The 2001 Gujarat earthquake occurred on January 26, 2001, at 03:17 UTC, and coincided with the 51st celebration of India’s Republic Day. The location of the epicenter was Bhuj (23. 6° N 69. 8° E) Gujarat, India. With a moment magnitude (Mw) of between 7. 6 and 8. 1, the quake killed more than 20,000 people and injured another 167,000, and destroyed near a million homes throughout Gujarat and parts of eastern Pakistan. The earthquake is considered an intraplate earthquake because it occurred a great distance from any plate boundary, where the theory of plate tectonics says most earthquakes of this size happen.
Because of this, this area was not well prepared for an earthquake of such size. The event was the result of stored energy in a collision margin, which describes when two continental plates collide and begin to rub, creating pressure, until the energy is released in a quake. The Effects Because of it size and location, the quake was very destructive in terms of lives lost and damage to property. As many as 20,000 people were reported dead, and 166,000 injured. All the deaths occurred in India’s western state of Gujarat, near the Pakistan border.
The final death toll of Kutch was 12,220. Bhuj, situated only 20 kilometers (14 miles) from the epicenter, was the most devastated town. Overall, over a million structures were damaged or destroyed, including many historic buildings and tourist attractions. The quake destroyed around 90% of the homes in Bhuj, eight schools, and flattened two hospitals. It partly destroyed the historic Swaminarayan temple in the city. Considerable damage also occurred in Bhachau. It also destroyed 4 km of road in Bhuj. In Ahmedabad, Gujarat’s commercial capital and a city of 4. million population, as many as 50 multi-storied buildings collapsed, and several hundred people were killed. Total property damage was estimated at $5. 5 billion and rising. The quake destroyed 75% of Kutch District and over 80% of usable food and water supplies. The district collector Anil Mukim oversaw the early delivery of aid and equipment to affected villages but then called for further aid deliveries to cease as they encouraged a “relief mentality” which would delay a return to normal life. In the history of natural calamities, the 2001 Gujarat earthquake was the most devastating in India. The 2001 Gujarat Earthquake took place at a distance of 20 kilometers from Bhuj, Gujarat, and was scaled as 6. 9 on the Richter scale. The 2001 Gujarat Earthquake took place on the 26th of January when the Republic Day celebration was going on. It was reported that around 19,727 people were killed and more than 166,000 thousand people were injured. Besides these, the 2001 Gujarat Earthquake rendered 600,00 people homeless, with 348,000 houses destroyed and nearly 844,000 houses damaged.
Talking about other resources, about 20,000 cattle were killed. It was estimated that the government had to bear a loss of about 1. 3 billion dollars; other losses indicate losses as high as 5 billion dollars. The 2001 Gujarat Earthquake, as the reports say, was an intra-plate earthquake that took place due to the collision of the tectonic plates. The worst affected areas of the 2001 Gujarat Earthquake were: Kutch: Bhuj , Anjar , Bhachau , Rapar , Gandhidam , Ahmedabad: Ahmedabad city, Rajkot: Morvi Jamnagar: Jodiya, Dhrol. The news of the 2001 Gujarat Earthquake spread like a bonfire.
Some immediate steps were taken by the Gujarat Government like the Cabinet Secretary activated the Crisis Management Group to move men, relief materials, and other necessary stuff to the most affected areas. The adjoining states of Rajasthan and Maharashtra were asked to contribute towards the cause of the 2001 Gujarat Earthquake. Hindusthan Zinc Limited, Udaipur, IFFCO and KRIBHCO were also asked to provide to the victims. National Disaster Management was activated. Cabinet Secretary was asked to respond to the emergency. Home Minister organized for the medical help.
Prime Minister released Rupees 500 crores for the 2001 Gujarat Earthquake. Indian Air force helped in reaching the food, clothing and medicines to the worst affected areas. Although the calamity was a tremendous blow, yet the people of Gujarat showed enormous courage in pulling their state up and making a new beginning. This building was one of many that were leveled in Ahmedabad, India, during Friday’s 7. 9 magnitude earthquake. In Ahmedabad alone, 40 to 50 high-rise buildings crumbled.
