Slides

[dr_wu002]

Timmus and I were hanging out at the South Slide on Tripyramid on Saturday and we were talking about slides a little. I'm not a geologist or anything but I've heard that slides will open up when it's dry and then gets a lot of rain. We agreed that it would be interesting to see a slide come down but not fun if it came down on top of us, despite the potential interest. Escaping death would outweigh any kind of intellectual interest in that case.

Anyway, it's been pretty dry recently. Not much precipitation. Anyone out there able to speculate if we get get some big rains, is there an increased chance this spring/summer to have some more big slides open up. You gotta believe they're more common than people think. There are tons of them in the Whites and a lot more I've found that are all grown over. Anyone ever see one come down? I remember two dudes in a boat see one last year or so in Vermont. Any stories? Any info about slides?

-Dr. Wu

 

[TDawg]

I have never personally seen one come down. But I have seen slides in one of my classes here at PSU of a 1994(?) rock fall on Cannon cliff. A guy was at one of the view points on 93 at the right time and got a few pics.

This rock fall was the one to the left of the former old man, you can recognize the brighter, newly exposed orange conway granite. The boulder on the side of the bike path fell at that time.

Not exactly a landslide but a similar type of mass wasting.

 

[blacknblue]

I haven't actually seen a slide, but I've heard them. It's pretty unsettling to hear rocks falling hundreds (thousands?) of feet, echoing in a narrow valley at night. Uh... we put the tent in a safe spot, right?...
This is the time of year for slides, for sure. After all the freeze/thaw cycles, the rocks are loosened up and susceptible to slide.

 

[David Metsky]

The last big slides in the Whites that I know of were in the late 1990's, in October IIRC after some nasty rains. That was the slide that closed the old Lions Head winter route and forced the creation of the new Lions Head winter route.

The Daks have had a few recent large slides. I'll let our NY brethren chime in on those.

-dave-

 

[dug]

A "new" slide (not really new, but a small slide got much, much bigger) opened up in the late 90's on South Twin. You could see the color change in the rock from West Bond. I happened to be up there two weeks apart, and it was very evident. This happened the same weekend a rather large slide occured in the Daks (Whiteface??). I believe there were fatalities in that one.

There are numerous factors that cause a slide, but yes dry conditions create fragile flora. When you have a lot of rain, it gets into places that it couldn't before and it acts like a lubricant. If the slope is right, and there is not friction holding everything together, that can cause a problem.

 

[lumberzac]

I believe the last major slide(s) in the Adirondacks were in the fall of 1999 caused by Hurricane Floyd Most notably the Mount Colden slide that partially filled in Avalanche Pass.

 

[Mike P.]

My wife & I were coming down Hinter Shoeneck in Italian Alps in 1998 when we witnessed some rock & likely ice fall from Mt. Ortler, one of the highest peaks in the park. (3,905M) Neat to watch, & although it never made it to the valley floor, we were happy to be on the other side of the valley on the non-glaciated peak.

 

[Stan]

Wasn't there a slide last summer that killed someone on Cathedral Trail, Katahdin? A minor one geologically but not to those directly in the path.

The most recent slide I am aware of is on the trail between Garfield and Galehead Hut. I believe this is of late '90's vintage. We'd seen it several months later but the fresh scar caught our attention.

 

[TCD]

Right you are, lumberzac. The last big run of slides in the adks was the Floyd event, in 9/99. Interestingly to this discussion, prior to that, it had been an extremely dry summer. My wife and I were camped on Labor Day weekend at Duck Hole, and it rained briefly on our hike out. We noticed that the soil on the trail was so dry the the rain was running off. Even where the surface water acumulated, if you pushed with your foot, it was all dust underneath.

Of course, the fire on Noonmark was burning at that time, also.

The following weekend, Floyd delivered 12 inches of rain overnight (with 100+ mph winds). A new slide fell on Colden, as noted. Also, there were two new slides on Wright, new slides on Basin and Gothics, and numerous smaller slides.

I have speculated that the effect of Floyd's rains was exacerbated by the preceeding dryness, which both weakened the vegetation and loosened the soil. I don't know of any studies on that (it would be kind of hard to study), but it seems to make sense.

TCD

 

[sardog1]

