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K-2 Resources

Lesson Collection

Land Forms (Geomorphology)

Geomorphology: the study of landforms

Except for volcanic landforms, most of what we can see are the results of erosion and deposition by...

Nature's fluid bulldozers:
1) Running water
2) Glacial action
3) Wind
4) Ocean waves

These are considered bulldozers because they flatten the high spots and fill in the low spots.

Where does the energy come from? 3 sources
1) Internal Earth Energy - throws up the mountains, rifts continents apart, opens ocean basins, foments volcanoes
2) Gravity - inexorably pulls everything down
3) Solar Energy - drives the fluid bulldozers by stirring up wind and water and pouring rain all over the landscape

Two kinds of geomorphic environments:

1) High-energy environments

a) Erosion and transport of eroded materials
b) Steep slopes - maximizes effect of gravity
c) Large volumes of wind, running water, and moving ice
d) High velocities of wind, water, (relatively) ice

Examples:
Himalayan Mountains
Rivers in flood
Hurricanes
Windward Coasts -- Na Pali & Molokai

2) Low-energy environments

a) Sediments acculumate
b) Virtually flat -- minimal effect of gravity
c) Little wind, running water, or moving ice
d) Wind, water, and ice at rest

Examples:
Lake bottoms
Lagoons
Calm weather
Sheltered valleys
Densely vegetated surfaced

At human scale, most of what we see are the result of nature's fluid bulldozers; except for volcanoes.

1) Running Water -- canyons, gullies, river valleys, gravel beds, deltas; miles - thick beds of sediments washed off continents accumulated on the ocean bed.
2) Ocean Waves -- sea cliffs, beaches, sand spits and bars, Barrier Islands.
3) Wind -- soft rocks scoured into grotesque shapes, dunes.
4) Glacial Ice -- u-shaped valleys, hanging valleys, various alpine features, moraines, disorganized drainage, with many lakes and bogs, of most of Canada.

Landforms that are built despite the fluid bulldozers are:

1) Volcanic features that rely on energies within the earth.
2) Coral reefs the thrive and grow best in high energy surf. Food and oxygen are more abundant in the coral reefs.

*Lecture notes from Bryce Decker, Ph.D.