Talk:Topographic prominence

Merits of Prominence should be objective

I see that of one the claimed "merits" of prominence is that "The peaks listed are usually amongst the best viewpoints, especially in clear weather." The source that is cited is "The Relative Hills of Britain". This statement (and the citation) are problematic for several reasons.

First off, whether any particular point is a good viewpoint is purely subjective, and therefore makes a weak statement in support of prominence.

Second, the cited "Relative Hills of Britain" deals only with hills in Britain, so can one reasonably assume that this statement applies to mountains in general, all over the world? If one chose another small country instead, say, South Korea, then the statement relating prominence and viewpoint would no longer be true (based on Chris Upton's trip reports of South Korean 2000ft prominence peaks).

Third, "The Relative Hills of Britain" was written to promote prominence, so can it be considered an unbiased choice? Please see Wikipedia:Verifiability, which states that "Articles should rely on reliable, third-party published sources with a reputation for fact-checking and accuracy."

Fourth, it has been noticed even in the prominence community that there are many situations in which high prominence has no correlation at all with good views. Examples are highpoints of plateaus, and island highpoints. This was one of the reasons that David Metzler started working on a alternate measure, spire measure, that directly factors local topography into the calculation, which prominence does not.128.173.49.45 21:38, 17 July 2007 (UTC)

As the editor who made the viewpoint claim, and created both the merit and criticism sections, I must respond to its above criticism. It seems to me that an open view is intrinsically a good view, but perhaps we should replace "best" with "most open", as there are some who may prefer a typical downtown ground level New York City view. That prominent summits usually make open viewpoints is implicit from the definition of prominence; the views are unobstructed by local topography, which is, by definition, lower than the viewpoint. Exceptions can occur if there is a very large summit plateau, or local summit vegetation, but few summits have sufficiently large plateaux, and the soil, exposure and climate borne by most summits mean that they are not inclined to support obstructive vegetation. In the UK, no P600m summit view is obstructed by a plateau or by vegetation, and very few P150m summit views are obstructed.

On the specific points: I think that it is intrinsic that an open viewpoint is a good viewpoint, both in Britain and elsewhere. I do not think that citing a pro-prominence source in a pro-prominence section contravenes WP:V. Please note that the words "usually among" are used, but the word "necessarily" is not.

Please can you source your claim that it has been noticed within the prominence community that there many situations in which high prominence has no correlation at all with good views. As for spire measure, its correlation with view quality probably is stronger than that of prominence, but that does not logically render the claim that you are challenging to be incorrect. Viewfinder 04:01, 18 July 2007 (UTC)

I'm not an expert on this topic, so just a point - many of the mountains in the eastern United States are covered with dense forest. Some are so flat that it'd be hard to know where the high point is if it weren't marked, and there's no view at all unless there's a clearing. Another point is that while high points may give the most distant and widest views, for scenic splendor a position near the base looking up at a handsome pinnacle is usually more aesthetic, IMO. ·:· Will Beback ·:· 05:08, 18 July 2007 (UTC)

Speaking as the aforementioned David Metzler, yes, spire measure was developed partly out of a response to situations where the prominence and "impressiveness" of a peak do not match. (Credit needs to go also to Bob Bolton and Edward Earl.) However I agree with Viewfinder that we should focus on prominence here.

As to the "best viewpoint" statement itself, I agree with the anon IP contributor that "best" is a subjective, value-laden word, which is unlikely to be appropriate in Wikipedia even with good sources, and definitely not with only one source which cannot be considered completely unbiased. (I'm not saying that Dawson is an inappropriate source; I'm saying that the standard of verifiability/credibility needs to be higher when dealing with subjective issues, which are inherently controversial.) I don't agree with Viewfinder that an open viewpoint is a good viewpoint, especially when other factors may intervene. A higher-elevation peak with lower prominence may have a more obstructed view than a lower-elevation peak with higher prominence, but many would prefer the view from the former. Many other factors could also come into the subjective determination of "good viewpoint."

