The following is the scenario from the state of Oregon for the IronOr Exercise
Disclaimer: This scenario is designed for exercise purposes only. The scenario is intended to be realistic but are not meant to be a precise representation of earthquake impacts or response activities. The information in this report is not predictive; there may be significant differences between this scenario and published modeled results and actual losses following a real-world Cascadia Subduction Zone earthquake and tsunami.
Exercise Scenario?Timeline
At 8:00 A.M. on October 25, 2024, the Cascadia Subduction Zone released the centuries-long stress built up on the margin between the Juan de Fuca Plate and the North American Plate. A 9.0 magnitude earthquake started and encompassed the nearly 700 miles (1100 km) long fault.??The earthquake impacted the entire fault zone, rupturing from end to end, causing one great earthquake that was felt throughout the Pacific Northwest.
Within seconds of the fault's rupture at the southern end, seismic waves started impacting coastal communities in Curry and Coos Counties. As the rupture expanded northward, shaking intensified on the south coast of Oregon and Northern California. The shaking intensity along the coast rose to MMVI (strong shaking) and continued to rise as the shaking continued.??
As the locked zone released the pressure, the North American Plate slipped ~80 feet (~25 meters) west, causing an uplift of the ocean floor. This displacement caused the water column to rise, generating a tsunami. The tsunami split with waves going both east and west at about 500 miles per hour.?
By 8:02 A.M. on October 25, 2024, Eugene, Salem, and Portland communities began to feel the first shaking. The shaking continued for 2-3 minutes. While the shaking was not as strong as on the coast, the nature of the long seismic waves generated by a subduction zone earthquake means that more damage likely occurred to larger, older structures. The rupture continued northward, and the coastal areas of Washington state began to feel the effect of ground shaking.??
Across Oregon, power went out, and cellular communication was significantly impacted. A significant number of unreinforced masonry, non-ductile concrete, and tip-up buildings collapsed, and bridges across the Coastal region and Willamette Valley collapsed or shifted off supports.?Coastal subsidence caused a drop of 3-6 feet (1-2 meters), depending on location, which in turn caused an inrush of ocean water.?
At 8:15 A.M. on October 25, 2024, the first tsunami surges arrived on the outer coasts of Curry and Coos Counties. On the North coast of Oregon, the leading trough of the tsunami caused a drawdown, and the water temporarily receded from the coast. The initial waves were followed by a series of increasingly larger surges, averaging 30-50 feet (9-15 meters) high and in some areas, even higher. At 8:45 A.M. on October 25, 2024, the tsunami surges reached the Clatsop Spit, entered the Columbia River, and impacted the town of Astoria.
The tsunami generated by the earthquake wrought destruction along the Pacific Northwest coastline. These waves inundated coastal towns, sweeping away homes, businesses, and critical infrastructure. Entire neighborhoods were reduced to rubble, and thousands of residents were either swept out to sea or trapped beneath the debris. The force of the water uprooted trees, overturned vehicles, and left a thick layer of mud and wreckage in its wake. Ports and marinas were decimated, disrupting the local fishing industry and cutting off essential supply lines. The environmental impact was severe, with the tsunami waves causing extensive erosion and depositing hazardous materials across the landscape.
Additional Tsunami inundation area can be found through the following ¨C areas in yellow and brown have been significantly impacted.
At 9:00 A.M. on October 25, 2024, the first of thousands of aftershocks was felt along the coast. These aftershocks will lessen in frequency and magnitude over time.?In the first 24 hours after the main shock, there were dozens of aftershocks in the 4.2-5.3 magnitude range.? With more intense aftershocks listed below those are listed below:?
¡¤???????? 7.4 Mw, October 26, 2024, at 12:31 A.M.??
¡¤???????? 7.1 Mw, October 26, 2024, at 3:37 P.M.?
¡¤???????? 5.7 Mw, October 27, 2024, at 1:15 P.M.?
Exercise Scenario?Impacts
This earthquake and subsequent tsunami had a significant impact across the State of Oregon, with the shake intensity felt last Friday shown in the image below:
The impact on Oregon was profound. The initial earthquake and subsequent tsunami resulted in an estimated 4,200 fatalities and over 14,000 injuries. Nearly 260,000 buildings, including schools and hospitals, suffered moderate to complete damage. Approximately, 438,000 people have been displaced, and 50,000 households are left homeless. Essential services, such as power, communication, and water, are severely disrupted. In total the estimated economic losses are expected to exceed $30 billion.
