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WHAT IS MASS MOVEMENT?. WHAT IS MASS MOVEMENT?. Downslope movement of Earth material under the influence of gravity . Downslope. Earth material (not alien!). Downslope. Earth material (not alien!). Downslope. Gravity. THE BIG PICTURE.
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WHAT IS MASS MOVEMENT? Downslope movement of Earth material under the influence of gravity.
Earth material (not alien!) Downslope
Earth material (not alien!) Downslope Gravity
THE BIG PICTURE Uplift – Creation of potential energy by forces from within the Earth
THE BIG PICTURE Erosion of materials from uplands to low land by gravity and other external forces. Uplift – Creation of Potential Energy by forces from within the Earth.
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: 2. Flows: 3. Heaves:
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: 2. Flows:
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: 2. Flows: 3. Heaves:
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: All the vertical displacement occurs along a single plane. 2. Flows: 3. Heaves:
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: All the vertical displacement occurs along a single plane. 2. Flows: Vertical displacement occurs throughout the moving material. 3. Heaves:
WHAT ARE THE TYPES OF MASS MOVEMENT? 1. Slides: All the vertical displacement occurs along a single plane. 2. Flows: Vertical displacement occurs throughout the moving material. 3. Heaves: Displacement by means of non- cancelling vertical movement of material.
SLIDE Shear Toe Plane All of downslope displacement (with small exception of the “toe”) occurs along a single plane, the “shear plane”.
ITALIAN DISASTER! Mini-tsunami Dam burst
FLOW All of downslope displacement occurs throughout the moving body.
OSO, WASHINGTON 1965 and 2006 movement scar “outside” bend of river 10 million cubic yards of earth material BEFORE AFTER
Shear plane 600’. Highest point in Florida 345, SLIDE OR FLOW? Clay/sand glacial lake deposits River Rotational Slide Flow Pre-movement land surface River http://baltimorepostexaminer.com/wp-content/uploads/Oso_landslide_WSP-630x310.png
1. Uplift: Perpendicular to slope. 2. Collapse: Vertically under the influence of gravity.
1. Uplift: Perpendicular to slope. 2. Collapse: Vertically under the influence of gravity. Resultant Vector: Downslope movement
UPLIFT COLLAPSE 1. 2. 3.
UPLIFT COLLAPSE 1. HEATING Ground heat flux Expansion 2. 3.
UPLIFT COLLAPSE 1. HEATING COOLING Ground heat flux Expansion Nighttime Radiative cooling Contraction 2. 3.
UPLIFT COLLAPSE 1. HEATING COOLING Ground heat flux Expansion Nighttime Radiative cooling Contraction 2. WETTING Clays expand when wet 3.
Clay Minerals occur in sheets, or “Laminae”. Water molecules get inserted between sheets causing expansion
UPLIFT COLLAPSE 1. HEATING COOLING Ground heat flux Expansion Nighttime Radiative cooling Contraction 2. WETTING DRYING Clays expand when wet Water dries and sheets Contract. 3.
UPLIFT COLLAPSE 1. HEATING COOLING Ground heat flux Expansion Nighttime Radiative cooling Contraction 2. WETTING DRYING Clays expand when wet Water dries and sheets Contract. 3. FREEZING Soil water freezes and expands
Like most substances the density of water increases as temperature decreases.
After 4°C (39°F) strange things happen – the density decreases!!!!!
ICE IS ABOUT 90% OF THE DENSITY OF – SO IT FLOATS IN WATER
At warmer temperatures the random motions caused by heat disrupt the tendency for water molecules to align As temperatures cool the bonds between adjacent molecules dominate and water adopts a regular structure.
Density = Mass / Volume Consider fixed mass of water (1 gram) in soil pore and Density of water = 1 gram /cc (cubic centimeter), then water occupies 1 cc. Temperature at night drops below 0°C (32°F), so water turns to ice, with a density of 0.92 gram/cc 0.92 = 1 gram/ Volume Volume = 1/ 0.92 = 1.09 ccs By freezing water increased the volume it occupies by about 9%
Density = Mass / Volume Consider fixed mass of water (1 gram) in soil pore and Density of water = 1 gram /cc (cubic centimeter), then water occupies 1 cc. Temperature at night drops below 0°C (32°F), so water turns to ice, with a density of 0.92 gram/cc 0.92 = 1 gram/ Volume Volume = 1/ 0.92 = 1.09 ccs By freezing water increased the volume it occupies by about 9%
Density = Mass / Volume Consider fixed mass of water (1 gram) in soil pore and Density of water = 1 gram /cc (cubic centimeter), then water occupies 1 cc. Temperature at night drops below 0°C (32°F), so water turns to ice, with a density of 0.92 gram/cc 0.92 = 1 gram/ Volume Volume = 1/ 0.92 = 1.09 ccs By freezing water increased the volume it occupies by about 9%
Density = Mass / Volume Consider fixed mass of water (1 gram) in soil pore and Density of water = 1 gram /cc (cubic centimeter), then water occupies 1 cc. Temperature at night drops below 0°C (32°F), so water turns to ice, with a density of 0.92 gram/cc 0.92 = 1 gram/ Volume Volume = 1/ 0.92 = 1.09 cc By freezing water increased the volume it occupies by about 9%
Density = Mass / Volume Consider fixed mass of water (1 gram) in soil pore and Density of water = 1 gram /cc (cubic centimeter), then water occupies 1 cc. Temperature at night drops below 0°C (32°F), so water turns to ice, with a density of 0.92 gram/cc 0.92 = 1 gram/ Volume Volume = 1/ 0.92 = 1.09 ccs By freezing water increased the volume it occupies by about 9%
UPLIFT COLLAPSE 1. HEATING COOLING Ground heat flux Expansion Nighttime Radiative cooling Contraction 2. WETTING DRYING Clays expand when wet Water dries and sheets Contract. 3. FREEZING THAWING Soil water freezes and expands Ice melts and occupies a smaller volume