I think that the statement can be replaced by, say, "The peaks listed tend to have unobstructed views over long distances, except in regions where only the highest summits are above the tree line." I'll try that and see how people like it. -- Spireguy 15:06, 18 July 2007 (UTC)

While I'm looking at this, I'll note that the last point under "merits" is also pretty mushy; its main claim is simply that prominence lists provide an alternative list to height lists, which is fairly obvious. The rest of it, about fitness etc., is not special to prominence, and would apply to any other alternative list. So I would suggest dropping this point altogether, or rephrasing it to just state the main point that it's nice to have alternate lists. -- Spireguy 15:15, 18 July 2007 (UTC)

This is what the Dawson reference actually states: The majority of Marilyns provide splendid views in favourable weather. I think that comment is generally applicable to high prominence summits worldwide, and should be quoted. I don't think many would dispute it. I concede that there is more of a tree cover issue in countries other than Britain, especially the eastern US; we can continue the debate about how, if at all, this should be pointed out. Re the last point, please don't let's drop it altogether. Viewfinder 16:20, 18 July 2007 (UTC)

Thanks for clarifying what the reference says; certainly since it doesn't mention tree cover, my version doesn't quite work. However (1) I still think it's important to use a high standard for references where subjective value judgements are involved, so I still would say that "best" or "splendid" or other terms are not apppropriate. (2) It's important to note that the overall issue here is what the merits of prom lists are, relative to other kinds of lists, particularly height lists (the default). Dawson does not explicitly state, nor is it clearly true, that the majority of Marilyns (or other high-prom summits) provide "better" views than peaks chosen in a different way, e.g. high-elevation peaks. -- Spireguy 17:10, 18 July 2007 (UTC)

I like the way you have phrased the statement about viewpoints, David. It makes a lot more sense now. For the sake of this discussion, it should be pointed out that a high-prominence peak merely needs to be higher than surrounding peaks to get the prominence, but it need not be higher by any minimal amount. Thus there are many instances when one peak is surrounded by peaks that are just slightly lower, thereby still obstructing the view. To make matters worse, due to faulty human perception, the surrounding peaks will often actually look higher. However, the point about line-of-sight is still probably true in most cases, so we can let the statement stand as it is.128.173.49.45 18:08, 18 July 2007 (UTC)

So?

I have a couple questions. First, regarding this statement in the article: A mountain that appears to be highly prominent from local viewpoints may not be ranked highly by topographic prominence, because high passes may connect that mountain to higher mountains in the same range. Okay, so the mountains are in the same range, what difference does that really make, isn't that the point of prominence, to measure how one may go to higher altitude along a route of prominence? The South Summit has a prominence value and it is in the same range as Everest. I don't understand the point of this statement. Second, what can be said about AMS and prominence? It appears to me that prominence would seem to negate the whole necessity of acclimitization. Maybe I'm reading too much into it, but it certainly seems that way. It still seems to me that elevation is of greater importance than prominence as elevation includes far more factors regarding safety, verticality, acclimitization, etc. for mountaineering. --Bentonia School 04:11, 23 August 2007 (UTC)

THe above statement was in the criticism section and is a valid criticism. The value of prominence lies in the fact that the status of a mountain is enhanced by being the highest point of a range or any other physical entity. If Everest's South Summit were its highest then that summit would be the goal of all those climbers. Mount Washington is 1917m high. So is the highest point of a parking lot in downtown Colorado Springs. Elevation isn't everything. Even lists ranked by elevation have to use prominence or something similar, otherwise their length would be indefinite. A good mountain to climb does not necessarily have to need acclimatisation, and regarding your point about safety, climbers die in Scotland too. Viewfinder 13:11, 23 August 2007 (UTC)

"A good mountain to climb does not necessarily have to need acclimatisation" And I didn't suggest such. --Bentonia School 16:06, 25 August 2007 (UTC)

To further explain the statement in the article: the criticism is that topographic prominence does not exactly correspond to visual prominence/impressiveness. A classic example is El Capitan, which is strikingly impressive from below, but has very little topographic prominence. While this criticism is valid, it does not negate the importance of topographic prominence; it just says that it does not do everything one can ask from a measure of mountains. That's not surprising, since there is no mountain measure that has all desirable features; different measures quantify different aspects of a mountain. A note about the article itself: given that you (Bentonia School) find that statement unclear as it is written, maybe we should clarify it further in the article.

