Seven Summits: Defining the Continents
© 2008 Adam Helman, Ph.D.

The Seven Summits Quest

"Seven Summits" are the highest mountains on each of seven continents. Climbing them all is a serious mountaineering challenge.¹

This essay explores all reasonable definitions of "continent" without any preconceptions about what the climbing community has ruled on the matter. A proliferation of Seven Summit lists result, each list based on a different and completely objective criterion for what is a continent. A second, independent online review is available as published by Eberhard Jurgalski.

The traditional Bass and Messner variants of the Seven Summits are two realizations within this superset of potential Seven Summit lists.

It is assumed that a Seven Summit list containing peaks based on different inclusion criteria is invalid.² Furthermore, only objective criteria are considered.³ No single resulting list is advocated among those lists generated by the rational considerations expounded here.⁴ Seven Summit lists that do not result from these considerations are of dubious merit since they are not based on sound, logical arguments.

We begin with a historical review.

Historical Development

In the 1980's Dick Bass set for himself the impressive task of climbing the highest peak on each continent. As a Texas businessman without climbing experience this was truly a daunting challenge. Being neither a geologist nor a geographer, quite naturally Mr. Bass defined each continent according to the lay person's concept thereof - the continental outlines. Hence Australia's highpoint, Mount Kosciuszko, was included in the Seven Summits.^5,6

With professional help, and much fortitude, Dick succeeded in his personal quest. His book, Seven Summits, remains a classic account of this original effort.⁷

Mr. Bass's list satisfies the cultural definition described below.

Renowned mountaineer Reinhold Messner revised Dick's list by substituting the far more difficult Carstensz Pyramid (Puncak Jaya) of New Guinea for Mount Kosciuszko.⁸

In 1986 Pat Morrow was first to climb this alternative Seven Summits list - one that passes the cultural definition described below.⁹

Rational Definitions

Several criteria exist to define the continents. The principal division is whether a physical criterion is employed, or one based on societal concepts. The physical criteria include geology, topography, and continental outlines.¹⁰ Societal criteria include culture and politics. These five criteria are discussed below.

Other criteria are not in the spirit of objectivity, such as religion, race, economic wealth, mineral resources ... the list is nearly endless.

I. Geology and Plate Tectonics

Plate tectonic theory is well-entrenched in the geology textbooks, explaining a large volume of geological observations. There are seven continental-scale tectonic plates and many more of lesser size.⁹ It is appropriate, therefore, to consider the highpoints of each major tectonic plate for generating a Seven Summit peaklist.

As Europe does not comprise a separate tectonic plate, Mount Elbrus has no place on a Seven Summit list based on purely geological (i.e. tectonic) considerations.

One rationale for inclusion of Carstensz Pyramid on a Seven Summit list is that it is the Australian tectonic plate highpoint. Indeed, the seas separating New Guinea from Australia are a shallow 250 feet. Hence New Guinea and Australia are nearly one continental landmass anyway: it would only take a 300 foot drop in sea level to make it so.

Seven Summit list I-A differs from the well-known, Carstensz Pyramid Seven Summits variant in the substitution of Hawaii's Mauna Kea for Mount Elbrus.

SEVEN SUMMIT LIST I-A		SIX SUMMIT LIST I-B
African Plate	Kilimanjaro	African Plate	Kilimanjaro
Antarctic Plate	Vinson Massif	Antarctic Plate	Vinson Massif
Australian Plate	Carstensz Pyramid	Australian Plate	Carstensz Pyramid
Eurasian Plate	Mount Everest	Eurasian Plate	Mount Everest
North American Plate	Mount McKinley	North American Plate	Mount McKinley
Pacific Plate	Mauna Kea
South American Plate	Aconcagua	South American Plate	Aconcagua

It is arguable that, of all the possible means for defining "continents", a geological criterion is most suitable. Countries (and their geographers) come and go; along with their cultures and mountain climbers. The existing set of tectonic plates will be around for tens of millions of years.

Restriction to continental plates (i.e. elimination of oceanic tectonic plates) removes the Pacific Plate from our list; and results, as List I-B, in the traditional Carstensz Pyramid variant of the Seven Summits with Mount Elbrus excluded. These "Six Summits" correspond to continents based on purely geological (tectonic plate theory) considerations.

Insistence on exactly seven highpoints, all which lie on continental tectonic plates, suggests the incorporation of the Indian tectonic plate's highpoint on the Seven Summit list. However the Indian plate is considered a minor tectonic plate - one that lacks continental scale.¹²

II. Topographic Prominence

A mountain's prominence is the elevation difference between its summit and the highest contour encircling it and yet not encircling any higher mountain.^13-15

Prominence is an excellent, objective measure of a mountain's vertical stature; and is relevant to us because the prominences of continental highpoints equal their summit elevations.¹⁶ Hence 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.¹⁷

SEVEN SUMMIT LIST II-A
Africa	Kilimanjaro
Antarctica	Vinson Massif
Asia	Mount Everest
Europe	Mont Blanc
North America	Mount McKinley
Oceania	Carstensz Pyramid
South America	Aconcagua

The former 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 by the lowest intervening terrain.

