Lori Dengler | Jurisdictional boundaries should not prevent preparation for major Cascadia earthquake – Times-Standard


There are many different moving parts to building resilient communities. There are multiple private and public entities, the built environment and infrastructure, and various economic interests. There are cultural issues and socio-economic issues, and everyone has their own priorities. The daily priorities of jobs, deadlines, child care, or elder care make it easier to plan events that don’t seem imminent.

Every individual, family, business or other organization has a role to play in resilience – to reduce our risk, know what to do during tremors and have supplies to be alone for weeks if needed. But the government also has important responsibilities. It is very difficult to prepare for something that you don’t know much about. When a Cascadia earthquake occurs, what will be the pattern of ground shaking and how far inland could a tsunami penetrate? How will roads, buildings and infrastructure be affected? It is not possible to provide precise answers, but with geophysical studies and technical modeling, a general picture can be drawn.

The government’s role in risk assessment is to build and maintain strong research capacities in public and academic institutions, to learn from similar events elsewhere, and to freely exchange ideas. Let’s take a Cascadia earthquake as an example. It is the worst event for our region and certainly on the list of the top five potential catastrophic natural disasters in the United States in terms of scale, long-term impact and damage.

We have two government agencies working hard to assess the danger of Cascadia. The USGS is focused on the earthquake and has developed ShakeMaps showing the likely extent and pattern of ground motions we might experience. Ocean hazards are the responsibility of NOAA and over the past three decades the agency has acquired better ocean depth data and improved numerical models.

It is not uncommon for governments to distribute solid land and ocean risks among different agencies. I have worked in Peru, Chile and New Zealand, which have also delegated these responsibilities. Most of the time it works fine. The vast majority of earthquake impacts are shaking related and most marine hazards do not involve earthquakes. But large subduction zone earthquakes like Cascadia blur those lines.

The USGS regularly publishes earthquake loss estimates. These estimates are based on population, building types and shaking strength. Typically available in 30 minutes, they provide a quick picture of the scale of impacts and highlight areas that may require response and rescue. These estimates only cover shaking impacts, and the USGS notes that tsunami impacts are not included. It is certainly possible to make similar loss estimates for tsunamis, but that is within the purview of NOAA and not included at this time.

Earthquake early warning is another area where greater integration between the USGS and NOAA could be helpful. If you were in Humboldt County and signed up for MyShake last December, you probably got an alert on your phone seconds before or just when you started shaking. It’s great to have your head up to get your head down and under a table before the jolt happens. But there was nothing in that tsunami warning. The December 20 earthquake was not large enough to cause a tsunami and NOAA’s National Tsunami Warning Center released this information about 4 minutes after the earthquake. It would have been so nice to have this information on your cell phone after you received the tremor alert.

This is not a problem in Japan where earthquakes and tsunamis are hosted at the Japan Meteorological Agency under the same roof. Earthquake alert and tsunami forecast are broadcast on the same platform and tsunami evacuation advice is provided as well as Drop, Cover, Hold On.

The tsunami/earthquake divide has also made its way into awareness. I have been fortunate enough to obtain grants through the NOAA Tsunami Program and the FEMA (Federal Emergency Management Agency) Earthquake Risk Reduction Program and until recently I I was able to mix earthquake and tsunami risks into our products. But this year a new barrier seems to be in place. I was told that FEMA funding could not be used for tsunamis. That’s why you won’t hear about a tsunami in our new Mendocino Triple Junction video, even though the small tsunami produced by the 1992 earthquake was one of the most important lessons.

I’m currently in a bit of a mess over FEMA funding for next year. We hope to update Living on Shaky Ground magazine to include earthquake early warning and new tsunami warning messages. They balk at any mention of tsunamis in the project, and I have to bend over backwards to demonstrate that we will be using other funds for the four-page tsunami magazine. I’m sure NOAA and USGS fully understand the earthquake/tsunami overlap, but other bureaucracies are building what I consider to be an artificial and potentially dangerous barrier.

Other jurisdictional boundaries can also impede resilience. Another responsibility of FEMA is to organize exercises to respond to disasters. The larger the event, the more complex the response, rescue and recovery. Two weeks ago, FEMA held a drill to practice the government’s response to a large earthquake and tsunami on the Cascadia subduction zone. The exercise, called Cascadia Rising22, brought together emergency managers, planners and government officials to discuss operational activities, logistics, resource management and communications for response operations.

Presented as a “complete exercise”, alas, this was not the case. It only included participants from FEMA Region X and it excluded California. California is in the FEMA IX region, as is Hawaii and the Pacific territories, all of which will be affected by a Cascadia earthquake/tsunami.

California state emergency officials are on top of this and shaking the chains. In November, FEMA IX will host a Cascadia exercise and when planning begins for Cascadia28, I’m crossing my fingers that we’ll be included.

Lori Dengler is professor emeritus of geology at Cal Poly Humboldt, specializing in tsunami and earthquake risk. Do you have questions or comments about this topic, or would you like a free copy of the Living on Shaky Ground readiness magazine? Leave a message at 707-826-6019 or email [email protected]

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