Denali 10 feet shorter than previously thought

[jdorje]

You are correct in a battle of semantics. Perhaps a better way to phase it would have been, "Denial is the world's 3rd highest peak in terms of prominence". However, the article I co-authored was written for a more general public, and the nuance of prominence vs elevation vs topography vs etc would be mostly lost on them - and would require many more definitions.

The people of Alasaka and the climbers who have conquered Denali believe it is #3, and that was also an important factor in my decision.

That's not semantics, that's "what words mean". I mean I guess that is semantics, if you want to get semantic about it.

Saying Denali is the third highest peak in terms of prominence is like saying Usain Bolt is the fattest person on earth in terms of being fast, which we can then shorten to say he's the "fattest person on earth" and anyone who objects is just entering a battle of semantics. "High" and "prominent" mean different, conflicting things - just like "fat" and "fast".

Semantically I'm going to stick with "third most prominent peak". Which has the advantage of being way less words while also being 100% clear. Sure the public may not know what "most prominent peak" means, but that's better than them incorrectly thinking that it means "highest peak".

https://en.wikipedia.org/wiki/List_of_p ... prominence" onclick="window.open(this.href);return false;

/semantics

[alpinenut]

Please tell me that he actually spelled "Denali" as "Denial" in his response.

Yes he did. Also spelled Alaska -> Alasaka. But, hey, I make tipos all the time so I'll cut him some slack there...

[sean bennett]

See what happens when you go changing the names of things?

I agree. It only makes sense, the less letters in the name, the less vertical feet.

Simple physics, really.

[peter303]

Interesting...I wonder if there are plans to do the same with the peaks in Colorado. Huron, Holy Cross, and Sunshine could be casualties with new measurements.

The original surveys in the 1800s were from were by eye and theodolites triangulated from the coasts.
They were surprisingly accurate considering the technology.
They've been recalibrated with various satellite technologies since the 1980s.
This case was a type of radar (SAR), but clock triangulation (GPS) and laser (lidar) have been used too.
Also reference sea level from which 14K is determined, called the geoid, has changed over the decades with improved measurements.

Not to mention the earth is dynamic, moving a small bit up or down each year for a whole variety of geologic reasons.
Over decades these can add up to feet.

These recalibrations have been the reason there are three different 5280 steps on the Colorado State Capitol.
It is been moved a bit.
The marginal 14ers, within 10 feet of 14,000 feet have come or gone with such resurveying.

[Traveler]

Interesting...I wonder if there are plans to do the same with the peaks in Colorado. Huron, Holy Cross, and Sunshine could be casualties with new measurements.

The marginal 14ers, within 10 feet of 14,000 feet have come or gone with such resurveying.

Is it likely this kind of resurveying would be done in Colorado any time soon?
What 13ers are closest to becoming 14ers?

[Le Marmot]

Interesting...I wonder if there are plans to do the same with the peaks in Colorado. Huron, Holy Cross, and Sunshine could be casualties with new measurements.

The marginal 14ers, within 10 feet of 14,000 feet have come or gone with such resurveying.

Is it likely this kind of resurveying would be done in Colorado any time soon?
What 13ers are closest to becoming 14ers?

grizzly, stewart and kat carson come to mind.

[Teresa Gergen]

I believe the reason Roach's Centennial book covers peaks that go down to 13,800 ft is because the earlier elevation list peakbaggers generally climbed the next several peaks below each Hundred level cut-off just to make sure, since the elevations of various peaks have changed over time. Traditionally, 13er finishers made sure they climbed the highest few 12ers before finishing their 13ers, so that their completion date would hold if someone determined later that those 12ers were actually 13ers. With the datum changes, the term "probable 13er" floated around for any 12ers within 7-10 feet or so of 13,000 ft. Same for the lower lists.

[Scott P]

It looks like measuring technology is improving, the mountain is now measured at 20,310 feet

Interestingly, that's the average of the two most widely accepted elevations. Before 1952 the mountain was known as 20,300 feet and after 1952, it was surveyed at 20,320.

