.7 33 0

1997 5 6 2 57 46.8 25.2 93.6 33 0

1997 5 19 15 32 57.9 25.1 93.9 33 4.4

1997 6 2 19 30 9.6 28.05 92.63 33 4.8

1997 6 24 14 9 16.2 25.4 92.6 38 01997 6 26 13 56 3.8 30.8 90.3 33 0

1997 6 27 16 37 7.3 26.7 92.7 33 0

1997 7 8 21 16 49.8 29.83 88.31 33 3.7

1997 7 9 7 18 52.9 29.9 88.4 33 4.1

1997 7 12 23 41 9.7 29.9 88.4 33 0

1997 8 4 22 31 36.3 28.23 91.44 33 4.5

1997 8 6 8 58 21.3 25.63 92.18 41 4.9

1997 8 10 11 53 17.2 29.16 89.49 33 3.4

1997 9 13 18 36 35.6 30.1 88 33 0

1997 9 13 18 38 6.3 30.1 88.2 10 4.3

1997 9 15 16 41 10.6 30.1 88.3 33 0

1997 10 12 19 45 25.8 30 88 33 0

1997 10 30 2 2 52 29.5 89.7 33 5.3

1997 10 30 20 3 0 29.2 89.4 0 4.9

1997 11 14 14 37 2.5 30.2 88.6 33 0

1998 1 6 3 9 47.5 26 91.8 33 4.5

1998 2 12 2 40 29.1 26.5 88.1 33 4.6

1998 3 16 10 35 2 26.9 89.68 33 3.8


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Appendix I

40



1998 3 18 18 12 18.9 27.36 88.33 33 4

1998 4 25 22 50 58.3 28.9 93.3 33 4.2

1998 5 13 1 24 55.6 28.18 89.8 10 4.9

1998 6 6 11 6 27.1 30.37 89.09 33 41998 6 6 11 13 8.3 30.37 89.22 33 4.8

1998 7 8 3 44 59.3 27.32 91.02 33 5.2

1998 7 20 1 5 58.3 30.13 88.17 33 5.4

1998 7 20 1 7 56.1 30.43 88.19 33 4.8

1998 7 20 1 18 14.5 30.2 88.06 33 4.7

1998 7 20 1 29 18.2 30.13 88.13 33 4.2

1998 7 20 1 31 19.1 30.14 88.03 33 4.6

1998 7 20 1 37 25.7 30.27 88.07 33 3.8

1998 7 20 23 41 11 30.02 88.17 33 4

1998 7 21 14 40 44.6 30.38 88.19 16 5

1998 7 23 10 54 37.2 30.37 88.2 33 3.81998 7 26 1 27 26 30.08 88.22 33 0

1998 8 7 21 8 37.7 30.21 88.16 33 4.3

1998 8 9 4 23 28.9 30.34 88 33 3.9

1998 8 16 23 34 21.6 30.06 88.26 33 0

1998 8 18 4 10 20.6 27.55 90.98 22 5.2

1998 8 25 7 41 40.1 30.08 88.11 33 5.3

1998 8 25 7 59 0.7 30.02 88.18 33 4.6

1998 8 25 8 1 45.6 30.06 88.17 33 4.1

1998 8 25 8 13 4.5 30.17 88.13 33 3.9

1998 8 25 9 43 6 29.99 88.09 33 4.1

1998 8 25 10 25 6 29.98 88.1 33 4.41998 8 25 12 29 45.1 30.02 88.06 33 4.6

1998 8 25 12 43 4.3 29.96 88.09 33 4.4

1998 8 25 13 39 49.5 29.92 88.12 33 3.8

1998 8 25 13 50 6.1 30.09 88.05 33 4.1

1998 8 25 15 16 2.7 29.97 88.1 33 4.4

1998 8 25 23 23 34.8 30.3 88.11 33 4.6

1998 8 28 22 1 55.7 30.19 88.15 33 4.9

1998 8 30 3 37 48.9 30.04 88.07 33 4.8

1998 8 30 4 11 35 30.03 88.08 33 4.6

1998 9 7 10 44 39 30.27 88.13 33 4.7

1998 9 8 2 3 29.7 30.34 88.14 33 4.4

1998 9 10 22 57 16.9 27.2 88.34 33 4.7

1998 9 21 23 24 40.6 29.94 88 33 4.1

1998 9 26 18 27 5.4 27.77 92.81 33 5.4

1998 9 26 19 8 21.4 27.6 92.58 33 3.9

1998 9 28 21 31 5.6 27.74 92.7 33 4.7

1998 9 30 2 29 55.1 29.94 88.11 33 5.1

1998 10 5 10 24 48.7 30.2 88.3 33 4.8


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1998 10 16 14 17 16.7 30 88.19 33 0

