Constructive and Destructive Processes Ms. Meskie Ms. Krutty

Check This Out! Volcanoes

Stations Station 1 Station 2 Station 3 Page 1, question 1: What do you think will happen when water is poured over the “hill”? Station 2 Page 2, question 9: What will happen when you rub sandpaper over the limestone? Station 3 Page 2, question 12: What is the effect of water on limestone? Page 2, question 13: What is the effect of the acid on limestone?

Constructive Processes Destructive Processes Build the earth up Destroy or break down part of the earth

Constructive or Destructive?

Volcanoes Constructive process Builds up land around the volcano 1943 in farmer’s field in Mexico – built a mountain in 9 years 1964 off coast of Iceland – now a large island

Constructive or Destructive?

Plate Tectonics and Mountain-Building Constructive Process Oceanic plate more dense than continental plate Oceanic plate pushed under continental plate, continental plate crumples Two plates collide and both are pushed up and crumpled Video 1 Video 2

Plate Tectonics and Mountain-Building Subduction – the process that takes place at convergent boundaries in which one tectonic plate sinks under another into the Earth’s mantle because it is more dense than the other Density – mass per unit volume (Density=Mass/Volume) Orogeny (uplift) – a process in which the forces produced by convergent tectonic plates produce mountains

Constructive or Destructive?

Weathering and Erosion Destructive Process Weathering 1st to weaken the rock, erosion 2nd to break it away 2 kinds of weathering: Mechanical – breaks down rocks Wind Water Plants Animals Chemical – changes rocks into something new Chemicals (Ex. Acid rain)

Weathering and Erosion Weathering – the breaking down of rocks, soil, and minerals through contact with the atmosphere In-Situ – with no movement; takes place in that spot Erosion – movement of rocks and minerals by agents such as ice, water, wind, and gravity Hydration – a process in which a rock takes in water, and the increased volume creates stress in the rock, breaking it up

Weathering and Erosion Carbonation – a process in which carbon dioxide mixes with rain, making the rain acidic, which in turn breaks down certain types of rocks Oxidation (rusting) – a process in which water and oxygen mix and weaken the rock (this occurs mostly with metal ores)

Weathering and Erosion Plant’s roots have grown into the rock Causes some of the rock to break apart Mechanical or chemical weathering?

Weathering and Erosion Iron in rock reacts with oxygen in air Creates rust and weakens the rock Mechanical or chemical weathering?

Weathering and Erosion Carries away weathered rock Wind blows dust off side of cliff Silt carried downstream by river Rocks fall off side of cliff due to gravity Wind Water Ice

What happens to the weathered rock that is carried away?

Deposition Constructive Sand and pieces of rock are deposited by water, wind, or ice as a result of erosion Constructive or destructive? Constructive

Summary Constructive Destructive Volcanoes Plate Tectonics and Mountain-building Subduction Density Orogeny Deposition Weathering and Erosion Weathering In-Situ Erosion Hydration Carbonation Oxidation

Station 1 Observations Which substance moved first? Next? Last? Did the size of the particles affect the rate of erosion? Would the amount of water affect the rate of erosion? Would the hardness of the rain affect the rate of erosion? If you wanted to control erosion on a hill, what type of particles would be best to use? What do you think happens to the surfaces of mountains that experience large amounts of rainfall?

Station 2 Observations How is rubbing sandpaper across a rock like windblown sand hitting a rock?

Station 3 Observations What is the effect of water on limestone? What is the effect of the acid on limestone? How long do you think it will take for the acid to completely dissolve the limestone? How might this process occur in nature? Is this an example of mechanical or chemical weathering?

Post-Lab Quiz What is the difference between a constructive process and a destructive process? Carbon dioxide in the air can combine with rain to create acid rain. When this acid rain hits limestone, it weakens the limestone through a process called carbonation. Would this be considered mechanical or chemical weathering?

3. Which process caused this change in landscape? Post-Lab Quiz 3. Which process caused this change in landscape?

4. Which process caused this change in landscape? Post-Lab Quiz 4. Which process caused this change in landscape?

5. Which process caused this change in landscape? Post-Lab Quiz 5. Which process caused this change in landscape?

6. Which process caused this change in landscape? Post-Lab Quiz 6. Which process caused this change in landscape?