EARTHQUAKE AND TSUNAMI OF 28 NOVEMBER 1945 IN SOUTHERN PAKISTAN
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On 28 November 1945, a great earthquake, off Pakistan’s Makran Coast (Balochistan) generated a destructive tsunami in the Northern Arabian Sea and the Indian Ocean. More than 4,000 people were killed along the Makran Coast of Pakistan by both the earthquake and the tsunami.
Also, the tsunami was responsible for the loss of life and great destruction along the coasts of Iran, Oman and western India (and possibly elsewhere).
Origin Time and Epicenter
The great earthquake occurred at 21:56 UTC (03:26 IST), on 28 November 1945. Its epicenter was at 24.5 N 63.0 E., in the northern Arabian Sea, about 100 km south of Karachi and about 87 km SSW of Churi (Baluchistan), Pakistan.
Magnitude and Earthquake Intensity
The earthquake’s Richter Magnitude (Ms) was 7.8. The Moment Magnitude (Mw) was revaluated to be 8.0; the quake was recorded by observatories in New Delhi, Kolkata (Calcutta) and Kodaikanal.
The earthquake’s intensity was high throughout the region. It was strongly felt in Baluchistan and the Las Bela area of Pakistan. It was reported that in the western and southern sections of Karachi the strong surface motions lasted for about 30 seconds. According to eyewitness reports, people were “thrown out of their beds”, doors and windows rattled, and windowpanes broke. The underwater cable link between Karachi and Muscat (Oman) was damaged, disrupting communications. The lighthouse at Cape Moze – 45 miles from Karachi – was also damaged. The earthquake was strongly felt also at Manora, where the lighthouse was damaged. It was moderately felt in Panjgaur and Kanpur.
Other Earthquake Effects
Reports by S.M. Mathur and D.N. Wadia (pertaining to the Geology of India) mention that the earthquake caused the eruption of a mud volcano a few miles off the Makran Coast of Pakistan. This eruption formed four small islands. It was reported that a large volume of gas emitted at one of these islands, sent flames “hundreds of meters” into the sky.
Such mud volcanoes are not uncommon in the Sindh region of the Makran coast. Their presence indicates the existence of high petroleum deposits. They are known to discharge flammable gases such as methane, ethane and traces of other hydrocarbons. Thus, the flames that were observed following the eruption of one of the mud volcanoes resulted from emitted natural gas, which caught fire after the earthquake.
The following is a brief overview of the overall tectonic setting and interactions that affect the seismotectonics of the Makran subduction zone in the Northern Arabian Sea.
Approximately 20 million years ago India was connected to the southeastern tip of Africa. Forces within the mantle caused the development of a rift in the crust, thus separating the Indo-Australian tectonic plate from the continent of Africa. For millions of years, this great tectonic plate drifted and moved in a north/northeast direction. Several millions of years later, its leading deep sea-floor edge begun colliding with the Eurasian tectonic plate and thrusting upward. Eventually, the continuous continent-continent collision raised the leading oceanic edge above sea level leading to continuing orogenesis the process that has created the Himalayan Plateau and the great Himalayan mountain ranges.
The India tectonic plate has been drifting and moving in a north/northeast direction, for millions of years colliding with the Eurasian tectonic plate and forming the Himalayan Mountains (USGS graphic showing the migration of the Indian tectonic plate)
As a result of such migration and collision with the Eurasian tectonic plate, a diffuse zone of seismicity and deformation developed in the entire region. Over additional millions of years, the earth’s crust further broke, deformed and folded, creating fractured microplates, great faults and subduction zones all with high seismic activity. Complex, kinematic earth movements along the boundaries of such active zones have caused numerous destructive earthquakes in India, Pakistan, Afghanistan, Iran, and Tibet.
Most earthquakes in Pakistan occur in the north, the northwestern and the western sections of the country along the boundary of the Indian tectonic plate with the Iranian and Afghan micro-plates.
