Japan’s earthquake is a global wake up call concentrating on the importance of preparedness to respond to such disasters. What we need in our day of testing is preparation.

By Dr Jagadish Ghosh

 

'After three years, even a disaster can be good for something’ goes a Japanese proverb. But in the midst of this appalling devastation, it might be obscene to suggest that a disaster of this magnitude could possibly be turned into good for something. Evidently, time and again, not only the human spirit but also the laws of economics have proved amazingly resilient in the face of the most terrible of adversities. The widespread destruction has been taken as a challenge and an opportunity to rewrite the triumphant history of growth and development with renewed spirit and zeal. The destruction spurs reconstruction and acts as a stimulus for economic enterprise.
 

A ferocious tsunami spawned by one of the largest earthquakes ever recorded slammed Japan’s east coast on 11 March 2011 sweeping away boats, cars, homes and people as widespread fires burned out of control. The magnitude 8.9 offshore quake places the earthquake as the fifth largest in the world since 1900. It is also the largest in Japan since modern instrumental recordings began 130 years ago. The two disasters were followed by the damage at nuclear reactors threatening harmful radiation. Japanese Prime minister Naoto Kan has described the catastrophic combination of earthquakes, tsunami and nuclear meltdown as the biggest crisis the country has had to face since the end of World War II.
 

The quake caused a 400-km long and 160-km wide rupture in the earth’s crust as one tectonic plate dove under another off the coast of northern Japan. This led to an upheaval in the sea above it, sending a 30 foot wall of water racing up to 10 km inland in Japan and reaching California across the Pacific Ocean 10 hours later. Tsunami warnings blanketed the entire Pacific as far away as South America, Canada, Alaska and the entire US West Coast. The quake was followed by more than 20 aftershocks for hours, most of them of more than magnitude 6.0. As many as six reactors at the Daiichi nuclear power plant in Fukushima are facing crisis at one level or the other verging of N-disaster. The death toll was likely to continue climbing over 10,000 given the scale of disaster. But without minimising the tragedy in any way, the damage in terms of human lives has been remarkably contained relative to what might have been. For that, all credit must go to successive Japanese administrations and civil society. Situated on the ‘Ring of Fire’ – an arc of seismic activity around the Pacific Basin – Japan has been hit time and again by devastating earthquakes, from the one in Tokyo in 1923 to Kobe in 1995. But the Japanese have drawn their lessons from these. So they have the world’s most sophisticated earthquake early warning systems and an extensive tsunami warning sensor network. They have building codes that keep such exigencies in mind. Similarly, they have thorough disaster management plans at every administrative level.
 

Insured Losses

The earthquake in Japan could lead to insured losses of nearly $35 billion, according to risk modelling company AIR Worldwide, making it one of the most expensive catastrophes in history. It is nearly as much as the entire worldwide catastrophe loss to the global insurance industry in 2010 and could be the triggering event that forces higher prices in the insurance market after years of decline. This temblor will go down as the costliest earthquake in modern history in terms of insured losses, surpassing the roughly $15 billion in losses of the 1994 Northridge earthquake in California.
 

2010 – The Year of Earthquakes

The most devastating earthquake of the year with more than 220,000 deaths struck Haiti, a country that was in no way prepared for such an event. Chile and New Zealand, on the other hand, were very well prepared. As a result, the challenges presented for reconstruction and the insurance underwriting aspects must be assessed differently for different countries.
 

Scientific Analysis

On 12 January 2010, Haiti suffered the most devastating seismic catastrophe since the destruction of Tangshan in China in 1976. The quake, with a magnitude of 7.0, did not come as a great surprise for seismologists. The danger had been clearly stated in a scientific publication dated 2008. The epicentre of the quake which ravaged the capital Port-au-Prince and the surrounding area was located near the boundary between the North American and Caribbean plates. The Enriquillo-Plantain-Garden Fault, which was originally considered to form the quake’s epicentre, runs in an east-west direction here. The situation was further aggravated by the fact that the rupture in the earth’s crust propagated towards the capital from its hypocentre west of Port-au-Prince.
 

