Posts Tagged ‘Nepal earthquake’

Help is often restricted by the ability to receive – be it Nepal or Baltimore

April 28, 2015

The news today about the riots and looting currently ongoing in Baltimore got me to wonder why in 2015 such behaviour is still possible in the US? Even with a black (or more accurately, half-black) President and a black Attorney General (Holder followed by Lynch). One hundred and fifty years after the Civil War, and after over 5 decades of “affirmative action”, why are “African Americans” still at the bottom of all social and economic league tables in the US? Why are they – as a group – being overtaken even by the “new immigrants” from Asia?

Could it be that the efforts to lift the African American community have been misguided, or that the particular measures on offer have not been capable of being received?

Take the situation in Nepal.

There is much international help on offer but much is not getting through because of the limitations on the ability (infrastructure and personnel) to receive it. The current death toll of over 4,000 may turn out eventually to be closer to 10,000 .

Planes arriving in Kathmandu have been slow in being unloaded and then the relief supplies have been stuck on the ground because many of the airport workers have left for their own damaged homes and injured relatives. The airport was never designed to handle this level of traffic. The aftershocks are continuing and everything comes to a halt when one occurs.

Relief and medical teams from India and China remained undeployed for many hours because there was nobody available to direct them where to go. And when the “authority” of who would decide was settled, they had no information as to where the teams could be best deployed. Infrastructure was poor in any case but is now damaged. Highways into the remote areas are blocked. Power and water distribution has been hit hard. Foreign teams arriving in Kathmandu have not had the local support necessary readily available. In fact, just finding the necessary support for the foreign teams (guides, interpreters, vehicles, maps, intelligence) itself has overloaded the few organised resources available. The Nepalese Army is overwhelmed. Many Gurkha villages have been hard hit and the primary concern of some of these Gurkha soldiers is to get to their villages and their relatives.

Even in Kathmandu itself – let alone relief and rescue in remote areas – heavy lifting equipment is limited. Even when available they cannot reach “at least 19” areas of the city because of the narrow lanes which have to be negotiated or because of rubble blocking their access.

It is often underestimated or forgotten that the provision of anything (help or education or technology) – once the will to provide is established – is still restricted by the ability to receive.

I am reminded of the struggles we had with “technology transfer” where the will and readiness to transfer technology was often restricted by the ability to receive and absorb technology. I recall that our efforts to open new factories in rural areas were severely limited by the ability of local villagers to absorb the change from working in a field to working in a factory.

The ability to receive trumps the will to give.

 

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Great Himalayan earthquake is still waiting to happen

April 27, 2015

This earthquake in Nepal – devastating as it was – has not released enough of the pent-up strain under the Himalayas. The death toll now exceeds 3,500 and most are due to collapsing buildings.

It would need about 50 such quakes with magnitude 7.9  or one super quake of magnitude 9 to release all the slip built up over centuries. The Indian tectonic plate is being subducted under the Eurasian tectonic plate with the Indian Plate moving North East at about 6 -7 cm per year while the Eurasian Plate is moving Northwards at about 2 cm per year. There is a net 2 – 3 cm of slip to be accumulated – or to be relieved by some form of energy release – every year.

The Great Himalayan Earthquake has still to come. The scale of loss of life and devastation will be magnified greatly if the Great quake is located in the central Himalayas such that the tremors extend into the densely populated Gangetic Plain. The central Himalayas have not seen any large quakes for about 700 years and the pent-up energy is ominous. It is highly unlikely that either in Nepal or in the vulnerable regions of India, that buildings will be sufficiently “earthquake-proofed” to minimise the loss of life (and over 90% of the loss of life is due to the collapse of buildings).

Down to Earth: … It has been hypothesised for long that a large earthquake, called the “great Himalayan earthquake”, can strike anytime, but its time and place cannot be predicted. In many locations in the Himalayan belt there is enough energy stored currently to lead to one.

At a magnitude of 7.9 on the Richter scale, the April 25 earthquake has caused devastation but it is not the anticipated “great Himalayan earthquake”.  This does not qualify as a great earthquake which needs to be of magnitude 8, says Roger Bilham, geologist with the University of Colorado Boulder who studies the seismicity of the Himalayan area. “The earthquake is in a region that is being compressed by18 mm each year,” he says. The amount today’s earthquake slip would have been exactly right to release all this accumulated stress, he adds. His team has identified some areas where the great Himalayan earthquake is anticipated (see image). The question mark shows the area where an earthquake is potentially possible but the magnitude is not known.

himakayan

Anticipated Himalayan Earthquakes

 “This (Nepal earthquake) has unfortunately not come as a surprise. We expected an earthquake of high magnitude in the region between Kathmandu and Pokhara,” says Paul Tapponnier from Nanyang Technological University’s Earth Observatory of Singapore who also studies earthquakes in the area. Tapponnier’s earlier work showed that the quakes in 1255 and 1934 were ground-breaking quakes or when ruptures develop in the earth’s crust and the pent up energy in the earth is released. As the areas west or east of the 1934 Nepal ground rupture do not have records of earthquakes, they are at a greater risk of a major earthquake.

