Experts Eliminate Earthquake-Risk Blind Spots (original) (raw)

Earthquake impact wave and seismic activity

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Most natural hazards are fairly obvious: If you live near a river, you could be in a flood zone. If you live in a drought-stricken forest or on a dry hillside covered with brush, you already know wildfire is a distinct possibility. If you live in tornado alley and a monolithic black cloud bank appears on the horizon, you probably at least consider that a twister may be coming.

Earthquakes are the opposite. They’re the stealthiest of threats. They strike fast and (to the layperson) seemingly out of nowhere, ultimately causing nearly US$40 billion in direct economic loss every year. If you’re not located in the handful of famous earthquake zones in the world, you may be at higher risk than you realize. And if you are in a known earthquake zone, you may hear “early” earthquake warnings triggered by sensors. By early, I mean early enough to let you evacuate, but not enough for you to prepare to prevent property damage or business interruption. Every second will matter when the event is under way. Better to know your risk and prepare ahead of time if you can.

Fortunately, scientists from government, academia and the private sector have joined forces to quantify the risk of earthquakes around the world so everyone, everywhere can better know their risk. Working under the aegis of the nonprofit NGO GEM (Global Earthquake Model) Foundation, they have teamed up in an effort to develop harmonized methods and techniques, and reanalyze data using a consistent methodology, to provide the best insights ever available.

A partial view of the FM Global Worldwide Earthquake Map

FM Global

The effort is yielding earthquake risk maps like this one, which removes blind spots from the views of insurers, bankers, enterprise risk managers, investors, executives, disaster planners, and disaster response agencies. The map tells you the likelihood that a given region will experience damaging earthquake ground motions. That likelihood ranges from less than a 1-in-50 chance each year in the most hazardous places down to a less-than-1-in-500 chance each year.

New methodology is more consistent and understandable

Global earthquake intelligence has always required information to be stitched together from many sources throughout the world. Organizations such as the U.S. Geological Survey (USGS) have continually improved their ability to integrate disparate regional data. In some cases, though, different nations had different maps that employed disparate methodologies, if they had maps at all. In other cases, maps reflected political or economic pressure to downplay the actual risk.

Some earthquake maps presented risk intelligence in ways inscrutable to nonscientists, e.g., peak ground acceleration of half a g with 10% probability over 50 years. Others used varying formulas to trace shaking or damage back to a presumed source and, hence, had different ways of characterizing risk of potential future ground motion. It is not uncommon to have one side of a national border showing very different risk than the other side even though they shared a boundary.

Bottom line: until now, although they often represented the best available science, earthquake maps have been prone to being inconsistent. GEM has accelerated and further improved the models and data consistency.

My company has been a member of the GEM partnership as a sponsor and a close technical collaborator for over 10 years. Using the open source model developed via the GEM partnership, our global map is presented in a way that anyone can understand. It’s informed by the same local experts that historically have been working separately, or in smaller groups, around the world, and is supplemented by our own data and analysis of two things that affect earthquake severity: local soil composition (softer soils may amplify seismic waves, making them more destructive), and average construction types for the location (some building types are naturally more susceptible to damage).

Most other earthquake hazard maps have shown, and still do show, only the expected ground shaking for a fixed return time (i.e., average, typical timespan between serious ground motion). Building on our prior methodology and maps first released in 2003, we continue to make it easier for anyone to see the estimated “return periods” of ground motion severe enough (given the soil conditions) to damage weak buildings (weak buildings signifying the worst case for conservative planning).

New methodology reveals real risk levels

For those who need to understand (and be resilient to) the earthquake risk to global businesses, supply chains, customer facilities, and key markets, it is now possible to go to one source for a consistent and clear picture of risk, based on best available models. Although global business was the main driver of its development, the resulting map is useful to many others, including governments, disaster planners, emergency response people, insurers, and reinsurers.

The methodology will continue to improve. High-resolution GPS data is now being used to track surface motion that can build up stresses that result in earthquakes. Hopefully, there will be fewer surprises in the future.

Earthquakes can occur on every continent. Whether you’re a global business leader or simply an individual seeking your own personal resilience to potential disasters, you can now know your risk and carry on with a good sense of it – just as you have with floods, wildfires, hurricanes, and twisters. Most importantly, you can prepare properly. No more blind spots.