The Big One Could Lead To Big Losses In Alameda, Experts Say

ALAMEDA, CA — The city of Alameda could be in big trouble when the 'big one" eventually hits,

According to the Mercury News article "‘A house of cards’: When the Big One comes, will Alameda be ready?" older wood-frame buildings, lack of water reservoirs and only five roads on and off the island — "all in hazardous liquefaction zones," are all areas of concern.

But the biggest issue, according to that April 17 article is the "structural reality of the island" which is mostly manmade.

“All those apartment houses along the South Shore, that’s all soup,” Dennis Evanosky, a longtime resident, documentarian and community historian, told the Mercury News. “Everything the water side of Otis, everything the water side of Clement, everything the water side of Main and Central, that’s all man-made land. All of it. Including schools.”

Up until 1902, the island of Alameda was actually the Alameda Peninsula, Bay Area Answers website reports.

"The peninsula was separated from the mainland by a canal to promote drainage of the northern estuaries to facilitate shipping. Landfill was used to extend the island into the bay," Bay Area Answers said.

And according to experts, that landfill will lead to liquefaction and that is what will create a problem when the big one finally hits.

“With fill, it’s a little like a house of cards,” Christine Goulet, director for the earthquake science center for the USGS, told the Mercury News. “Usually what happens is they dredge material from nearby sea or bay, which has a mix of clay and silt, and then they just put that in without compacting it appropriately.”

When serious shaking causes water-logged soil to lose its strength and behave like a liquid, that's liquefaction and so Alameda, with its acres and acres of manmade land is at risk.

"Buildings could tilt and sink into the ground. Bridges and roads leading to them could be severely damaged or destroyed," the Mercury News said, adding that projections warn of dire scenarios for Alameda in the event of a major earthquake on the Hayward fault.

The last major earthquake along the Hayward fault was in 1868 and with major earthquakes historically occurring about every 150 years, the area is overdue.

While the city of Alameda is working to prepare itself for the worst-case scenario, there are no guarantees and according to some experts the safest form of earthquake preparation for the island community would be to "entirely rebuild parts of the island."

“It’s not the fact that it’s reclaimed, it’s how it’s been built,” Goulet, told the Mercury News. “You can remediate today.”

According to the Mercury News article, Evanosky sees the outcome for Alameda to be much of what the Marina district in San Francisco, another neighborhood built on fill, saw after the 1989 Loma Prieta earthquake when entire buildings crumbled into the Earth.

“The only difference between Alameda and San Francisco is that they’re fully aware of what they’re doing,” Evanosky said.

Read the complete story in the Mercury News.