The Associated Press 4 months ago
Study, maps, show more landslides in Astoria
Maps, study show city of Astoria has more landslides than previously thought.
ASTORIA, Ore. (AP) — Leaders in Astoria say the city shouldn't "freak out" because of a newly released maps and a study that show about half the damage to the city from a major earthquake would be from landslides.
The hilly city at Oregon's northwest tip is known for landslides and unstable geology, but the new maps show many more landslides than had been known: 120 within the city limits, 83 of which have moved in the past 150 years.
"I was surprised how many were pointed out on this map, but anyone who has lived in Astoria should not be surprised that we've had landslides," said Mayor Willis Van Dusen.
The state Department of Geology and Mineral Industries used laser-mapping technology, the Daily Astorian (http://bit.ly/1fQy7UF) reported. The study shows that 55 percent of the city is highly susceptible to shallow landslides, 37 percent to deep landslides.
The deeper the slide, the less likely measures such as retaining walls will do any good, city officials said.
City Manager Paul Benoit said the city has long been aware of the jeopardy — it had the maps for five years before they were released publicly last week.
"We're continuing to work with the experts to know how best to interpret these maps," he said. "... It's important not to freak out. It's where we live, and this just helps us to understand where we live better."
Officials say the maps are not specific to individual lots but rather describe areas, and they can assist in emergency operations, evacuation maps and planning.
"They give planners an idea of what is out there and where to focus their efforts," said state scientist Bill Burns.
Over the years, the city has dealt with several major slides. Houses have been moved from areas near the hospital and the Chamber of Commerce offices, for example.
Van Dusen recalled the largest landslide in recent history was in 2007, a deep one at 85 feet. He said damage was minimized because "the city didn't allow any to be built there after the previous slide in 1954."
Information from: The Daily Astorian, http://www.dailyastorian.com