Transportation infrastructure was severely impacted. Access to the most severely impacted areas is limited for ground assets and primarily available through air assets due to damaged surface transportation infrastructure. Highway bridges, railways, airports, and port facilities sustained widespread damage. Nearly half of Interstate 5, spanning from southern Oregon to the Columbia River, was rendered impassable. U.S. Highway 101 along the coast suffered significant damage with initial reports sharing limited, to no movement capabilities. As many as 700 bridges may have collapsed or be in danger of collapsing. Landslides triggered by the earthquake blocked key routes through the east of the Cascade Mountains, isolating communities and complicating evacuation efforts. Coastal areas, now accessible only by sea or air, faced monumental challenges in receiving emergency supplies. Status of locally managed roadways is currently not well known. Portland International Airport (PDX) suffered moderate to severe structural damage, and its runways are cracked and require repairs. Most airports west of I-5 are damaged or still require assessments.
Communication networks are similarly devastated. Cellular and landline infrastructure was largely destroyed. Although communication facilities in eastern Oregon sustained less damage, intermittent power outages hampered their functionality.
Food and water supplies were severely disrupted. The destruction of transportation and power networks jeopardized food storage, particularly frozen and refrigerated goods. Potable water is scarce, with coastal areas potentially facing weeks or months without safe municipal drinking water.? Much of the potable water systems in western Oregon have suffered medium damage, including widespread breaks and leaks. Food preparation and processing facility inspection requirements exceed local capabilities.
Health and medical systems have been overwhelmed. Many hospitals sustained medium to high damage and drastically reduced bed availability. Hospitals and medical facilities that can operate lack enough staff and equipment to handle the surge in patients seeking medical attention. Medical facilities are suffering from compounding issues related from the lack or power, fuel, clean water, and supplies. Pharmaceutical supplies are dwindling rapidly, and reestablishing medical supply chains is hindered by damaged transportation networks. Limited refrigeration compounded the crisis.
Energy infrastructure was crippled. Large regions of Oregon plunged into darkness minutes after the earthquake, and restoring power was projected to take weeks, if not months. The state face a severe shortage of refined fuel due to damage to fuel storage, transportation, and pumping infrastructure. Fuel availability at any storage facilities are at 50% of routine capacity, and the Olympic Pipeline has been damaged and is not operational. Most gas stations west of the Cascades are not operational, there are not impacts to gas stations east of the Cascades. Generator support is insufficient to meet demand. The cascading effects of power outages hinders efforts to stabilize other lifelines.
The safety and security situation are evolving. Local communities have shown remarkable resilience, with residents banding together to support each other. Public services, such as fire and police departments, are operating at reduced capacity, struggling to manage the increased demand. While there have only been limited reports of looting and rioting after the earthquake, there are concerns that the security situation will deteriorate as supplies become scarcer. Police forces, already stretched thin, struggled to operate in heavily damaged areas, and essential government services are overwhelmed. Evacuation efforts are hindered due to the lack of public safety personnel and compromised transportation infrastructure.
Hazardous materials incidents further exacerbated the disaster. Chemical facilities along the coast were inundated by tsunami waves, resulting in major maritime hazardous material incidents. The Critical Energy Infrastructure Hub in Portland suffered catastrophic damage, resulting in a massive spill of millions of gallons of oil and hazardous materials into the Columbia River. This environmental disaster compounded the region's challenges, threatening aquatic ecosystems and contaminating drinking water sources. Additionally, Natural gas pipelines suffered significant breaks, complicating recovery efforts. Thousands of fires have broken out in areas thought the state.
In the face of such overwhelming devastation, the response efforts began. The people of the Pacific Northwest faced immense challenges in the aftermath of the Cascadia Subduction Zone disaster.
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From Tyson Brooks EC
Union County ARES
??? Power has finally been stabilized at the EOC with the emergency generator working once more. Commercial power is having to do rolling blackouts in residential areas due to problems with the Columbia River Dams. Local Power is now relying on the local solar power project, local hydro and residential reverse feed solar power to feed Union County.
Starting at 9am today, please use the local K7UNI repeater to check on your fellow ham radio operators. Make sure that you announce that your traffic is an exercise only and is part of the State IronOr24 SET.
When you can today, using Winlink, found in the templates section of messages, fill out and send an Oregon SITREP message to W7BL.
This is a multi-day exercise. I will be sending out injects via groups.IO and once we get going also into Winlink. If you are having problems with Winlink, please give me a call and lets see if we can work through the issues. 541-910-2784. But it might have to wait till after work.
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Tyson Brooks
W7BL
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