halhiker wrote:I thought it was interesting that some entries say that MSJ has 8,339 feet of prominence but that it has a 10,000 foot escarpment on its north face. I have to wonder where they measure from because from the east the mountain have about 10,400 feet of prominence.
Prominence is the height over the col to the closest point higher than SJ.
ie How far you have to go down to go higher.
I'm pretty sure there is another term to describe that "prominence" to the east; but I can't remember it.
From peakbagger
http://www.peakbagger.com/help/glossary.aspx#clean
Clean Prominence
Prominence is the vertical distance a given summit rises above the lowest col connecting it to a higher summit. To calculate it, you must know the elevation of a summit and the elevation of its key col. A problem arises when one or both of these elevations are not known precisely. Most commonly, col elevations are not given on topographic maps, so all that is known is a range based on a contour interval. Many summits also are represented by just a closed contour and no exact elevation.
There are three ways to deal with this uncertainly when calculating prominence:
Optimistic Prominence: Use the lowest contour line at a col, and the highest possible elevation for peaks, yielding the maximum possible prominence value.
Interpolated Prominence: Use the middle elevation between contours for cols and peak closed contours.
Clean (or Pessimistic) Prominence: Use the highest contour line at a col, and the lowest contour line for peak closed contours, yielding a minimum possible value.
This site uses clean prominence for ranking peaks and setting cut-off values, mainly because it is impossible to overstate a peak elevation or prominence value using that method. Values may be higher, but no peak will ever get extra undeserved elevation. This seems like the safest method, and is commonly used by current prominence researchers.