Talk:Saltation (geology)

Start of Talk:

Saltation: 1-a geophysics process(+biology); 2-a concept[edit]

The orginal Saltation article was focussed on fluid transport in the field of Fluid dynamics-(stream flow). My original meeting with saltation was in sand-dune, and sand, (but see also loess), and later I saw the process used in analyzing river bottom movements of the "River load", the transport of particles downstream (which can end up: upstream in eddies, etc.)-

However, I still contend the "process" of saltation is a more important concept when used with time and the "rate-of-change" that occurs. To pick a geoligic time: "hundreds of years" or "thousands of years", is a statement that is 'unknowable'. I would assume with the speciation, and the overabundance of off-spring, -(the conclusion has to be): "Generations are Shortened!"--under some environmental conditions, I would err on the side, of more rapid 'Geologically-bsed' changes, as opposed to the extended: "thousands of years"; it may apply to some mammals, but I think the time frames, have to be shortened..[And....I do think this goes towards understanding the positions taken on the Punctuated equilibrium discussion-](I think some species come along so fast, one doesn't see them coming..) ... Just some thoughts--at... "part-of-1-year" after the original article was split. //--From the Arizona-Desert--Mmcannis 20:50, 19 November 2006 (UTC)[reply]

fluid dynamics[edit]

I added much of the original content on this page. FWIW, fluid dynamics is not the same as stream flow. The expression fluid dynamics refers to the dynamics of a fluid in an engineering sense, where air is as much a fluid as water.

Anyway, is it worth starting a page on transport of particles by fluids? —Preceding unsigned comment added by 142.207.115.25 (talk) 21:09, 25 February 2008 (UTC)[reply]

I think it would be good to rename the title of the article, because the mechanism of saltation in fluid dynamics is just the same.--Graham Proud (talk) 05:57, 29 September 2012 (UTC)[reply]

Parabolic trajectory[edit]

A parabolic trajectory could not possibly be a defining characteristic. Particles only move in parabolic arcs when they are in a vacuum, NOT in a fluid. There might be something close to parabolic when the saltation occurs at low velocities, and I'm sure the math is interesting, based on the vector, velocity and viscosity of the fluid, and the mass and size of the particle. Maybe even the coefficient of friction on the surface of the particle. But sand particles in a sandstorm fly in a very complex motion, going up and down depending on which way the wind blows. The particles shown in the wind-tunnel photo at the bottom of the main page are not traveling in parabolic arcs, either. So I'm deleting that phrase.

I am also disturbed by the explanation of the physics in the third paragraph. Some of it is clearly true, but some is suspicious. I'm going to watch this page to see if anyone can clean it up.

--cbdorsett (talk) 03:43, 2 August 2011 (UTC)[reply]

I agree that the physics in the third (and fourth) paragraph was incorrect, and I've tried to fix it. Also, the particles move in approximately ballistic trajectories, indeed not parabolic.

--Jfk nl80 (talk) 22:53, 4 April 2014 (UTC)[reply]

External links modified (January 2018)[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Saltation (geology). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 06:11, 25 January 2018 (UTC)[reply]