The key saddle for Mont Blanc is near sea level at 371 feet (113 meters).¹⁸ 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' key saddle.

Using Mont Blanc as its highpoint, a prominence-based definition of Europe is delimited by the Volga River and not by the Ural Mountains as is commonly done in geography books. It makes no sense to delimit areas of high terrain, as "continents", from one another by defining their borders as a high elevation mountain range. It is far more reasonable to delimit their areas by low elevation terrain - and the prominence concept correctly addresses this issue.

THE EUROPEAN HIGHPOINT BASED ON TOPOGRAPHIC CONSIDERATIONS IS MOUNT BLANC.

List II-A is the topographic definition Seven Summit list. It differs from the traditional, Carstensz Pyramid variant of the Seven Summits by the substitution of Mount Elbrus in favor of Mont Blanc.

III. Continental Outline Definition

Europe as a separate continent is a cultural and political concept. Hence based on their outlines there are only six continents - and Six Summit list III-A results. List III-A is the traditional, Mount Kosciuszko variant of the Seven Summits as first proposed by Dick Bass; with, however, Mount Elbrus absent.

SIX SUMMIT LIST III-A
Africa	Kilimanjaro
Antarctica	Vinson Massif
Asia	Mount Everest
Australia	Mount Kosciuszko
North America	Mount McKinley
South America	Aconcagua

IV. Political Definition

Once the arena of geology and topography is left there is greater room for interpreting the meaning of "continent". Numerous definitions of "continent" exist in the lay sense.¹⁹ In many western societies the concept of seven continents is taught - in order of area, Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

As there is no water separation between them, division of the Eurasian landmass into the continents of Asia and Europe is maintained only for cultural and historical purposes. Thus in Russia, which spans both regions, the concept of six continents is taught.

This process may be continued with the inclusion of North and South America into a single continent - "America", so yielding five continents because of the Panama land bridge. Finally Africa is not strictly separated from Eurasia; and we are left in such a model with just four continents.

Unless we wish to admit of culturally-dependent "Seven Summit" lists with only four, five, or six members, subdivision of the major landmasses into less than seven continents will not define suitable peak lists. We restrict our considerations to the seven continent model.

A political definition for the continents results in Seven Summit List IV-A. It differs from the continental outline definition Seven Summit list by the substitution of Mount Kosciuszko in favor of Mawson Peak. The Australian Commonwealth owns Heard Island, a remote speck in the Indian Ocean. Mawson Peak is the island highpoint - a glaciated 9,006 foot volcano and hence higher than Mount Kosciuszko.

One could argue that since Mawson Peak lies outside the Australian continent itself, that it does not constitute a valid list member. The author agrees with this sentiment. As the intent of this essay is to include all possible definitions, List IV-A is included for completeness only.

SEVEN SUMMIT LIST IV-A		SEVEN SUMMIT LIST IV-B
Africa	Kilimanjaro	Africa	Kilimanjaro
Antarctica	Vinson Massif	Antarctica	Vinson Massif
Asia	Mount Everest	Asia	Mount Everest
Australia	Mawson Peak	Oceania	Mount Wilhelm
Europe	Mount Elbrus	Europe	Mount Elbrus
North America	Mount McKinley	North America	Mount McKinley
South America	Aconcagua	South America	Aconcagua

An alternative is to enlarge the definition of continent to include the smaller landmasses that geopolitically comprise a continental-scale region. Thus is born "Oceania", and, with it, the eastern one-half of New Guinea (Papua New Guinea), plus New Zealand and a multitude of far-flung Pacific islands are appended to Australia.

Most printed atlas and geographical societies consider Indonesia, including the western one-half of New Guinea ("West Irian"), to be politically part of greater Asia. In contrast, the same authoritative sources treat the independent nation of Papua New Guinea, as the eastern half of New Guinea, as part of Oceania. This subdivision of New Guinea has no geological or even cultural basis - it is purely political - and yet results in perfectly valid Seven Summits list IV-B.

These atlases list Oceania's highpoint as Mount Wilhelm.

Mount Wilhelm is the highpoint of Papua New Guinea with an elevation of 14,793 feet (4,509 meters). It is the highpoint of Oceania in Seven Summit list IV-B. List IV-B differs from the traditional, Carstensz Pyramid variant of the Seven Summits in the substitution of Carstensz by Mount Wilhelm.

V. Cultural Definition

A cultural definition for the continents yields Seven Summit List V-A Here, Antarctica, having no permanent inhabitants, is assumed to have a unique "culture of science". List V-A is the traditional, Mount Kosciuszko variant of the Seven Summits as first proposed by Dick Bass.

