State rolls out new tsunami hazard maps

Coos Bay tsunami mapThe state has issued the first of a planned series of 80 new, high-resolution maps that graphically illustrate the risks of tsunamis on the Oregon coast, this one covering Coos Bay.

The 48-by-52-inch map, published this week by the Oregon Department of Geology and Mineral Industries (DOGAMI) shows in great detail which low-lying areas around Coos Bay are greatest at risk for tsunami inundation, by either a near-shore Cascadia Subduction Zone earthquake or a more distant quake that sends waves traveling across the sea.

The agency is in the process of upgrading all its coastal tsunami maps, first produced in the early 1990s, to “incorporate all the best tsunami science that is available today,” according to a DOGAMI news release announcing the new map.

The map, in a printable, high-resolution format, is available on CD for $10.

The new, more detailed maps are based on the geologic record of previous tsunamis, as well as knowledge gained from recent earthquakes in Sumatra (2004), Chile (2010) and Japan (2011). They include projected tsunami wave height time series charts and a measurement of the exposure each community has to various tsunami scenarios, including a count of the number of buildings that would be inundated under each scenario. Evacuation routes are also shown.

DOGAMI has been working with many collaborators, including Oregon Sea Grant, to get the new maps produced and in the hands of the public, planners, emergency managers, elected officials and other local decision makers. The effort is tied to  NOAA’s National Tsunami Hazard Mitigation Program, which DOGAMI administers in Oregon.

The agency plans to release additional maps as soon as they are ready, with a goal of having new maps for the entire coast by the middle of next year. The next set, due for release in February, will cover the North Coast from Netarts to Rockaway Beach, including Tillamook.

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