Talk:Elevation

Elevation vs. altitude

"Elevation is mainly used when referring to points on the Earth's surface, while altitude is used for points in the air, such as an aircraft."

In my experience, this statement is only true in US English. I've done a lot of hiking/backpacking with both British and American groups. Usually Americans seem to use "elevation", while Brits use "altitude" or "height". I've never heard "elevation" in this context in the UK (actually I didn't know the meaning of the word when I first arrived in the US). The legends on UK Ordnance Survey maps use "height above sea level". Also, I have noticed that Americans use "elevation change" while Brits use "ascent" or "descent", to quantify the gain or loss in height. However, I haven't found any documented evidence of this linguistic difference, so I'm reluctant to edit the article. Can anyone else comment? Mtford 08:32, 20 October 2006 (UTC)[reply]

In engineering and surveying, the term elevation is most commonly used for surface features, waterways, structures, and mines. The term altitude is commonly used for elevations in the atmosphere or space. The term height is usually used to denote elevation above a reference level, such as the height of a building above the ground. --Buaidh 13:43, 26 September 2007 (UTC)[reply]

Lowest point?

There are several references to highest elevations, but what about lowest elevations? All I can think of are Death Valley in the US and Lake Baikal in Russia (deepest lake). What about the lowest elevation in the world? -kotra 10:03, 31 October 2006 (UTC)[reply]

Lake Elevation

What about lake elevation as used by the Army Corps of Engineers to measure water level? I assume it is the number of feet above mean sea level but don't see it discussed anywhere.

This concept should be added to the elevation page. It's called stage. Stage is the water level above some local reference point, often the lake or stream bed. The term is used for flood monitoring and discerning ecological implications. Stage is rarely linked to sea level, so it's only useful over small spatial scales. Lovethemountains (talk) 16:01, 8 July 2009 (UTC)[reply]

Elevation Signs

When you enter a population center in the US, there is usually a sign that shows the name and elevation. Where is that elevation measured? One thing I do know is that it is NOT measured where the sign is placed. ```` —Preceding unsigned comment added by 71.243.195.217 (talk) 01:33, 3 September 2007 (UTC)[reply]

Proposed merge

This article has content that is similar to the one on hypsography (the study of the distribution of elevations). Someone else might like to merge the two articles. I am just going to add merge templates to alert readers to the existence of the two related articles. JonH (talk) 08:57, 26 April 2009 (UTC)[reply]

I think it would be fine to move the content of the hypsography article onto the elevation page. Hypsography is an approach to characterization of terrain that is unique, so we shouldn't cut it. On the other hand, because it is much more technical than what most people who search "elevation" will be interested in, perhaps it would make sense to keep it on it's own. Lovethemountains (talk) 16:05, 8 July 2009 (UTC)[reply]

I need help?

would you call the middle elevation middle elevation —Preceding unsigned comment added by 65.29.155.253 (talk) 23:00, 1 October 2009 (UTC)[reply]

Other uses of the term elevation

Architecture: horizontal view of a structure typically showing the facade for purposes of comparison between different styles as in houses. Mechanical engineering: the Y dimension of an object in the X-Y-Z coordinate system, where X is the length, Y is the width and Z is the height. 166.20.224.12 (talk) 19:17, 2 July 2010 (UTC)[reply]

Merge above mean sea level here

The definition is the same. fgnievinski (talk) 15:19, 8 June 2016 (UTC)[reply]

No it isn't. MAMSL is a unit of measurement used to describe Altitude as well as Elevation. Burninthruthesky (talk) 15:55, 8 June 2016 (UTC)[reply]

Wrong: the physical unit is metres; the quantity is "vertical position above mean sea level" (elevation). fgnievinski (talk) 16:11, 8 June 2016 (UTC)[reply]

You have proposed to merge Metres above sea level here. The point of my previous comment applies both to the unit and the quantity. Burninthruthesky (talk) 16:54, 8 June 2016 (UTC)[reply]

