http://www.telegraphindia.com/1110314/jsp/northeast/story_13709663.jsp
Experts map effects of 1950 quake
- Study shows massive loss
ROOPAK GOSWAMI
Burnt-out vehicles, which were parked for export, are piled in disarray at a port at Tokai village in Japan’s Ibaraki prefecture after the tsunami. (AFP)
Guwahati, March 13: When an earthquake-ready Japan was swept away, defenceless, by the powerful tremor last Friday, many in Guwahati and the rest of the quake-prone zone began wondering what the damages would be like if the 1950 Assam quake that killed 1,500 people hit the state in 2011.
Two scientists — Kishor Jaiswal and David Wald of the United States Geological Survey — have developed an earthquake scenario in the Northeast applying the parameters of the 1950 earthquake on the Prompt Assessment of Global Earthquakes for Response.
This assessment is an automated system developed by the geological survey that produces content concerning the impact of significant earthquakes around the world, informing emergency responders, government and aid agencies, about the scope of potential disasters.
A background paper on Recreating 1950 Earthquake Scenario in 2011 was presented at the National Conference on Earthquake Risk Mitigation Strategy in Guwahati on February 24-25.
The 1950 Assam recorded 8.7 magnitude on the Richter scale, compared to the 8.9 tremor that North Japan experienced last Friday.
If the 1950 quake struck Assam today, 19,000 people may experience violent shaking, 370,000 people may experience “severe shaking” which generally contributes to heavy damage, and approximately 14 million people may experience moderate to very strong shaking, the research states.
The model prepared the United States Geological Survey also categorises earthquake-related damages into three categories and indicates the response required.
If the indicator is “green”, then no response is required, for “yellow”, the response is required locally, “orange” requires national response while “red” requires international response.
This model indicates that in case of a 1950-like quake in 2011, it would be a “red alert”, with probability of high casualties.
It also gives “red alert” for economic losses. The damage and economic impact will be widespread and may require national or international response.
On the cities to be affected by the quake, the study said towns like Tinsukia, Sivasagar, Dibrugarh, Jorhat, Margherita, Golaghat and Naharkatia would bear the maximum brunt.
Other towns in the region, including, Pasighat, Kohima, Dimapur, Khonsa, Myitkyina will also be affected.
Besides killing 1,500 people, the 1950 quake had triggered a large number of landslides that affected many tributaries of Brahmaputra and changed the course of the river itself.
Large areas of the river valleys were flooded; tracts of fertile agricultural land became parts of river bed, while many areas irrigated by river water became dry.
The scientists from the geological survey have clarified that this is a hypothetical scenario described based on discussions with Indian counterparts and the location, depth, magnitude and other parameters inferred from the 1950 earthquake.
P.G. Dhar Chakrabarti, executive director, the National Institute of Disaster Management, said the 1950 earthquake had killed 1,500 people when the total population of the Northeast was about 10 million and the urban population hardly 2 lakh.
“Today, the population of the region has multiplied nearly five times to nearly 49 million and the urban population has swelled 45 times to nearly 9 million. Simple application of arithmetic would suggest a casualty figure that would not be very different from some of the worst earthquakes recorded in recent years elsewhere in the world,” he said.
He said the epicentre of the 1950 earthquake was located far away from the inhabited areas in a remote corner of the Arunachal-Tibet border.
If a similar earthquake occurs in a location nearer the capital cities, like the densely populated Guwahati, the casualties could be beyond anybody’s imagination.
It is necessary that reputed academic and research institutions, including the National Institute of Disaster Management, develops such worst-case scenarios based on available information to identify critical gaps in earthquake mitigation and preparedness in the region.
The road map developed by the National Institute of Disaster Management for earthquake risk management in the Northeast says that the scenarios developed for earthquakes with more than 8 on the Richter scale project massive loss of life and property and enormous damage to infrastructure and environment.
