Some geophysical parameters as inputs for Tsunami surge models

DR.K.S.R.MurthyNational Institute of Oceanography, Regional Centre, Visakhapatnam. 530 017Email: ksr@nio.org

Paper presented at the International Workshop on “Tsunami and non-linear waves” held at the Saha Institute of Nuclear Physics, Kolkata, 6th – 10th March, 2006

COASTAL MORPHOLOGYCOASTAL MORPHOLOGY

● ● General morphology of Eastern Continental Margin of India General morphology of Eastern Continental Margin of India (ECMI)(ECMI)

• Impact of morphology on Tsunami Surge and Inundation – Impact of morphology on Tsunami Surge and Inundation – Case Study from Tamil Nadu Margin, East Coast of India Case Study from Tamil Nadu Margin, East Coast of India

Table 1 Shelf / Slope characteristics off selected places over the ECMI

LocationLocation

(See Fig. 1)(See Fig. 1)Water depth Water depth

atat

Shelf break Shelf break (m)(m)

Shelf edgeShelf edge

Distance Distance from coast from coast

(km)(km)

Shelf Shelf gradientgradient

(ratio)(ratio)

Slope Slope gradientgradient

(ratio)(ratio)

Depth at which Depth at which marginal high marginal high

(M.H.) is recorded (M.H.) is recorded (m)(m)

Remarks (onlyRemarks (only

relative terms)relative terms)

ParadipParadip 100100 6868 1 : 3201 : 320 1 : 501 : 50 Not clearNot clear Wide shelf,Wide shelf,

gentle slopegentle slope

PuriPuri 130 shelf,130 shelf, 5656 1 : 3001 : 300 1 : 431 : 43 Not clearNot clear Wide shelf, Wide shelf, gentle slopegentle slope

Chilka LakeChilka Lake 220220 5252 1 : 2001 : 200 1 : 281 : 28 800? 800? Wide shelf, Wide shelf, gentle slopegentle slope

South of Chilka South of Chilka LakeLake

220220 4747 1 : 2001 : 200 1 : 351 : 35 Not clearNot clear Wide shelf, Wide shelf, gentle slopegentle slope

South of South of GopalpurGopalpur

220220 5151 1 : 2001 : 200 1 : 161 : 16 1500 – 20001500 – 2000 Wide shelf, Wide shelf, steep slopesteep slope

KalingapatnamKalingapatnam 120120 4444 1 : 2801 : 280 1 : 161 : 16 1800 – 20001800 – 2000 Narrow shelf, Narrow shelf, steep slopesteep slope

South of South of KalingapatnamKalingapatnam

130130 5353 1 : 3451 : 345 1 : 151 : 15 2000 – 21002000 – 2100 Wide shelf, Wide shelf, steep slopesteep slope

VisakhapatnamVisakhapatnam 200200 5454 1 : 2501 : 250 1 : 121 : 12 1900 – 21001900 – 2100 Wide shelf, Wide shelf, steep slopesteep slope

North of North of KakinadaKakinada

200200 5757 1 : 2251 : 225 1 : 121 : 12 2400 – 26002400 – 2600 Wide shelf, Wide shelf, steep slopesteep slope

Krishna riverKrishna river 7070 3535 1 : 3001 : 300 1 : 251 : 25 Uncertain due to Uncertain due to slumping over theslumping over the

slopeslope

Narrow shelf, gentle slopeNarrow shelf, gentle slope

NizampatnamNizampatnam 7070 5757 1 : 3001 : 300 1 : 251 : 25 Uncertain due to Uncertain due to slumping over theslumping over the

slopeslope

Wide shelf, gentle slopeWide shelf, gentle slope

MadrasMadras 200200 5555 1 : 2001 : 200 1 : 8 1 : 8 27002700 Wide shelf, Wide shelf, very steep very steep slopeslope

North of North of PondicherryPondicherry

9090 5151 1 : 4001 : 400 1 : 61 : 6 30003000 Wider shelf, Wider shelf, very steep very steep slopeslope

KaraikalKaraikal 70 70 2929 1 : 200 1 : 200 1 : 191 : 19 30003000 Narrow shelf, Narrow shelf, steep slopesteep slope

NagapatnamNagapatnam 7070 4747 1 : 3401 : 340 1 : 171 : 17 30003000 Narrow shelf, Narrow shelf, steep slopesteep slope

0.00 2.00 4.00 6.00 8.00 10.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

CB4

CB3

CB2

CB1

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00 16.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

0.00 4.00 8.00 12.00D istance (cm ) from the coast

4000

3000

2000

1000

0

Ba

thym

etr

y

CB8

CB7

CB6

CB5

0.00 2.00 4.00 6.00 8.00D istance (cm ) from the coast

2000

1600

1200

800

400

0B

ath

yme

try

CB9

Bathymetry sections of Cauvery basin (for locations please see Fig. 5a)

COASTAL SEISMICITYCOASTAL SEISMICITY

Low to Moderate Seismicity from Low to Moderate Seismicity from coastal regions- Case Studies from coastal regions- Case Studies from East Coast of IndiaEast Coast of India

NATURAL HAZARDS IN THE INDIAN SUB-CONTINENTNATURAL HAZARDS IN THE INDIAN SUB-CONTINENT

• Peninsular India is often faced with two Peninsular India is often faced with two major natural hazards namely the major natural hazards namely the cyclone and storm surges in the coastal cyclone and storm surges in the coastal areas and the intraplate seismicity in the areas and the intraplate seismicity in the main land and coastal areas.main land and coastal areas.

• We have now fairly a well established We have now fairly a well established weather forecasting mechanism to cope weather forecasting mechanism to cope up with high cyclone and storm surges. up with high cyclone and storm surges.

• The other natural hazards is the continental earthquakes The other natural hazards is the continental earthquakes like the Latur (1993), Jabalpur (1997), Bhuj (2001) which like the Latur (1993), Jabalpur (1997), Bhuj (2001) which caused huge devastation, including heavy human losses. caused huge devastation, including heavy human losses. These earthquakes are the result of the reactivation of These earthquakes are the result of the reactivation of subsurface weak zones beneath the continental shield. subsurface weak zones beneath the continental shield. The reactivation is due to compressional stress The reactivation is due to compressional stress accumulated on the Indian Plate as it moves northward in accumulated on the Indian Plate as it moves northward in the overall plate Kinematics of this part of the earth. the overall plate Kinematics of this part of the earth.

Seismic Zonation Map of India

Fig. 7