Unknown: As Alaska's climate becomes warmer and wetter, landslides are a growing problem for some mountainous communities here.

They can be sudden and leave affected families uncertain about the future.

I think the question is more, do we feel safe, returning home?

And that answer is no.

What have geologists learned from destructive landslides in our state?

And how might that science inform future development plans and early warning systems?

We'll discuss it tonight on Alaska Insight.

Good evening.

The human toll from climate change effects in Alaska are real.

The small community of Haines in Southeast Alaska experienced a deadly landslide late last year, and is still coming to terms with the catastrophic damage and the loss of life.

Claire Stremple from member station KHNS reports.

Haines is a coastal town just 100 miles north of Juneau in the Lynn canal.

In December, part of the mountainside just south of downtown slid into the sea.

Two people died when dirt, trees, rocks and debris swept away everything in the slides path.

It was the most destructive of dozens of landslides that pulverized roads and destroyed nine homes in the area.

The slides were triggered by more than 10 inches of rain in two days, what meteorologists call a 200 to 500 year storm.

Climate change is making these storms, and the conditions for deadly landslides, more frequent.

We have no control over when a landslide happens.

And the rebuilding process is so long.

And we need studies.

You need engineering.

Mayor Douglas Olerud is caught between families who want to return to their homes and the liability of allowing them to enter an area that experts say is geologically extremely unstable.

We're standing at the entrance to the Beach Road area where we still, we're over two months after the incident and we still have community members that can't live in their houses and we don't know when they will be able to live in their houses.

So not being able to give them an answer to that and tell them when that can happen, it's hard.

This slide came down about 500 feet from Vanessa Wishstar's home.

She was inside with her husband and two children under five years old when the side of the mountain broke loose.

The sounds were the most terrifying and the feeling of the whole earth - I mean, everything was shaking.

And I just remember grabbing my kids and trying to get out.

But they couldn't wish dar says as soon as they were in the car, they realized the slide had cut off the road to town.

They were trapped.

They and their neighbors organized in the downpour and found a set of stairs that led to the beach about 100 feet below the road.

There, harbor staff and volunteers met them in boats and took them to safety.

Many of the evacuees are not yet back in their homes.

Geologists say the risk of another slide is too great to rebuild the road or re-inhabit some properties, including the Wishstars' I think the question is more, do we feel safe returning home?

And that answer is no, for us.

People down the road just a tiny bit, they do feel safer.

Because we're in the red zone, because there's a huge crack, because there still has a lot more to fall possibly basically right above our houses, we've lost all confidence in our house.

Mayor Olerud is quick to acknowledge the damage is more than financial.

But repairs are expensive for a small town with limited resources, especially after a year without tourism and another lien season on the horizon.

Until relief money comes in the Haines Borough is paying for road and infrastructure repairs from its small fund balance.

And the risk of landslides and flooding in extreme weather also means financial loss in other ways.

January 1 is when we do our base assessment for property values and we're taking a $1.5 million hit on property tax assessment.

That's not what the borough would be getting, but they lowered the value of real property by one and a half million dollars this year due to the storm.

Most roads are patched up for now.

Waiting for a real fix in the spring.

Homeowners have repaired washed out driveways and dried flooded basements.

But the Beach Road slide still cuts a wide snowy scar down the side of the mountain that's visible from town.

A reminder of the homes beyond saving and the lives lost in the storm.

for Alaska Public Media, I'm Claire Stremple.

My guests this evening are Ron Daanen, a geologist with the Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys in Fairbanks.

And Lisa Busch is the executive director of the Sitka Sound Science Center.

Welcome to both of you.

Thanks so much for being here.

Lisa, I want to start with you.

After the 2015 event that led to multiple landslides in the region around Sitka on Baranof Island, your organization started looking for scientific partners to help build information that could help mitigate risk.

Tell us about this.

Who did you reach out to and how did that come together?

Well, when the slide happened in Sitka, we realized that we didn't have a plethora of geologic resources in our small town, like most small towns in Alaska.