Geodetic data from the epicentral region acquired in February were remeasured by CMMACS, Bangalore, and CU Boulder, in July 2001 to reveal postseismic displacements of roughly 1 mm/month. Coseismic displacements at a dozen historical monuments of the Great Trigonometrical Survey of India have been interpreted in terms of subsurface rupture geometry and slip (SriDevi et al, 2003). Aftershock data suggest a 45-50° south-dipping fault at depth (9-40 km). The Mw7. Bhuj earthquake that shook the Indian Province of Gujarat on the morning of January 26, 2001 (Republic Day) is one of the two most deadly earthquakes to strike India in its recorded history. One month after the earthquake official Government of India figures place the death toll at 19,727 and the number of injured at 166,000. Indications are that 600,000 people were left homeless, with 348,000 houses destroyed and an additional 844,000 damaged. The Indian State Department estimates that the earthquake affected, directly or indirectly, 15. 9 million people out of a total population of 37. 8 million.
More than 20,000 cattle are reported killed. Government estimates place direct economic losses at $1. 3 billion. Other estimates indicate losses may be as high as $5 billion. An informative assessment of the damage has been assembled by the Indian Institute of Technology, Kanpur, and EERI. Some historical structures that survived the 1819 earthquake have been destroyed in the 2001 earthquake. Despite the complete collapse of some multistory concrete buildings in moderately shaken regions, many structures remain intact, indicating that poor quality construction has aggravated the damage during this event.
Within one week of the earthquake, Ahmedabad police had registered 37 cases of culpable homicide and criminal conspiracy against builders, architects, and engineers of buildings that collapsed in the earthquake. The above figure shows some of the faults mapped by Malik et al. (2000) and by Rajendran and Rajendran (2001) with mainshock and one large aftershock mechanism from USGS/NEIC. In 1819 a lake was formed south of the Allah Bund that remains a depression (Lake Sindri) that is flooded during the summer monsoon.
The region has experienced above normal levels of microseismicity throughout the past 200 years, and probably for many millennia. Damaging earthquakes occurred in 1845, 1846, 1856, 1857, 1869, and 1956 in the same general region as the 1819 and 2001 earthquakes. Vertical deformation in 1819 reached 6 m and in 1956, 1 m. The figure below (b) shows how dilatational (volume) strain accompanying the 1819 earthquake may have loaded contiguous regions resulting in subsequent earthquakes, including the 2001 event, and how the region of loading (+)has now moved eastward.
The earthquake occurred far from the edge of the Indian Plate and quite close to an M=7. 7 earthquakes that occurred in 1819. The 2001 felt region extends from Madras to Kathmandu, just as it did in the 1819 earthquake (see isoseismal section below). Damage reports from Bhuj and Anjar are distressingly similar to the damage reports of the 1819 earthquake when fewer than 2000 were killed. The population of Kachchh is now many times greater than in 1819 but the percentage of the local population killed is roughly the same, despite the implementation of a seismic-resistant building code.
Field Reports
Power was disrupted on the night of the earthquake extinguishing city lights in the epicentral region. Preliminary seismic data from an aftershock array suggest a south-dipping thrust with a surface projection near 23. 8°N near the central Rann of Kachchh. Aftershocks are unusually deep (up to30 km). It would appear that the earthquake may have severed the lithosphere. No surface rupture — A neotectonics team (Seeber, Rockwell, and Wesnousky) report a number of minor en-echelon cracks but no significant scarp.
