Tag Archives: Earthquake

Billions in Liabilities: Man-Made Earthquakes at Europe’s Biggest Gas Field

The Groningen gas field, discovered in 1959, is the largest in Europe and produces up to 15 per cent of the natural gas consumed across the continent. With original reserves of more than 100 trillion cubic feet, over the decades the field has been an extraordinary cash cow for the Dutch government and the two global energy giants, Shell and ExxonMobil, which partner in managing the field. In 2014 alone, state proceeds from Groningen were approximately €9.4 billion ($9.8 billion).

But now, costs to the Dutch government are mounting as the courts have ordered that compensation is paid to nearby propery owners for damage caused by the earthquakes induced by extracting the gas. Insurers who were covering liabilities at the field now find that the claims have the potential to extend beyond the direct shaking damage to include the reduction in property values caused by this ongoing seismic crisis. And the potential for future earthquakes and their related damages has not disappeared – a situation which again illustrates the importance of modeling the risk costs of liability coverages, a new capability on which RMS is partnering with its sister company Praedicat.

The Groningen gas reservoir covers 700 square miles and, uniquely among giant gas fields worldwide, it is located beneath a well-populated and developed region. The buildings in this region, which half a million people live and work in, are not earthquake resistant: 90% of properties are made from unreinforced masonry (URM).

The ground above the gas field has been subsiding as the gas has vented out from the 10,000-feet deep porous sandstone reservoir and the formation has compacted. This compaction helps squeeze the gas out of reservoir, but has also led to movement on pre-existing faults that are present throughout the sandstone layer, a small number of which are more regional in extent. And these sudden fault movements radiate earthquake vibrations.

How A Shake Became a Seismic Crisis

The first earthquake recorded at the field was in December 1991 with a magnitude of 2.4. The largest to date was in August 2012 with a magnitude of 3.6. In most parts of the world, such an earthquake would not have significant consequences, but on account of the shallow depth of the quake, thick soils and poor quality building construction in the Groningen area, there were more than 30,000 claims for property damage, dwarfing the total number from the previous two decades.

Since the start of 2014 the government has limited gas production in an attempt to manage the earthquakes, with some success. But the ongoing seismicity has had a catastrophic effect on the property market, which has been compounded by a class-action lawsuit in 2015. It was filed on behalf of 900 homeowners and 12 housing co-operatives who had seen the value of their properties plummet. The judge ruled that owners of the real estate should be compensated for loss of their property’s market value, even when the property was not up for sale. The case is still rumbling on through the appeal courts but if the earlier ruling stands, then the estimates of the future liabilities for damage and loss of property value range from €6.5 billion to €30 billion.

Calculating the Risk

While earthquakes associated with gas and oil extraction are known from other fields worldwide, the massive financial risk at Groningen reflects the intersection of a moderate level of seismicity with a huge concentration of exposed value and very weak buildings. And although limiting production since 2014 has reduced the seismicity, there still remains the potential for further highly damaging earthquakes.

Calculating these risk costs requires a fully probabilistic assessment of the expected seismicity, across the full range of potential magnitudes and their annual probabilities. Each event in the simulation can be modeled using locally-calibrated ground motion data as well as expected property vulnerabilities, based on previous experience from the 2012 earthquake.

There is also the question of how far beyond actual physical damage the liabilities have the potential to extend and where future earthquakes can affect house values. The situation at Groningen, where it took almost thirty years of production before the earthquakes began, highlights the need for detailed risk analysis of all energy liability insurance covers for gas and oil extraction.

After the devastating 2015 earthquake how is Nepal recovering?

It’s more than 20 months since a magnitude 7.8 earthquake hit Nepal in April 2015, swiftly followed by another earthquake of magnitude 7.3 the next month.

Nearly 9,000 people died. More than 600,000 houses were destroyed and around 290,000 were damaged, according to the United Nations.

On the face of it local people now appear to be getting on with life as normal but look closer and reminders of the disaster are never far away. Whether it be a snaking crack in a wall, large enough to put an arm through – or the still air now taking the space where temples once stood.

International donors have pledged some $4 billion following the earthquake but this is yet to produce the required progress in Nepal’s rebuilding or significantly improve the life of people on the ground.

Framing of a schoolhouse in village hit by earthquake

The scale of the damage is huge and the reconstruction costs – to a country already poor – are overwhelming. The challenge is to rebuild in a way that makes Nepal more resilient to future earthquakes which, in such a seismically active region, are more a question of ‘when’ not ‘if’.

