NEPAL MAY FACE MORE EARTHQUAKES IN FUTURE

 Written on 3rd May, 2015

NEPAL MAY FACE MORE EARTHQUAKES IN FUTURE

 

                                                                                           Nikunja Bihari Sahu

              Geophysicists and other experts had warned for decades that Nepal was riding on a volcano and vulnerable to a deadly earthquake, particularly because of its geology, urbanization, and architecture. Nepal faces larger and more deadly earthquakes, even higher than the recent temblor that shook the country on April 25, 2015.

           Earthquake experts say that the quake did not release all of the pent-up seismic pressure in the region near Kathmandu. According to GPS monitoring and geological studies, some 33 to 50 feet of motion of the Tectonic Plate (Giant rock slabs that make up the Earth's upper layer) may need to be released   triggering a more catastrophic earthquake in the days to come.

MOST POWERFUL TREMOR

        The recent quake was the most powerful disaster to strike Nepal since the Nepal-Bihar Earthquake  of 1934 that killed nearly 10,000 people. The earthquake occurred at a depth of approximately  15 km below the Earth’s surface (which is considered to be too shallow and therefore more damaging than the  quakes that originate deeper inside the ground) with its Epicentre approximately 34 km east-southeast of Lamjung in  Nepal. Lasting for about 20 seconds, the earthquake was measured to be of Magnitude 7.8 in the Richter scale.

DEVASTATION

       The devastation caused by the Earthquake was immense and unprecedented. The quake killed more than 6000 people in Nepal mostly due to people being trapped inside the collapsing houses and some casualties have also been reported in the adjoining countries  of India, China and Bangladesh.

         It triggered an avalanche on Mt Everest  killing at least 19 people and in  Langtang valley where 250 people were reportedly missing. Many heritage  monuments were damaged  at the  World Heritage Sites of UNESCO in the Kathmandu valley including the Durbar Squares of  Kathmandu, Patan  and Bhaktapur . Nepal Government has declared three days of mourning after the quake. The country was battered by continued aftershocks with one shock reaching a Magnitude as high as 6.7 in the Richter scale. The catastrophe has indeed left everybody scared and scarred!

 THE CAUSE

             The terrible earthquake was the latest result of an ongoing collision between the two giant tectonic plates of our planet. According to the US Geological Survey, the temblor was caused by a sudden Thrust, or release of built-up Stress, along the major Fault line where the Indian Plate  carrying India is slowly diving underneath the Eurasian Plate carrying much of Europe and Asia. 

            Between 55 million and 40 million years ago, the Northern edge of what is now called India began to slam into the giant slab of Earth's crust that today carries Nepal and Tibet.  India bulled its way under Nepal those many millions of years ago, shoving the northern land skyward. That move began to create the towering Himalayan folding mountains. The collision is still going on as India moves several centimeters north every year. This has created an unstable fissure in the planet's crust known as the Himalayan Frontal Thrust Fault. This boundary zone is highly unstable from geological point of view and continues to release enormous energy that might have created the recent devastating earthquake.

  RECONSTRUCTION MEASURES

       This is a very catastrophic event for a very poor mountainous nation like Nepal. The cost of the reconstruction over the next few years will be massive. Rebuilding costs could easily exceed an estimated 5 billion US Dollar which would be about 20% of Nepal's Gross Domestic Product. Massive international disaster relief and rescue efforts will be needed urgently as well as large scale global financial and technical support for long-term reconstruction of the country’s economy.

 PREVENTIVE MEASURES

      On average, one 8 Magnitude quake strikes somewhere every year around the globe and some 10,000 people die in earthquake events  annually. Collapsing buildings claim by far the majority of lives; but the destruction is often compounded by  other disasters mud slides, fires, floods, or tsunamis. Smaller temblor after-shocks that usually occur in the days following a large earthquake can complicate rescue efforts and cause further death and destruction. Loss of life can be avoided through emergency planning, sensitization measures and by adopting  earthquake prone construction design of buildings that sway like a single structure  rather than caving in  under the stress of the tremor.

             Unfortunately, like other natural calamities like floods and cyclones, occurrence of earthquakes cannot be predicted and, hence, early warning cannot be issued. The only clue to foretell the catastrophe is to observe the anomalies in the animals behavior which the Chinese has greatly improved over the years. Certain animals like elephants are said to be capable of hearing the low pitched rumbling sound of the lithosphere plates motion  and migrate to safer places to avoid the imminent danger. But this method of relying on the animals behavior is not very accurate. Under this limitation of the present day technology in forecasting the earthquake, the only option remains at hand is the greater human preparedness and the efficient relief and rescue operation to mitigate the challenge by minimizing the loss of life and property.

                                                                                                       Education Officer

                                                                                                  Regional Science Centre

                                                                                                            Bhopal