Anyway, I wouldn't expect the 20,310 figure to stick around. In 1989, it was announced that the peak was 20,306 feet. In 2013 it was announced that the peak was 20,237 feet.

http://www.adn.com/article/20130911/sur ... on-83-feet" onclick="window.open(this.href);return false;

For peaks such as Denali and Everest new elevations are often claimed to be more accurate than old ones, but more often then not, they don't stick.

What 13ers are closest to becoming 14ers?

Since GPS's became popular, serveral people believe that Ouray might be a 14er since several people get a GPS reading of just over 14,000 feet. Although GPS's aren't 100% accurate, it isn't just a few people, but several who have gotten readings over 14K.

[martinleroux]

Since GPS's became popular, serveral people believe that Ouray might be a 14er since several people get a GPS reading of just over 14,000 feet. Although GPS's aren't 100% accurate, it isn't just a few people, but several who have gotten readings over 14K.

In my experience the typical margin of error for hand-held GPS elevation readings is roughly 30' or so. If the true elevation of Ouray is really 13,971 then about one out of every six people that carries a GPS to the top will end up with a reading of 14,000' or more, just because of random error.

[Alpine]

After reading the article, I have a question - how do they determine where the actual highest point is? Obviously any snowfall could change the location of the highest point of snow but that could change daily, or hourly during a storm. The highest boulder/bedrock underneath the snow? That would be pretty hard to find? The highest spot of "permanent" snow? How would that be determined? The article makes it sound as if it is indeed the highest point of snow but that just sounds weird to me.

I am sure someone here knows, but I didn't see this point explained in the article.


Quoting the article:

"The summit team arrived at the top of North America’s highest peak around 3:15 p.m. on June 24. Their first task was to identify the true summit. A small diamond of snow was prominent near the south-face cliff edge and was identified as the highest point of the mountain. A range pole was driven into the snow near the true summit, leveled with the summit, and GPS equipment was installed and powered on."

and the photo caption there adds:
"The lower section of a one-meter range pole was driven into the snow about a half-meter north of the summit point. Using one section of the metal snow probe and a torpedo level, the top of the range pole was leveled with the summit point. The second range pole was then driven into the snow 2.5 meters away from the summit range pole and away from the trail. This second setup gave redundancy to the survey and its off-trail location reduced the risk of tampering. The second range pole was leveled with the first using the tank antenna and a level ."

[martinleroux]

how do they determine where the actual highest point is? Obviously any snowfall could change the location of the highest point of snow but that could change daily, or hourly during a storm.

That's a good question. In practice the summit is so wind-scoured and icy I don't think it changes all that much due to snow accumulation. In 1989 a USGS team placed a summit marker on a steel rod that they drilled four feet into ice (they didn't hit bedrock). When I was there in 2008 it was just about flush with the surface. A quick Google search brought up several pictures in subsequent years showing it either close to the surface or no more than a foot higher. Here's a picture from the 2015 survey that shows the marker in the foreground (scroll to the bottom of the page): http://www.nps.gov/dena/blogs/Field-Report-July-6.htm. Here's more information about how they placed it: http://www.lastingimpressionsbook.com/p ... kinley.pdf.

[peter303]

I googled the geologic literature which says Denali is rising about 1.5 mm a year. 10 feet is about 3000 mm, so it would take 2000 years to catch up with the surveying error. The summit height is a tug of war between uplift and erosion. I dont know an erosion rate. For example the summit could be eroding a half foot per century, which would wipe out the uplift.

Geologists use a couple of uplift measures which depend on when rock became shallow and cool enough to start recording radioactive decay. Then these rocks erode down to the surface and collected by geologists. They get a number like so many meters per million years until it was deep enough to start the radioactive clock..
There is a "real time" uplift measurement method called continuous GPS that can measure changes as little as millimeter per year. This is widely used along the US west coast. But only in central Alaska after the huge 2002 Denali earthquake. Between 2002-2004 Denali rose 15 times faster or about 25 millimeters (one inch) a year. But that is thought to be a temporary rebound after the large earthquake and will settle to its long time average rate.