Perth, Wellington, Bali make 1-in-100 disaster list
An intense cyclone hitting Perth and a massive volcanic explosion covering Bali and Lombok with thick ash are among one-in-100 year Asia-Pacific catastrophes that risk being underestimated, modeller RMS says.
The firm has released a list of ten potential catastrophes, that also includes a 7.5 magnitude earthquake directly hitting Wellington and causing liquefaction and a category three typhoon taking an unusual path to make landfall near Bangkok.
RMS Chief Research Officer Robert Muir-Wood says the list reflects credible catastrophes that are not repeats of disasters already seen, and that may be less well anticipated.
“We are all subject to the proximity or framing bias, whereby because a major catastrophe has already happened we become totally focused around the repeat of that iconic event,” he told insuranceNEWS.com.au.
“We need to think sideways around catastrophes, learning from the events that have previously happened, but then seeing how we can apply that learning to other classes of events.”
The Perth scenario suggests a transitioning cyclone could make a direct hit at category three intensity, bringing torrential rainfall and damaging winds.
Perth’s latitude at 32 degrees is further south than Brisbane, but still 10 degrees closer to the equator than Boston, which is in the Atlantic hurricane belt, Mr Muir-Wood says.
In 1938 one of the most powerful hurricanes in recorded history devastated parts of the US New England region leading to 700 deaths, the US National Weather Service says on a web page marking last month’s 80th anniversary.
The Asia-Pacific region this year has been hit by disasters such as the Palu earthquake in Indonesia and Typhoon Jebi in Japan, but RMS says more destructive events at the 1% level of annual probability can be expected.
Each of the catastrophes on the RMS list would cause many billions of dollars of economic loss and in several cases the cost could reach tens of billions of dollars.
Widely planned-for events such as a Tokyo earthquake are not listed, but RMS includes a 6.9 magnitude earthquake on the Uemachi Fault southeast of Osaka that causes damage and casualties in Suita city.
It also highlights the scenarios of a shallow 6.7 quake on the Shanchiao Fault next to Taipei and a 7.8 magnitude quake in China’s Hebei Province between Baoding and Shijizhuang
South Korea could endure a succession of stalled depressions causing rainfall that overwhelms Seoul’s flood defences.
In the Philippines, a category four typhoon that passes south of Luzon could make a near direct hit on Manila, which has dodged several recent intense typhoons.
In India, there is the possibility of 100-year flooding of the greater Mumbai area, allied with extensive wind damage, caused by a category four cyclone making landfall and stalling close to the city.
“As we develop large stochastic simulations in catastrophe loss models, we discover a very large number of potential extreme events,” Mr Muir-Wood said.
“Any one of these catastrophic events would have major implications for the region, country, people and insurance industry.”
RMS’ ten one-in-100 year Asia-Pacific catastrophe scenarios:
1. New Zealand: A 7.5 magnitude earthquake is a direct hit on Wellington and is accompanied by massive liquefaction on roads and the docks, which were reclaimed from the sea, as well as some localised changes in coastal land levels. Over the past decade the earthquakes that battered Christchurch have been “migrating” towards the New Zealand capital.
2. South Korea: A succession of stalled depressions cause very widespread river flooding, in particular affecting the city of Seoul. While the city has spent money on multiple flood defences, these are overwhelmed by the water levels.
3. China: A magnitude 7.8 earthquake occurs in Hebei Province 200km south of the capital, between the cities of Baoding and Shijiazhuang, leading to widespread destruction, and tens of thousands of casualties.
4. The Philippines: An intense typhoon that passes south of Luzon makes a near direct hit on Manila at category 4, causing extraordinary damages. The city has dodged several recent intense typhoons.
5. Indonesia: A massive eruption at the volcano on Lombok, up to 6 on the Volcanic Eruption Intensity scale, triggered by earthquakes. The eruption covers Lombok and Bali with a 20cm-plus layer of volcanic ash, causing roofs to collapse, killing agricultural crops and closing the tourist industry.
6. Australia: A transitioning cyclone, comparable to the 1938 hurricane in the US, makes direct landfall on the city of Perth at category 3 intensity, bringing intense rainfall and damaging winds.
7. Japan: A magnitude 6.9 earthquake occurring on the Uemachi Fault to the southeast of the city of Osaka, causing much damage and many casualties in Suita City.
8. India: Extensive ‘100-year’ flooding of the greater Mumbai area, allied with extensive wind damage, caused by a category 4 cyclone making landfall and stalling close to the city.
9. Taiwan. A shallow magnitude 6.7 earthquake on the Shanchiao Fault next to the city of Taipei causing huge destruction as well as coastal flooding from tectonic subsidence.
10. Thailand. A category 3 typhoon taking an unusual westerly path, enters the Gulf of Thailand and makes landfall close to Bangkok. The combination of the shallow-water storm surge and the intense rainfall, allied with long-term land subsidence from water extraction, sends the whole of Bangkok under water.