And so we reached out to the University of Alaska, to the US Geological Survey to the National Park, U.S. Forest Service, Geophysical Institute in Fairbanks, University of Alaska, Sitka Tribe of Alaska.

We just, we gathered as many entities as we possibly could, and brought them together to see, to basically tell us what we needed to know as a community, and what kinds of questions we should be asking, and where we should be heading.

And after the years of research that have happened now, what have you learned?

And what have the scientists that you've been working with learned?

And how is that information?

How will it be used to help mitigate risk in the future?

So I think the what have we learned is that it takes a lot of different kinds of scientists to work on these very difficult questions.

And what we're doing in our community, and what we've come up with is the idea of, can we develop an, a warning system, an early warning system, to put together the information that we know we can gather.

So we can, we can tap, we can look at soil moisture, and core pressure, we can look at the forecast, we can gather rain data, we can gather river gauge data, and we can put that all together to create a threshold for danger.

And what we're doing in our community now is creating a dashboard, if you will, that will combine all those different data streams into one where people can go and look and see what the danger level is.

And the idea is to protect people's lives, and then eventually to protect property.

And do you have an idea of when this dashboard system may be ready to deploy to local residents and and how will it work?

What will it look like?

Well, so one thing that is exciting and unique about what we're doing is it is a community based system.

So the community is gathering data, we have rain gauges in people's backyards, the community is helping to design the dashboard, what it will look like and how it will be used.

And we're hoping to finish this by early next year.

We're hoping that the dashboard will be ready early next year.

All right, what was the second part of your question?

Well, just sort of how it would be designed and what it would look like but it sounds like it's still being designed.

It is still being designed and it will be tested.

And the community will be asked to give their input because that's a really important part of this is how is the community going to be using this?

How will individual community members be using this information to make decisions?

Absolutely.

Thank you so much, Lisa.

Let's turn to Ron now.

Ron, Haines the site of the most recent lethal landslide is about 150 miles north, a little east of Sitka on Baranof Island.

How similar or different are the soils and conditions there compared to Baranof?

Is there enough known about that that you can say how different they may be?

Yes.

We, we do know quite a bit about that.

So soils on Baranof being close to Mount Edgecumbe, a volcano there and there are lots of volcanic ash deposits around town.

And these ash deposits are fairly loose and, and so these tend to be makeup the bulk volume of landslides in the Sitka area.

But what happened in Haines, so there you have, you don't have those ash deposits, but they have silts and marine clays and columbium basically sands and rocks from the mountains.

And the difference between the landslides themselves is that the Haynes landslide actually originated in bedrock.

So the slides in Sitka, they are just that ash that is on top of the bedrock.

But in Haines, a big chunk of that bedrock came down the mountain and pushed, so to say, the soils and the trees down the hill and all that water, the tremendous amount of water that accumulated in the slope caused that mud, the trees to keep running down all the way down to the ocean, to the bay.

Are, there was some discussion earlier this week about quick clays?

Is that what happened, was that part of what the process was in Haines and what exactly are quick clays?

What does that mean?

Okay, so quick clays are marine deposits.

And so the ocean puts down layers of material and the clay that is deposited underwater is very loosely stacked.

And so and these deposits obviously happen in areas where the ocean has been in the past.

And now the Southeast of Alaska has been rising a lot due to due due to the rebound, you know, since the glaciers have retreated.

But so, so you'll find these deposits basically close to the water, but then gradually up the hill, even up to a height of about 600 feet above sea level, and, but not at the elevation where the Haines landslide actually started.

So these clays, so because they are stacked so loosely, they tend to fall apart when you shake them.

So pretty hard shaking for a reasonably long period of time, like minutes, these clays become like a liquid soup, and even on very small slopes, they tend to start drifting, like what happened during the '64 earthquake in Anchorage.

The extreme rainfall that led to the landslide in Sitka, and, you know, around Baranof and Chichagof Islands, was called a 50 to 75 year rain event.

In Haines, the rainfall in December was described as a 200 to 500 year event.

