Weathering, erosion and deposition: how land is worn down and built up
Grade 6 Science Worksheet - Challenge Me
Circle the best answer.
On Esme's river map, P is the outside bank of a bend, Q the inside bank, and R a straight stretch. Over many years, which bank wears away most?
- P, on the outside bend, where water is fastest
- Q, on the inside bend, where sand piles up in a bar
- Both banks wear away equally
- Neither; banks change just in big floods
On the same map, which spot does Jun predict will grow new land over the years?
Use the picture in question 1.
- Q, the inside bend, where slow water drops sand
- P, since erosion builds land there
- P, the outside bend, where fast water drops sand
- R, the straight stretch, where the water speeds up
Luz's friend says weathering and erosion are two words for the same thing. Which response is best?
- Agree: both words mean rock slowly wearing down over time
- Agree: and water is the one agent for both
- Disagree: erosion is when pieces are dropped
- Disagree: weathering breaks rock; erosion moves the pieces
A post claims only water shapes land, because wind is too weak to move rock. Milo checks it. Which response is best?
- Disagree: wind carries sand and builds dunes
- Agree: wind can weather rock but cannot move it
- Agree: water does the shaping
- Disagree: wind melts rock in deserts
Steep, narrow, dark rock walls with the river at the bottom. Noah's cousin says a canyon as deep as the Black Canyon of the Gunnison could form within one person's lifetime. Which response is best?
- Agree: one strong flood could carve it
- Agree: rivers carve that deep in about a century
- Disagree: canyons form by deposition
- Disagree: the river began cutting it about 2 million years ago
Gentle slope, 20 g of sand moved; medium slope, 45 g; steep slope, 80 g. Pia's class read about a stream-table test: the same water poured for 1 minute down sand at three slopes. What does the data show?
- Steeper slopes mean faster water and more erosion
- Steeper slopes make the water drop more of its sand
- The sand was weathered, not moved
- Slope makes no difference
At the bottom of the stream table, the water spreads out and slows. What does Ren predict happens to the sand there?
- It is weathered into clay there
- It dissolves into the water there
- It settles into a fan, like a small delta
- The water picks up even more sand from the bottom there
Rain keeps washing soil off a bare slope beside Zee's school. Which plan would slow the erosion most?
- Pile loose sand on top
- Nothing; rain cannot move soil
- Leave the slope bare so the rain can run off faster
- Plant grass and shrubs whose roots hold the soil
Waves keep carrying sand away from a town beach. Ari looks for an idea that works by slowing the water near shore. Which one?
- Digging the beach deeper
- Speeding up the waves so sand settles
- Removing the dune plants so sand can move freely
- A line of rocks offshore that breaks the waves
Wind blows dry topsoil off a flat, bare farm field. Which plan does Bo pick to help most?
- Water the field once a year
- Nothing; wind cannot move soil
- Plant rows of trees as a windbreak
- Plow the field bare and smooth so the dust settles