CASCADIA EARTHQUAKE SCIENCE AND IMPACTS IAN MADIN, DEPUTY DIRECTOR OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES MAY 12, 2017

OREGON AND JAPAN: GEOLOGIC MIRRORS SOURCE: DOGAMI SOURCE: DHS, 2011 IAN MADIN | DOGAMI | MAY 12, 2017

THE CASCADIA SUBDUCTION ZONE Although there are many faults that threaten Oregon with future earthquakes, the Cascadia subduction zone is by far the greatest threat to western Oregon, because of its size and frequency of earthquakes. Produces larger earthquakes than any other source. SOURCE: DOGAMI IAN MADIN | DOGAMI | MAY 12, 2017

HOW LIKELY IS OUR NEXT GREAT SUBDUCTION ZONE EARTHQUAKE? The last M 9 Cascadia Subduction Zone earthquake struck Oregon on January 26, 1700. M 9 earthquakes affect Oregon every 530 years on average. M 8+ earthquakes on the south coast combine with the M 9 events to bring the average time for southern Oregon to 240 years. 300 years since the last event, we are not overdue! But - we will experience another Cascadia earthquake. IAN MADIN | DOGAMI | MAY 12, 2017

IMPACT ZONES - Extreme damage in the Tsunami Zone - Heavy damage in the Coastal Zone - Moderate damage in the Valley Zone (but most of Oregon’s population will be affected) - Light damage in the Eastern Zone SOURCE: DOGAMI IAN MADIN | DOGAMI | MAY 12, 2017

Damage in the tsunami zone will be almost total PHOTO CREDIT: US NAVY Modeled M9 tsunami at Rockaway Beach M9 Tohoku earthquake & tsunami Damage in the tsunami zone will be nearly complete. The M 9 tsunami zone in Oregon contains 1900 businesses, 10,500 housing units occupied by 22,000 residents, and 247 miles of state highway. SOURCE: DOGAMI IAN MADIN | DOGAMI | MAY 12, 2017

Severe ground movement in Western Oregon will cause widespread damage to lifelines and infrastructure SOURCE: DOGAMI IAN MADIN | DOGAMI | MAY 12, 2017

Damage to lifelines and interdependency will slow restoration of services and rebuilding of the economy Lifelines are structures that are important or critical for a community to function, such as roadways, pipelines, power lines, sewers, communications, and port facilities. They’re interdependent, and the earthquake will damage them all at the same time. The resilience of the transportation network is considered a key factor for re-establishing other lifelines after a major Cascadia subduction zone earthquake. IAN MADIN | DOGAMI | MAY 12, 2017

Oregon Department of Geology and Mineral Industries IAN MADIN Deputy Director Oregon Department of Geology and Mineral Industries ian.madin@Oregon.gov OregonGeology.org @OregonGeology Facebook.com/OregonGeology