Anomalies happen, of course, records fall, but are you seeing definitive trends that indicate there will be increases in this and that that time frame between these huge events will be shortened?

This, this is a very difficult question to answer.

Because, as you basically say, if you have a 200 year event, well, statistically, it's a 200 year event.

But we don't even have 200 years of data.

So this this is the most difficult part of doing science, I think, in Alaska is that the data, the records of data are fairly short compared to other major cities are typically much longer.

And so even though you have bigger events, we don't really know if those bigger events have happened in the past, because we don't have the data.

So it's really hard to make that call whether things are getting wetter or not.

It certainly looks like it's gets wetter.

So theoretically, the idea of climate change means more warmer atmosphere, more moisture can be put into that atmosphere.

And that can concentrates in what's called atmospheric rivers.

And they tend to bring a lot of moisture further inland from the coast.

And that seems to be the mechanism, what caused the Haines landslide to happen.

All right, thank you.

Lisa, I want to turn back to you.

What is the psychological toll on community members.

A story from KCAW not long after the 2015 landslide that killed three residents of Sitka noted that citizens have always considered the mountains as a place of safety from tsunamis, but now citizens are sort of between hazards of the sea and and now of the mountains.

How, how are people reconciling this in that beautiful community of Sitka?

I think it's very difficult.

The rain of Southeast Alaska, I mean, I know people from the Interior, you know, kind of make fun of us, but it's our lifeblood here.

The rain keeps the forest healthy, keeps the salmon the fish healthy.

It's part of our everyday lives.

It's something that's quite comforting.

And now, when it rains hard for short amounts of time, people are anxious.

And we have parents calling the school district, is it safe to send my children to school?

And we're on edge and a little, a little worried.

And I mean, our big slide happened five years ago, but in the last few years, we've had other big slide events.

And at the end of October, we had a big rainstorm that caused 18 slides in Sitka that, by the way, caused hundreds of slides on Prince of Wales Island.

And that just adds to the anxiety.

Everybody looks around and says 'Is my neighborhood going to be next?

Is my driveway, is my house, is my road system near my house going to be next?'

And it just it causes a lot of anxiety.

Mm hmm.

How much baseline research is there about the frequency of landslides and how climate change is affecting that rate?

Is there much yet?

I would say, one thing that came out during our Geo Taskforce when we first started was the fact that the U.S. Forest Service has a landslide inventory that has been kept and that, that's wonderful.

It's, it says where the landslides have been.

It doesn't say necessarily what exact weather conditions were connected to those landslides, and we might not know exactly when they happened.

There's a lot more research that can be done on each one of those landslides.

But that has helped us identify the fact that yes, landslides have been happening for a while.

But the feeling is, with climate change, and warming temperatures, we will be having more intense precipitation events.

And in general, yes, like Ronnie said, this is a difficult - we can't predict how many more and when landslides will happen?

But the general feeling among the scientific community is we will have more landslides and flooding and natural disasters.

What do you want people to know about the complexity of designing what has to be a very tailored early warning system?

Every one of them will have to be quite different correct?

Because of differing soil conditions and the rate of incline of a hillside, so many factors.

It is complicated.

And we will be the first community in Alaska.

But we're not the first community in the world.

When we first started, there were two other communities in the United States that had already developed, or two other places that had developed landslide warning systems.

And it is, it is complicated.

But I think in on sort of the positive side, look at the tsunami warning system.

That started also in a very sort of primitive way, and has gotten more and more sophisticated and now protects millions of people around the world, annually.

And they're also developing an earthquake warning system in other parts of the world.

So I would say that I want people to know that we're in the early phases of this, but you got to start somewhere.

And the scientific community is quite hopeful that we'll be able to put something together to develop thresholds that will protect people in the future.

Great.

That's good news.

Ron, let's turn back to you now.

On Talk of Alaska, a caller from Haines expressed frustration that the homeowners that were cut off from from the community after the landslide have not been able to return to their homes.

What can you tell us about why it's not safe for them to return?