The Owen Fault Zone is a transform fault in the Arabian Sea that is associated with a tectonic boundary. It extends from the Gulf of Aden in a northeast direction towards the Makran coast where it enters the Balochistan region. Then it continues as a land fault known as the Chaman Fault along Pakistan’s western frontier with Afghanistan. It begins near Kalat, in the northern Makran range, passes near Quetta and continues to Kabul, Afghanistan. Both the Owen Fault Zone and the Chaman Fault Zone can generate large destructive earthquakes. The great Quetta earthquake of 1935 occurred along the Chaman Fault. Other major thrust zones exist along the Kirthar, Sulaiman and Salt mountain ranges of Pakistan.
Four other major faults exist in and around Karachi and other parts of deltaic Indus, and along the southern coast of Makran. The first of these is the Allah Bund Fault. It traverses Shahbundar, Jah, Pakistan Steel Mills, and continues to the eastern parts of Karachi – ending near Cape Monz. Earthquakes along this particular fault have been responsible for considerable destruction in the past. A major earthquake in the 13th century destroyed Bhanbhor. Another major earthquake in 1896 was responsible for extensive damage in Shahbundar
British Geological Survey graphic of the seismicity of Southern Asia of the Carlsberg Midoceanic Ridge and of the southern portion of the Arabian Peninsula and the Red Sea.
The second major fault near Karachi is an extension of the one that begins near Rann of the Kutch region of India. The third is the Pubb fault which ends into the Arabian Sea near the Makran coast. Finally, the fourth major fault near Karachi is located in the lower Dadu district, near Surajani.
Geology of the Makran Coastal Region
The coastline of Pakistan along the Arabian Sea extends for about 1,050 km (650 mi) with 800 km of it belonging to the Balochistan Province and 250 km to the Sindh Province. The Makran Coastal Range forms a narrow strip of mountains along about 75 percent of the total coast length, or about 800 km (500 mi). The steep mountains rise to an elevation of up to 1,500 m (5,000 ft).
The Makran coast is rugged and tectonic in origin with uplifted terraces, cliffs, and headlands. The entire coastline is characterized by extreme sediment accretion (Closs et al., 1969, White and Louden, 1983; Platt et al., 1985; Minshull et al., 1992, Fruehn et al., 1997). It is one of largest sediment accretionary wedges on earth, with up to 7 km of sediments deposited in the Gulf of Oman to the west and major rivers contributing a vast amount of sediment to the offshore region in the east. The accretionary complex is more than 900 km long and there is no evidence of very active volcanism. The complex has an east-west orientation and is bounded on both sides by large transform faults associated with tectonic plate boundaries.
The Balochistan section of the Makran coast of Pakistan has several small river deltas. In the eastern Sindh region of Pakistan, the Indus River has formed one of the largest deltas in the world. Past meandering of Indus has formed extensive deltas east of Karachi. Extensive sedimentation from the erosion in the Himalayas has widened the continental shelf of the Sindh coast to about 150 km. Along the Balochistan region where there is less sedimentation; the continental shelf measures only 15-40 km.The Makran Subduction Zone
The Makran Subduction Zone
The northward movement and subduction of the Oman oceanic lithosphere beneath the Iranian micro-plate at a very shallow angle of subduction of about 20 degrees, has dragged tertiary marine sediments into an accretionary prism at the southern edge of the Asian continent (White and Louden, 1983; Platt et al., 1985) – thus forming the Makran coastal region, a belt of highly folded and densely faulted mountain ridges which parallel the present shoreline. To the west of the accretionary prism, a continental collision of about 10 mm/yr has formed the Zagros fold and thrust belt. To the east, the area comprises of a narrow belt, which truncates against the Chaman transform fault an extensive system that extends on land in a north-northeast direction along Pakistan’s frontier with Afghanistan.
Offshore, the active tectonic convergence of the India plate with the Arabian and Iranian microplates of the Eurasian tectonic block has created a tectonic plate margin – an active subduction zone along the boundary of the Arabian plate on the Makran coast. The tectonic plates there converge at an estimated rate of about 30 to 50 mm/y (Platt et al. 1988). Thus, an east-west trench has been formed south of Makran and, additionally, a volcanic arc has emerged. Specifically the underthrusting of the Eurasian plate by the Arabian plate has resulted in the formation of the Chagai volcanic arc, which extends into Iran. The Koh-e- Sultan volcano and other volcanic cones in the Chagai area are side products of this active subduction (Schoppel, 1977).