I'm an Aeronautical Information Service technician. In my area (Aeronautics, and thus also in Aviation in general), the definitions adopted are these ones:

Level: a generic term relating to the vertical position of an aircraft in flight and meaning variously, height, altitude or flight level.^[1]
Datum: any quantity or set of quantities that may serve as a reference or basis for the calculation of other quantities (ISO 19104).^[1]
Altitude: the vertical distance of a level, a point or an object considered as a point, measured from the mean sea level (MSL).^[1]
Height: the vertical distance of a level, a point or an object considered as a point, measured from an specific datum.^[1]
Elevation: the vertical distance of a point or a level, on or affixed to the surface of the earth, measured from mean sea level.^[1]

This picture thus describes such concepts pretty well:

►Sampayu 17:44, 8 June 2016 (UTC), updated at 18:17, 8 June 2016 (UTC)[reply]

Addendum: note that, on the picture above, the datum used in height is the elevation, because the objects whose heights are indicated are objects located above the earth's surface. However, if e.g. that airplane was above the ocean, its datum would change to MSL (mean sea level), thus causing its height to become the vertical distance of such airplane, measured from the MSL (instead of from the earth's surface): because the airplane can move on a height above different surfaces (terrain, water...), the use of the generic word datum is more appropriate.►Sampayu 18:04, 8 June 2016 (UTC)[reply]

Thank you for these. I'm a geodesist. I'm glad to find the ICAO definitions agreeing with the ISO definitions (see altitude, height, and depth). The above definition of elevation (as the altitude of the ground or buildings) indicates that altitude is synonymous with above mean sea level. Wikipedia should adopt these authoritative definitions across all articles. fgnievinski (talk) 18:03, 8 June 2016 (UTC)[reply]

You're welcome. I totally agree with you.

►Sampayu 18:13, 8 June 2016 (UTC)[reply]

Great, so let's merge/rename as follows:

fgnievinski (talk) 18:16, 8 June 2016 (UTC)[reply]

Agree.

►Sampayu 18:19, 8 June 2016 (UTC)[reply]

I've mentioned the ICAO definitions in the ISO article: [1]. fgnievinski (talk) 18:30, 8 June 2016 (UTC)[reply]

Agree.

Shelbystripes (talk) 01:41, 24 July 2016 (UTC)[reply]

Agree

as per fgnievinski, good discussion. E x nihil ^(talk) 23:29, 7 August 2017 (UTC)[reply]

Oppose for the reason stated above (e.g. Victor airways and Bethlehem both have wikilinks to Metres above sea level; one means altitude, the other means elevation.) I understand the proposal was changed to merge Metres above sea level into Altitude. However, due to all the redirects appearing in this discussion the proposal was unclear. It was never advertised at Altitude. Since it hasn't been actioned after a year, this is probably a moot point. Burninthruthesky (talk) 11:11, 8 August 2017 (UTC)[reply]

Agree

with this new proposal. Hulten (talk) 12:58, 8 November 2017 (UTC)[reply]

The merge destinations had become confused. I removed reference to Elevation and changed to Altitude. E x nihil ^(talk) 10:30, 10 October 2017 (UTC)[reply]

References

^ ^a ^b ^c ^d ^e United Nations - International Civil Aviation Organization. "Annex 4: Aeronautical Charts - Chapter 1 (Definitions, Applicability and Availbility)" (PDF). Note: Annex 4 is one of the (currently) 19 annexes to the Chicago Convention on International Civil Aviation (ICAO Doc. 7300).

[annex4-1] United Nations - International Civil Aviation Organization. "Annex 4: Aeronautical Charts - Chapter 1 (Definitions, Applicability and Availbility)" (PDF). Note: Annex 4 is one of the (currently) 19 annexes to the Chicago Convention on International Civil Aviation (ICAO Doc. 7300).

[1]