Tuesday, May 10, 2005


3 Dimensional View of Sethusamudram  Posted by Hello

Sedimentation in Palk Bay, Gulf of Mannar

2001 Current Science paper by Chandramohan et al., click here to download.

Sunday, April 10, 2005

Some Basic Facts on the First Tsunami Wave

December 26th Earthquake onset time : 6.29 am IST


Tsunami Wave Arrival Time (WAT)1,
Wave Travel Time (WTT), Wave Speed


Chennai WAT 8.40 am WTT - 2 hrs 11 min (131 min)
Distance from Epicenter (DfE) – 2020 km
Wave Speed – 15.41985 km / min
925.19084 km / hr

Cuddalore WAT 8.00 am WTT - 1 hr 31 min (91 min)
DfE - 1990 km
Wave Speed - 21.86813 km/min
1312.08791 km/hr

Tuticorin WAT 9.57 am WTT - 3 hrs 28 min ( 208 min)
DfE – 2040 km
Wave Speed - 9.80769 km / min
588.46154 km/hr

Kochi WAT 11.10 am WTT - 4 hrs 41 min ( 281 min)
DfE - 2270 km
Wave Speed - 8.07829 km/min
484.69751 km/hr




1Data from Tide gauges maintained by Survey of India (at (Vishakapatnam Port Trust, Tuticorin Port Trust, Kochi Port Trust and Mormugao Port Trust) acquired and processed by the National Institute of Oceanography (NIO), Goa and posted at its website http://www.nio.org/jsp/tsunami.jsp

The website also has given the WAT data shared with it by the Survey of India for Cuddalore and Chennai.


Note: The NIO website has a map which shows the locations of the tide gauzes network maintained by the Survey of India. In it, Nagapattinam is marked as one among the various locations. However, no WAT data is presented for this location in the NIO website. Could it be due to the destruction and the loss of the tide guaze itself at Nagapattinam?


Also note: NIO had collected the data directly from the VPT, TPT, KPT and MPT and had processed the data by itself. However, it has not done the same for Chennai, Cuddalore and Nagapattinam. It had merely relied on the data shared with it by the Survey of India. Does this mean, that the gauzes at these ports had been destroyed by the tsunami and the SoI had only empirically observed facts to be shared with NIO? Could the lack of data at Nagapattinam mean, that even for sharing the empirically observed data, no port officials were available even for the Survey of India?

Epicenter Distance Map; Indian Ocean Tsunamigenic Areas; Hypothetical Indian Ocean Tsunami Animation by Las Alamos National Laboratory

Distance from epicenters

Download the high resolution map of the distances of various South Indian/Sri Lankan towns from the epicenters of the Dec 26th and March 28th eartquakes.



Tsunamigenic Areas in Indian Ocean


(1) The Andaman sea

(2) Area about 400-500 kilometers SSW of Sri Lanka

(3) The Arabian Sea about 70-100 kilometers south of Pakistan Coast -- off Karachi and Baluchistan


Source: T. S. Murty , A. Bapat , “Tsunamis on the coastlines of India”, Science of Tsunami Hazards, Vol 17, No.3 (1999), p-167 to 172


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Animation of a hypothetical tsunami generated by a meteor falling in the Indian Ocean

This is a hypothetical animation of a tsunami generated by a meteor falling in the Indian Ocean 4000 km south of Cape Comorin. The cavity was 38 km wide and 4000 meters deep.

Note in this animation: The tsunami wave reaches Cape Comorin at 4 hours and embraces the southwest and the southeast coast of India and the coast of Sri Lanka, there after.

This animation can be downloaded from:
http://t14web.lanl.gov/Staff/clm/tsunami.mve/tsunami.htm . The file name is: INDIA.zip

This site contains numerous animations of tsunamis (as of June, 2001) performed so far using using the SWAN code described in the monograph "Numerical Modeling of Water Waves," by Dr. Charles L. Mader, published in 1988 by University of California Press. The site also says that, ‘A few calculations were performed using the full Navier-Stokes ZUNI or SOLA codes’.

