Earthquakes in Nepal: a domino effect – BBC Russian

• 27 April 2015

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Background of this earthquake, scientists say, there were ’81 ago

devastating earthquake on Saturday in Nepal, was ordained in ’81 ago, when no less powerful tremors destroyed a quarter of the country’s capital Kathmandu and killed more than 17,000 people.

According to scientists, these two cataclysm linked and stacked in the same scheme of double earthquakes that have occurred here over 700 years ago.

This “domino effect” in both cases was caused by the fact that the first earthquake led to the spread of voltage in the earth’s crust along the passing of the area geological fault.

Researchers have found probable existence of this dual effect a few weeks ago, during field work in the region.

Moreover, according to scientists, Saturday’s earthquake in the area between Kathmandu and Pokhara has far-reaching consequences.

According to the latest data, as a result of this natural disaster has killed more than three and a half thousand people in Bangladesh, India, China, as well as on Mount Everest, where the tremors triggered avalanches.

The official death toll is likely to grow in the coming days, and the risk of landslides on unstable slopes indicates that the danger is far from being passed.

But apart from this danger remains threat of a new earthquake in the near future, geologists warn.

Research fault

The fact that the earthquake in the area fit into a pattern, said group of geologists under the leadership of Laurent Bolenzhe Commissariat of nuclear power in France.

Scientists warn that in the coming decades Nepalese waiting for a new earthquake

Working in Nepal in March, scientists have discovered this pattern and predict earthquakes is in the area where it happened.

The team dug trenches Bolenzhe along the main geological fault in Nepal (which stretches over a distance of 1000 km from west to east of the country) in the place where it enters the earth’s surface.

The researchers took samples found in the fracture of coal and radiocarbon analysis identified when the fault last moved.

In ancient texts, you can find descriptions of several major earthquakes in the region, but certainly they are very difficult to localize.

The seasonal rains washed away the relief of rolling hills, lush jungle cover large areas, and all this very quickly disguises faults in the earth’s crust caused by earthquakes.

However, the group Bolenzhe could prove that this fault did not move for a long time.

“We have shown that this fault was not responsible for the major earthquakes in 1505 and the second in 1833′s. The last time he moved, most likely in 1344, “- says the French geologist.

The results of the study he presented two weeks ago on the site of the Geological Society of Nepal.

Prior to that, he the team worked on another fault, which runs to the east of Kathmandu, and showed that this segment experienced a powerful earthquake in 1255-m and 1934.

Death pattern of earthquakes around Kathmandu

• Saturday’s earthquake of magnitude 7.8 occurred in the north-west of Kathmandu.
• The last time the tremors on the fault occurred in 1344.
• Prior to this, in 1255 there was an earthquake east of Kathmandu.
• The last earthquake happened in 1934, after which the voltage in the fault could accumulate in the west.
• Earthquake 2015 year fits into this pattern, it happened in ’81 later.

When Bolenzhe and his colleagues discovered this historical pattern is greatly alarmed them.

“We have seen that Kathmandu and Pokhara can be subject to an earthquake on the main fault, between the two cities, where it is likely to happen in 1344 “- says working in this team Paul Tappone Earth Observatory of Singapore.

When a major earthquake, underground tremors are often passed on deformation along the fault, which seems to be what happened in 1255.

Over the next 89 years of accumulated deformation in the adjacent, western segment of the fault, which finally in 1344 there was a break .

Now, history repeated itself. The earthquake in 1934 led to the deformation and stress along the fault to the west, and later broke out in ’81.

Scientists worried that in this region, as they believe we can expect new earthquakes.

“Early estimates indicate that 7.8 magnitude earthquake Saturday was probably not strong enough to break the Earth’s crust to the surface. Therefore, it is likely that it has survived the voltage, so in the coming decades we can expect another large earthquake to the west and south of the present “, – says Bolenzhe.