What Are Mountains?

mountain

ˈmaʊntɪn/

noun

plural noun: mountains

1. 1. 

   a large natural elevation of the earth's surface rising abruptly from the surrounding level; a large steep hill.

   
   

   "we set off down the mountain"

   
   

   synonyms:

   peak, height, elevation, eminence, prominence, summit, pinnacle, mountaintop, alp, horn; More

2. 

a large pile or quantity of something.

"a mountain of paperwork"

synonyms:

a great deal, a lot, heap, pile, mound, stack; More

This was on my previous post which was my initial research before committing to mountains, but it includes my discovery into what mountains are. These are notes on how mountains are formed.

I had the book Planet Earth on hand so decided to start reading the chapter on mountains to get some ideas flowing. I annotated in the book but here are some notes: 

I particularly liked the description of the Andes in South America and the Rocky Mountains in North America, being described as "the spine of America" so I did a very small and quick cellulose experiment on how it might look. 

Other notes:

What constitutes a mountain depends on the surrounding landscape and who is looking at it. 

7% of the world's fresh water is stored in glaciers which cover 10% of land (ice age 32%). If this melted, it is estimated that sea level would rise approx. 70m (p.157).

Frozen people. Preservation. 

Harshness of nature. People can't accept this- cities. Why then is nature so attractive to us? Contrast? 

People of Nepal/ Tibet. Mountains and religion. 

Mountains mentioned:

The Andes (where there are the highest active volcanoes in the world. Longest mountain chain on the planet). 

The Ethiopian Highlands (largest mountainous area in Africa).

The Rockies (The Rocky Mountains. Dead mountains). 

The Himalayas (has the highest mountain- Everest-8850m, the highest pass, the deepest gorge, the highest-living plants and animals. "The greatest physical feature on Earth" Kenneth Mason. Still growing).

The Karakoram Mountains (K2 at 8611m)

The Alps

Animals mentioned:

Ethiopian wolf

The gelada (monkey group) 

Patagonian puma

Guanacos ('mountain camel')

Grizzly bears

American mountain goat

The markhor (Himalayan goat)

Snow leopard

Yunnan snub-nosed monkeys (highest living non-human primate)

Panda

Red panda

Demoiselle cranes

On the right hand page, I have noted the different types of mountain and by that the different ways in which they can form. I found a diagram on BBC Bitesize that shows how fold mountains work.

  

Formation of Fold Mountains from BBC Bitesize

I then looked back at the Creado search I did (notes in top image) as I wanted to look back at the way mountains are formed and I want to have the information here. 

The Origins of Mountains

Mountains and mountain ranges have varied origins. Some are the erosional remnants of plateaus; others are cones built up by volcanoes, such as Mt. Rainier in Washington, or domes pushed up by intrusive igneous rock (see rock), such as the Black Hills of South Dakota and the Henry Mts., Utah. Fault-block mountains (see fault) are formed by the raising of huge blocks of the earth's surface relative to the neighboring blocks. The Basin and Range region of Nevada, Arizona, New Mexico, and Utah is one of the most extensive regions of fault-block mountains.

All the great mountain chains of the earth are either fold mountains or complex structures in whose formation folding, faulting, or igneous activity have taken part. The growth of folded or complex mountain ranges is preceded by the accumulation of vast thicknesses of marine sediments. It was first suggested in the late 1800s that these sediments accumulated in elongated troughs, or geosynclines, that were occupied by arms of the sea. While some of the sediment was derived from the interior of the continent, great quantities of sediment were apparently derived from regions now offshore from the continent. For examples, sedimentary rocks of the Appalachian Mts. formed in a vast geosyncline that extended from the Gulf states northeastward through the eastern states and New England, and into E Canada. It is now recognized that great thicknesses of sediment can occur wherever there is subsidence (lowering of the earth's crust).

The best modern analogues of geosynclines appear to be the thick deposits of sediment making up the continental shelves and continental rises (see ocean). Most geologists now believe that the geosynclinal sediments found in mountain ranges were initially deposited under similar conditions. The period of sedimentation is followed by folding and thrust faulting, with most high mountain ranges uplifted vertically subsequent to folding. The movements of the earth's surface that result in the building of mountains are compression, which produces folding, thrust faulting, and possibly some normal faulting; tension, which produces most normal faulting; and vertical uplift. Mountains are subject to continuous erosion during and after uplift. Sharp peaks are formed and are subsequently attacked and leveled. Mountains may be entirely base-leveled, or they may be rejuvenated by new uplifts.