Regarding elevation versus prominence: that is related to another valid comment about lists ranked by prominence. Namely, prominence does not correlate exactly to climbing difficulty. There are plenty of easy, high-prominence mountains (e.g. Mauna Kea), and hard, low-prominence mountains, e.g. Lhotse Middle. Again, this is not surprising: prominence is not supposed to measure climbing difficulty. It has some correlation with it, but that correlation is far from perfect. As you point out, pure elevation does correlate strongly with climbing difficulty; but that correlation is also far from perfect, e.g. Cerro Torre versus Aconcagua.

To sum up: if one assumes from the outset that topographic prominence is supposed to measure something that it doesn't (e.g. visual impressiveness or climbing difficulty) then it will appear to be highly flawed. But it's important not to make that assumption. I hope that clarifies the issues that you raised. -- Spireguy 15:17, 23 August 2007 (UTC)

Good explanation. Thank you. --Bentonia School 16:10, 25 August 2007 (UTC)

This defined measure of a summit is properly called topographic prominence to distinguish it from other, often subjective, measures of prominence. --Buaidh 17:26, 23 August 2007 (UTC)

Alternative Definition

The purpose of the 'prominence' concept is clearly to have an objective measure stick for the degree in which a (named) mountain summit 'sticks out' in the landscape. I believe the current definition, which defines prominence as the lowest contour line that encircles no higher peak than the summit concerned, does not do this purpose justice, as indeed e.g. Mt Mckinley would have a prominence al the way to sea level, whereas there are cols at a much higher level. I therefore suggest an alternative definition: "The lowest contour line that encircles a named mountain, and no other named mountain". With 'named' I mean any geographic feature that in the English language features the connotation 'peak', 'mountain', or 'summit' in its official name. For Mt McKinley this would mean that the prominence only goes to the col with Mt Hunter, far less the the current value of its prominence. — Preceding unsigned comment added by Tavernsenses (talk • contribs) 07:49, 4 January 2012 (UTC)

A question about original research on certain mountain lists

The following is copied from Wikipedia talk:WikiProject Mountains: I want to bring up an issue that has been bothering me for a while. User:Buaidh has been putting in a lot of good work on creating various mountain lists, such as Mountain peaks of North America and Mountain peaks of the Rocky Mountains, among others. However I'm concerned about one of the statistics that Buaidh includes in the tables, namely the product of Topographic prominence and elevation, which Buaidh refers to as "summit eminence." In my opinion, both the inclusion of this statistic and the term "summit eminence" are original research. Note that WP:NOR excludes material if "it defines new terms" or if "it introduces an analysis or synthesis of established facts, ideas, opinions, or arguments in a way that builds a particular case favored by the editor." The former covers the term "eminence" and the latter covers the concept itself and its inclusion in the tables, which implies an importance for the particular combination prom*elev which is not justified by any reliable source.

I've noted to Buaidh that I personally like ranking mountains by prom*elev, but that doesn't matter, since it isn't done in any source that I know of. Rather than being bold and deleting much of the info in Buaidh's tables, which I thought would be rather rude, I wanted to get some more input from this group on the issue. (My apologies for those who read this twice.) Thanks -- Spireguy 14:53, 28 August 2007 (UTC)

It looks like the discussion on this will take place at Wikipedia talk:WikiProject Mountains#Lists in Infobox, so please direct all comments there. -- Spireguy 21:48, 28 August 2007 (UTC)

Why Sea Level?

This may be a sort of specious comment, but if we are talking about topological prominence of land formations, why does the ocean get treated as though it is made of land. Shouldn't the topological prominence of Mauna Kea (and other island peaks, continental islands included) be measured from the highest col on the sea floor? Mention is made of the "rising sea model," and, in this talk page, of the rising sea level. I wonder about the lowering sea model. Again with Mauna Kea as the example, how low would the Pacific Ocean have to drop before Mauna Kea was not the highest peak on its landmass? maxsch (talk) 21:35, 28 April 2008 (UTC)

There are two varieties of topographic prominence: wet prominence and dry prominence. Wet prominence is the more commonly used topographic measure. Wet prominence assumes that the surface of the earth includes all permanent water, snow, and ice features. Thus, the wet prominence of the highest summit of an ocean island or landmass is always equal to the summit's elevation.

