Geohazards in Washington State

(Andra) This is Andra Nordin, a student correspondent with Spark Science. Today’s show was recorded at the 2018 geohazard symposium in Seattle Washington and at Western Washington University. Thank you to David Cabernus [sp?] Dr. Cathy Trust [sp?] and Dr. Robert Mitchell in order of their appearance. In this episode we’ll be featuring interviews conducted at the 2018 geohazard symposium with at large attendees and one of the organizers as well as a discussion on geological disasters in Western Washington with a geology professor from WWU. We hope you enjoy the show.

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(Andra) I’m here with David at the 2018 geohazrd symposium. I’m curious, did you know much about geology of Western Washington before coming to this event? Did you know?

(David) Basic fault line.

(Andra) What do you think was the most important take away for you coming to the symposium or that you learned while you were here?

(David) How much data is available to the public? There is so much data and it’s at our fingertips. You don’t have to be a researcher to access it.

(Andra) Right. There’s public access. How has your initial reaction to the term geologic disaster changed after coming to this symposium. What comes to mind now? What do you think about it?

(David) how ubiquitous it is. It effects everything. There it’s an aspect of life that a major disaster won’t effect.

(Andra) I agree. And how is this symposium effected your view on preparedness for natural disasters?

(David) Get the boat away from the dock as quickly as possible. I don’t know. I generally park my car on the north side of the ship canal because if something happens, I don’t want to have to get across a bridge to get home. I figure I can walk across a damn at the locks or at the rails to get back to the boat. So, we have pitch bags on the boat you know, that sort of probably should be in the car as well. I guess it’s one of the things we got for the boat but not for the car. Just a thought. Having preparedness bags. Access is huge. This is great. I had no idea. I think if more people knew about this information and preparedness we’d be better. You can gage how much danger by where you’re living with these maps.

(Andra) You can look up your address. It’s amazing. I didn’t know about it either.

(David). Yeah. That’s huge.

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(Andra) What important takeaway would you like attendees to gain at this symposium?

>> So, one is, I think, residence in this state, they all need to take it upon themselves to get informed about the hazards in their neighborhood and get prepared. Because there’s no question that we will experience large earthquakes here among other types of hazards. And there’s a great way to get informed. That is through some of the country, city and state websites. They have great map your hazards kind of portals that you can go into, type in your address, and see what kind of hazards you have. A lot of those same portals will give you basic information: what do to in the event of an earthquake, how to recognize a land slide, what not to do if you live on a slope, that sort of thing. That’s one of the takeaways.

The other takeaway which was pretty humbling today for me to hear is as a result of the research the geological survey is doing, they have found that within sort of the Puget low land area, as a result of all of the active crustal faults we have in the area, our earthquake risk is now known to be greater than what I even knew of yesterday. So, the current thinking is that within this box we are likely to see an earthquake on one of these shallow faults about every 200 years. These are like north ridge California earth quakes, not like Nisqually earthquake, we’re talking shallow earthquakes where the ground is going to shake a lot harder. That’s really humbling to me even as a geologist. I didn’t have an earthquake kit before. I’m going to put one together now.

(Andra) Me too! [Laughing]

>> Right? We’ve got wonderful vendors here with great information on what to put in your earthquake kits and one more take home message is, try to plan for two weeks of not having the typical infrastructure and amenities that we have.

(Andra) That’s what surprised me in my engineering geology class last quarter, the infrastructure that is effected in these disasters. Really, you should be worried about going two weeks without access to anything.

>> Hundreds of bridges in this state, especially in the Puget low land. A lot of those bridges, half of them, have not been retrofitted so there could be failures during these earthquakes. That will effect a lot of people not being able to get home, not being able to get to their kids, to parents, to spouses, it’s a humbling thing.

(Andra) You said that you put this on every five years. What are some themes you have done in the past?

>> Typically there are two organizations that are jointly putting this on today, yesterday and tomorrow. Northwest Geological Society, and the Association of Environmental and Engineering Geologists. This is the first time we’ve done it joint and the first time we’ve done a public outreach event like today.

(Andra) Which I loved by the way.

>> Yes, thank you. Me too. Many of us geologists feel passionate about sharing our information and we want citizens to be better informed. So, in the past the North West GS has done one every 5 years. It’s generally about cutting edge science. This is the first time we’ve focused on geological hazards and the cutting edge research in geologic hazards was presented yesterday. Then some of that is being presented today. But today, we are adding in the concept of, how do we get prepared. What do we do in the event of a tsunami or an earthquake.