In a paper published just two months ago scientists from the Jawaharlal Nehru Centre for Advanced Scientific Research conclude that “the frontal thrust in central Himalaya may have remained seismically inactive during the last ~700 years. Considering this long elapsed time, a great earthquake may be due in the region”.

The Himalaya has experienced three great earthquakes during the last century—1934 Nepal-Bihar, 1950 Upper Assam, and arguably the 1905 Kangra. Focus here is on the central Himalayan segment between the 1905 and the 1934 ruptures, where previous studies have identified a great earthquake between thirteenth and sixteenth centuries. Historical data suggest damaging earthquakes in A.D. 1255, 1344, 1505, 1803, and 1833, although their sources and magnitudes remain debated. ….. Age data suggest that the last great earthquake in the central Himalaya most likely occurred between A.D. 1259 and 1433. While evidence for this rupture is unmistakable, the stratigraphic clues imply an earlier event, which can most tentatively be placed between A.D. 1050 and 1250. …. Rupture(s) identified in the trench closely correlate with two damaging earthquakes of 1255 and 1344 reported from Nepal. The present study suggests that the frontal thrust in central Himalaya may have remained seismically inactive during the last ~700 years. Considering this long elapsed time, a great earthquake may be due in the region.

Other scientists also estimate that this current quake has dissipated only a very small part of the energy stored under the Himalayas and waiting to be released:

Indian Express:

“We know there is a huge amount of accumulated strain in this area. It is due for a major earthquake, perhaps a series of earthquakes, bigger than 8 on the Richter scale. That is the kind of energy that is estimated to be accumulated there. This was certainly not one of those earthquakes that is probably imminent. In terms of energy release, I would say this would not have released even four or five per cent of the energy that is estimated to be stored there,” said Harsh K Gupta, former director of the Hyderabad-based National Geophysical Research Institute and a former member of the National Disaster Management Authority.

Prof Sankar Kumar Nath of IIT Kharagpur, who has studied seismic activity in the Himalayan region, said the energy released from Saturday’s earthquake “was equivalent to the explosion of about 100mn tonnes of TNT, comparable to the energy in detonation of small nuclear bombs”.

“This earthquake would only be classified as medium in terms of energy released. That area, the 2500-km stretch from the Hindukush region to the end of Arunachal Pradesh, is capable of generating much bigger earthquakes, even nine on Richter scale,” he said.

“If you look at it differently, we are actually lucky that only a 7.9-magnitude earthquake has come. I would be very happy to have a few 7.9-magnitude earthquakes than a 9-magnitude earthquake which would be absolute disaster. The trouble is that in terms of energy release, which is what causes the damage, it would take 40 to 50 earthquakes of magnitude 7.9 to avoid an earthquake of magnitude 9,” he said.

Death toll in Nepal still rising as aftershocks put rescue efforts on hold

April 26, 2015

A strong 6.7 magnitude aftershock hit Nepal this morning, 25 hours after the primary quake, as the death toll continues to climb. At least 30 shocks of magnitude greater than 4.0 have been felt. Kathmandu airport which was open has been closed till 4pm local time because of the aftershocks. Rescue efforts have been put on hold while the aftershocks continue. Air Traffic Control staff have been evacuated from the airport for now.

Indian Air Force Mi-17 helicopters reached Mount Everest and began ferrying injured back to Kathmandu with the first relief flights reaching this morning. So far the IAF has deployed 5 helicopters and another 6 are on their way. It is feared that 65 mountaineers on Mt. Everest may have been killed at the base camp and in the avalanche yesterday. The aftershocks have caused at least 3 further avalanches on Everest today.

Tremors from the aftershocks have been felt in Delhi, UP, Bihar, W.Bengal, and Assam. The final toll may exceed 2,000 as rescuers reach more remote regions.

USGS:

  1. Aftershock: 6.7 magnitude, 17km S of Kodari, Nepal2015-04-26,  07:09:08 UTC, 10.0 km deep
  2. Secondary quake: 6.6 magnitude, 49km E of Lamjung, Nepal2015-04-25, 06:45:21 UTC, 14.6 km deep
  3. Primary quake: 7.8 magnitude, 34km ESE of Lamjung, Nepal, 2015-04-25, 06:11:26 UTC, 15.0 km deep

Both India and China see Nepal as being within their natural “sphere of influence” and a hint of that competition is visible as the two countries now lead the international rescue efforts. In addition to a Chinese medical team that was already in Nepal, three further medical teams from neighboring Sichuan, Chongqing and Yunnan have gone to Tibet.

Xinhua:A 62-strong China International Search & Rescue Team left for Nepal early Sunday. With six sniffer dogs and relevant rescue and medical equipment, the team is expected to arrive in Kathmandu midday Sunday on a chartered plane, according to the China Earthquake Administration.

