This past weekend Nepal experienced a massive earthquake centered about 50 miles from Nepal’s capital Katmandu. The Nepal earthquake was rated as 7.8 on the Richter scale, which was created in 1935 by Charles Richter at the California Institute of Technology. Each whole number increase means a 10 times increase in the seismograph that is measuring the ground’s movement. Each time the rating goes up by a whole number, such as from 6.0 to 7.0 thirty-one times more energy is released. The 7.8 magnitude earthquake destroyed many historic temples in Kathmandu and killed thousands of people.
The world has had numerous large earthquakes. During the spring of 2011 Japan was hit with a 9.0 earthquake centered in the ocean off its north-eastern coast. This one killed relatively few people even though a huge Tsunami happened after the quake. In 1906 the city of San Francisco was wiped out by an earthquake. Because the San Francisco quake happened before Richter invented his scale, the exact magnitude is uncertain. The best guess was that the San Francisco quake was either 7.9 or 8.0 on the Richter scale and most of the city was destroyed.
The key point about earthquakes is that the economically richer the country, the smaller the amount of death and destruction for a given magnitude of earthquake. For example, Haiti had a 7.0 quake in Jan. 2010 near its capital that killed over 300,000 and left 1 million homeless. Chile one month later had an 8.8 quake near its capital in Feb. 2010 that killed over 1,000. Chile’s earthquake was much larger in terms of energy released but the death toll was dramatically lower.
Why does the difference exist? The key reason is that the richer the country the tougher the building codes. It is not only having strong building codes. Richer countries also have less corruption between builders and building inspectors. Having tough rules without appropriate enforcement is meaningless.
Understanding this key reason is important. The world needs to prepare for another massive disaster that will happen sooner or later in Turkey. Istanbul, the capital of Turkey, sits where two continental plates meet and it is geologically unstable. Since WWII the population in Istanbul has increased from 1 million to 10. More importantly, as the NY Times points out, building standards are extremely lax and buildings have been constructed extremely haphazardly.
The core and ancient monuments of Istanbul are at much lower risk, because they were built centuries ago to withstand earthquakes. Major hotels and office towers have reputedly been constructed to the highest standards and supposedly will survive a major quake. The damage from a major earthquake in the rest of Istanbul, however, will likely be massive.
What can Turkey and other countries at risk do to avoid another disaster? Government officials should dedicate part of each real increase in GDP to reconstructing the most dangerous public buildings and roads and educate the public on the dangers of shoddy construction. As a country grows economically these dedicated funds improve the likelihood that more of the population will survive a deadly quake. We cannot stop quakes but we can increase the likelihood that the human and economic toll is small.
What a wonderfully written article. Really worth reading.
Kartikeya Sharma
aajsamaaj.com/kartikeya-sharma
The full scope of the disaster is not yet known, but we all know that its cost goes well beyond the damage to property and has immense economic and social impact.
The earthquake that happened in Haiti in 2010 was large. The economy of Haiti was in the list of poorest nations based on the UN. The government in poor countries should give more attention to people in a earthquake risk zone because their live would be threatened. Government in the rich countries know to prepare the earthquake mitigation such as Chile. The mitigation towards earthquakes has not been established in poor nations look at why do more earthquakes happen
One of the methods of contrast with earthquakes is seismic retrofitting of buildings.
Therefore, old and unsafe buildings should be strengthened by methods such as strengthening with FRP in accordance with ACI 4402R or retrofitted by classical methods such as FEMA 360.
Systems based on FRP composite materials are one of solutions to make structures more resistant to seismic seismic activity, ground motion, or soil failure due to earthquakes.
Over the past decades, fiber reinforced polymers (FRP) productshave been widely used for retrofitting and strengthening existing structures such as building, bridges, etc.
David you are right….
Systems based on FRP composite materials are a proper solution for earthquake damage mitigation. I think the advantages such as: corrosion resistance, low weight-to-strength ratio, flexibility, etc. are the prime reasons have led to increasing applications of, FRP composite systems in structural retrofitting.