The associated interference of seismic waves magnified the vibrations. Intensive geological and geophysical investigations after the quake have revealed a highly complex rupture process. It appears that a previously concealed blind thrust fault was also involved and interacted with the Enriquillo-Plantain-Garden Fault. This is of significance for the future earth quake potential in the Port-au-Prince area. It may be assumed that the stresses accumulated in the Enriquillo-Plantain-Garden Fault since the earthquakes of 1751 and 1770 were not fully released on 12 January. Moreover, the investigations have also shown that strong shaking was not restricted only to areas with soft, unconsolidated sediments. Due to the topography, it also occurred on a hillside in the Petionville district, south of the city centre.
 

 

The Chilean earthquake six weeks later did not strike unexpectedly either. The strongest earthquake ever recorded by instruments worldwide with a magnitude of 9.5 had already occurred in the Valdivia/Puerto Montt region, on the boundary between the Nazca and South American plates, in 1960. To the north of this region, a magnitude 8.0 quake off the coast of Valparaiso caused damage all the way to Santiago in 1985. The area between these two rupture zones, however, had remained relatively quiet since 1835. This ‘seismic gap’ was filled by the Maule quake on 27 February, with a magnitude of 8.8.
 

A third earthquake, which struck Qinghai province in Central China on 13 April, paled in comparison to these two major catastrophes. Its magnitude was similar to that of the Haitian quake and claimed roughly 2,700 lives. The earthquake which struck New Zealand’s South Island on 3 September attracted greater publicity. This was not due to its magnitude of 7.0, similar to that of the quakes in China and Haiti. What made this quake different was that, unlike the Haiti and Chile cases, an earthquake had not been expected here, 40 kilometres west of Christchurch. Experts had focused more on the Alpine Fault to the northwest which marks the boundary between the Indo-Australian plate in the west and the Pacific plate in the east. The Darfield earthquake (named after the town closest to the epicentre), however, occurred along a previously unknown fault system under the sediments of the Canterbury Plains. Unlike Port-au-Prince, the rupture proceeded away from the city in this case but the energy emitted was unusually high for a quake of this magnitude.
 

Why Haitian earthquake proved most devastating

Buildings of every kind – from representative buildings, such as the government palace and the Hotel Montana, to mud huts – were damaged more or less indiscriminately by the earthquake in Haiti. The corporate headquarters and production facilities of foreign companies remained structurally intact. Yet the few insured losses stemmed primarily from this sector. There are several reasons why the Haitian earthquake proved to be the most devastating ever in recent times, as expressed by the overall loss in relation to gross domestic product. Among others, they include the lack of building regulations, poor building material and a shortage of qualified labour as well as the absence of an institutional framework ensuring that construction projects are completed in an orderly fashion.
 

The Maule quake in Chile was the first earthquake of high magnitude and correspondingly long duration (over 120 seconds) to test modern high-rise buildings. The high overall loss of US$30 billion was not caused by instability. Both the quality of Chile’s earthquake building code and its implementation are very good on a global scale. Only five of the 12,300 buildings erected since the last major earthquake in 1985 collapsed. Another 50 or so had to be demolished on account of massive structural damage. The magnitude of the overall loss is due above all, to the damage to non-structural elements in addition to the small number of major losses. Among other things, these include non-supporting walls, false ceilings and façade elements. Evidently, the building code must be updated in order to avoid or reduce the extent of such damage to property. In some cases, infrastructure also proved unexpectedly unstable as in the case of the motorway linking the international airport and the city of Santiago.
 

In Chile, the load-bearing structure of mid-rise buildings (up to 20 floors) is primarily made up of shear walls parallel to the axis of the building. Compared with framed structures, such buildings are fairly rigid when exposed to seismic stresses. Newer buildings, however, tend to have thinner walls. The necessary transverse reinforcements also proved inadequate in some cases. Most of the few cases of major damage are attributable to such shortcomings. Low buildings with up to four floors are frequently built with confined masonry. In this case, the individual brick wall elements are connected by cast pillars of reinforced concrete. This type of construction has also proved to be very good.
 