The morphology of the region is further complicated by the extensive sedimentation, which takes place as a result of erosion of Himalayan mountain ranges and the numerous rivers flowing into the North Arabian Sea. A very thick sedimentary column enters the subduction zone (Closs et al., 1969, White and Louden, 1983), so the trench associated with the present accretionary front in the offshore region of Makran has been buried by sediments and does not have much of a morphological relief as other trenches around the world’s oceans.
The region of subduction along the Makran coast of Pakistan and the Gujarat Region of India where major earthquakes have occurred – one as recently as 2001.
Seismotectonics of the Makran Region
The seismicity of the Makran region is relatively low compared to the neighboring regions, which have been devastated regularly by large earthquakes (Jacob and Quittmeyer, 1979). Although infrequent, large earthquakes such as the 1945 event do occur from time to time on the eastern portion of the Makran subduction zone and have generated destructive tsunamis recently and in the distant geologic past. The great earthquake of 28 November 1945 is an example of the size earthquakes this subduction zone can produce. It generated a very destructive tsunami in the Northern Arabian Sea.
Large earthquakes in the region appear to be preceded by increasing activity of smaller events. For example, for ten years prior to the 1945 Makran earthquake, there was a concentration of seismic activity in the vicinity of its epicenter. Although infrequent, it is believed that large earthquakes can also occur along the west region of the Makran subduction zone and can generate destructive tsunamis.
Destructive tsunamis have been generated from large earthquakes along the subduction zone off the Makran coast of Pakistan in the past. Although the historical record is incomplete, it is believed that such tsunamis were destructive on the coasts of Pakistan, Iran, India, and Oman and possibly had significant effects on islands and other countries bordering the Indian Ocean. The most significant tsunamigenic earthquake in recent times was that of 28 November 1945. The tsunami was responsible for great loss of life and destruction along the coasts of Pakistan, Iran, India, and Oman. The tsunami run-up heights varied from 1 to 13 m. Unfortunately, the effects of the tsunami to other countries bordering the Indian Ocean have not been adequately documented. The information on this event is still inadequate.
PAKISTAN – Along the Makran coast of Pakistan, the tsunami reached a maximum run-up height of 13 m (40 feet). Its waves destroyed fishing villages and caused great damage to port facilities. More than 4,000 people died from the combined effects of the earthquake and the tsunami, but most deaths were caused by the tsunami.
The waves completely destroyed and killed all the people at Khudi, a fishing village about 30 miles west of Karachi. At Dabo Creek, 12 fishermen were swept into the sea.
Karachi was struck by waves of about 6.5 feet in height. According to reports, the first wave was recorded at 5:30 am local time, then at 7:00 am, 7:15 am and finally at 8:15 am. The last wave at 8:15 was the largest. The tsunami arrived from the direction of Clifton and Ghizri. There was no reported damage to the port and boats in the harbor of Karachi. However, at Keamari the waves flooded a couple of compounds along the harbor’s oil installations.
There were considerable destruction and loss of life at the towns of Pasni and Ormara but no details are available. Many people were washed out to sea. At Pasni the waves destroyed government buildings rest houses and postal and telegraph facilities.
INDIA – Tsunami waves as high as 11.0 to 11.5 m struck the Kutch region of Gujarat, on the west coast of India. There were extensive destruction and loss of life. Eyewitnesses reported that the tsunami came in like a fast rising tide.
The tsunami reached as far south as Mumbai. Bombay Harbor, Versova (Andheri), Haji Ali (Mahalaxmi), Juhu (Ville Parle) and Danda (Khar). In Mumbai, the height of the tsunami was 2 meters. Fifteen (15) persons were washed away. According to reports, the first wave was observed at 8:15 am (local time) on Salsette Island in Mumbai (3). There was no report on damage at Bombay Harbor.
