An earthquake is a sudden shaking of the ground caused by the passage of seismic waves through Earth’s rocks, in simple words it is what happens when two blocks of the earth suddenly slip past one another. The fault or fault plane is the surface where the blocks slip. The hypocenter is known as the point of origin, it is where the earthquake ruptures or a nuclear explosion starts. The epicenter commonly known as the focus is the point on the earth’s surface directly above a hypocenter. Sometimes earth has foreshocks. The foreshock is a mild tremor that happens in the same place as the larger earthquake that follows. Until the larger earthquake happens, scientists cannot tell whether or not an earthquake is a foreshock.
The main shock is the largest, main earthquake. The mainshock always has aftershocks that follow. These are similar earthquakes that occur afterward in the same place as the mainshock. Aftershocks can continue for weeks, months, and even years after the mainshock, depending on the size of the mainshock. An elastic wave in the earth produced by an earthquake is called a seismic wave. The seismometer is a divide that scientists use to measure the seismic waves. A seismometer detects seismic waves below the instrument and records them as a series of zigs- zags. Through the information recorded by the seismometer, scientists can determine the time, location and intensity of an earthquake.
According the US news blog this record also provides information about the rocks the seismic waves traveled through. Tectonic movements in the earth’s crust cause earthquakes. When tectonic plates collide, one rides over the other, causing orogeny, earthquakes, and volcanoes which is one of the main causes. The largest fault surfaces on earth are formed due to the boundaries between the moving plates. The earthquakes are caused by the vibrations set up in the earth’s crust which spreads outwards in all directions from the source of the disturbance. Some earthquakes are artificial while, some are natural. But without any doubt, it is true that all the earthquakes are caused due to the disequilibrium in the earth’s crust.
Causes of earthquake fall into the following broad categories:
• Volcanic activities
• Folding and faulting
• Plate tectonics
• Human interference with nature
According to the Bureau of Indian Standards (BIS), our country falls into four seismic zones. The earthquake zones number 5 and 2 consists of several crucial cities, where zone 5 is seismically the most active region and zone 2 is the least. The entire Northeast of India falls in zone 5, with the highest risk, and the region has a turbulent history of 18 devastating earthquakes in the past century. In fact, Northeast India is one of the six most seismically active regions on the earth along with California, Japan, Turkey, and Taiwan.
According to the National Centre of Seismology, Guwahati city of Assam has the highest risk of an earthquake. Small tremors are a usual affair in the capital city which gets a fair amount of predictions monthly. Throughout the North-eastern region, the 2018 earthquake with a 5.5 magnitude spread tremors.
Assam faced its biggest nightmare on the day of June 12, 1897. It is considered one of the deadliest earthquakes to hit the country as it claimed about 1,542 casualties. An earthquake of around 8.0. magnitude occurred at 5:15 pm in the evening. The size of the earthquake hit was approximately equal to that of Europe and the property damage was very heavy. Tremors were felt across India, as far as Kolkata, Ahmedabad, Peshawar, and Myanmar. Numerous buildings in Bhutan were also heavily damaged. In Shillong, the earthquake damaged many houses. In Cherrapunji, it resulted in a landslide, which led to 600 deaths. In Goalpara, it resulted in waves from the Brahmaputra river. Earth waves and water waves were reportedly sighted in Nalbari.
In Guwahati, the earthquake lasted for 3 minutes. The earthquake resulted in the Shillong plateau being thrust violently upwards by about 11 meters. Another major earthquake hit Assam on August 15, 1950. This earthquake caused widespread devastation throughout the frontal regions of Northeast Himalaya. This earthquake came to be known as the Great Assam Earthquake. This earthquake was caused by the convergence of two continental plates of India and Eurasia and it was felt throughout Eastern India. The ground got cracked and fissured, bridges, rail lines were destroyed and river beds silted up. Immediately after the shock, several tributaries of the Brahmaputra river were blocked by landslips caused by the violent shaking of the earthquake causing drastic flooding afterward.
Recently in July 2019, a 5.6 magnitude earthquake hit Arunachal Pradesh, Assam, and other North-eastern states. As per reports, tremors were also felt in Guwahati, Dimapur in Nagaland and other parts of Assam. There are possibilities of a higher earthquake in the future as our region is dangerously prone to earthquakes, so being aware of the safety measures of an earthquake is very important.
Few crucial measures one should follow before and after an earthquake are given below-
Before earthquake:
• Quake! Protect yourself first.
• Check all fire sources. Put out the fire quickly.
• Keep calm.
• Make sure you have ways out of the danger zone.
• Keep away from gateposts and walls.
After an earthquake:
• Stay away from fire.
• Get the right information. Take the right action.
• Make sure your family and neighbors are safe.
• Work together on rescue and first aid.
Are our loved ones safe? This is the one question we often end up asking ourselves. We never know when a major natural disaster like an earthquake might hit us, and the thing that concerns us most is the safety of our family and friends.
So how can we be prepared in such situations?
Although the above-given precautions are a few of the basic crisis management steps everyone should be aware of, what most of us do not know is that earthquake does not hurt as much as steel and concrete do. To put it in simple words, when an epicenter arises below the ground surface of a building, the tremors first hit the foundation of the steel TMT bars. From there the cracks start extending, and slowly either the entire building collapses or gets major cracks. To avoid all of that, make a smart move and build a strong foundation of your house by installing the best steel TMT bars.
Install steel TMT bars from XTech, a leading steel industry with 8 years of experience in the Northeast. XTech is the only firm in India to have a tie-up with TATA sponge for technical up gradation. All of XTech’s products are ISI marked. According to BIS, the standard percentage of ductility for 500 FE TMT bars is 12% and the standard percentage for 500 D is 16%, but in XTech, you will get the best quality TMT bars. The steel TMT bars of XTech, offer ductility for 500 FE that ranges from 14-18% and 500 D offers elongation or ductility that ranges from 18-24%, which is way more than what any other company has to offer for the safety of your house.
Building a home with a strong and solid foundation by installing materials from the best of the best industry will ensure the safety of yourself, your family and your home. So go ahead and build a home that will guarantee everyone’s safety.
