Amidst a prediction of major seismic activity, lots of preparation and investment have been diverted for disaster preparedness
Earthquake: The last major seismic activity recorded in Bhutan was some 300 years ago.
Another major seismic event could occur with a magnitude of not less than eight on the Richter scale, experts say.
A major seismic activity is long overdue along the fault running parallel along southern Bhutan, officials from the Department of Geology and Mines confirmed.
But even top scientists across the globe cannot predict when such major seismic events will occur.
“Seismology is not a rocket science, it cannot be predicted,” the director general of geology and mines department Phuntsho Tobgay said.
Along the 2,500km Himalayan arc, the seismic behaviour of the Bhutan region is unknown. The country sits on a portion of the arc where no evidence of major earthquakes has been reported for the last three centuries.
But Bhutan cannot delay its preparedness, the director general said.
Chief of earthquake and geophysics division under the department, Dowchu Drukpa said the subduction of the Indian plate underneath the Eurasian plate is estimated at 20 millimeters (mm) annually.
When the plates are free flowing, he said there is no threat. “But the plate where Bhutan sits is locked against the Indian plate,” he said, meaning that stress has been accumulating for the last 300 years.
Should the plates rupture, a slip of 8 metres (m) is anticipated. Nepal experienced a slip of 2m when the 7.8 magnitude tremor hit the country in 2015. The fault dips under Bhutan at a shallow angle of around 20 to 30km deep, which means the depth of the quake could be shallow.
“With every point increase in magnitude the impact is 32 times more,” Dowchu Drukpa said.
Slip, in geology, is the relative displacement of formerly adjacent points on opposite sides of a fault.
If a major seismic activity takes place along the Bhutan region, Dowchu Drukpa said the western and central part of Bhutan could be affected the most.
What can be a solace for Bhutan is that there is a theory indicating that stress accumulated in the locked plates might have been accommodated by the fault that is segmented along the Kurichhu basin. “But we cannot be complacent,” he said.
The authority met yesterday to discuss disaster preparedness. The meeting will continue on Monday.
The authority, Lyonchoen said has discussed the need to assess all schools and hospitals in the country for earthquake vulnerabilities.
“Since the hospitals and schools would have patients and students we want to make sure they are as safe as possible,” Lyonchoen said.
The government has decided to evacuate schools that are extremely vulnerable, regardless of whether they look sound now, Lyonchoen added.
He said the disaster management department (DDM) has been strengthened and is now fully operational with its three divisions. Every dzongkhag has a disaster management committee and a focal point. Ten dzongkhags and four thromdes have search and rescue teams.
“There are a lot of preparations and we have been investing as much resources as we can,” he said. “But if we say we’re fully prepared then that would be foolish. If we say we are not prepared that would be irresponsible,” Lyonchoen said.
An assessment of Jigme Dorji Wangchuck National Referral Hospital was conducted in 2012 by a joint team from the World Health Organization, health ministry, DDM and GeoHazards International (GHI).
While the hospital will have an essential role following an earthquake, the evaluation team found that the hospital had a number of seismic vulnerabilities in its buildings, on-site utility infrastructure, medical equipment and emergency preparedness.
The central medical store is about one kilometre away from the hospital.
Another study revealed that Bhutanese traditional masonry and timber houses with modern concrete additions attached to it, pose great risk. In the event of a significant earthquake, these additions, which lack shear walls, could collapse.
An earthquake that causes heavy damage in Thimphu is also likely to damage the only international airport in Paro and cause landslides that will block the roads into the city.
Very large earthquakes will also cause significant damage in neighbouring states of India, which will hinder India’s response and further disrupt transportation links to Bhutan.
The recent 6.9 magnitude earthquake in Myanmar affected 146 structures across Bhutan, a preliminary report from the disaster management department revealed.
However, the Royal Insurance Corporation of Bhutan (RICBL) has received claims for 250 so far. Of these, 109 damages were reported in Mongar and two in Gasa.
The RICBL has rendered its insurance service to 68,832 rural households as of 2015. The company earned Nu 34 million (M) from the premiums and it has already paid Nu 37M in claims during the fiscal year 2015-16.
RICBL’s general manager of general insurance department, Sangay Wangdi said rural house insurance covers all forms of disaster.
Should all the rural houses insured with RICBL succumb to a disaster in one go, the company has to disburse a claim of Nu 8.35 billion (B).
“We have to look at our capacity to pay back and carry the risk of those which we can carry,” he said. If it is beyond the company’s capacity, he said the company has reinsurance.
For instance, the hydropower projects and aircrafts are reinsured with reputed international insurance companies like Lloyds London and Swiss Re group. RICBL has reinsurance with 13 international companies.
|Emergency Preparedness Kit
Food: non-perishable, easy-to-prepare items (3-day supply for evacuation, 2-week supply for home)
First aid kit
(Source: Red Cross)
“We are comfortable even if we have to pay out claims for all the structures insured in one go,” said the executive director, Sonam Dorji.
As for the commercial buildings, the general manager said fire is the basic coverage. If people want to cover their risk for other disasters like flood, landslide and earthquake, they have to pay little more on the premiums.
Since the 2009 and 2011 earthquake that affected Bhutan and recent tremors of Myanmar, Sangay Wangdi said more people are coming forward to insure for earthquake. Kuensel could not obtain the figures for commercial buildings.
The premium however will depend on the assessment. For example, concrete buildings will have to pay lesser premium for fire and than wooden structures and houses with mud walls will have to deposit more premium for earthquake. The company will charge higher premium for flood, if the house is located near a river.
Although Bhutan has experienced several earthquakes of moderate magnitudes between 5 to 6, the last major seismic activity in the country dates back to around 1713.
Dowchu Drukpa said some religious scripts revealed that during the time of the third Je Khenpo, Sacha Rinchen, Bhutan witnessed a massive earthquake. Although there was no record of magnitude, going by the description on the scripts, he said it could not have been less than seven on the Richter scale.
As a part of his research, his team has excavated two sites lying on the fault in Sarpang.
Bhutan is located between the great Himalayan ruptures of 1934 and 1950, where no similar great earthquakes have ever been documented.
Investigations in the east and west of Bhutan, suggest that this medieval event may have broken an 800km-long portion of the main Himalayan fault line, including Bhutan, with a magnitude approaching 9.
Carbon dating obtained from one of the sites in Sarpang indicated that the first event occurred after 1570.
Investigations on another site in Sarpang indicated that the penultimate event occurred after 1150.
These two findings suggested the two last surface-rupturing events along the Bhutanese frontal thrust were great earthquakes with magnitudes that may have been above 8.
Dowchu Drukpa said the recurrence interval between two major seismic activities could range between 300 to 1,000 years, making it difficult to even estimate when the next one is due.