The capital, Kathmandu, wasn’t affected as badly as many feared but as you head out into the hills you see conditions deteriorate considerably. Partially collapsed buildings and piles of rubble are a common sight. Rural Nepalese houses normally consist of three stories, with the first used for livestock, the second for living and the third for agricultural use. These tall buildings are made from heavy and brittle materials, typically stone and mud mortar, which produce a vulnerability to earthquake to match that in many other regions of the world.

Earthquake damage to a traditional three-story house

Recently I saw the damage for myself. Along with four of my RMS colleagues, I travelled to Nepal to support Build Change’s work to strengthen the resilience of rural communities. It’s an organization focussed on helping people in developing countries make their homes and schools better able to withstand earthquakes and hurricanes.

Immediately after the 2015 Nepal earthquake it deployed teams to the affected areas to perform surveys of the damage and validate engineering assumptions as to why some buildings remain standing when others had collapsed.

Build Change’s site engineers oversaw the retrofitting and rebuilding work carried out by local builders who themselves had been trained by Build Change. Being scientists and engineers, the RMS team was impressed to see the high quality of workmanship and design, the positive response of Build Change’s staff to our suggestions for incremental improvements – as well as the engagement of the wider community.

RMS and Build Change staff advise on house retrofitting

And on a personal level, it was this community which made an especially powerful impression on me. Kindness and generosity were shown by the Nepalese who have been hit so hard, yet are so willing to share – we were routinely offered food by the local people who were so interested to know why there are foreigners in their village. Perhaps they took hope from seeing that they hadn’t been forgotten.

Money is not abundant in Nepal, but the engineering expertise is developing. And along with this expertise there is more than enough human grit and determination among the Nepalese people to rebuild their country stronger.

The Cost of Shaking in Oklahoma: Earthquakes Caused by Wastewater Disposal

It was back in 2009 that the inhabitants of northern Oklahoma first noticed the vibrations. Initially only once or twice a year, but then every month, and even every week. It was disconcerting rather than damaging until November 2011, when a magnitude 5.6 earthquake broke beneath the city of Prague, Okla., causing widespread damage to chimneys and brick veneer walls, but fortunately no casualties.

The U.S. Geological Service had been tracking this extraordinary outburst of seismicity. Before 2008, across the central and eastern U.S., there were an average of 21 earthquakes of magnitude three or higher each year. Between 2009-2013 that annual average increased to 99 earthquakes in Oklahoma alone, rising to 659 in 2014 and more than 800 in 2015.

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During the same period the oil industry in Oklahoma embarked on a dramatic expansion of fracking and conventional oil extraction. Both activities were generating a lot of waste water. The cheapest way of disposing the brine was to inject it deep down boreholes into the 500 million year old Arbuckle Sedimentary Formation. The volume being pumped there increased from 20 million barrels in 1997 to 400 million barrels in 2013. Today there are some 3,500 disposal wells in Oklahoma State, down which more than a million barrels of saline water is pumped every day.

It became clear that the chatter of Oklahoma earthquakes was linked with these injection wells. The way that raising deep fluid pressures can generate earthquakes has been well-understood for decades: the fluid ‘lubricates’ faults that are already poised to fail.

But induced seismicity is an issue for energy companies worldwide, not just in the South Central states of the U.S.. And it presents a challenge for insurers, as earthquakes don’t neatly label themselves ‘induced’ and ‘natural.’ So their losses will also be picked up by property insurers writing earthquake extensions to standard coverages, as well as potentially by the insurers covering the liabilities of the deep disposal operators.

Investigating the Risk

Working with Praedicat, which specializes in understanding liability risks, RMS set out to develop a solution by focusing first on Oklahoma, framing two important questions regarding the potential consequences for the operators of the deep disposal wells:

  • What is the annual risk cost of all the earthquakes with the potential to be induced by a specific injection well?
  • In the aftermath of a destructive earthquake how could the damage costs be allocated back to the nearby well operators most equitably?

In Oklahoma detailed records have been kept on all fluid injection activities: well locations, depths, rates of injection. There is also data on the timing and location of every earthquake in the state. By linking these two datasets the RMS team was able to explore what connects fluid disposal with seismicity. We found, for example, that both the depth of a well and the volume of fluid disposed increased the tendency to generate seismic activity.

Earthquakes in the central U.S. are not only shallow and/or human-induced. The notorious New Madrid, Mo. earthquakes of 1811-1812 demonstrated the enormous capacity for ‘natural’ seismicity in the central U.S., which can, albeit infrequently, cause earthquakes with magnitudes in excess of M7. However, there remains the question of the maximum magnitude of an induced earthquake in Oklahoma. Based on worldwide experience the upper limit is generally assumed to be magnitude M6 to 6.5.

Who Pays – and How Much?