Dry prominence ignores water, snow, and ice features and assumes that the surface of the earth is defined by the solid bottom of those features. The dry prominence of a summit is equal to the wet prominence of that summit unless the summit is the highest point of a landmass or island, or a summit surrounded by snow or ice. If a summit is completely surrounded by a water, snow, or ice feature, the dry prominence of that summit is equal to the wet prominence plus the depth of the highest col.

The dry prominence of Mount Everest is equal to its wet prominence (its elevation, or 8850 m) plus the depth of the deepest hydrologic feature (the Challenger Deep at 10,911 m), or 19,761 m. The dry prominence of Aconcagua is equal to its wet prominence (6962 m) plus the depth of the highest col of the Bering Strait (about 50 m), or about 7012 m. --Buaidh (talk) 21:58, 28 April 2008 (UTC)

Buaidh is quite correct that it is possible to calculate "dry prominence", and various people have looked into such calculations. However dry prominence has very little significance for the visual, cultural, or mountaineering aspects of a peak, which are very relevant to how prominence is used. It is also arguably more artificial, as it makes an unnecessary distinction between rock/soil/land and water/ice/snow. So it's usually considered esoteric even to prominence enthusiasts.

Note that Antarctica, and to a lesser extent Greenland, would have drastically different prominence data under a "dry" (including no ice/snow) model.

It's important to distinguish between the illustrative picture of the "rising sea model", which is just intended to explain the idea of prominence, and the dry prominence model. For example, the prominence of K2 is significant even though the sea will never rise nearly to the key col for K2.

As to the specific question of the dry prominence of Mauna Kea, it's about 9,330 meters (#2 in the world after Everest), according to "The Finest Peaks---Prominence and Other Mountain Measures," Adam Helman, 2005. -- Spireguy (talk) 02:52, 29 April 2008 (UTC)

Thanks for the explanations, that's very helpful. I see how dry prominence is less useful as a cultural measure, but do you think that the article (called "Topographic prominence") should at least mention the idea of dry vs wet prominence. I'm sure that topographic prominence is also relevant to undersea land formations, and Mauna Loa, for example, could then have Mauna Kea as a parent, certainly a geological truth. maxsch (talk) 16:15, 29 April 2008 (UTC)

Wet prominence and dry prominence are the same for all but a handful of continental summits. The dry prominence of island summits and summits in Antarctica and Greenland can be very much greater than their wet prominence. Submerged seamounts can have very substantial dry prominence and topographic isolation. Wet prominence is very appropriate for mountaineering, but dry prominence can also highlight extremes of topography. See Extreme Geography. --Buaidh (talk) 19:33, 29 April 2008 (UTC)

I added a short section to the article explaining the difference between wet and dry prominence. --Buaidh (talk) 21:01, 29 April 2008 (UTC)

Thank you for this interesting section. Can you provide a reference for the terms "wet" and "dry" prominence and their meanings? I am merely suggesting that a reference should be supplied but other editors might think a reference is essential. I understand all this is a logical deduction but WP should perhaps be following established usage in this area. The whole article is rather weak on references but happily this does not seem to have caused too much argument. Thincat (talk) 14:14, 30 April 2008 (UTC)

"Debates" section

See User talk:Spireguy for a discussion of why I put the {{refimprove}} tag on that section. -- Spireguy (talk) 22:17, 8 October 2008 (UTC)

Re "key cols" and List of mountain passes

I'm wondering what to do for hjeights of land which are passes, but are not so officially named and so not (at present) on List of mountain passes. I'm thinking the Rose Lake Pass/Bulkley-Endako Divide, Summit Lake/McLeod Lake and the Okanagan-Shuswap divide at Spallumcheen; none of these are passes, though they are important prominence cols (for Waddington, Orizaba and Rainier respectively, I think) and "mountain passes" seems awkward; but they are notable and in a technical sense are passes; just plopping this here for further discussion/points.Skookum1 (talk) 23:30, 8 October 2008 (UTC)

Example of Prominence as an excellent metric to create peak lists

A world list of most prominent peaks corresponds to a Seven Summit list provided that all seven selected mountains have key saddles at or only slightly above sea level and are well-separated from each other.

