The 25 April earthquake in Nepal has caused thousands of fatalities. Scientists hope it can lead to a better understanding of the region's seismicity and better earthquake resilience.
Emergency rescue workers clear debris in Kathmandu's Basantapur Durbar Square while searching for survivors on 25 April. Credit: Omar Havana/Getty Images By Randy Showstack 10 hours ago
Scientists hope that the devastating earthquake that shook Nepal on 25 April could lead to a better understanding of seismicity in the region and prompt more efforts toward earthquake resilience.
The earthquake, which the U.S. Geological Survey (USGS) estimates as magnitude 7.8, killed about 4000 people and destroyed many ancient and new structures. The number of fatalities could increase as rescue workers reach mountain villages, according to the Associated Press. The quake also poses continued hazards, including aftershocks, landslides, avalanches, and other risks, according to USGS.
The earthquake occurred 80 kilometers northwest of the Nepalese capital, Kathmandu. According to USGS, the preliminary location, size, and focal mechanism of the earthquake "are consistent with its occurrence on the main subduction thrust interface between the India and Eurasia plates." USGS also noted that 3–14 aftershocks with a magnitude of 5 or greater are expected in the coming week and that some aftershocks could be even larger.
Quake Is Consistent with Hazard in the Region
Cecily Wolfe, USGS associate program coordinator for earthquake hazards, told Eos, "This is one of the most active regions in the world. This type of earthquake is really consistent with what we know about the earthquake hazard in the region, and it is not unexpected."
Wolfe, who also is the coordinator for the Advanced National Seismic System USGS, said that more than one million people were exposed to the earthquake, according to the agency's Prompt Assessment of Global Earthquakes for Response (PAGER) system. She said that the U.S. Agency for International Development's Office of Foreign Disaster Assistance will be considering whether to activate an earthquake disaster assistance team from USGS.
USGS also organized a 26 April conference call to help coordinate efforts with scientists from some agencies and nongovernmental organizations in the United States—including USGS and NASA, among others—through its National Earthquakes Hazard Reduction Program post-earthquake investigation responsibility.
"Typically, it is not the earthquake that kills people. It's the response of the buildings and the infrastructure.""This is obviously a humanitarian crisis, but people [on the call were] focused on providing science and engineering studies to learn for the future," Wolfe said. "Scientists will look at the incredible characteristics of this earthquake and try to learn from it, which will help mitigate impacts in the future and also have analogies for other parts of the world."Wolfe added that engineers will look at the responses of human-made structures and why they performed the way that they did. "Typically, it is not the earthquake that kills people. It's the response of the buildings and the infrastructure," she said. "This is a region where you have a high population and a lot of relatively poorly constructed infrastructure."
Risk Was Well Publicized
Scientists cannot predict or forecast the time or dates of earthquakes beyond saying that where they have happened in the past, they will happen again in the future. However, "the understanding that Kathmandu was at considerable risk has been a well-publicized fact for many decades, certainly since the last very big one in 1934," according to James Jackson, head of the Department of Earth Sciences at the University of Cambridge. Jackson is the lead principal investigator on the Earthquakes Without Frontiers project, a consortium funded by the United Kingdom's Natural Environment Research Council and the Economic and Social Research Council. He was at an 11–13 April meeting in Kathmandu with other scientists and policy makers focusing on increasing the resilience to earthquakes in the Alpine–Himalayan–central Asian earthquake belt.
Jackson pointed to two organizations, one in Nepal and one in India's state of Bihar, that are working to raise awareness and sponsor practical involvement in reducing earthquake risk, such as retrofitting schools, promoting preparedness, training masons, and educating the community. These organizations—Nepal's National Society for Earthquake Technology (NSET) and the Bihar State Disaster Management Authority (BSDMA)—face many challenges, Jackson told Eos.
People clear rubble in Kathmandu's Durbar Square, a U.N. Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site severely damaged by the 25 April earthquake. Credit: Prakash Mathema/AFP/Getty Images "The difficulty faced by good leaders and organizations like NSET and BSDMA is in getting people to concentrate and invest in reducing earthquake risk, which seems remote, when they have everyday concerns common to Asian urban life that are much more real and pressing, like pollution, air and water quality, traffic, and simply poverty," Jackson said. "Those immediate priorities are understandable, but that doesn't mean the earthquake threat will go away, as this tragedy has demonstrated. This is not a problem limited to Nepal and Kathmandu but is common to most countries in the Alpine-Himalayan-Asian earthquake belt."
A Key Lesson: Be Prepared
Harsh Gupta, president of the Geological Society of India, told Eos that the 25 April earthquake was to be expected, with the Indian plate continuing to dive below the Eurasian plate at a velocity of about 5 centimeters per year. He noted that four earthquakes in the region exceeded 8 on the Richter scale between 1897 and 1950, but none of that magnitude had occurred since then. "Over the time, enough strains have accumulated to cause several M > 8 earthquakes. It is quite normal. The August 15, 1950, India-China border earthquake of M 8.7 had aftershocks that continued for 4 years. These included an M 8 earthquake on November 18, 1951, and 46 earthquakes of M ≥ 6," he told Eos in an email.
However, Gupta cautioned, "There is a plethora of rumors floating around about earthquakes of M ~ 8 to occur after 2 hours, next day, etc., etc. I have tried to explain that there is no scientific basis of such predictions. Social media is generating fear in the minds of people, which needs to be properly handled."
He added that the best way to protect against earthquakes "is to prepare the public and the civil administration." He stressed the importance of making all "lifeline" buildings—such as hospitals, fire and police stations, and schools—earthquake resistant. He also noted the importance of educating school children on a routine basis about the earthquakes and how to live with them.
A Scientific Opportunity to Better Understand the Hazard
Kip Hodges, founding director of the School of Earth and Space Exploration at Arizona State University, told Eos that he has not yet been able to contact any colleagues in Nepal.
Hodges said that in addition to the earthquake being a human tragedy, it also provides an important opportunity for advancing scientific knowledge. Hodges, who has focused much of his research on the Himalayan region, said that the earthquake could provide scientists with a much better understanding of the region's geology and seismic potential. "And I think it could tell us some pretty fundamental things about the overall structure of the range," he said.
The earthquake "is such an exciting thing, but I think about all my friends in Nepal, and this is not a very exciting time for them. I am worried about them, but at same time, it's a great opportunity to understand how the tectonics of this range is happening in real time today. You can't really deny that. So from a scientific point of view, it's great. But the personal tragedy, you just don't want forget that."
Hodges added that policy makers can learn from this event as well. "All of us in the Earth sciences should put ourselves in the camp that we are not good at predicting earthquakes. But what we are good at predicting is earthquake potential," he said. "The one thing I think needs to be done more critically by politicians is to pay attention to those predictions of where the earthquake hazards really are and take a longer view of society."
—Randy Showstack, Staff Writer
Citation: Showstack, R. (2015), Scientists hope to learn lessons from Nepal earthquake, Eos, 96, doi:10.1029/2015EO029013. Published on 27 April 2015.
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