(Andra) Right. Asking those logistical questions.

>> Yesterday we called it our technical day. We had a similar turn out to that one that we had of our previous two events. Today we had no idea what to expect of a public turn out. It turns out it’s really hard to get the message out that you are doing this kind of thing. We contacted a lot of media outlets, we put ourselves on events calendars, etc. Turns out, most people heard about this event either through some website through work or word of mouth. Not as much through media. Which tells us somehow we have to find a better way to get the word out if we do this again. I think we will.

There is so much people need to know to get ready. I really believe that if you are informed about what your risks are, you are more apt to get prepared for them right? One of the things that I’ve seen, I do a lot of field geological mapping in urban areas, we have a pretty smart citizens degree in Washington. I’ll knock on doors to ask to cross their property to look at their hill side and people are pretty smart about what the earthquake risks are here. We’ve got new information that increases our risk so we really want to try and get that information out some how. If anybody has suggestions for more outreach, we’d be happy to hear it.

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(Andra) What do you consider the most impactful geologic hazards within Washington State?

>> I think the ones that get the most attention in terms of hazards that are typically those that don’t happen as much but have more devastation. I’d say earthquakes because of our tectonic setting here, we’re an active earthquake region. Even though we have not in our life time experienced many earthquakes, I think the effect of that is going to be dramatic when it does occur. In terms of both, not so much lives, I think the United States is very proactive on building codes and ensuring that buildings withstand a certain amount of ground shaking. I think it’s going to be infrastructure that’s going to be a big problem.

When I’m thinking about infrastructure, I’m not thinking about homes or buildings but what we consider to be the life lines that are feeding those homes and industries such as underground pipelines, waterlines, gas, electricity, our freeways, you know if you went out on a bridge in Bellingham and count how many semi trucks that go under that bridge in a day, you realize that most of our goods and food etc. are delivered to us by truck. If there is devastation to a bridge or a freeway and we can’t get access to that, it’s going to be a problem.

That would be, I would say, I would consider being one of the more impactful. That said, there are a lot of more common geologic hazards that are constantly happening and constantly impacting people. That could be, I think, we are all aware of landslides. The Oso land slide brought a lot of attention to landslides but those are occurring quite often especially in the winter months. [Toilet flushes] When it starts raining and the earth is more started and weaker structurally. Another one of those that I think commonly effect people are floods. There’s a lot of major rivers draining these cascades. As they sweep over the low land landscapes they’ve been engineered and levied. When there’s severe rain storm and these rain [inaudible] events. For rain fall that impacts a lot of people in terms of floods. Those are I think some of the more common ones.

(Andra) That’s something that is really interesting to me when I was first learning about geology such as how interconnected the different hazards are. If you have a lot of rain fall, if you have an earthquake happen in the winter months its worse because of how unstable the ground is. I think that is a huge thing in Washington.

>> If you have an earthquake in the winter months, not only are you getting the ground shaking that can effect obviously faulting and infrastructure, it can create a lot of landslides.

(Andra) Yeah. A lot. So, that leads into how do you classify different mass wasting events. We have landslides and we also have rock falls and a lot of different types of things that the average person doesn’t know about.

>> I would kind of broadly categorize it into three types. I think of mass wasting as kind of shallow mass wasting events that we commonly see in these high elevations where we get these thin soil failures which can sometimes turn into debris flows because they’re occurring in these steep drainages and get started with water and deliver a lot of sentiment and debris. Logging and slash, those are dramatic, the debris flows. I think the other type of land slide failure in soil is deep seeded landslides that are quite common.

The failure occurs deeper underground in kind of a curved surface. Usually in these geologic — these glacial deposits, Whidbey Island, the land slides you’ve been hearing about, the Ledgewood slide for example, a lot of those on Whidbey Island because of the glacial. There’s a lot of these deep seeded land failures. Here close to us, because we have the Chuckanut sand stone are these bedrock failures. As you’re driving down Chuckanut Drive, it seems like every year we have one or two failures in the winter months along Chuckanut Drive. We have failures along I-5 in the Chuckanut sandstone.

As you’re driving down there you can see the rock bolts where engineers have tried to stabilize theses. These are high risk areas occurring all over Washington state where there’s a crops of, we call them transportation corridors whether they be highways or freeways or railroads or even gas pipeline corridors. When you have to carve into these bedrock surfaces, sometimes it leaves them unstable. Obviously it requires a lot of maintenance to keep them from failing. Those are the three classes.