Five people died at Versova (Andheri, Mumbai), and six more at Haji Ali (Mahalaxmi, Mumbai), Several fishing boats were torn off their moorings at Danda and Juhu.
IRAN – There was extensive flooding of the low-lying areas, after the tsunami but no details are available.
OMAN – There was considerable loss of life and destruction but no details are available. The tsunami was recorded at Muscat and Gwadar.
Past historical tsunamis
Though Southern Asia is a seismically active region, tsunamis along the coastlines of Pakistan and India have been relatively rare, but not unprecedented. Destructive earthquakes and tsunamis have occurred in the North Arabian Sea throughout geologic history and in recent times. Most of these events have not been adequately documented. On the western side of India, the earthquakes of 1524 and 1819 in the Kutch region probably generated destructive tsunamis.
The oldest known tsunami in the region may have been generated by a large magnitude earthquake, which occurred in the Indus delta/Kutch region in 326 B.C. It has been reported in the literature (Lietzin 1974, Murty and Bapat 1999) that this earthquake generated a tsunami in the Arabian Sea, which destroyed Alexander the Great’s Macedonian fleet on its journey back to Greece after India’s conquest.
Although the Makran Subduction Zone in the Northern Arabian Sea is an active seismic zone, large tsunamigenic earthquakes have been relatively rare. It is quite possible that tsunamis in this region have not properly reported or documented. A thorough analysis of historical records may reveal their occurrence. Such past tsunamis could have affected Southern Pakistan, India, Iran, Oman, the Maldives and other countries bordering the Indian Ocean.
The Makran region has the potential for very large earthquakes, which can generate destructive tsunamis in the future. Recent seismic activity indicates that a large earthquake is possible in the region west of the 1945 event (Quittmeyer, 1978). Such an earthquake could generate a destructive tsunami.
A factor that could contribute to the destructiveness of a tsunami along the Makran coastline would be the relatively large astronomical tide, which is about 10-11 feet. A tsunami generated during high tide would be significantly more destructive. Also, the compacted sediments in this zone of subduction could contribute to a greater tsunami. A bookshelf type of failure within the compacted sediments as that associated with the 1992 Nicaragua earthquake could generate a more destructive tsunami. The significance of the astronomical tide and of the thick sedimentary layers to tsunami generation to the tsunami vulnerability of the region will be discussed further in another paper.
Ambrasseys, N. and Bilham, R., 2003, “Earthquakes and Associated Deformation in North Baluchistan 1892-2001”, Bulletin of the Seismological Society of America, Vol .93, No. 4, p. 1573 – 1605.
Berninghausen, W.H., 1966. “Tsunamis and Seismic Seiches reported from regions adjacent to the Indian Ocean”, BSSA, Vol 56, No.1, 1966.
Byrne Daniel E., Sykes Lynn R. Davis Dan M., 1992. Great thrust earthquakes and aseismic slip along the plate boundary of the Makran subduction zone. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 97, NO. B1, PAGES 449478, 1992
Closs, H., Bungenstock, H., Hinz, K., 1969. Ergebnisse seismischer Untersuchungen im nrdlichen Arabischen Meer: ein Beitrag zur internationalen Indischen Ozean Expedition. METEOR Forschungsergebnisse, Reihe C, 2, 28 pp. Flueh, E. R., Kukowski, N., Reichert, C. (Editors). FS Sonne Cruise Report SO-123 – MAMUT, Maskat – Maskat 07.09. – 03.10.1997, GEOMAR Rep. 62, 292 pp.
Dorostian A., Gheitanchi M. R., SEISMOTECTONICS OF AFGHANISTAN AND ITS BORDERING REGIONS.College of Science, & Institute of Geophysics, Islamic Azad Univ. North Tehran Branch, Iran.
