Six months after a major earthquake rocked Idaho, the rumble continued with an earthquake shaking near Stanley as late as Monday morning. Since March 31, earthquakes have puzzled scientists and in some cases reshaped the landscape of the Sawtooth Mountains near their epicenter.
The initial 6.5 magnitude earthquake and its aftershocks caused multiple avalanches in the sawtooth, but many effects were masked by snow. As the weather warmed – and strong earthquakes continued – new ramifications emerged: the “liquefaction” of a popular Stanley Lake beach, overturned climbing destinations, structural damage to the trees. Lava tubes from the Craters of the Moon National Monument and Preserve and debris strewn with trails.
âThe earthquakes and their effects on the Sawtooth skyline have been an interesting exclamation point over an already surreal year,â said Ed Cannady, former backcountry manager of the Sawtooth National Recreation Area. , in an email.
He noted the loss of Arrowhead and Finger of Fate, two separate peaks favored by mountaineers, in the March 31 earthquake, as well as Baron Spire, who collapsed in August. Video of Baron Spire collapsing and triggering a landslide has gone viral online.
âAs a mountaineer, I can tell you this has changed a decent amount of rock climbing in the sawtooth,â Blake Bolton wrote in a Facebook comment on the Idaho Hiking and Backpacking page. ââ¦ Another characteristic known as Coffin has disappeared with Arrowhead, and the summit terrain on Warbonnet has changed as well. I’m sure there are other changes, but that’s the extent of what I’ve seen so far.
Cannady said some of the changes went unnoticed as they didn’t affect any of the protruding peaks of the jagged sawtooths.
âThere were a lot of other changes that were much less noticeable because they didn’t change the look of the skyline,â Cannady said. âSeveral walls have been partially sheared, such as the towers over Hansen Lakes, the east face of Grand Mogul, peak 9565 and many more. Due to the chaotic nature of much of the sawtooth these will not be very noticeable unless one knows the boulder fields at the base of these slopes and a color difference on the faces. because of the newly exposed granite.
Earthquakes add to backlog of trail maintenance
The jagged trails also suffered damage, mainly due to falling rocks or avalanches shaken by earthquakes.
According to Brian Anderson, Assistant Ranger of the Sawtooth National Recreation Area, most of the infrastructure in his jurisdiction – trails, bridges, etc. – remained intact during the tremors.
âWe had a number of places where we encountered large rockfalls that impacted the trails,â Anderson said.
This summer, the Idaho Mountain Express reported that Trail 101 was cut by “a boulder the size of a two-story house.” This trail, which is near Redfish Lake, as well as one near Grandjean had to be diverted due to debris. But this is not the end of the work for the Forest Service.
â(Reroutings are) probably not long-term solutions, so we’ll have to see to putting the trails back there,â Anderson said.
It’s easier said than done. Kelly Hughes, spokesperson for the Idaho Trails Association, said she saw rockslides and other debris on the Alice-Toxaway Loop in the sawtooth this summer. The incidents only add to an existing backlog of trail maintenance in the state.
âThis kind of job is really tough,â said Hughes. “When part of the trail is swept like this it really isn’t safe for people to pass.”
The Idaho Trails Association runs many volunteer maintenance trips to the trails around Idaho every year. Hughes said cleaning up the slip debris would be a challenge for their groups.
âYou have to have people who are really up to the task,â she said. âMoving stones is hard, hard work. “
Kathryn Grohusky, executive director of the Sawtooth Society, said she also noticed avalanche fields across the trails, although she was not sure they were caused by earthquakes. Yet, they contribute to the maintenance issues that the Sawtooth Society is also working to address.
Despite the slips and the unpredictable rumble, Anderson said there had been no reports of serious injuries as a result of the quake. He reminded hikers and backpackers to be aware of seismic activity if they recreate in the area.
âYou might not think that an earthquake is something that you necessarily have to be concerned about,â Anderson said. âYou are smart to look for dangerous trees above your campsite (which might fall) and make sure to watch out for steep slopes which might collapse under a replica.â
“Proof that the Earth is alive”
Cannady also stressed the importance of safety in the sawtooth, even when there is no threat of shaking. He said he finds joy in earthquakes – after all, it’s the same geological changes that created the mountain range he loves so much.
“I’m sure I won’t let the possibility of an earthquake take me away from Sawtooth,” he said. âI love earthquakes because they are proof that the Earth is alive. When we feel an earthquake, it is as if we are feeling the pulse of the Earth. And the heart of the Earth beats on a very different timescale than we can even understand, so when we feel the jolts and see the changes, we are just witnessing a process that has created the mountains that we love so much.
âIt can certainly be annoying to see the ground moving beneath you, when the mainland becomes unstable,â he added. “But it’s very natural, and we’ll probably remember the experience for the rest of our lives.”