Yeah, so when the landslide happened in Haines, as I said, it's part of the bedrock actually failed and came down the mountain.

And we have flown LiDAR to look at carefully the, the geomorphology of that hill where the landslide happened.

And we found that there was a crack extending from the headscarf of the landslide into the rock that is still up there.

And so we, that crack was about 160 feet long.

And there were small hints of that crack potentially being longer.

And the morphology of the hillside just stood out as being too steep really to be able to handle a crack like that in the rock.

And so we decided that we need some very specific engineers looking at that problem, because we cannot assess just from looking at it, whether this is going is a big danger or if that rock is just going to stay in place.

A crack the bedrock sounds very serious and concerning.

Will geologists be able to really determine what it means in terms of future risks?

How optimistic are you that they'll be able to really be able to tell, from the surface that they can map, when this could either give way, or if it in fact, seems more stable?

It could go either way.

And honestly, I can't tell you what will happen.

The engineers will go on the ground and do their best in assessing their view of the problem.

And they will install instrumentation, like they will measure the bedrock crack, if it gets wider or not.

They will install some GPS sensors around the hill slope to make sure that nothing else might be moving.

And, and then, after they have gathered some data, they will either say it's safe to move into the houses, or they will say 'no, this cannot happen.'

And how do you anticipate that this information could be used to help inform where homes and other infrastructure should and should not be developed in the future?

Yeah, that, that is a good question.

So we, we work with FEMA on landslide assessments and hazard maps, to to inform communities where it is safe to to develop and where it is not safe to develop.

And so this is something that we can do for, for the communities and for the entire state.

And FEMA is interested in helping out with that.

All right, thank you.

Lisa, let's turn back to you now.

We only have a couple of minutes left here.

Outside of Sitka and Haines, you talked a little bit about this - Prince of Wales Island, Juneau have also had recent landslides.

Tell us about how you're working with those communities to better understand how to provide possible early warning to them and guidance on infrastructure work in the future?

Well, our, the research project that we're working on right now, it's about $2.6 million.

And that's in collaboration with state, with the National Weather Service, with the US G - USGS, the RAND Corporation, University of Oregon, and University of Southern California.

We're you know, just in the early stages of what we're I mean, we're in our warning system, but we have presented to various organizations and communities throughout the region, telling them what we're doing.

And we've gotten a lot of phone calls and community members and community representatives and tribal organizations, calling us asking us, how can we get in on this?

And what we've done so far is basically offered the expertise that we've been able to gather.

So we and to, and our model and how we're doing it from a community standpoint.

And so that's what we're sharing.

And we're hoping that the USGS, there will be federal dollars from the USGS to help us not only maintain our system in Sitka, but build these systems in other communities in the region.

All right, and just in a few seconds here, are you consulting with other countries outside of the states that you're working with on landslide mitigation and early warning systems?

Well, one thing that I find comforting is that while we feel very isolated in Southeast Alaska in our little towns that aren't accessible by roads, we're not the only place in the world that has landslides and there are places that sort of have more experience and maybe a little more sophisticated that have dealt with landslide areas.

And so there's places like Switzerland and Italy and Hong Kong that have developed systems to work around living with the threat of landslides and I can't tell you exactly what we've learned yet from them, but we we are doing research that is looking into what those places are doing.

Thank you so much, Lisa and Ron for your time tonight.

Landslides occur naturally and often happen in wilderness areas where the harm is more a blight on the land than a serious problem for people.

But as Alaska's climate continues to warm and precipitation rates rise, communities located at the base of mountains will have increased risk and will need scientists to help them make informed decisions about where it is safe to build and where it is not.

That's it for this edition of Alaska Insight.

Be sure to tune in daily to your local public radio station for Alaska Morning News and Alaska News Nightly every weeknight.

Be part of important conversations happening on Talk of Alaska on Tuesday morning and visit our website alaskapublic.org for breaking news and reports from across the state.

We'll be back next Friday.

Thanks for joining us this evening.

I'm Lori Townsend.

Good night.