“While it would not be possible to prevent the occurrence of such mega earthquakes, it is possible to mitigate the impact of such earthquakes by retrofitting the built environment and reduce the loss of lives and property by better preparedness,” it said.
eom
Experts map effects of 1950 quake
- Study shows massive loss
ROOPAK GOSWAMI
Burnt-out vehicles, which were parked for export, are piled in disarray at a port at Tokai village in Japan’s Ibaraki prefecture after the tsunami. (AFP)
Guwahati, March 13: When an earthquake-ready Japan was swept away, defenceless, by the powerful tremor last Friday, many in Guwahati and the rest of the quake-prone zone began wondering what the damages would be like if the 1950 Assam quake that killed 1,500 people hit the state in 2011.
Two scientists — Kishor Jaiswal and David Wald of the United States Geological Survey — have developed an earthquake scenario in the Northeast applying the parameters of the 1950 earthquake on the Prompt Assessment of Global Earthquakes for Response.
This assessment is an automated system developed by the geological survey that produces content concerning the impact of significant earthquakes around the world, informing emergency responders, government and aid agencies, about the scope of potential disasters.
A background paper on Recreating 1950 Earthquake Scenario in 2011 was presented at the National Conference on Earthquake Risk Mitigation Strategy in Guwahati on February 24-25.
The 1950 Assam recorded 8.7 magnitude on the Richter scale, compared to the 8.9 tremor that North Japan experienced last Friday.
If the 1950 quake struck Assam today, 19,000 people may experience violent shaking, 370,000 people may experience “severe shaking” which generally contributes to heavy damage, and approximately 14 million people may experience moderate to very strong shaking, the research states.
The model prepared the United States Geological Survey also categorises earthquake-related damages into three categories and indicates the response required.
If the indicator is “green”, then no response is required, for “yellow”, the response is required locally, “orange” requires national response while “red” requires international response.
This model indicates that in case of a 1950-like quake in 2011, it would be a “red alert”, with probability of high casualties.
It also gives “red alert” for economic losses. The damage and economic impact will be widespread and may require national or international response.
On the cities to be affected by the quake, the study said towns like Tinsukia, Sivasagar, Dibrugarh, Jorhat, Margherita, Golaghat and Naharkatia would bear the maximum brunt.
Other towns in the region, including, Pasighat, Kohima, Dimapur, Khonsa, Myitkyina will also be affected.
Besides killing 1,500 people, the 1950 quake had triggered a large number of landslides that affected many tributaries of Brahmaputra and changed the course of the river itself.
Large areas of the river valleys were flooded; tracts of fertile agricultural land became parts of river bed, while many areas irrigated by river water became dry.
The scientists from the geological survey have clarified that this is a hypothetical scenario described based on discussions with Indian counterparts and the location, depth, magnitude and other parameters inferred from the 1950 earthquake.
P.G. Dhar Chakrabarti, executive director, the National Institute of Disaster Management, said the 1950 earthquake had killed 1,500 people when the total population of the Northeast was about 10 million and the urban population hardly 2 lakh.
“Today, the population of the region has multiplied nearly five times to nearly 49 million and the urban population has swelled 45 times to nearly 9 million. Simple application of arithmetic would suggest a casualty figure that would not be very different from some of the worst earthquakes recorded in recent years elsewhere in the world,” he said.
He said the epicentre of the 1950 earthquake was located far away from the inhabited areas in a remote corner of the Arunachal-Tibet border.
If a similar earthquake occurs in a location nearer the capital cities, like the densely populated Guwahati, the casualties could be beyond anybody’s imagination.
It is necessary that reputed academic and research institutions, including the National Institute of Disaster Management, develops such worst-case scenarios based on available information to identify critical gaps in earthquake mitigation and preparedness in the region.
The road map developed by the National Institute of Disaster Management for earthquake risk management in the Northeast says that the scenarios developed for earthquakes with more than 8 on the Richter scale project massive loss of life and property and enormous damage to infrastructure and environment.
“While it would not be possible to prevent the occurrence of such mega earthquakes, it is possible to mitigate the impact of such earthquakes by retrofitting the built environment and reduce the loss of lives and property by better preparedness,” it said.
eom
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