From our studies of the induced seismicity in the region, RMS can now calculate the expected total economic loss from potential earthquakes using the RMS North America Earthquake Model. To do so we run a series of shocks, at quarter magnitude intervals, located at the site of each injection well. Having assessed the impact at a range of different locations, we’ve found dramatic differences in the risk costs for a disposal well in a rural area in contrast to a well near the principal cities of central Oklahoma. Reversing this procedure we have also identified a rational and equitable process which could help allocate the costs of a damaging earthquake back to all the nearby well operators. In this, distance will be a critical factor.

Modeling Advances for Manmade Earthquakes

For carriers writing US earthquake impacts for homeowners and businesses there is also a concern about the potential liabilities from this phenomenon. Hence, the updated RMS North America Earthquake Model, to be released in spring 2017, will now include a tool for calculating property risk from induced seismicity in affected states: not just Oklahoma but also Kansas, Ohio, Arkansas, Texas, Colorado, New Mexico, and Alabama. The scientific understanding of induced seismicity and its consequences are rapidly evolving, and RMS scientists are closely following these developments.

As for Oklahoma, the situation is becoming critical as the seismic activity shows no signs of stopping: a swarm of induced earthquakes has erupted beneath the largest U.S. inland oil storage depot at Cushing and in September 2016 there was a moment magnitude 5.8 earthquake located eight miles from the town of Pawnee – which caused serious damage to buildings. Were a magnitude 6+ earthquake to hit near Edmond (outside Oklahoma City) our modeling shows it could cause billions of dollars of damage.

The risk of seismicity triggered by the energy industry is a global challenge, with implications far beyond Oklahoma. For example Europe’s largest gas field, in the Netherlands, is currently the site of damaging seismicity. And in my next blog, I’ll be looking at the consequences.

[For a wider discussion of the issues surrounding induced seismicity please see these Reactions articles, for which Robert Muir-Wood was interviewed.]

Indonesia’s Protection Gap – How the Sumatra Earthquake Shows that Coverage Must Spread

On December 7, 2016, a shallow magnitude 6.5 earthquake struck northern Sumatra in Indonesia, severely damaging or destroying more than ten thousand homes and many businesses, as well as causing over a hundred deaths. The disaster struck a poorer area away from the major cities, where the standards of building design, construction methods, and material quality are not sufficient to withstand such an earthquake.

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USGS Shake map for Mw 6.5 Earthquake

We have up-to-date research on local building design and construction practices in Indonesia, which we have incorporated into the latest version of the RMS® Indonesia Earthquake Model. This research was done last year when members of the RMS vulnerability team, including me, visited southeast Asia as part of the process to update the model. We held workshops with local earthquake engineering experts who practice there, and attended an earthquake engineering conference, as well as visiting commercial and industrial buildings, including those under construction, to see first-hand how they were designed and built.

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A workshop with local experts

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International Conference – Jogja Earthquake in Reflection (May, 2016)

This on-the-ground research provided insights into Indonesia’s rules and practices around construction, seismic design, code enforcement, as well as information on the relative quantities of different types of buildings in the country. We discovered significant differences between mainstream construction and those buildings covered by earthquake insurance, namely:

  • Past earthquakes have demonstrated that single family dwellings and/or low rise buildings are the most vulnerable building types compared to those built for commercial and industrial use, because of a lack of engineering design, poor construction, and lower material quality.
  • Buildings outside of major cities are mostly low rises and they may not be designed for earthquake risk.
  • Major cities such as Jakarta, Bandung, and Surabaya enforce a strict structural design review process for the construction of mid- and high-rise buildings.
  • Insurance penetration rates are higher for commercial and industrial buildings in and near major cities, with much lower penetration for residential properties in rural areas.

It’s perhaps not surprising that if poorer communities have less insurance protection, that they also cannot afford to invest in the higher quality construction that is designed to better withstand earthquakes. This is one of the primary reasons for the ‘protection gap’. As these countries become more developed, there’s the potential for that gap to start closing. In fact, Indonesia is one of the fastest growing economies in southeast Asia, with the property insurance and (re)insurance market expanding rapidly.

But as the earthquake disaster demonstrated, there are still many poorer regions with low insurance penetration which are also prone to repeated natural disasters. Sadly, there is still a long way to go before people in those places benefit from the resilience in their built environment which other, richer parts of the world may take for granted.

Understanding Risk Accumulations in Taiwan’s Science Parks

“The 6.4 magnitude Tainan earthquake in February 2016 resulted in a sizeable insured loss from the high-tech industrial risks and reminded the insurance industry of the potential threat from the risk accumulated in science parks.” (A.M. Best Special Report, Sept 2016)

Reading the sentence above you might be forgiven for wondering why science parks would give insurers and reinsurers any particular cause for concern. But consider this statistic: although Taiwan’s three major science and industrial parks occupy only 0.1% of the island’s total land mass, they represent 16% of Taiwan’s overall manufacturing – they are hugely significant, both economically and with regards to the insured exposure in Taiwan.