(Andra) For a road like Chuckanut, that was built a really long time ago, what 100 years ago?

>> I would say, I think it is. I can’t say for sure but I think it was one of the original highways that connected us with Seattle.

(Andra) is there a lot more known now about breaking into bedrock surfaces like that?

>> I think there is, yes. You know, that said though, there are engineers; mining has existed for a long time. Mining engineers, there are probably some of the original engineers in terms of history in this country. Most engineering institutes, like where I got my engineering degree at Michigan Tech I started out as a mining engineering. Colorado school of mines started out as a mining engraining, New Mexico Tech, all of these technical engineering schools started out as mining engineering schools. I think they knew a fair amount about rock failures and probably had to somewhat mitigate those. Because there are so few roads put in at that time, we have such a high density of roads here we are imposing more on those types of landscapes.

(Andra) Interesting. You touched on this already a little bit. Can you speak to why in Washington state, the high rain fall effects landslides and how we are so at risk here?

>> Well, it turns out that the strength of these unconsolidated materials like glacial deposits that form some of our sea cliffs in other regions, the strengths of those are by grain to grain contact. The more grain to grain contact you have the stronger they will resist those gravitational forces that are trying to pull them down. Water that infiltrates into those pour spaces to grades that grain to grain contact.

You are essentially pushing those grains apart and therefore there is less fractional resistance to those and you get more failures because of that. You’ll note that most of our landslides in these unconsolidated deposits occur during the rainiest months of the year. That was documented with the Oso landslide. It was one of the rainiest months of March before that. It contributes as part of that failure. That’s why trees are important on these landscapes.

They pull a lot of water out of that soil and keeps it dryer. The roots offer structural integrity as well as the roots pull water out of the soil that keep them dryer, that keep the grain to grain contact. If you go to Kill Slope and log that hill slope, not only are you removing that kind of root structure that holds that soil in place, you’re allowing the soil to get more saturated. There’s going to be more failures as a result of that.

(Andra) That’s something, I know when I hike, sometimes I think of the basic overarching principals, you notice it when you’re walking through. There’s a lot of tree cover and you’re not getting rained on much if at all. That principle of how it helps landslides but also when you’re on a bank and just a little small bit falls off from being so saturated. Those things you notice that are bigger wide spread, this is what’s happening in the bigger landslides. That’s fun to go out and notice that. So, you’ve done research on the water sheds of Whatcom County, the Nooksack specifically. So, how does your research relate to forecasting events like this?

>> One of the things that scientists are projecting for the future in terms of there’s all kinds of models they use to predict what that climate’s going to look like in the future. Not only in terms of temperatures but maybe in terms of what the precipitation looks like and these basins in the Cascades are what we call transient basins meaning that they’re very sensitive to whether it’s going to be raining or snowing. Experience that at Mt. Baker. It could be raining one weekend and snowing the next. We’re right at the threshold where the temperature regime could be rain or snow.

Right now it’s in a situation where we are developing a fair amount of snow pack in the winter months. That snow pack buffers the rain fall on the landscape. So, what we have been seeing as time marches on and climate gets warmer, that snow line is going to be increasing in elevation meaning the Mt. Baker ski area could be getting a lot more rain than snow in the future. That holds true for the landscape below that. Given my previous statement about what’s detrimental to these hill slopes is infiltrating water. If you have more landscape that’s going to receive more rain fall now rather than snow, there’s going to be a higher risk of more saturated sediments, and more mass wasting events, higher sediment in streams.

The more sediment you put into streams, not only is that detrimental to salmon and salmon habitat, it’s detrimental to flooding events because it starts building up and degrading in the stream channels. The river channel rises meaning that it can hold less water and you’ll get more flooding events. Scientists also predict that these rain fall events could be more dramatic. Not dramatic in the sense of higher intensity, longer duration. We think of these, formally we call them pineapple expresses now we call them rivers that will deliver these huge volumes of rain fall over the period of two or three days.

Some believe these will occur more often. It’s hard to predict. I think if they do occur more often and if the rain fall is falling on landscapes that are now not protected by snow, there’s going to be more risk of mass wasting and landslides.

(Andra) Riparian zones along the river are going to be at their more important?

>> They’re important for stream temperatures too. One of the things we’ve been looking at in our modeling is, if air temperatures are going to make it warmer there’s going to be less snow pack. Right now, snow melt is responsible for buffering those stream temperatures during spring and summer as is glacier melt. If we have less snow pack in the future, because of warmer temperatures, we’re going to have warmer stream temperatures. Not only because there is less snow melt but there’s also warmer air temperatures that are warming those streams. One of the risks we are facing here, salmon are already threatened. If we have higher sedimentations in the streams and warmer stream temperatures, it’s going to be a problem.

