Rabinder Shekher
At about 06.20 GMT on 28.03.2025, there was news of devastating earthquake in Myanmar and Bangkok. The earth has jolted with seismic scale of 7.2 and as usual aftershocks of 6.6 and has experienced three aftershocks. Many buildings and under construction structures collapsed. Reports of more than 2000 unfortunate human deaths and 3900 injuries have been also pouring in.No one knows when the earthquake will occur, however earthquakes of low to very low intensities continue to jolt the earth and we only feel the earth shaking when either the time of shake is long or the tremor is above 4.0. Engineers and scientists all over the world continue to work on codes of practice on which the design of structures may be followed to resist the tremors of high intensity. Japan is very advance in this filed and has developed advanced methods of seismic complaint structures.
The big question is, will ever earthquake of 10 happen? The answer is in negative, yes, this is fact that no earthquakes of magnitude 10 or larger can happen. The magnitude of an earthquake is related to the length of the fault on which it occurs. That is, the longer the fault, the larger the earthquake. A fault is a break in the rocks that make up the Earth’s crust, along which rocks on either side have moved past each other. No fault long enough to generate a magnitude 10 earthquake is known to exist, and if it did, it would extend around most of the planet.The largest earthquake ever recorded was a magnitude 9.5 on May 22, 1960 in Chile on a fault that is almost 1,000 miles long…a “megaquake” in its own right . Recent earthquake of Manymar is example, the epicentre of the earthquake was 16 Km northwest of Town Sagaing, near Myanmar’s city Mandalay. The energy flow was along the fault line and damaged the structures far off from the epicentre. So, the fault lines are very vulnerable to eruption of seismic activities.
Earthquakes cannot be controlled and there is major two reasons for earthquakes. One is also due to faultlines. A faultline is a long crack in the surface of the earth. Earthquakes usually occur along faultlines.A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake – or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers.Fault surfaces are often nearly planar, and that planar surface is referred to as a “fault plane.” There are four types of faulting — normal, reverse, strike-slip, and oblique.
Integration of geological/geomorphic and seismological data has led to the identification of 67 active faults of regional scale, 15 in the Himalaya, 17 in the adjoining foredeep with as many as 30 neotectonic faults in the stable Peninsular India.The Western and Central Himalayan region, the north-eastern part of India, the Rann of Katch, the Indo-Gangetic Plains, Kashmir and Rajasthan are considered as the dangerous zones for earthquakes in India.Nearly 60 lakh people in Jammu and Kashmir out of total 125 lakhs live in high-risk seismic Zone-V which could have devastating results in case of a high intensity earthquake hits the state as predicted by American geologists few years back.
Though a detailed Disaster Management Report was prepared in erstwhile J&K state but not much has been done to create a mechanism to deal with man made or natural disasters nor is there any check on illegal construction in cities and towns of the state. Unabated, ill designed or under specification mushrooming infrastructures is coming up in almost all cities and villages of J&K UT and a of major worry for the experts of two capital cities-Jammu and Srinagar, which has a major concentration of population and rapid unplanned construction of commercial buildings and houses, which could spell doom. No design ethics or design parameters are being followed in most of the structures and owners are leaving the design at the hands of masons who have no knowledge of codes or design.
The Rawat Fault is a geological fault in Pakistan. It runs through Punjab, from Rawat, Islamabad to Kashmir.Although the entire mountain belt from Hindukush and greater Himalayas to Uttarakhand have become seismically active in recent years, scientists continue to remain worried about the Reasi fault line which is piling up enormous amounts of energy generated by plate movement but has not released it for decades as there has been no major earthquakes since decade.
Region also falls in Zone IV and Zone V and in revised code IS1983-2025, Zone VI(Highest risk zone). 2005 earthquake 7.6 magnitude was the biggest in recent memory, had epicentre in Pakistan occupied Kashmir (POK).
Studies by geologists from Jammu University have revealed that rock structures in the Reasi fault line are able to absorb energy generated by seismic activity for centuries. But how long they are able to withstand pressure, we don’t have an answer. It is not releasing much energy and remains in geological terms inactive.
“Earthquake prediction is very difficult science. Beds of sedimentary rock formation south of Reasi towards Jammu are acting like sponges. Energy needs an escape in a big way to ease pressure. We have no option but to wait”, said a geologist in JU.
Scientists have known about the Riasi fault in Indian Kashmir, but it wasn’t thought to be as much as a threat as other, more active fault systems. However, following a magnitude 7.6 earthquake in 2005 on the nearby Balakot-Bagh fault in the Pakistan side of Kashmir – which was not considered particularly dangerous because it wasn’t on the plate boundary – researchers began scrutinizing other fault systems in the region.What they found is that the Reasi fault has been building up pressure for some time, suggesting that when it does release or “slip,” the resulting earthquake may be large – as much as magnitude 8.0 or greater.
“The fault hasn’t slipped for a long time, which means the potential for a large earthquake is strong. It’s not a question of if it’s going to happen. It’s a matter of when. There is direct evidence of some seismic activity on the fault, where the researchers could see displacement of the Earth where an earthquake lifted one section of the fault five or more meters – possibly about 4,000 years ago. Written records from local monasteries refer to strong ground-shaking over the past several thousand years.But the researchers don’t have much evidence as to how frequent major earthquakes occur on the fault, or when it may happen again.
“The Reasi fault isn’t prominent on hazard maps for earthquake activity, but those maps are usually based more on the history of seismic activity rather than the potential for future events,” said Andrew Meigs, a geology professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and co-author on the study. “In actuality, the lack of major earthquakes heightens the likelihood that seismic risk is high.”
Gavillot said a major earthquake at the Reasi fault could have a major impact on Jammu, the Indian capital of the Indian state of Jammu and Kashmir, 700,000 people live in towns located right on or near the fault line.
“There are also several dams on the Chenab River near the fault, and a major railroad that goes through or over dozens of tunnels, overpasses and bridges,” Gavillot said. “The potential for destruction is much greater than the 2005 earthquake.”That’s is the reason that Railways have designed Chenab Railway Bridge complaint to seismic Richter scale of more than 8.
The 2005 Kashmir earthquake killed about 80,000 people in Pakistan and India.New geologic mapping in the Himalayan mountains of Kashmir suggests that the region is ripe for a major earthquake that could endanger the lives of as many as a million people, according to an Oregon State University statement.
It is high time for the town planning organisation, Municipalities and town area committees to ensure that no structure is granted permission until the architectural plans are supported with structural designs and drawings duly stamped by certified structural engineer who shall be having B.Tech degree if not M.Tech in civil/structural engineering. It shall also be made mandatory that during construction and after completion of structure, structural safety certificate of building be made available to the building permission authorities and the certificate should also be issued by the certified structural engineers. Remember earthquakes do not kill human beings but it more the structures and infrastructure which are ill designed and constructed with poor specifications which do not tolerate the earth jolts and fall killing precious lives.
(The author is Superintending Engineer (Retired) Structural Wing DIQC PWD J&K)
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