WHAT IS MASS MOVEMENT?

Downslope movement of Earth material under the influence of gravity.

Downslope

Earth material (not alien!)

Downslope Earth material (not alien!) 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 Plane Toe All of downslope displacement (with small exception of the “toe”) occurs along a single plane, the “shear plane”.

ITALIAN DISASTER! Mini-tsunami Vajont Dam burst 1963

Vajont Dam Burst, 1963 Over-topped dam Landslide scar Landslide toe Reservoir shoreline

FLOW All of downslope displacement occurs throughout the moving body.

HEAVE

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. 1. Uplift: Perpendicular to slope. Resultant Vector: Downslope movement

UPLIFTCOLLAPSE

UPLIFTCOLLAPSE 1. HEATING Ground heat flux Expansion

UPLIFTCOLLAPSE 1. HEATING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.3. Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet

Clay Minerals occur in sheets, or “Laminae”. Water molecules get inserted between sheets causing expansion

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.3. Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract.

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.FREEZING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract. 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!!!!!

Once ice forms density drops to about.917!

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%

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.FREEZING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract. Soil water freezes and expands THAWING Ice melts and occupies a smaller volume

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.FREEZING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract. Soil water freezes and expands THAWING Ice melts and occupies a smaller volume “Dry Heaves”

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.FREEZING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract. Soil water freezes and expands THAWING Ice melts and occupies a smaller volume “Dry Heaves” “Wet Heaves”

UPLIFTCOLLAPSE 1. HEATING 2.WETTING 3.FREEZING Ground heat flux Expansion COOLING Nighttime Radiative cooling Contraction Clays expand when wet DRYING Water dries and sheets Contract. Soil water freezes and expands THAWING Ice melts and occupies a smaller volume “Dry Heaves” “Wet Heaves” “Cold Heaves”

HOW DO MASS MOVEMENT PROCESSES DEMONSTRATE THE IMPORTANCE OF THE MAGNITUDE AND FREQUENCY OF FORCES IN SHAPING THE LANDSCAPE?

GEOMORPHOLOGY – STUDY OF THE SHAPE OF THE EARTH’S SURFACE “How much work does a particular process (slides, flows, creeps) complete in shaping the surface of the Earth?” Work Completed = Magnitude of Process X Frequency of Process

Total Yards = Yards per Carry X Carries per Game 100 yds = 2 X yds = 10 X Fullback Running back Work Completed = Magnitude of Process X Frequency of Process

Total Yards = Yards per Carry X Carries per Game 100 yds = 2 X yds = 10 X Fullback Running back Work Completed = Magnitude of Process X Frequency of Process

Total Yards = Yards per Carry X Carries per Game 100 yds = 2 X yds = 10 X Fullback Running back Work Completed = Magnitude of Process X Frequency of Process

Total Yards = Yards per Carry X Carries per Game 100 yds = 2 X yds = 10 X Fullback Running back Low magnitude Low frequency High magnitude High frequency Work Completed = Magnitude of Process X Frequency of Process

Creep/ Heave Flow/ Slide Low magnitude Low frequency High magnitude High frequency Work Completed = Magnitude of Process X Frequency of Process