1998 10 16 22 22 39.2 26.03 91.21 33 0

1998 10 24 13 19 53.2 30.41 88.15 46 4.1

1998 12 2 13 25 4.2 26.34 93.49 33 51998 12 4 4 42 45.6 26.6 92.38 40 0

1999 2 1 6 52 60 30.29 92.01 15 0

1999 2 14 14 43 2.3 25.6 91.92 5 0

1999 2 21 21 4 19.1 26.5 92.77 33 3.5

1999 3 25 5 4 54.3 28.51 88.28 33 3.8

1999 4 5 22 32 58.2 25 93.51 33 4.9

1999 4 15 6 48 17.9 25.8 93.33 110 4.5

1999 5 7 17 53 52.3 27.22 90.64 33 0

1999 5 9 8 8 57.7 27.4 89.45 15 0

1999 5 11 16 39 19.2 26.49 92.76 15 3.9

1999 5 17 13 56 14.6 26.82 92.71 96 3.91999 6 20 1 14 58.4 26.34 92.7 36 4

1999 6 26 21 36 28.2 26.83 92.12 15 3.9

1999 7 4 6 5 15.2 25.42 90.28 33 3.8

1999 7 28 17 55 5.5 25.77 93.23 10 3.7

1999 8 3 4 18 27.9 27.76 92.74 9 0

1999 9 21 11 13 7.5 25.4 92.86 20 0

1999 9 21 13 54 39.8 25.16 88.86 2 3.9

1999 10 3 6 38 41.9 30.17 88.12 33 3.8

1999 10 5 17 4 48 26.26 91.93 33 5.3

1999 10 9 1 39 44.5 26.38 92.08 19 4

1999 10 15 7 33 1 29.61 90.06 33 4.41999 10 23 16 32 42.7 26.03 91.72 33 3.8

1999 10 26 5 28 52.8 30.13 92.95 96 4.8

1999 11 17 5 27 14 28.09 89.18 33 3.6

2000 1 2 10 23 59.1 28 92.51 33 5.3

2000 1 25 12 7 33.3 29.94 89.72 0 5

2000 1 25 16 43 24.8 27.96 92.5 33 5.3

2000 1 26 21 12 2.2 27.47 92.05 33 4.8

2000 1 30 6 35 10.1 29 91.76 33 5.1

2000 2 5 13 58 34.7 25.99 91.74 10 3.1

2000 3 17 15 44 9.3 26.81 92.03 35 3.4

2000 4 10 15 2 8.5 30.23 88.18 33 4.3

2000 4 18 7 53 45.2 26.55 90.26 33 3.3

2000 5 14 17 18 28.3 28.03 91.42 15 5.2

2000 6 20 7 16 43.8 26.04 90.31 33 4.3

2000 7 17 6 52 11.1 27.43 92.28 33 4

2000 8 16 23 6 30.2 26.52 92.71 33 4.6

2000 9 10 23 32 43 28.31 92.45 33 4.2

2000 9 17 19 46 37.2 26.22 91.8 13 4.1


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2000 10 3 17 8 22.4 26.88 89.8 33 2.8

2000 10 8 6 15 1.1 30.3 88.32 33 4.4

2000 10 16 0 14 43.3 26.29 92.85 15 3.4

2000 11 3 0 33 37.9 26.37 91.25 4 3.12000 11 9 17 31 52.4 25.3 91.44 33 3.6

2000 11 15 21 55 54.7 26.21 91.88 33 2.8

2000 12 29 10 43 40.5 25.7 92.07 15 2.9

2001 1 16 8 6 57.4 26.42 90.24 33 0

2001 1 24 23 57 18.5 27.64 92.71 10 4.3

2001 2 9 10 20 55.7 27.24 89.67 13 3.9

2001 2 11 1 20 54.3 25.23 92.18 96 4.5

2001 2 27 1 46 7 26.48 90.55 20 4.7

2001 3 10 0 20 20.2 27.81 91.87 33 4.7

2001 4 6 3 32 16.5 26.38 92.09 55 4.5

2001 4 8 18 35 49.3 28.16 88.57 20 3.92001 4 12 22 8 55.4 30.03 88.15 33 4.9

2001 4 20 18 35 2.7 26.13 90.67 33 4.6

2001 4 27 12 28 33.9 25.88 91.4 33 4.2

2001 5 3 16 2 59.6 27.63 90.47 33 3.8

2001 6 7 5 36 49.9 26.16 91.44 33 4.3

2001 6 20 14 44 31.5 26.5 91.87 33 4.3

2001 7 3 19 16 18.4 26.15 89.2 6 3.6

2001 7 6 23 4 3.4 27.65 88.64 10 2.7

2001 8 29 19 26 40.9 27.37 92.26 33 4.4

2001 9 4 0 30 2.5 25.7 91.71 15 3.3

2001 9 4 22 8 3.7 25.37 90.96 15 3.72001 10 26 8 22 59.5 26.07 93.11 33 4.2

2001 11 6 14 9 25 27.54 92.24 135 4.8

2001 11 12 21 55 13.4 25.81 91.61 19 3.2

2001 11 15 9 52 59.1 25.11 93.76 33 3.3

2001 11 28 17 18 37.2 26.4 91.13 33 3.1

2001 12 2 22 41 14.8 27.18 88.33 15 4.8

2002 1 11 14 51 7.3 27.54 91.81 10 4

2002 1 12 10 1 13.9 27.09 91.42 33 3.5

2002 1 16 17 37 4 26 93.61 39 3.2

2002 2 10 7 23 28.8 26.23 90.92 15 3.4

2002 3 12 7 33 3.2 25.35 92.35 33 3.9

2002 3 23 4 56 27.6 29.98 88.33 33 4.9

2002 3 24 3 48 35.1 25.71 90.31 33 3.3

2002 3 27 7 46 43.9 30.47 88.48 33 3.6

2002 3 27 16 49 9.7 26.76 92.5 33 4.5

2002 3 31 12 40 29.3 30.11 88.15 33 4.4

2002 4 12 15 48 33.5 25.09 92.06 28 0

2002 5 9 1 9 22.5 30.12 88.31 3

ii iit roorkee seismic report

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