For example, the Hsinchu Science Park (HSP), known for semiconductor production, employs more than 150,000 people and contributes over $32 billion in revenues – approximately 6% of national GDP. By one estimate HSP represents over $319 billion in total insured values. In addition, some of the latest high tech areas within HSP, such as advanced “clean rooms,” present additional challenges due to their vulnerability to ground shaking or power interruption. The importance of this risk was observed in February’s Tainan earthquake where some significant losses to high-tech industrial risks were caused by damage to the equipment and the related business interruption due to power outage.

Improving data quality for advanced and detailed modeling is an important way to manage these risks, concludes the A.M. Best report quoted above. This is so as to accurately assess the potential loss impact on insurers’ books. RMS has already been analysing earthquake risk in Taiwan for 12 years – long before this year’s Mw 6.4 event – and in that time our view of seismic risk in Taiwan has not changed, since our model benefits from spectral response-based hazard and damage functions, that even include local liquefaction and landslide susceptibilities.

The 1999 Chi-Chi Earthquake (known in Taiwan as the 921 Earthquake) was the key event in building the RMS® Taiwan Earthquake Model in terms of the quake’s seismicity, ground motion, soil secondary effects and building response. Since then there have been no significant events to justify a re-calibration of the components of the model. In fact, the damages observed in this year’s event were broadly in line with RMS’ expectations and validated the robustness of the current model.

But although A.M. Best views the Taiwan insurance industry as prudently managed with relatively high catastrophe management capability, there are still lessons to be learnt from the 2016 event, and RMS has solutions which offer additional insight into understanding the risk posed by these business parks in Taiwan.

Concentration of Exposure into Science Parks

The RMS® Asia Industrial Clusters Catalogs were released in 2014 to identify hotspots of exposure, and profile their risk. The locations and geographic extent of the science parks within Taiwan are detailed to help understand risk accumulations for industrial lines and develop more robust risk management strategies.

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Example of industrial cluster captured in the RMS Taiwan Industrial Clusters Catalog. The red outline illustrates the digitized boundaries of the Formosa Petrochemical Co. Plant in Yunlin Hsien.

High Fragility of the Semiconductor Industry

For coding of Industrial Plants, the RMS® Industrial Facilities Model (IFM) captures the unique nature of different industrial risks, as a high percentage of property value is often associated with machinery and equipment (M&E) and stock. This advanced vulnerability model supports the earthquake model to define the damageability of a comprehensive set of industrial facilities more accurately, and calculate the financial risk to these specific types of facilities, including building, contents, and business interruption (BI) loss estimates. The IFM differentiates the risks for different types of business within the science parks, and highlights the higher fragility of semiconductor plants compared to other industrial units, as shown below.

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Lessons Learnt?

The huge damage from the 1999 Chi Chi earthquake has not halted the rapid development of Taiwan’s science parks in this seismically active area – indeed the island’s third biggest science park has since been built there. But this year’s comparatively small Mw 6.4 event further highlighted the substantial exposures concentrated within this sector, reminding the industry of the potential for significant losses without sound accumulation management practices, informed by the best modeling insights.

“Italy is Stronger than any Earthquake”

Those were the words of the then Italian Prime Minister, Matteo Renzi, in the aftermath of two earthquakes on the same day, October 26, 2016. As a statement of indomitable defiance at a scene of devastation it suited the political and public mood well. But the simple fact is there is work to do, because Italy is not as strong as it could be in its resilience to earthquakes.

There’s a long history of powerful seismic activity in the central Apennines: only recently we’ve seen L’Aquila (2009, Mw6.3), Amatrice (August 2016, Mw6.0), two earthquakes in the area near Visso (October 2016, Mw 5.4 and 5.9) and Norcia (October 2016, Mw6.5). These have resulted in hundreds of fatalities, mainly attributed to widespread collapse of old buildings, emphasizing that earthquakes don’t kill people – buildings do. Whilst Italy’s Civil Protection Department provides emergency management and support after earthquakes, there is too little insurance help for the financial resiliency of the communities most affected by all these events. While the oft-repeated call for earthquake insurance to be compulsory continues to be politically unobtainable, one way it could be spread more widely is through effective modeling. And RMS expertise can help with this, allowing the market to better understand the risk and so build resilience.

