What is the difference between weathering and erosion?
AThey are the same thing -- both words mean rocks breaking apart
BWeathering is the breaking down of rocks into smaller pieces; erosion is the carrying away of those pieces to a new location
CErosion breaks rocks and weathering moves them
DWeathering only happens in warm climates and erosion only happens in cold climates
Weathering and erosion are two separate but related processes. Weathering is the breakdown -- water seeps into cracks and freezes, expanding and splitting the rock; roots grow into cracks and pry them apart; acid in rain slowly dissolves certain minerals. Erosion is the transport -- rivers carry sand and pebbles downstream; wind blows dust across the desert; glaciers drag rock fragments along. The two often work as partners: weathering creates the pieces, erosion moves them.
Question 2 True / False
The Grand Canyon was carved quickly by a single large flood.
TTrue
FFalse
Answer: False
The Grand Canyon was carved by the Colorado River over roughly 5 to 6 million years. The river slowly wore away rock layer by layer through continuous erosion. This is one of the most powerful lessons about erosion: it is usually slow, but given enough time, water can carve through solid rock and create enormous landforms.
Question 3 Short Answer
Name two natural forces that can break down rocks (weathering) and explain how each one works.
Think about your answer, then reveal below.
Model answer: Water: water seeps into cracks in rock and freezes in cold weather. When water freezes, it expands, pushing the crack wider and eventually splitting the rock apart. Plant roots: tree roots grow into small cracks in rock and slowly push them apart as the roots get thicker. Both processes slowly break large rocks into smaller pieces over time.
Other correct answers include wind (blowing sand particles that scrape against rock), chemical weathering (slightly acidic rain dissolving minerals in rock), and temperature changes (repeated heating and cooling causing rock to expand and contract until it cracks).