EARTHQUAKE HAZARD MAPS RELEASED FOR COASTAL OREGON

Portland, Oregon: Relative Earthquake Hazard Maps for nine coastal communities highlighting areas of high risk are being released Monday, October 25th in Florence by the Oregon Department of Geology and Mineral Industries (DOGAMI). Maps for Astoria-Warrenton, Brookings, Coquille, Florence-Dunes City, Lincoln City, Newport, Reedsport-Winchester Bay, Seaside-Gearhart-Cannon Beach and Tillamook will be available for viewing during a press conference and question-answer session to be held at the Florence Events Center in conjunction with DOGAMI’s quarterly Governing Board Meeting.

These maps combine the effects of ground shaking amplification, liquefaction and earthquake-induced landsliding to show the earthquake hazards relative to the local geologic conditions. Individual maps for ground shaking amplification, liquefaction and earthquake-induced landsliding for each community will be available on CD-Rom. All maps and CD-Roms will be available for purchase through Nature of the Northwest and DOGAMI field offices (see end of release for more information).

Data was collected and analysis was conducted over a two and a half year period by Ian P. Madin and Zhenming Wang with cartography by Paul Staub. The maps were produced by DOGAMI with funding by the State of Oregon and the U.S. Geological Survey, Department of the Interior (USGS).

Dr. John Beaulieu, Oregon State Geologist and Director of DOGAMI, notes the importance of these new maps. "Coastal communities have long known of the dangers of earthquakes and tsunamis and have already begun taking steps to make their communities safer. These new maps give them even better tools to help reduce the risks involved with earthquakes. A big earthquake like a subduction zone event will still do a lot of damage, but we can significantly reduce the amount of damage by planning ahead. These maps can be used in conjunction with other earthquake and tsunami maps to determine each communities’ most vulnerable areas." Beaulieu includes the following uses for the Relative Earthquake Hazard Maps:

Emergency Response and Hazard Mitigation

One of the key uses of these maps will be to develop emergency response plans. The areas indicated as having higher hazard would be the areas where the greatest and most abundant damage will tend to occur. Planning for disaster response will be enhanced by the use of these maps to identify which resources and transportation routes are likely to be damaged.

Land-use Planning and Seismic Retrofit

Efforts and funds for both urban renewal and strengthening or replacing older and weaker buildings can be focused on the areas where the effects of earthquakes will be the greatest. The location of future urban expansion or intensified development should consider earthquake hazards. Requirements placed on development could be based on the hazard zone in which the development is located.

Lifelines

Lifelines include road and access systems including railroads, airports and runways, bridges, over and under passes, as well as utilities and distribution systems. The Relative Earthquake Hazard Map and its component single-hazard maps are especially useful for expected damage estimation and mitigation for lifelines. The distributed character of lifelines often requires regional as opposed to site-specific hazard assessments. These hazard maps allow quantitative estimates of the hazard throughout a lifeline system. This information can be used for assessing vulnerability as well as indicating priorities and approaches for mitigation.

The press conference for the release of the Relative Earthquake Hazard Maps will take place Monday, October 25th at 9:00AM at the Florence Events Center, 715 Quince St. (541) 997-1994. Additional earthquake hazard maps for Western Oregon communities will be released January 26, 2000, the 300th anniversary of the last great Cascadia subduction zone earthquake.

Relative Earthquake Hazard Maps and CD-Rom data sets for the nine coastal communities, plus additional earthquake related information, are available from the Nature of the Northwest Information Center, 800 NE Oregon Street, #5, Portland, Oregon 97232, (503)-872-2750 or www.naturenw.org or DOGAMI field offices at 1831 First Street, Baker City, (541) 523-3133, 5375 Monument Drive, Grants Pass, (541) 476-2496

Please ask for map set (including CD-ROM) IMS-10 Relative Earthquake Hazard Maps for Selected Urban Areas in Western Oregon (Astoria-Warrenton, Brookings, Coquille, Florence-Dunes City, Lincoln City, Newport, Reedsport-Winchester Bay, Seaside-Gearhart-Cannon Beach and Tillamook). Each maps set is $20

The Oregon Department of Geology and Mineral Industries is headquartered in Portland and is an independent agency of the State. It has a broad responsibility in developing a geologic and engineering understanding of natural hazards, then applying this information to help mitigate the risks of earthquakes, landslides, floods, and tsunamis. The Department is also the lead state regulatory agency for mining, oil, gas and geothermal exploration, production and reclamation.

For more information on The Department of Geology and Mineral Industries’ current projects, contact James Roddey at 800 NE Oregon St., Portland, OR 97232, (971) 673-1555, ext. 242 or DOGAMI field offices at 1831 First Street, Baker City, (541) 523-3133, 5375 Monument Drive, Grants Pass, (541) 476-2496, and the Mined Land Reclamation Program, 1536 Queen Avenue SE, Albany OR 97321, (541) 967-2039.