Dorostian A., Gheitanchi M. R., SEISMICITY OF MAKRAN
European Geophysical Society 2003. Tectonics of a Lateral Transition Between Subduction and Collision:The Zagros-Makran Transfer Deformation Zone (SE IRAN) Geophysical Research Abstracts, Vol. 5, 01210, 2003
Fruehn, J., White, R. S. and Minshull, T. A., 1997. Internal deformation and compaction of the Makran accretionary wedge, Terra Nova, 9: 101-104.
Harms, J. C., Cappel, H. N. and Francis, D. C., 1984. The Makran coast of Pakistan: Its stratigraphy and hydrocarbon potential. In: Haq, B. U., and Milliman, J. D. (Editors), Marine Geology and Oceanography of the Arabian Sea and Coastal Pakistan: 3-27.
Hutchinson, I., Louden, K. E., White, R. S., 1981. Heat flow and age of the Gulf of Oman, Earth Planet. Sci. Lett., 56: 252-262.
Jacob, K. H., and Quittmeyer, R. L., 1979. The Makran region of Pakistan and Iran: Trench-arc system with active plate subduction. In: Farah, A. and de Jong, K. A. (Editors), Geodynamics of Pakistan: 305-317.
Jadoon, I.A.K., 1992, “Ocean/continental transitional crust underneath the Sulaiman Thrust Lobe and an evolutionary tectonic model for the Indian/Afghan Collision Zone”, Pakistan Journal of Hydrocarbon Research, v.4, no.2, p.33-45.
Kopp C., Klaeschen D., Fruehn J., Flueh, E.R., Reichert, C. and N. Kukowski. Seismic Velocities and Images of the Makran Subduction Zone.
Mathur, S.M. “Physical Geology of India”
Minshull, T. A., White, R. S., Barton, P. J. and Collier, J. S., 1992.Deformation at plate boundaries around the Gulf of Oman, Marine Geology, 104: 265-277.
Mokhtari, M. and Farahbod, A.M. 2005. Tsunami Occurrence in the Makran Region. Tsunami Seminar, Tehran, 26 February 2005
MunichRe, “World Map of Natural Hazards”, 1988 (Updated 1993).
Murty. T. and A. Bapat, “Tsunamis on the coastlines of India”, International Tsunami Symposium, May 1999 (Abstract).
Pacheco and L. Sykes, 1992. “Seismic Moments of Great Shallow Earthquakes 1900-1990 with Magnitude > 7”, Seismological Society of America, 1992.
Pakistan Meteorological Department 2005. History of Tsunamis in Pakistan/Arabian Sea., January 2005.
Pararas-Carayannis, G., 2005. “The Earthquake of 8 October 2005 in Northern Pakistan”
Pararas-Carayannis, G., 2001, “The Earthquake of 25 January 2001 in India” http://www.geocities.com/CapeCanaveral/Station/8361/Quake2001India.html
Pararas-Carayannis, G., 2001, “The Earthquake and Tsunami of 28 November 1945 in Southern Pakistan”http://www.drgeorgepc.com/Tsunami1945Pakistan.html
Platt, J. P., Leggett, J. K., Young, J., Raza, H. and Alam, S., 1985. Large-scale sediment underplating in the Makran accretionary prism, Southwest Pakistan, Geology, 13: 507-511.
Quittmeyer, R.C., and Jacob, K.H., 1975 “Historical and Modern Seismicity of Pakistan, Afghanistan, N.W. India and S.E. Iran,” Bulletin of the Seismological Society of America, 69/3, pp. 773-823, 1979.
Ramanathan, K., and Mukherji, S., 1938, “A seismological study of the Baluchistan, Quetta, earthquake of May 31, 1935”, Records of the Geological Survey of India, Vol. 73, p. 483 513.
Times of India Newspaper archives (Mumbai), India, November 1945
Wadia, D.N., “Geology of India”, Tata-McGraw-Hill, New Delhi 1981.
White, R. S., Louden, K. E., 1983. The Makran Continental Margin: Structure of a Thickly Sedimented Convergent Plate Boundary. In: J. S. Watkins and C. L. Drake (Editors), Studies in Continental Margin Geology. Mem. Am. Ass. Petrol. Geol. 34: 499-518.
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