Weathering 10-1 & 10-2
6 types of Mechanical Weathering
ice wedging, wind, water, gravity, plants, & animal
If a rock has a larger surface area how is it effected by weathering?
more exposed surface which causes faster weathering *1 big rock = slow weathering over time *100 small rocks = faster weathering because they each have more exposure to the weathering agents.
What is the term for when metal is exposed to water and oxygen and rust forms - (example - iron, cars)?
oxidation
sediment
small particles produced by the weathering of rocks
Weathering
the breakdown of rock into smaller pieces on the Earth's surface
Mechanical Weathering
the physical BREAK of rocks from
Plant Weathering
type of mechanical weathering where small roots make cracks in the rock as they grow bigger *sidewalk example
Ice wedging
type of mechanical weathering where water seeps into the rocks, freezes & expands to make a crack
erosion
weathered material moving from one place to another
Acid Precipitation
when certain gases, LIKE FOSSIL FUELS, mix with water in the atmosphere
Deposition
when the broken down rock or sediment is laid down.
Oxidation
A chemical reaction in which an element, such as iron, combines with oxygen to form rust
3 types of Weathering with Acids
Acid Precipitation, Acid in Ground Water, & Acid from Living things
Acid in Ground Water
Acids get into water that travels underground and can result in a cave
What type of chemical weathering creates caves or caverns?
Acids in groundwater.
Animal Weathering
Animals that burrow, such as rabbits, mice, ground hogs, and break the rocks as they dig into the earth
2 types of weathering
Chemical & Mechanical
How do humans increase the effects of erosion?
Humans disturb and damage rocks and soil. Construction (blasting, digging, mining) disturb rocks. Poor farming strip the plants from soil and expose them to wind erosion. Building on steep slopes causes rock fall and landslides. Deforestation causes mudslides.
What type of climate does chemical weathering happen faster?
Humid and warm
How do lichens break down rock?
Lichens are living things and they have weak acids that chemically weather rocks.
Is chemical weathering faster in higher temperatures or lower temperatures?
Lots of chemical reactions speed up in higher temperatures because there is a quicker breakdown of the rock
Acids from Living Things
Organisms like lichens produce acids to break down rocks into nutrients for life processes
Water Weathering
Over time water can break bonds in minerals making the rocks break apart
Differential Weathering
Process by which softer rock wear away leaving harder rocks behind
How does elevation affect the rate which rock weathers?
Rocks at higher elevations weather more quickly than those at lower elevations. They are more exposed to wind, rain, and cold temperatures. Rocks that are higher are also more effected by gravity. The rocks fall away from the sides of mountains, breaking into small pieces, increasing the amount of surface area to be weathered.
What factors contribute to deep, fertile topsoil in temperate regions?
Temperate areas have frequent changes in temperature, which leads to frost action. Mechanical weathering makes the soil thicker. Temperate regions also get enough rain to cause a high level of chemical weathering, but not so much that the nutrients are leched out of the soil. The thick soil is fertile.
Types of Chemical Weather
Water, Air, Acids
Why do small rocks weather faster than large rocks?
When a large rock is broken into smaller blocks, the total volume of the rocks is the same. There is now more surface area though. Weathering happens over a greater surface area. The smaller rock weathers faster than if it was one large chunk.
Chemical Weathering
breakdown of rocks by CHANGING THE COMPOSITION OF IT
abrasion
a type of mechanical weathering that occurs when rocks rub against each other - caused by wind or water. (examples - rocks tumbling against one another in a fast moving river; rocks falling down a mountain, rocks shaped by sand blown against them by the wind)