2001 Bhuj Earthquake

2001 BHUJ EARTHQUAKE Time: 8.46 AM (IST), 26th January, 2001 Epicentre: SSW of Chobari, Gujarat (23.6N, 69.8E) Fault rupture details The rupture occurred in a Causative fault. Slippage is believed to have occurred on the south dipping North Wagad reverse fault in the Kachchh aulacogen (failed rift). Slip is believed to have totalled between 1 m to 4 m. The earthquake is an intraplate event, as it occurred within the Indian plate, away from its edges. The lack of a primary surface rupture implies that the earthquake was blind due to the causative fault. Widespread ground deformation in the form of lateral spreading and strike-slip faults were found as well as local upwarping. Intensity measures defining the earthquake Violent ground shaking was felt in Bhuj for nearly 85 seconds with several minutes of lower level shaking. Using broad band velocities recorded by the IMD at Bhuj and a rupture model based on teleseismic data, an estimated value of 0.38g(vertical) was obtained for Bhuj. The moment magnitude of the earthquake was recorded between 7.6 and 7.7. It was found that the maximum felt intensity was X (Intense) on the Mercalli intensity scale. Locations greatly affected by the earthquake At a depth of only 23 kms below surface this quake generated intense shaking which was felt in 70% region of India and far beyond in neighbouring Pakistan and Nepal too. 21 of the total 25 districts of Gujarat were affected in this quake. Around 18 towns, 182 talukas and 7904 villages in the affected districts have seen large-scale devastation. The worst damage was caused in eastern Kachchh and in the old city of Bhuj. The most significant damage however, occurred in the two large cities of Ahmedabad and Surat. The affected areas spread up to 300 km from the epicentre. Estimated damage incurred and the number of fatalities At least 20,005 people were killed, 166,836 injured, approximately 339,000 buildings destroyed and 783,000 damaged in the Bhuj-Ahmedabad-Rajkot area and other parts of Gujarat. Many bridges and roads damaged in Gujarat. Bhuj, situated only 20 kilometres from the epicenter, was devastated. Over a million structures were damaged or destroyed, including many historic buildings and tourist attractions. The quake destroyed around 40% of homes, 8 schools, 2 hospitals and 4 km of road in Bhuj. In Ahmedabad, as many as 50 multi-storied buildings collapsed and several hundred people were killed. Total property damage was estimated at $5.5 billion. Preparedness for a similar quake Immediately after the 2001 earthquake Gujarat established the Gujarat Disaster Management Authority (GSDMA). The State Government has prepared comprehensive State Level Earthquake as well as Tsunami Disaster Management Plans covering various phases of the disasters right from emergency response, relief, recovery to mitigation and preparedness. The roles and responsibilities of every stakeholder are mentioned in the Plans and copies of the Plans have been shared with the stakeholders for its implementation. Early Hazard Warning and Emergency Communication System is established in Gujarat. The GSDMA through Indian Institute of Technology, Kanpur (IITK) identified the inadequacies in the existing BIS codes related to Earthquake, Wind and Fire and recommended changes/improvements in the above codes to ensure hazard resistant building construction.

A project on active fault mapping initiated by GSDMA through Indian Institute of Technology (IIT) – Kanpur and Institute of Seismological Research (ISR) in the eastern part of Kutch is undergoing. The State Government is in process of establishing five Regional Emergency Response Centres (ERCs) at Gandhinagar/Ahmedabad, Surat, Vadodara, Rajkot and Gandhidham. . The objective of these ERCs is to provide more effective and timely response to disasters. By observing the measures taken by the GSDMA, Gujarat seems to be prepared for such disaster. But still many projects are yet to be completed which will make Gujarat fully prepared for an earthquake like the 2001 Bhuj earthquake.

Figure: Intensity of the earthquake in the Indian subcontinent References: 1. Amateur Seismic Centre, Pune, www.asc-india.org 2. 2001 Bhuj Earthquake: Preliminary Report from IIT-Kanpur, SAARC Disaster Management Centre, www.saarc-sdmc.nic.in 3. Image: Intensities throughout subcontinent, www.pasadena.wr.usgs.gov 4. United States Geological Survey, www.earthquake.usgs.gov 5. Gujarat State Disaster Management Authority, www.gsdma.org