Examining High Building Fragility

The two most significant factors for earthquake risk in Italy are (i) construction materials and (ii) the age of the buildings. The majority of the damaged and destroyed buildings were made from unreinforced masonry, and built prior to the introduction of the most recent seismic design and building codes, making them particularly susceptible. With the RMS® Europe Earthquake model capturing both the variations in construction types and age, as well as other vulnerability factors, (re)insurers can accurately reflect the response of different structures to earthquakes.  This allows the models to be used to evaluate the cost benefits of retrofitting buildings.  RMS has worked with the Italian National Institute for Geophysics and Volcanology (INGV) to see how such analyses could be used to optimize the allocation of public funds for strengthening older buildings, thereby reducing future damage and costs.

Seismic Risk Assessment

The high-risk zone of the central Apennines is described well by probabilistic seismic hazard assessment (PSHA) maps, which show the highest risks in that region resulting from the movement of tectonic blocks that produce the extensional, ‘normal’ faulting observed. The maps also show earthquake risk throughout the rest of Italy. RMS worked with researchers from INGV to develop our view of risk in 2007, based on the latest available databases at that time, including active faults and earthquake catalogs. The resulting hazard model produces a countrywide view of seismic hazard that has not been outdated by newer studies, such as the 2009 INGV Seismic Hazard Map and the 2013 European Seismic Hazard Map published by the SHARE consortium, as shown below:

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The Route to Increased Resiliency

Increasing earthquake resiliency in Italy should also involve further development of the private insurance market. The seismic risk in Italy is relatively high for western Europe, whilst the insurance penetration is low, even outside the central Apennines. For example, in 2012, there were two large earthquakes in the Emilia-Romagna region of the Po valley, where there are higher concentrations of industrial and commercial risks. Although the type of faults and risks vary by region, such as the potential impact of liquefaction, the RMS model captures such variations in risk and can be used for the development of risk-based pricing and products for the expansion of the insurance market throughout the country.

Whilst Italy’s seismic events in October caused casualties on a lesser scale than might have been, the extent of the damage highlights once again the prevalence of earthquake risk. It is only a matter of time before the next disaster strikes, either in the Central Apennines or elsewhere. When that happens, the same questions will be asked about how Italy could be made more resilient. But if, by then, the country’s building stock is being made less susceptible and the private insurance market is growing markedly, then Italy will be able to say, with justification, it is becoming stronger than any earthquake.

Earthquake Hazard: What Has New Zealand’s Kaikoura Earthquake Taught Us So Far?

The northeastern end of the South Island is a tectonically complex region with the plate motion primarily accommodated through a series of crustal faults. On November 14, as the Kaikoura earthquake shaking began, multiple faults ruptured at the same time culminating in a Mw 7.8 event (as reported by GNS Science).

The last two weeks have been busy for earthquake modelers. The paradox of our trade is that while we exist to help avoid the damage this natural phenomenon causes, the only way we can fully understand this hazard is to see it in action so that we can refine our understanding and check that our science provides the best view of risk. Since November 14 we have been looking at what Kaikoura tells us about our latest, high-definition New Zealand Earthquake model, which was designed to handle such complex events.

Multiple-Segment Ruptures

With the Kaikoura earthquake’s epicenter at the southern end of the faults identified, the rupture process moved from south to north along this series of interlinked faults (see graphic below). Multi-fault rupture is not unique to this event as the same process occurred during the 2010 Mw 7.2 Darfield Earthquake. Such ruptures are important to consider in risk modeling as they produce events of larger magnitude, and therefore affect a larger area, than individual faults would on their own.

Map showing the faults identified by GNS Sciences as experiencing surface fault rupture in the Kaikoura Earthquake.
Source: http://info.geonet.org.nz/display/quake/2016/11/16/Ruptured +land%3A+observations+from+the+air

In keeping with the latest scientific thinking, the New Zealand Earthquake HD Model provides an expanded suite of events that represent complex ruptures along multiple faults. For now, these are included only for areas of high slip fault segments in regions with exposure concentrations, but their addition increases the robustness of the tail of the Exceedance Probability curve, meaning clients get a better view of the risk of the most damaging, but lower probability events.

Landsliding and Liquefaction

While most property damage has been caused directly by shaking, infrastructure has been heavily impacted by landsliding and, to a lesser extent, liquefaction. Landslides and slumps have occurred across the region, most notably over Highway 1, an arterial route. The infrastructure impacts of the Kaikoura earthquake are a likely dress rehearsal for the expected event on the Alpine Fault. This major fault runs 600 km along the western coast of the South Island and is expected to produce an Mw 8+ event with a probability of 30% in the next 50 years, according to GNS Science.

As many as 80 – 100,000 landslides have been reported in the upper South Island, with some creating temporary dams over rivers and in some cases temporary lakes (see below). These dams can fail catastrophically, sending a sudden increase of water flow down the river.

 

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Examples of rivers blocked by landslides photographed by GNS Science researchers.