As with the cultural definition of continents, one may replace Australia with Oceania for a political definition. Here, New Guinea is not split down the middle. The inhabitants of New Guinea consider themselves a culture apart from Asia, being more aligned with the peoples of the Pacific islands. This schism arises because Indonesia, although owning West Irian (the western one-half of New Guinea), owns the territory by decree rather than consent. Hence the political boundary is a fictitious one that is not reflected in the local culture.

Seven Summit List V-B is the result of a cultural definition for the continents, Oceania having supplanted Australia. List V-B is the traditional, Carstensz Pyramid variant of the Seven Summits as first proposed by Reinhold Messner.

Lists I-A,B, II-A, III-A,B, IV-A,B, and V-A,B are all perfectly valid Seven Summit lists. List V-A is the traditional, Mount Kosciuszko variant of the Seven Summits. List V-B is the traditional, Carstensz Pyramid variant of the Seven Summits.

SEVEN SUMMIT LIST V-A		SEVEN SUMMIT LIST V-B
Africa	Kilimanjaro	Africa	Kilimanjaro
Antarctica	Vinson Massif	Antarctica	Vinson Massif
Asia	Mount Everest	Asia	Mount Everest
Australia	Mount Kosciuszko	Oceania	Carstensz Pyramid
Europe	Mount Elbrus	Europe	Mount Elbrus
North America	Mount McKinley	North America	Mount McKinley
South America	Aconcagua	South America	Aconcagua

Discussion

Dick Bass and Reinhold Messner selected Seven Summit lists V-A and V-B, respectively, for defining the highpoints of each continent. They almost certainly made their choices without the detailed, logical selection process outlined in this essay. Remarkably, both traditional Seven Summit lists correspond to a cultural definition; and differ only as to whether Australia is enlarged, as Oceania, to include neighboring islands.

It is provocative to consider how the climbing community's Seven Summit aspirations would differ had the alternative lists of this essay been selected instead.

The author views climbing all the peaks on any of one these nine lists as a valid ascent of the Seven (or Six) Summits.²⁰

Bibliography and Footnotes

¹ See http://en.wikipedia.org/wiki/Seven_Summits.

² This claim should be self-evident. Otherwise one compares the proverbial apple with orange.

³ Consider a list of "best" or "most difficult" mountain climbs - subjective descriptors.
  No agreement will be reached as to which peaks comprise the list.

⁴ The author maintains his personal favored continent definitions; and yet recognizes that
  alternative definitions, if advocated in this essay, are equally valid.

⁵ That Mount Kosciusko is a mere hike has no logical bearing on
  how to define continents. The inclusion of this peak by Mr. Bass is justified.

⁶ The Australian Commonwealth's highpoint is Mawson Peak in the Indian Ocean.
  At over 9,000 feet this nearly inaccessible, glaciated mountain is higher than Mount Kosciusko.
  Its existence is presumably irrelevant to Mr. Bass since he considered the continent
  of Australia - not the sovereign nation of that name.

⁷ Seven Summits, Dick Bass and Frank Wells with Rick Ridgeway, 384 pgs. (Grand Central Publishing, 1988).

⁸ Puncak Jaya is Indonesian for "jewel summit".

⁹ Seven Summits - The Quest to Reach the Highest Point on Every Continent,
  Steve Bell (editor), forewords by Dick Bass and Pat Morrow, 144 pgs. (Bulfinch Press, 2000).

¹⁰ Topographic prominence is the metric employed for a topographic definition of continent.

¹¹ See http://en.wikipedia.org/wiki/Plate_tectonics.

¹² See http://en.wikipedia.org/wiki/Indian_Plate.

¹³ See peaklist.org for a general discussion and dozens of prominence-based peak lists.

¹⁴ See this web page for links to most known on-line prominence resources.

¹⁵ The Finest Peaks, Adam Helman, Ph.D., 241 pgs. (Trafford Publishing, 2005).
    See this web page for ordering information.

¹⁶ The low key saddles of Mount McKinley (in Nicaragua) and Kilimanjaro (Suez Canal)
    are exceptions that do not detract from the arguments.

¹⁷ 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. Similarly, Mount Logan is too close to Mount McKinley in Alaska.

Orizaba of Mexico is also eliminated due to a 2,300 foot (700 meter) key saddle with Mount Logan.
The text describes why Mount Elbrus is eliminated.

¹⁸ The key saddle is the unique saddle that determines a mountain's prominence.
    It is the highest saddle connecting the given summit to any higher summit.

¹⁹ See http://en.wikipedia.org/wiki/Continent.

²⁰ To meet the criteria of all nine lists requires climbing twelve mountains. In this manner one satisfies all rational Seven Summit definitions as herein described. In descending elevation the summits are Mount Everest, Aconcagua, Mount McKinley (Denali), Kilimanjaro, Mount Elbrus, Vinson Massif, Carstensz Pyramid (Puncak Jaya), Mont Blanc, Mount Wilhelm, Mauna Kea, Mawson Peak, and Mount Kosciuszko.