Topographic Prominence - Interesting Prominence Situations

Interesting Prominence Situations

The key col and parent peak are often close to the subpeak but this is not always the case, especially when the key col is relatively low. It is only with the advent of computer programs and geographical databases that thorough analysis has become possible.

• The key col of Mount McKinley (also called Denali) in Alaska (6,194 m) is a 56 m col near Lake Nicaragua (unless one accepts the Panama Canal as a key col; this is a matter of contention). McKinley’s encirclement parent is Aconcagua (6,960 m), in Argentina, and its prominence is 6,138 m. To further illustrate the rising-sea model of prominence, if sea level rose 56 m, North and South America would be separate continents and McKinley would be 6138 m above sea level. At a slightly lower level, the continents would still be connected, and the high point of the combined landmass would be Aconcagua, the encirclement parent. Note that, for the purposes of this article, man made structures such as the Panama Canal are not taken into account. If they were, the key col would be along the 26 m Gaillard Cut and McKinley would have a prominence of 6,168 m.

While it is natural for Aconcagua to be the parent of Mount McKinley, since Mount McKinley is a major peak, consider the following situation: Peak A is a small hill on the coast of Alaska, with elevation 100 m and key col 50 m. Then the encirclement parent of Peak A is also Aconcagua, even though there will be many peaks closer to Peak A which are much higher and more prominent than Peak A (for example, Mount McKinley). This illustrates the disadvantage in using the encirclement parent.

• Mount Whitney (4421 m) has its key col 1,022 km (635 mi) away in New Mexico at 1347 m on the Continental Divide. Its encirclement parent is Pico de Orizaba (5,636 m), the highest mountain in Mexico. Orizaba’s key col is back along the Divide, in British Columbia.
• The key col for Mount Mitchell, the highest peak of the Appalachians, is in Chicago—the low point on the divide between the St. Lawrence and Mississippi River watersheds.