Source: http://info.geonet.org.nz/display/quake/2016/11/18/ Landslides+and+Landslide+dams+caused +by+the+Kaikoura+Earthquake

 

 

 

 

 

 

 

 

Liquefaction occurred in discrete areas across the region impacted by the Kaikoura earthquake. The Port of Wellington experienced both lateral and vertical deformation likely due to liquefaction processes in reclaimed land. There have been reports of liquefaction near the upper South Island towns (Blenheim, Seddon, Ward), but liquefaction will not be a driver of loss in the Kaikoura event to the extent it was in the Christchurch earthquake sequence.

RMS’ New Zealand Earthquake HD Model includes a new liquefaction component that was derived using the immense amount of new borehole data collected after the Canterbury Earthquake Sequence in 2010-2011. This new methodology considers additional parameters, such as depth to the groundwater table and soil-strength characteristics, that lead to better estimates of lateral and vertical displacement. The HD model is the first probabilistic model with a landslide susceptibility component for New Zealand.

Tsunami

The Kaikoura Earthquake generated tsunami waves that were observed in Kaikoura at 2.5m, Christchurch at 1m, and Wellington at 0.5m. The tsunami waves arrived in Kaikoura significantly earlier than in Christchurch and Wellington indicating that the tsunami was generated near Kaikoura. The waves were likely generated by offshore faulting, but also may be associated with submarine landsliding. Fortunately, the scale of the tsunami waves did not produce significant damage. RMS’ latest New Zealand Earthquake HD Model captures tsunami risk due to local ocean bottom deformation caused by fault rupture, and is the first model in the New Zealand market to do this, that is built from a fully hydrodynamic model.

Next Generation Earthquake Modeling at RMS

Thankfully the Kaikoura earthquake seems to have produced damage that is lower than we might have seen had it hit a more heavily populated area of New Zealand with greater exposures – for detail on damage please see my other blog on this event.

But what Kaikoura has told us is that our latest HD model offers an advanced view of risk. Released only in September 2016, it was designed to handle such a complex event as the Kaikoura earthquake, featuring multiple-segment ruptures, a new liquefaction model at very high resolution, and the first landslide susceptibility model for New Zealand.

New Zealand’s Kaikoura Earthquake: What Have We Learned So Far About Damage?

The Kaikoura Earthquake of November 14 occurred in a relatively low population region of New Zealand, situated between Christchurch and Wellington. The largest town close to the epicentral region is Blenheim, with a population near 30,000.

Early damage reports indicate there has been structural damage in the northern part of the South Island as well as to numerous buildings in Wellington. While most of this has been caused directly by shaking, infrastructure and ports across the affected region have been heavily impacted by landsliding and, to a lesser extent, liquefaction. Landslides and slumps have occurred across the northeastern area of the South Island, most notably over Highway 1, severing land routes to Kaikoura – a popular tourist destination.

The picture of damage is still unfolding as access to badly affected areas improves. At RMS we have been comparing what we have learned from this earthquake to the view of risk provided by our new, high-definition New Zealand Earthquake model, which is designed to improve damage assessment and loss quantification at location-level resolution.

No Damage to Full Damage

The earthquake shook a relatively low population area of the South Island and, while it was felt keenly in Christchurch, there have been no reports of significant damage in the city. The earthquake ruptured approximately 150 km along the coast, propagating north towards Wellington. The capital experienced ground shaking intensities at the threshold for damage, producing façade and internal, non-structural damage in the central business district. Although the shaking intensities were close to those experienced during the Cook Strait sequence in 2013, which mostly affected short and mid-rise structures, the longer duration and frequency content of the larger magnitude Kaikoura event has caused more damage to taller structures which have longer natural periods.

From: Wellington City Council

Within Wellington, cordons are currently in place around a few buildings in the CBD (see above) as engineers carry out more detailed inspections. Some are being demolished or are set to be, including a nine-story structure on Molesworth Street and three city council buildings. It should be noted that most of the damage has been to buildings on reclaimed land close to the harbor where ground motions were likely amplified by the underlying sediments.

From: http://www.stuff.co.nz/national/86505695/quakehit-wellington-building-at-risk-of-collapse-holds-up-overnight; The building on Molesworth street before the earthquake (L) and on Tuesday (R).

From: http://www.stuff.co.nz/national/86505695/quakehit-wellington-building-at-risk-of-collapse-holds-up-overnight; The building on Molesworth street before the earthquake (L) and after on November 16 (R).

Isolated incidences of total damage in an area of otherwise minor damage demonstrate why RMS is moving to the new HD financial modeling framework. The RMS RiskLink approach applies a low mean damage ratio across the area, whereas RMS HD damage functions allow for zero or total loss – as well as a distribution in between which is sampled for each event for each location. The HD financial modeling framework is able to capture a more realistic pattern of gross losses.