From the NH State Parks site. Note the preceding dry weather:
Willey Family
During the fall of 1825 Samuel Willey, Jr. of Bartlett moved into a small house in the heart of Crawford Notch with his wife, five children, and two hired men. The first year the three men enlarged and improved the house which the family operated as an inn to accommodate travelers through the mountains on the desolate notch road. The little cluster of buildings was situated in the shadow of what is now called Mount Willey. In June, following a heavy rain, the Willeys were terrified when they witnessed a great mass of soil and vegetation, torn loose from the mountainside across the river, slide in a path of destruction to the valley floor. As a result, Mr. Willey built a cave-like shelter a short distance above the house to which the family could flee if a slide threatened their side of the valley. During the night of August 28, 1826, after a long drought which had dried the mountain soil to an unusual depth, came one of the most violent and destructive rain storms ever known in the White Mountains. The Saco River rose twenty feet overnight. Livestock was carried off, farms set afloat, and great gorges were cut in the mountains. Two days after the storm, anxious friends and relatives penetrated the debris-strewn valley to learn the fate of the Willey family. They found the house unharmed, but the surrounding fields were covered with debris. Huge boulders, trees, and masses of soil had been swept from Mt. Willey's newly bared slopes. The house had escaped damage because it was apparently situated just below a ledge that divided the major slide into two streams. The split caused the slide to pass by the house on both sides leaving it untouched. Inside, beds appeared to have been left hurriedly, a Bible lay on the table, and the dog howled mournfully. Mr. and Mrs. Willey, two children, and both hired men were found nearby, crushed in the wreckage of the slide. The bodies were buried near the house and later moved to Conway. Three children were never found. The true story of the tragedy will never be known. Poets and writers have conjectured many possibilities. Perhaps the family, awakened by a threatening rumble, fled from the house to their cave, and were caught in one stream of the slide. It seems more likely the Willeys started to climb the slope of the mountain to escape the rising floods and were caught in the landslide. Whatever the circumstances of the tragedy, it has endowed this part of the White Mountains with a legend enhanced by the awesome crags which rise guardians over the site of the former Willey home. Following the tragedy, an addition was built onto the house which was operated as an inn until it burned in 1898.

 

[Rob S]

The last big run of slides in the adks was the Floyd event, in 9/99.

Yup. 3 friends and I were camping at Whispering Pines the night when the new slide on Colden fell. (It was either the 2nd or 3rd week in September.) The next day we began a 3 day, 2 night backpack. When we arrived at Marcy Dam, a helicopter was hovering in Avalanche Pass near the slide. We were told by a ranger that the trail through Avalanche Pass was closed. It was kinda cool to get pictures of a slide that had not existed one day before.

 

[dr_wu002]

Here is a post from last year.
http://www.vftt.org/forums/showthread.php?t=7386

and here is a quick link to the news article cited:
http://www.caledonianrecord.com/pages/top_news/story/b77f6ff85

Pretty Cool!

-Dr. Wu

 

[jbrown]

A buddy of mine showed me a video of a landslide that emptied into a river that some guys were kayaking on. I don't know for sure if he was there, if they were friends of his or if he just found it on the internet.
The people in the water were being pelted with rocks and dirt for a minute or so, then this whole section of the hill above them came loose and rocks, mud and trees rained down in this gorge and filled it to a significant depth.
It was a pretty scary videol.
(I'll try and find out the details and update here.)

 

[Tom Rankin]

I watched a video that a japanese tourist made of a landslide. There were whole trees just moving down the hill, still upright! Freaky!

 

[dr_wu002]

Huh?

The most recent slide I am aware of is on the trail between Garfield and Galehead Hut. I believe this is of late '90's vintage. We'd seen it several months later but the fresh scar caught our attention.

Where is this slide? I don't recall...

-Dr. Wu

 

[el-bagr]

A buddy of mine showed me a video of a landslide that emptied into a river that some guys were kayaking on. I don't know for sure if he was there, if they were friends of his or if he just found it on the internet.
The people in the water were being pelted with rocks and dirt for a minute or so, then this whole section of the hill above them came loose and rocks, mud and trees rained down in this gorge and filled it to a significant depth.
It was a pretty scary videol.
(I'll try and find out the details and update here.)

That's the Sultan River landslide (link to a description and downloadable video). Freaky.

 

[cbcbd]

That's the Sultan River landslide (link to a description and downloadable video). Freaky.

Wow, that's insane Must be awesome to witness first hand mother nature changing the shape of the land (that is, if you are in a safe viewing spot)

Most recent slide I witnessed was probably mostly ice and some rock - Ice climbing on the West side of Smuggler's Notch on a warm April day - The East side was getting all the sun and we'd hear thunder and then look back and see tons of huge ice boulders thrashing down the mountain. The thunderous sound was scary and reverberated inside the notch, very impressive.

 

[TDawg]

Thats crazy video el-bagr.

That reminds me of the landslide that caused the massive tsunami in Lituya Bay, Alaska, in the late 50's. It caused a world record wave (that humans have witnessed/measured), 1,720 ft. high! Just shows the power these things possess.

This event was way before my time and I'm sure some of you may have heard of it. It was caused by a 7.9 magnitude earthquake.

Read about it here.

 

[Peakbagr]

A huge thunderstorm got stuck on Giant Mt in June 1963. . I understand it dropped huge amount of rain. It super-saturated the soil, and all those slides you can see on Giant from the Ausable Club fell, came down the Roaring Brook Valley, and completely covered route 73 with deep rubble. When the build-up water dam collapsed, the flood destroyed route 73 and many cars.
Take a look at how far Giant is from the road and then picture the slide running all the way down and then completely burying the road. For a good description, take a look at the 46ers book, " Of the Summits, of the Forests" on page 50.

My understanding about slides is that when the gradient is just right, the underlying rock suitable, and the soil gets enough saturation, the slope can let go. I'm not sure the previous dryness would have anything to do with it once the soil reaches carrying capacity. I'm sure there are some geologists who would have a much better explanation.

 

[sardog1]

That Sultan River slide is not far from the place in WA that I described in another thread re: encountering a hillside that had been scoured right down to the bedrock. Seeing this one on video was awesome; thanks!

Lituya Bay is notorious among Alaska Natives who live in the vicinity. More than a few boats have been lost by the waves that have been generated there over the years.