The logic for this statement is available, see Seven Summits Essay Countyhighpointer (talk) 18:50, 9 October 2008 (UTC)

Unfortunately Pico Cristobal Colon and Mount Logan, which rank 5th and 6th by prominence respectively, are not continental high points, however much we tinker with continental boundaries. Viewfinder (talk) 18:58, 9 October 2008 (UTC)

The key phrases are "key saddles at or only slightly above sea level" and "well-separated from each other". The longwinded explanation follows. In it, the exclusion of Pico Colon and Mount Logan will become clear.

1) "key saddles at or only slightly above sea level"

This stipulation is needed because two mountains separated by a high elevation saddle do not correspond to the highpoints of two continental landmasses. Continents are separated by water, and, barring that, it is logical by extension to separate continents (hence defining them from a prominence perspective) by the lowest available intervening terrain.

As an example, the key saddle for Mont Blanc is near sea level at 371 feet (113 meters). The key saddle for Mount Elbrus lies at 2,956 feet (901 meters). Earth's oceans need rise only 400 feet for Europe to be separated from Asia at Mont Blanc's key saddle. The oceans would have to rise 3,000 feet for Europe to be separated from Asia using Mount Elbrus' saddle.

Hence from a prominence aspect Mount Blanc is the European highpoint.

2) "well-separated from each other"

This eliminates Pico Cristobal Colon of Colombia, Earth's fifth most prominent peak; and also Mount Logan of the Yukon Territory in Canada, Earth's sixth most prominent peak.

Pico Colon is too close to higher ground, as Chimborazo in Ecuador, to be considered a continental highpoint based on solely a prominence criterion. Such a continent would comprise only Colombia. Similarly, Mount Logan is too close to Mount McKinley in Alaska. Were it to define a "continent" then Mount McKinley's "continent" would comprise only Alaska. No reasonable person would consider Colombia or Alaska as continents. Hence Colon and Logan are not reasonable candidates for a Seven Summits list based on prominence.

Furthermore, even if one does not accept their exclusion on the grounds of proximity to higher peaks; Pico Colon and Mount Logan have high elevation saddles connecting them to higher ground. Then, by the first criterion (a near sea level saddle), both of these peaks are excluded anyways.

Pico de Orizaba of Mexico is also eliminated due to a 2,300 foot (700 meter) key saddle with Mount Logan.

Thereby through the use of two criteria world ranked prominences 5 (Colon), 6 (Logan), 7 (Orizaba), and 10 (Elbrus) are eliminated. The resulting peak list contains summits ranked 1-4, 8-9, and 11 - and is identical with the traditional Carstensz variant of the Seven Summits with the replacement of Gora Elbrus by Mont Blanc.

One may debate the merits of these two criteria. However they are based on exactly what is required to define a continental landmass: a low key saddle to higher ground; and sufficient area to be considered a continent as distinct from an island. 66.75.51.144 (talk) 20:00, 9 October 2008 (UTC)

Assuming that, put into a nutshell, you are claiming that Everest/Aconcagua/Denali/Kilimanjaro/Vinson/Carstensz/Blanc is correct from a prominence point of view, then I agree. A link pointing that out may be OK at Seven Summits may be accepted. But Messner's Seven Summits list makes sense from a political point of view, in that the local populations of the Caucasus and West Papua consider themselves to be European and Australasian repectively. Whatever the commercial atlases, who mostly copy each other, may claim, the continental partition of New Guinea seems to most Seven Summiteers to be nonsense from a topographical or political point of view. That is why they have rejected it.

Viewfinder (talk) 20:23, 9 October 2008 (UTC)

Correct - one applies the two criteria as one goes down the world prominence list, and the first seven peaks satisfying the criteria form the Seven Summits. It is of note that a co-worker (Edward Earl) independently reached the same list years ago. That two people would arrive at the identical, prominence-based list without correspondence speaks volumes for its sanity.