India sent two relief planes of air force to disaster-struck zones hours after the quake took place. Indian Prime Minister Narendra Modi called up his Nepalese counterpart Sushil Koirala, and assured him of all help. Two military aircraft, a C-130 Hercules and a C17 Globemaster, took off from the Hindon air base in Delhi to Kathmandu with relief workers, medicines and blankets, said Press Trust of India.

Disaster teams from the UK, US and Israel are already on their way as well and many other countries have offered assistance.

Nepal earthquake toll near 1500 with casualties also in India and Tibet

April 25, 2015

The Indian Tectonic Plate is being subducted under the Eurasian Plate. The collision is still going on with the Indian Plate moving North East at about 6 -7 cm per year while the Eurasian Plate is moving Northwards at about 2 cm per year. The subduction occurs in fits and starts and relies on earthquakes to release the slip pressure. The likelihood of a single Himalayan earthquake of magnitude 8 or a series of magnitude 7 quakes was discussed a few years ago

If a great earthquake has not occurred on a specific segment in the Himalaya for 200 years, that segment will slip 4m because the convergence rate between India and Tibet is roughly 2cm each year. If it has not occurred for 500 years the segment would slip 10m, enough for an event that would measure 8, or Magnitude Eight on the Richter Scale. The time interval between great earthquakes thus determines the amount of slip that will occur in the next one.

…. A large segment of the Himalaya between Kathmandu and Dehradun has a record of several earthquakes but only two large ones: an event in 1803 and another in 1833. If these were great earthquakes then there is now roughly 3m of slip ready to go. However, if they were magnitude 7 earthquakes, then there may be more than 20m of slips availabIe for a future great earthquake.

Nepal earthquake map

graphic: BBC

It would seem that this earthquake near Kathmandu was a large one (7.8 magnitude) and may have released around 5 – 8 m of slip but as has been pointed out there may be a total of around 20m of slip waiting to occur. The current quake has so far seen some 16 aftershocks of magnitude 4.5 or greater. Deaths in India are over 40 and the Indian government is mounting a large rescue effort in support of the Nepali government, “Fifty doctors have arrived from India to provide emergency services. India dispatched as many as four aircraft including a C-130 plane carrying three tonnes of relief supplies and a 40-member rescue team to Nepal.” Three more planes are to follow carrying a mobile hospital and medical supplies.

FirstPost: The quake measuring 7.9 on Richter scale, which was followed by 16 aftershocks of magnitude 4.5 or greater, striking heavy casualties in Kathmandu and injuring thousand others. Hundreds were feared missing across the country. “Army estimates death toll as much as 1457 so far,” Nepal’s Finance Minister Ram Sharan Mahat tweeted. …….

The earthquake around 11:56 am with epicentre at Lamjung, around 80 kilometers northwest of Kathmandu, had its impact in several cities in Bihar, West Bengal and Uttar Pradesh and tremors were felt across vast stretches of east and North East India. It was also felt in Southern and Western parts of India, China, Bhutan and as far as Pakistan and Bangladesh.

The US Geological Survey reports:

The April 25, 2015 M 7.8 Nepal earthquake occurred as the result of thrust faulting on or near the main frontal thrust between the subducting India plate and the overriding Eurasia plate to the north. At the location of this earthquake, approximately 80 km to the northwest of the Nepalese capital of Kathmandu, the India plate is converging with Eurasia at a rate of 45 mm/yr towards the north-northeast, driving the uplift of the Himalayan mountain range. The preliminary location, size and focal mechanism of the April 25 earthquake are consistent with its occurrence on the main subduction thrust interface between the India and Eurasia plates.

Although a major plate boundary with a history of large-to-great sized earthquakes, large earthquakes on the Himalayan thrust are rare in the documented historical era. Just four events of M6 or larger have occurred within 250 km of the April 25, 2015 earthquake over the past century. One, a M 6.9 earthquake in August 1988, 240 km to the southeast of the April 25 event, caused close to 1500 fatalities. The largest, an M 8.0 event known as the 1934 Nepal-Bihar earthquake, occurred in a similar location to the 1988 event. It severely damaged Kathmandu, and is thought to have caused around 10,600 fatalities.

Was this the big earthquake that was predicted in the Himalayas?

In an interview to The Hindu in May 2013, Vinod Kumar Gaur, seismologist with the Centre for Mathematical Modelling and Computer Simulation, had said: “Calculations show that there is sufficient accumulated energy [in the MFT], now to produce an 8 magnitude earthquake. I cannot say when. It may not happen tomorrow, but it could possibly happen sometime this century, or wait longer to produce a much larger one.”

In a study published in the journal Nature Geoscience in December 2012, a research team led by Nanyang Technological University (NTU) discovered that massive earthquakes in the range of 8 to 8.5 magnitudes on the Richter scale had left clear ground scars in the central Himalayas

High resolution imagery and dating techniques showed that in 1255 and 1934, two great earthquakes ruptured the surface of the Earth in the Himalayas. The 1934 earthquake broke the surface over a length of more than 150 km.


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