print this page The South Asian Earthquake of October 8, 2005 – An Eyewitness Account Dr. Siddiqui is an APGO member and he was a member of the APGO Communication Committee until taking a professional assignment in Pakistan earlier this year. The Earthquake Tremors are nothing unusual in the Punjab. A short distance north of Lahore, Pre-Cambrian rock, in isolated hills, is evidence of an ancient mountain chain buried under the alluvium of this ‘Land of Five Rivers’. Occasional tremors felt by people of Lahore are believed to originate from alluvium suddenly subsiding down the slopes of the buried ridges. Although the tremors on October 8 th felt a bit stronger than usual to Lahorites, it was only through the electronic media reports, later in the morning, that one became aware of the true magnitude of the earthquake and the scale of catastrophic damage caused to life and property. According to reports the earthquake occurred at 8:50 a.m. with an intensity of 7.6 on the Richter Scale. The epicenter was located approximately 10 km north of Muzaffarabad, the capital of Pakistani-controlled Kashmir and about 325 km from Lahore. The tectonic failure occurred at a depth of 26 km. The Human Devastation The earthquake damaged an area of 28,000 square kilometres, including some areas in Indian held Kashmir. USGS estimated 79,000 dead while the World Bank put the fatalities at 86,000. The injured exceed 128,000, more than half of them seriously injured, including 558 rendered paraplegic. The number of families affected was over 500,000. The UN rated the earthquake worse than the Tsunami of last year. It is the greatest earthquake of the last one hundred years. A particularly sad blow to the geological profession was the death of ninety students of three classes that perished in the collapsed ruins of the Geology Department, University of Azad Kashmir, in Muzaffarabad. The Land Slides In this region of steep slopes, the earthquake triggered widespread land sliding that made long sections of the road network inaccessible, seriously delaying relief work and supplies. After each major landslide, plumes of dust could be seen from miles around. Terrified survivors mistook the dust plumes as smoke from volcanic vents. The Relief Agencies called in the Geological Survey of Pakistan (GSP) to investigate and the Director of GSP Islamabad had to appear on the national TV to put the rumours at rest. Figure 1
(Photo taken during relief flight by Mustafa K. Siddiqui/author's brother, Chief of Operations, Helicopter Wing, The Agha Khan Foundation, Islamabad.)None of the landslides, however, came close to the one that dumped an estimated 8 million cubic metres of material just above the confluence of two Jehlum River tributaries, creating instant earth fill dams in both streams. By December 7 th, sufficient water accumulated behind the dams to create a new lake of 25 m and another of 15 m depth. Figure 1 is an aerial photograph of the larger of the two lakes. Canopies of trees, partially submerged in the lake, provide an awesome sense of the height of the dam, estimated at 350 m. With these substantial bodies of water accumulating behind the natural dams, the populations along the river downstream and to the south of the dams, including and more ominously the residents of the town of Hatian on the Jehlum River, face an uncertain future. Figure 2
Figure 2 shows the web of thrust fault lines around the epicentre of the South Asian Earthquake of October 8, 2005. The solid red line is the trace of the Main Kashmir Thrust (MKT) believed to be the source of the earthquake. Grid lines are from 72 to 75 degrees E and 33 to 35 degrees N (modified from Tectonic Map of Pakistan by Kazmi and Rana of the Geological Survey of Pakistan, 1982)Geological Background The epicenter of the earthquake lays deep inside the ‘hairpin’ syntaxis that is one of the most striking features of Himalayan tectonics. Figure 2 is an edited portion of the tectonic map of Pakistan, covering the epicenter and the surrounding area. As can be seen, the epicenter is surrounded by a web of regional mainly major and minor thrust faults that testify to the fragile structure of the area. The dominant structure is the Main Boundary Thrust (MBT) that follows the hairpin bend almost continuously. After the earthquake, general geological opinion suspected fresh activity along the MBT. There is, however, no geological evidence of activity along this fault for over 2 million years. Later, as the trail of destruction was plotted, all the severe damage occurred along a NW-SE trending 140x70 km corridor, directionally different from the MBT. In a joint meeting of the Pakistan Geological Society and Pakistan Science Foundation, on October 18, 2005, it was revealed that the catastrophic failure had not occurred along the MBT but along a less known thrust fault called the Main Kashmir Thrust. The approximate surface trace of this fault, along with the approximate area of maximum devastation, is shown in red on Figure 2. A recurrent observation after looking at individual buildings was an obvious sudden shift at the foundation level in one direction leaving the roof lagging behind by virtue of inertia. The roof, with little support, either tilted in the opposite direction or collapsed entirely. (See Figure 3) Figure 3
(Photo taken during relief flight by Mustafa K. Siddiqui/author's brother, Chief of Operations, Helicopter Wing, The Agha Khan Foundation, Islamabad.)Aftershocks As expected, tremors continued to be felt for weeks, some as intense as 5.6 on the Richter Scale that I personally experienced in Islamabad. It was also revealed, in the above mentioned geological meeting, that the source of the aftershocks gradually moved NW reaching a depth of 35 km. This may indicate an extension of the Main Kashmir Thrust into the Paleozoic crystalline rocks to the northwest. Previously this fault appeared to be restricted in extent to the Miocene-Pleistocene continental sediments in the core of the syntaxial bend. Relief Effort As the horrific scale of devastation and human suffering unfolded to the Pakistani people, army and the leadership rose as one. Relief volunteers and supplies began arriving from all over Pakistan and international assistance poured in from all corners of the world. The Canadians distinguished themselves particularly by the caring they gave to the injured and the sick in the field. All the international assistance is well documented in electronic and print media. As the effort moves from relief to reconstruction, it is suffice to say here the three top priorities right now: Warm housing! Warm housing! And Warm Housing! Perhaps Figure 3 captures the scene on the ground well. A group of survivors watch a destroyed home while winter snows creep down from the hilltops in the background. What can the APGO members do? Well if you wish to assist, and do not know how, you may consider the innovative “Adopt a solar heated home” scheme being developed by the Pakistan Alternative Energy Development Board (AEDB). Although tents have been supplied in large numbers to affected families, most tents tend to collapse under the weight of the snowfall. Wish to know more? Please drop me an email at siddiquf@yahoo.com. Individual, group or corporate inquiries are equally welcome. |
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On October 8, 2005 at 9:00 a.m., I was upstairs in a house in Lahore, Punjab Province when suddenly the steel grills in the window tinkled like an alarm clock. When the tinkling lasted more than a couple of seconds, I realized it was an earthquake and instinctively rushed downstairs and out onto the road. The ground ebbed and swelled under their feet as neighbours stood terrified on the roadsides. We felt muffled thuds under our feet and a low but distinct growl was heard that passed over in a general north to south direction. These ten seconds of terror felt like eternity.