I can certainly incorporate into text your statement that the inhabitants of New Guinea consider themselves to be Australasian. However I would first like you to provide evidence for that statement - and analogously for the peoples of the Caucasus.

The resulting logic for generating a politically-based Seven Summits list would then change - and, in theory, the Messner variant of said list would correspond to a politically-based continent definition... with the Bass variant corresponding to a strict geographic continent definition (no change there). Countyhighpointer (talk) 21:37, 9 October 2008 (UTC)

It seems to me evident enough that West Papua is ethnically and culturally closer to Papua New Guinea than other parts of Indonesia. That the Georgians consider themselves to be European does not need citing, and if the south side of the Caucasus is considered to be in Europe then ditto the north side or Europe becomes discontiguous. Viewfinder (talk) 14:25, 11 October 2008 (UTC)

I agree that culturally Irian Barat ("West Irian"), as the western part of New Guinea currently owned by Indonesia is most closely allied to Papua New Guinea from a cultural perspective.

The essay is designed to consider **all possible** means by which a Seven Summits list can be generated - and this concept is completely independent of a climbing community's existence - let alone "approval". That is why such unique concepts as using tectonic plate highpoints and using topographic prominence are included: Mr. Bass had several possible means of defining what is meant by "continent", and he chose the most obvious definition based on continental outlines. From a purely theoretical viewpoint all of the remaining definitions are equally viable.

Then, given this all-inclusive concept, it behooves me to split-out a cultural definition for Oceania as separate from a political definition thereof. The ramifications are simple - for "cultural/ethnic Oceania" Puncak Jaya ("jewel summit" in Indonesian) is the highpoint, corresponding to the Messner Seven Summit list. For "political Oceania" Mount Wilhelm is the highpoint, and as promoted by John Christiana who climbed it instead in his Seven Summits quest. The political version is well documented by commercial atlases, who I admit nonetheless probably just copy one another.

Some atlases portray world regions in specialized maps such as language families, religion, and, yes, ethnicity. It would be interesting to examine some high-end atlases to learn what the division is according to these "experts".

I believe that political and cultural/ethnic Europe can be made to coincide for the essay's purposes - and similarly for the remaining continents. Interestingly, Antarctica has no culture except that of science. If one can call that a "culture" than a culture-based lists maintains a count of seven.

Again, the essay was never designed to compete with or negate existing definitions for the Seven Summits. That would indeed constitute a most minority opinion. No sir - the essay is a study of all possible means by which a Seven Summit list could be generated; with each list based on its own unique criterion.

As a completely separate question, one that I pose "tongue-in-cheek", how many of the Seven Summits must I climb in order to become an "authority" on the subject? This is relevant to linking my essay, yes? Are all seven required? How about six? Or is a simple majority sufficient as four peaks? I am not trying to be facetious here - only slightly amusing. 8-)

         Sincerely,
                    Countyhighpointer (talk) 18:13, 11 October 2008 (UTC) (Adam Helman)

"Topographically awkward" examples

In this edit a user has requested clarification of "Normally it will suffice to find the nearest higher and more prominent neighbour. However, some regions are topographically awkward." I'm in a bit of a rush so I'm putting some thoughts here rather than trying to formulate a suitable paragraph for the article. If no-one has beaten me to it when I get home next week, I'll try to put something in the article.

Examples can be found by looking at cell maps such as this one of California or mine of Wales. Both maps show multiple levels of prominence cell — 2900 ft and 5000 ft in the former; 150 m, 300 m, 600 m and 900 m in the latter. Examples of this "awkward topography" can often be found by locating low-ish prominence mountains that are near the boundary of a large prominence cell for a distance peak. (Sorry, that's not very well explained.) A concrete example: the parent of Plynlimon (in the Cambrian Mountains in mid Wales) is Pen y Fan (in the Brecon Beacons in south Wales); however the nearest higher and more prominent neighbour is Cadair Idris (in southern Snowdonia). This works because Plynlimon is at the far end of a long ridge spanning south and mid Wales.

— ras52 (talk) 08:12, 16 April 2009 (UTC)