EERI investigators report an east-west belt of intense surface cracking presumably associated with a subsurface rupture. A 2 km long approximately east-west zone of intense deformation reported at N 23° 20′ 30. 4″ E 70 11′ 40. 1″ to N 23 20′ 30″ E 70 11′ 53. 9″ by Oyo scientists, corresponds to the zone of catastrophic lateral spreading reported by the EERI team These observations are reconciled in an explanation by Bill Lettis. The bulge-like deformation near this feature may be similar in structure to that which occurred in the 1819 event. An alleged 1. m scarp previously reported north of Bhuj is interpreted as a slump feature in river alluvium. Liquefaction — On 4 February liquefaction phenomenon were reported by hydrologists and by local villagers, with an indication that the flow was sufficient in some cases to activate desert rivers that have been dry for more than a century. Widespread liquefaction was confirmed by SPOT imagery and by field observation (5 Feb. ). Many mud-volcanoes in the Rann of Kachchh have dimensions of hundreds of meters: one covers a 5 km diameter stretch of the southern Rann with dark sand and mud.
Numerous ancient river channels have been illuminated by a pockmark pattern of sand vents, and some have clearly flowed and breached their old channels. Isoseismal Intensities are being investigated by several groups of scientists in India. The importance of these data is that it will be possible to estimate the attenuation of acceleration across the Indian craton for the first time from a large well-calibrated earthquake. These data may then be used to examine data from historic Indian earthquakes (see, for example, Ambraseys and Bilham, 2000) and to revise their estimated magnitudes.
Sue Hough (USGS, Pasadena) and Stacey Martin have compiled perceived intensity data from the 1819 and 2001 earthquakes which will be refined as further data are reported. These intensity maps already show several interesting features. The distribution of strong-motion accelerometers in India is not as dense as one would like for this exceptional earthquake but is probably adequate to calibrate the FSK or Modified Mercalli scale relative to physical ground accelerations.
Aftershocks were frequent in 1819 and in 1844-45 attaining intensities sufficient to cause alarm for 1 month after these earthquakes, and sufficient to be felt for several years. Numerous aftershocks exceeding Ms=5 have been reported by Indian seismologists, and one aftershock approached Ms=6. A subset of these aftershocks is plotted on the map above. It is likely that aftershocks will occur throughout 2001 in Gujarat with diminishing intensity. Aftershocks currently outline an ENE trending south-dipping thrust (45°-50° dip) to great depths (20-30 km).
The neotectonic GEOLOGY of Kachchh (Malik et al. 2000) consists of a series of folds and faults with a general WNW/ ESE trend. A morphological analysis suggests that the entire Kachchh system may be thrust and fold belt. An early geological map of Kachchh (Wynne 1872) shows most of the significant faults. The fault that ruptured on 26 January appears to lie on the southern edge of the Rann of Kachchh north of Bhuj. Several mapped faults follow the low hills that are bordered by this salt waste.
The figure below illustrates a series of ancient grabens in the Kachchh region. The locations of the 1819 and 1956 ruptures are reasonably well located, but the location of the 2001 rupture is currently approximate. The strike of the 1819 event parallels folds axes within the Kutch Graben which is currently in a state of compression from India/Asian collisional stresses.
Geodesy
The first order Survey of India Cutch Coast Series and Kathiwar Meridional Series was first measured in 1856.
Some of these points were occupied by first-order leveling in 1880. The leveling line was remeasured in the ’70s to reveal uplift of 1 m associated with the Anjar 1956 earthquake. Two immediate targets are to estimate the co-seismic strain-field by occupying these historic points and to measure the viscous response of the lower crust and upper mantle over the next decade. Preliminary mechanisms from Tokyo suggest that the fault that slipped may have been the southern boundary fault system to the Kutch Graben with a strike N30E rather than N30W as depicted below.
The maximum slip is estimated to be 6. 2 m. These solutions have a similar strike to those in the University of Tokyo special event page USGS solutions and Harvard CMT solutions, however, favor an N30W strike, parallel to the mapped faults in the southern Rann of Kachchh. Iris Special Event Page Eeri Field Inspection Reports IPGP Paris Javed Malik home page Kanpur IIT Dept of Engineering Steve Wesnousky Field Report Damage to historical monuments