The ultimate cause of mountain-building forces has been a source of controversy, and many hypotheses have been suggested. An old hypothesis held that earth movements were adjustments of the crust of the earth to a shrinking interior that contracted and set up stresses due either to heat loss or gravitational compaction. Another hypothesis suggested that earth movements were primarily isostatic, i.e., adjustments that kept the weights of sections of the crust nearly equal (see continent). A third hypothesis, popular from the early 1960s to today, ascribed mountain-building stresses to convection currents in a hot semiplastic region in the earth's mantle.

According to the plate tectonics theory, the lithosphere is broken into several plates, each consisting of oceanic crust, continental crust, or a combination of both. These plates are in constant motion, sideswiping one another or colliding, and continually changing in size and shape. Where two plates collide, compressional stresses are generated along the margin of the plate containing a continent. Such stresses result in the deformation and uplift of the continental shelf and continental rise sediments into complex folded and faulted mountain chains (see seafloor spreading; continental drift).

Library Visit 

I couldn't find many books from the library search online so I thought I would start with one and and just brows the section to see what I could find. 

I had not heard this word, this project so far is making me discover words I never even knew existed! I took this to remind me to look it up later.

orogeny

ɒˈrɒdʒəni/

noun

GEOLOGY

1. a process in which a section of the earth's crust is folded and deformed by lateral compression to form a mountain range.

   
   

   "present rates of denudation and orogeny"

   
   

   
   

The Use of Landsat Data to Monitor Iceberg Production

I'm not looking at data yet but this cover and shape of the book caught my eye. It almost looks like a screen print, only a few colours and the shape of the book is one that goes with the idea of a mountain range- landscape. I opened up the book and was pleasantly surprised! 

The use of transparent acetate to show points on the image behind. I would like to combine this into work I do. Layers, layers, layers.

The book I have found the most enlightening, and intact the only one I could find of interest to me at this stage is Mountain Environments by A.J.Gerrard. 

The introduction alone was full of interesting places to potentially visit of my research travels 

Contrary to what wiki says- Mountains are extremely diverse land forms- proved difficult to achieve consistency in description and analysis. 

Criteria:

elevation 

volume

relief

steepness

spacing 

continuity

Impressive

Individuality 

Difference between mountainous terrain and the rock structures. 

The word mountain can bring grandeur: 'dome mountain for Weald uplift (South-East England).

Altitude is not enough to define mountains.

Definition should include relative relief (and slope steepness & land volume).

Horizontal distances between ridges and valleys are just as important to the definition of mountains as the vertical distribution  s that establish relief. 

"An elevated landform of high local relief e.g. 300 m (1000') with much of its surface in steep slopes, usually displaying distinct variations in climate and associated biological phenomena from its base to its summit." -Price (1981)

Although most scientist working in mountains areas disagree with 300 m- should be more like 700 m. 

Low mountains -relief of 1000-3000 ft (Appalachian Mountains, Guyana Highlands, coastal mountains of Brazil)

High mountains- should rise above Pleistocene snow line, should extend above the regional timber line and should display cryonival process (processes comprising cryergic and nival mechanisms).- Alpine Zone - varies in latitude.(Rocky Mountains, European Alps- 4000m, Alaska, Iceland Northern Scandinavia and Labrador- 700 m). 

Difficult to apply these to arid mountains because of the timber line. 

"Mountains can be distinguished not only by altitude considerations but also on the basis of areal extent. 

A mountain can be a single isolated feature outstanding within a belt of mountains. A mountain range is a single ridge but a mountain chain, although also a linear feature, implies major features that persist for hundreds or even thousands of miles. 

A mountain mass is usually a group of mountains or irregular shape not characterised by simple linear trends. They may be block-faulted terrain, volcanic areas, or uplifted areas of complex igneous rocks such as batholiths.

The term 'mountain system' is usually reserved for the greatest continent-spanning features. Mountain systems have complex histories and comprise sub-diversion of age and types such as combination chains, ranges ad masses." p.5-6

Look into further:

MOUNTAIN RANGE

MOUNTAIN CHAIN

MOUNTAIN MASS

MOUNTAIN SYSTEM

Mountain Environments

Physical Map of the World, April 2004 https://en.wikipedia.org/wiki/List_of_mountain_ranges