Business Interruption

The Kaikoura Earthquake will produce business interruption losses from a variety of causes such as direct property or content damages, relocation costs, or loss of access to essential services (i.e. power and water utilities, information technology) that cripple operations in otherwise structurally sound buildings. How quickly businesses are able to recover depends on how quickly these utilities are restored. Extensive landslide damage to roads means access to Kaikoura itself will be restricted for months. The New Zealand government has announced financial assistance packages for small business to help them through the critical period immediately after the earthquake. Similar assistance was provided to businesses in Christchurch after the Canterbury Earthquake Sequence in 2010-2011.

That earthquake sequence and others around the world have provided valuable insights on business interruption, allowing our New Zealand Earthquake HD model to better capture these impacts. For example, during the Canterbury events, lifelines were found to be repaired much more quickly in urban areas than in rural areas, and areas susceptible to liquefaction were associated with longer down times due to greater damage to underground services. The new business interruption model provides a more accurate assessment of these risks by accounting for the influence of both property and contents damage as well as lifeline downtime.

It remains to be seen how significant any supply chain or contingent business interruption losses will be. Landslide damage to the main road and rail route from Christchurch to the inter-island ferry terminal at Picton has disrupted supply routes across the South Island. Alternative, longer routes with less capacity are available.

Next Generation Earthquake Modeling at RMS

RMS designed the update to its New Zealand Earthquake High Definition (HD) model, released in September 2016, to enhance location-level damage assessment and improve the gross loss quantification with a more realistic HD financial methodology. The model update was validated with billions of dollars of claims data from the 2010-11 Canterbury Earthquake Sequence.

Scientific and industry lessons learned following damaging earthquakes such as last month’s in Kaikoura and the earlier event in Christchurch increase the sophistication and realism of our understanding of earthquake risk, allowing communities and businesses to shift and adapt – so becoming more resilient to future catastrophic events.

New Zealand Earthquake – Early Perspectives

On Monday 14 November 2016 Dr Robert Muir-Wood, RMS chief research officer who is an earthquake expert and specialist in catastrophe risk management, made the following observations about the earthquake in Amberley:

SCALE
“The November 13 earthquake was assigned a magnitude 7.8 by the United States Geological Service. That makes it more than fifty times bigger than the February 2011 earthquake which occurred directly beneath Christchurch. However, it was still around forty times smaller than the Great Tohoku earthquake off the northeast coast of Japan in March 2011.”

CASUALTIES, PROPERTY DAMAGE & BUSINESS INTERRUPTION
“Although it was significantly bigger than the Christchurch earthquake, the source of the earthquake was further from major exposure concentrations. The northeast coast of South Island has a very low population and the earthquake occurred in the middle of the night when there was little traffic on the coast road. Characteristic of such an earthquake in steep mountainous terrain, there have been thousands of landslides, some of which have blocked streams and rivers – there is now a risk of flooding downstream when these “dams” break.

In the capital city, Wellington, liquefaction and slumping on man-made ground around the port has damaged some quays and made it impossible for the ferry that runs between North and South Island to dock. The most spectacular damage has come from massive landslides blocking the main coast road Highway 1 that is the overland connection from the ferryport opposite Wellington down to Christchurch. This will take months or even years to repair. Therefore it appears the biggest consequences of the earthquake can be expected to be logistical, with particular implications for any commercial activity in Christchurch that is dependent on overland supplies from the north. As long as the main highway remains closed, ferries may have to ship supplies down to Lyttelton, the main port of Christchurch.”

SEISMOLOGY
“The earthquake appears to have occurred principally along the complex fault system in the north-eastern part of the South Island, where the plate tectonic motion between the Pacific and Australian plates transfers from subduction along the Hikurangi Subduction Zone to strike-slip along the Alpine Fault System. Faults in this area strike predominantly northeast-southwest and show a combination of thrust and strike-slip motion. From its epicenter the rupture unzipped towards the northeast, for about 100-140km reaching to about 200 km to the capital city Wellington.”

WHAT NOW?
“Given the way the rupture spread to the northeast there is some potential for a follow-on major earthquake on one of the faults running beneath Wellington. The chances of a follow-on major earthquake are highest in the first few days after a big earthquake, and tail off exponentially. Aftershocks are expected to continue to be felt for months.”

MODELING
“These events occurred on multiple fault segments in close proximity to one another. The technology to model this type of complex rupture is now available in the latest RMS high-definition New Zealand Earthquake Model (2016) where fault segments may now interconnect under certain considerations.”