Since buildings with shear walls or confined masonry are more widespread in Chile than in other countries, the experience gathered there cannot simply be applied to other regions. Framed constructions prevail in the American Pacific Northwest Region (Oregon, Washington), for example. As for the earthquake mechanism, Chile provided a blueprint for a future quake at the Cascadia subduction zone where the Juan de Fuca plate is subducting under the North American continent from the west. Portland, Seattle and Vancouver are all about the same distance from the epicentre of a future earthquake as Santiago was from the February quake.
 

In Christchurch, New Zealand, many residential buildings were damaged above all by collapsing chimneys. They frequently crashed through the roofs of homes, most of which were lightweight constructions. Many historical buildings of unreinforced masonry in the city centre also suffered significant damage. As in Chile, non-structural damage played a major part here, too. Unusually widespread soil liquefaction was one particular characteristic of the New Zealand quake. Near-surface sediment layers on the Canterbury Plains are particularly prone to this phenomenon, which causes extensive damage that is also difficult to repair, as the substrate settles to varying degrees during the liquefaction process, causing buildings to tilt.
 

Lessons for Nepal

Going by the past records, Nepal has been experiencing major quakes every 70-75 years. According to seismologists, Nepal ranks 11th among the 30 most quake prone countries in the world. In Nepal, the tectonic motion – the movement of plates in the Indian subcontinent towards Tibet – that caused the Himalayas to rise have also been causing buildings to collapse and cities get razed since the 13th century. And it is likely that Nepal would be faced with a similar situation in the near future, with Western and Central Nepal including the Kathmandu Valley the most prone to damage.
 

The 1934 Quake, that devastated Bihar, measured 8 on the Richter scale, killing nearly 11,000 people and 20 per cent of the buildings in the valley. The National Seismological Centre of Kathmandu draws an apocalyptic version of the disaster: that it would kill more than 40,000 people and injure another 100-200,000 if it happens today. It would also destroy 60-70 per cent of the buildings and leave 60-70,000 people homeless. There is no such term as earthquake-proof as no building can be entirely safe from earthquakes. The actual term used is earthquake-resistant which means that the damage to life and property caused following an earthquake will be minimised.
 

Establishment of the Disaster Preparedness Plan and Disaster Relief Plan makes a huge difference in earthquake-prone regions, when the catastrophes do occur as we have experienced in the two Latin American countries: Haiti and Chile. By comparing these countries to Nepal and taking a closer look at Nepal’s situation, it is evident that Nepal is in dire need of a strong mitigation plan. In Kathmandu Valley which is a former lake-bed, 2.5 million people live in poorly constructed buildings. Kathmandu has only one airport and three roads connecting it to the outside world. In the event of an earthquake, these roads are most likely to be damaged rendering them unfit for transportation. Nepal has a National Seismological Network comprising 21 short period telemetric seismic stations that started with the first seismometer set up at the top of the Phulchowki Hill, 14 km southeast of Kathmandu, in 1978. The Nepali Diaspora needs to come together and build a procedural mechanism to protect the country by setting up a Disaster Preparedness Plan, and a Disaster Relief Plan. The National Society for Earthquake Technology (NSET) - Nepal, established as a non-governmental and non-profit organisation in 1994, has been actively pursuing the earthquake risk and mitigation planning and earthquake awareness projects.
 

Protracted political wrangling in Nepal is preventing a key piece of disaster preparedness legislation from reaching parliament. Though endorsed by the cabinet in October 2009, the National Strategy for Disaster Risk Management (NSDRM) has yet to be made into law. The passing of this bill is critical. Without this, the country’s disaster preparedness efforts cannot move forward.
 

Development of better building codes, strict enforcement of the existing one, creation of disaster management plans and response bodies from the local level to the central must be ensured. Similarly, streamlining of relevant administrative machinery with funding, clearly demarcated jurisdiction and insurance awareness are measures that the government must take seriously. Unless these measures are taken, the cost of country’s lack of preparedness may turn out to be devastating. The right lesson to be drawn from events unfolding – a combination of righteous knowledge and righteous actions helps us for sustaining survival.

(Dr Ghosh is the CEO of National Insurance Company Ltd. This article is based on material provided from various sources including Munich Re)