(Andra) So, it’s like providing shade to the stream. Is that what it’s doing?

>> The riparian buffers do. They provide shade to keep the streams cooler. But ground water also serves to keep the stream temperatures cooler as well. There’s a chance, if we do have more rain fall and there is higher water levels in the aquifer systems, that too could buffer those stream temperatures. So that could be a positive but we’re not sure how much of an influence that is.

(Andra) Wow. You talked about Oso land slide a little bit. Why was that such an overwhelming loss in terms of gaps in information between the scientific community and housing developers in that area and also the public?

>> I think even — there were geologic studies in that valley that identified the risk. I think what was learned from that was, what was unique about that land slide was how far it ran out. What we mean by run out is that it fails how much landscape does it inundate below it.

It inundated a lot of landscape. More than anybody would have anticipated. Because of how saturated it was and it could have potentially could have liquefied onto that flood plain of the Stillaguamish, it kind of hydroplaned across the river valley. I think there was always this balance between policy and development and natural systems are hard to nail down. I think the government learned a lot from that and they’ve made strides. The state provided resources to the DNR to do more landslide mapping and to do more analysis of the landscape of the lidar [sp?] There is more attention placed on that. It takes, unfortunately the ramifications of a big disaster for things to happen.

(Andra) Do you think we need more geologists in policy?

>> Oh yes. And I think every county should have geologists. Most are aware of these natural hazards. All of this requires resources. Many times the state is stripped and doesn’t want to raise taxes. Those are risks you face when you are not willing to provide those kind of services and have the proper — I think one thing that has helped the public quite a bit is geologists are licensed in Washington State. The whole idea of licensor is for the protection of people property. I’ve been on the licensing board 8 years. My term is just finishing as of today. [Laughing.] Or this week any way.

I spent 8 years on the licensing board and saw firsthand complaints and so forth about the need for having licensor having professionals out there and watch dog services out there making sure that geologists are making proper decisions about people’s property and risk levels. I think the licensing has helped quite a bit in Washington State.

(Andra). Wow. Off the top of your head, do you know of resources online for people? What websites should they be going to if they want to read about these risks?

>> The first place I’d go is to Washington DNR. They have a really good section on hazards and how to prepare for hazards. They director you to the Washington department of emergency management which I highly recommend visiting. If you go to DNR site they will point you to the emergency management site which used to be to prepare for three day events. Now their coaching people on how to prepare for two weeks.

How much water to have, food supplies for your family for two weeks. Which makes sense to me. If we had a major earthquake in Bellingham and our services were cut off, most of the intention is going to be placed on huge metropolitan areas like Seattle. It’s going to be a while before areas like Bellingham will get attention. To be prepared for that is important. The two sites to visit which I’ll echo would be DNR of course has forced practices. The earth science division has a section there on geologic hazards. There’s information on what they are and how to prepare for them.

(Andra) there’s a lot that goes into it. Just sitting down and taking a day to plan that out is useful. What do you think are little things that people should be doing to prepare for geologic hazards on a local level? If they were to have a landslide that blocked off a road or something?

>> Just be aware about when you are buying a house or what you’re renting or if you’re on a hike, what kinds of potential risks might be involved with that. That’s why it’s important to have a little bit of geological prowess I think. I think everybody should be required to take geology 101 just to get a sense and know what are the risks out there.

What other geologic hazards– many of those are easy to avoid in terms of — it’s like when you’re hiking in the Cascades. You know how to avoid a crevasse, it’s just — what river valleys might be more sensitive. I’m a big road cyclist and I typically avoid Chuckanut Drive just after a big rain event in the winter. Those are the type of things that are common sense to be aware of. Maybe common sense to us but not to everybody else who didn’t have the opportunity to take geology 101. I guess my advice would be, if you haven’t had that opportunity or can have that opportunity, afford the time to visit the DNR website. There’s a lot of educational materials on that.

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(Andra) Thanks for listening to Spark Science. If you missed any of the show, go to our website sparksciencenow.com. If there’s a science idea you’re curious about, send us a message on twitter or Facebook @sparksciencenow. Spark science is produced in collaboration with KMRW and Western Washington University. Our producer is Regina. Our audio engineer for this episode is Andra Nordin. Our theme music is chemical clsjtc by Blackalicious and Wondeland by Janelle Monet.

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