Searching for Clues After the Ecuador Earthquake

Reconnaissance work is built into the earthquake modeler’s job description – the backpack is always packed and ready. Large earthquakes are thankfully infrequent, but when they do occur, there is much to be learned from studying their impact, and this knowledge helps to improve risk models.

An RMS reconnaissance team recently visited Ecuador. Close to 7pm local time, on April 16, 2016, an Mw7.8 earthquake struck between the small towns of Muisne and Pedernales on the northwestern coast of Ecuador. Two smaller, more recent earthquakes have also impacted the area, on July 11, 2016 an Mw5.8 and Mw6.2, fortunately with no significant damage.

April’s earthquake was the strongest recorded in the country since 1979 and, at the time of writing, the strongest earthquake experienced globally so far in 2016. The earthquake caused more than 650 fatalities, more than 17,600 injuries, and damage to more than 10,000 buildings.

Two weeks after the earthquake, an RMS reconnaissance team of engineers started their work, visiting five cities across the affected region, including Guayaquil, Manta, Bahía de Caráquez, Pedernales, and Portoviejo. Pedernales was the most affected, experiencing the highest damage levels due to its proximity to the epicenter, approximately 40km to the north of the city.

Sharing the Same Common Vulnerability

The majority of buildings in the affected region were constructed using the same structural system: reinforced concrete (RC) frames with unreinforced concrete masonry (URM) infill. This type of structural system relies on RC beams and columns to resist earthquake shaking, with the walls filled in with unreinforced masonry blocks. This system was common across residential, industrial, and commercial properties and across occupancies, from hospitals and office buildings to government buildings and high-rise condominiums.

URM infill is particularly susceptible to damage during earthquakes, and for this reason it is prohibited by many countries with high seismic hazard. But even though Ecuador’s building code was updated in 2015, URM infill walls are still permitted in construction, and are even used in high-end residential and commercial properties.

Without reinforcing steel or adequate connection to the surrounding frame, the URM often cracks and crumbles during strong earthquake shaking. In some cases, damaged URM on the exterior of buildings falls outward, posing safety risks to people below. And for URM that falls inward, besides posing a safety risk, it often causes damage to interior finishes, mechanical equipment, and contents.

Across the five cities, the observed damage ranged from Modified Mercalli Intensity (MMI) 7.0-9.0. For an MMI of 7.0, the damage equated to light to moderate damage of URM infill walls, and mostly minimal damage to RC frames with isolated instances of moderate-to-heavy damage or collapse. An MMI of 9.0, which based on RMS observations, occurred in limited areas, meant moderate to heavy damage of URM infill walls and slight to severe damage or collapse to RC frames.

While failure of URM infill was the most common damage pattern observed, there were instances of partial and even complete structural collapse. Collapse was often caused, at least in part by poor construction materials and building configurations, such as vertical irregularities, that concentrated damage in particular areas of buildings.

Disruption to Business and Public Services

The RMS team also examined disruption to business and public services caused by the earthquake. A school in Portoviejo will likely be out of service for more than six months, and a police station in Pedernales will likely require more than a year of repair work. The disruption observed by the RMS team was principally due to direct damage to buildings and contents. However, there was some disruption to lifeline utilities such as electricity and water in the affected region, and this undoubtedly impacted some businesses.

RMS engineers also visited four public hospitals and clinics, with damage ranging from light to complete collapse. The entire second floor of a clinic in Portoviejo collapsed. A staff doctor told RMS that the floor was empty at the time and all occupants, including patients, evacuated safely.

Tourism was disrupted, with a few hotels experiencing partial or complete collapse. In some cases, even lightly damaged and unaffected hotels were closed as they were within cordoned-off zones in Manta or Portoviejo.

Tuna is an important export product for Ecuador. Two plants visited sustained minor structural damage, with unanchored machinery requiring repositioning and recalibration. One tuna processing plant reached 100% capacity just 16 days after the earthquake. Another in Manta reached 85% capacity about 17 days after the earthquake, and full capacity was expected within one month.

The need for risk differentiation

Occupancy, construction class, year built, and other building characteristics influence the vulnerability of buildings and, consequently, the damage they sustain during earthquakes. Vulnerability is so important in calculating damage from earthquakes that RMS model developers go to great lengths to ensure that each country’s particular engineering and construction practices are accurately captured by the models. This approach enables the models to differentiate risk across thousands of different factors.

Residential insurance penetration in Ecuador is still relatively low for commercial buildings and privately owned or financed homes, but higher amongst government-backed mortgages, as these require insurance. The knowledge gained from reconnaissance work is fundamental to our understanding of earthquake risk and informs future updates to RMS models. Better models will improve the insurance industry’s understanding and management of earthquake risk as insurance penetration increases both here and around the world.