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Saturday, April 09, 2005

Distance of various cities/towns of South India and Sri Lanka from the Old and New Epicenters

Epicenter of the 2004, 26th
December 9R Earthquake: 3.4 N 95.7 E

Epicenter of the 2005, 28th

March 8.7 R Earthquake: 2.093 N 97.016 E

.........................................................................................


Distance of various cities/towns
of South India and Sri Lanka from
the Old and New Epicenters:


All distances shown in Kilometers

Red - Dec 26' 04 Black - March 28' 05


.....................................................................

Chennai

2020

2200

Kalpakkam Reactors

1990

2180

Kalpakkam DAE Quarters

2000

2180

Marakkanam

2000

2180

Pondicherry

1990

2180

Cuddalore

1990

2170


Thirumullaivayal

1960

2140


Tranquebar

1950

2130


Karaikal

1940

2120


Nagapattinam

1940

2120


Vedaranyam

1920

2100


Point Pedro

1860

2030


Mullaithivu

1770

1950


Trincomalee

1710

1870


Batticola

1630

1790



Hambatota

1640

1800


Galle

1740

1900


Kaluthura

1780

1940


Colombo

1800

1960



Male (Maldives)


2480


2630



Ernakulam


2270


2450


Kayankulam

2220

2390


Kollam

2210

2360


Thiruvanathapuram

2160

2320


Colachal

2110

2270


Cape Comorin

2080

2240


Kudankulam

2060

2220


Kulasekarapattinam

2040

2200


Thiruchendur

2030

2200


Tuticorin


2040


2200


Vembar

2020

2190


Rameshwaram

1930

2100

Dhanushkodi

1910

2090

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Friday, April 08, 2005

Credits and Sources

History of Tsunamis that have hit South India

A very comprehensive compilation of all the available literaure on the tsunamis that have hit the South Indian Coastline has been made by Dr.Lareef Zubair of International Research Institute for climate prediction at Coumbia University, USA. It is available here.

Here is Dr.Zubair's blog.

Satellite Bathymetry data

Professor David T.Sandwell of Scripps Institute of Oceanography, La Jolla, CA, USA . The data can be accessed from here .

DEM creation free software

Mr.John Childs's BLACKART v 4.02 . Mr.Childs's web portal, from where the software can be downladed can be accessed from here.

DEM rendering 3 D GIS free software

Mr.Richard Horne's 3 DEM v.18.9.9. The web portal from where the software can be downloaded can be accessed from here .

Thanks to:

Mr.Richard B.Cathcart, who is a constant source of encouragement.



Technique used by me to measure the width of the continental shelf:

1. A map of the area was prepared using the commercial GIS software Mapinfo Professional v.7 using its World data set.

2. Sandwell's bathymetry map for the area was then aligned with this Mapinfo map, using the commercial image processing software Photoshop CS.

3. The 'Mapinfo aligned Sandwell bathymetry map' was then opened in Mapinfo Pro. Co-ordinates were then registered for the various locations.

4. The measuring tool available in the software was then used to measure the width of the continental shelf as presented in Sandwell's map.

5. The measured distance was then verified for its accuracy from the published data on the actual measurement of the width of the continental shelf. Only one study is available so far, for this area, and that is on the Mahabalipuram micro-region. The work is by G.Gaitan Vaz: "Relict coral reef and evidence of Pre-Holocene sea level stand off Mahabalipuram, Bay of Bengal" in CURRENT SCIENCE, Vol.71,No.3, 10 August 1996.

The value for the width of the Mahabalipuram continental shelf measured virtually and presented by me here, interestingly, coincides with the value generated by the field study by Dr.G.G.Vaz

Thursday, April 07, 2005


csmr Posted by Hello