Many Lower Mainand residents likely believe that the greatest financial losses in a catastrophic west coast earthquake would occur in the city of Vancouver.

That's because it's home to the tallest buildings, largest population, most jobs, costliest real estate, and major port and rapid-transit infrastructure.

But according to insurance risk-management expert Justin Morscsco, the biggest financial hit is more likely to occur in the region south of Vancouver that straddles the main arm of the Fraser River.

Roscsco, a senior product manager with RMS, wrote an article explaining why in the August issue of Canadian Underwriter magazine.

He pointed out that for thousands of years, sand, silt, and other sediments were carried to this area by the Fraser River, creating a network of islands.

"Today, those islands and their surroundings are home to the fast-growing City of Richmond, the Vancouver International Airport, Deltaport container terminals, and more, all of which sit on top of what geologists call sedimentary basin," Roscsco wrote.

In insurance terms, this area accounts for 20 percent of B.C.'s earthquake-exposed value, compared to just 13 percent within Vancouver city limits, according to Roscsco.

The reasons for this are related to why losses occur during earthquakes, such as through ground motion and liquefaction.

"The Fraser River Delta in British Columbia has all of these liquefaction triggers present: shallow ground water; loose, sandy soil; and a web of river channels," he wrote. "It also has the most important trigger of them all, nearby faults and the Cascadia Subduction Zone, with the capacity to produce large earthquakes."

Roscsco concluded his article in Canadian Underwriter by stating that risk-modelling techniques have improved as a result of advances in earthquake science, and the insurance industry needs to be aware of them.