Earth's Changing Surface — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A deep, narrow canyon with a river at the bottom most likely formed from
A) wind blowing sand for a few years
B) a river slowly cutting rock for millions of years
C) one strong earthquake last week
D) a glacier that melted overnight
Grade 4 NGSS expects students to predict that river erosion over geologic time creates canyons.
2. A wide U-shaped valley high in the mountains is best explained by
A) a fast-moving river
B) wind erosion in a desert
C) a glacier carving the valley long ago
D) a single landslide
Grade 4 students learn glaciers create U-shaped valleys, while rivers cut V-shaped ones.
3. Tall, curved sand dunes in a hot, dry region were most likely shaped by
A) ocean tides
B) wind blowing loose sand
C) a melting glacier
D) tree roots
Grade 4 NGSS identifies wind as the main erosion and deposition agent in deserts.
4. A tall mountain range with frequent earthquakes is most likely the result of
A) river deposition
B) two tectonic plates pushing together
C) wind erosion only
D) small puddles freezing
Grade 4 students predict that converging tectonic plates build mountains and trigger earthquakes.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A landform with smooth, rounded boulders piled at the foot of a melted glacier is a moraine.
Grade 4 NGSS uses moraines as evidence that glaciers once moved through an area.
2. Layers of sediment fanning out where a river meets a lake show deposition at work.
Grade 4 students predict deposition forms deltas and fans where moving water slows.
3. A long, straight crack in the ground after an earthquake is most likely a fault.
Grade 4 NGSS uses faults as visible evidence of tectonic plate motion.
4. A cone-shaped mountain that erupted lava in the past is a volcano.
Grade 4 students recognize the cone shape as a classic volcano-building landform.
5. Sharp jagged peaks above a U-shaped valley were carved by ice.
Grade 4 NGSS predicts ice erosion produces U-shaped valleys and jagged peaks above.