7th grade earth and rocks

Question 1

In the path from igneous to sedimentary rock, what comes straight after "igneous rock at the surface"?

• A. compaction and cementation form sedimentary rock
• B. weathering breaks it into pieces
• C. layers of sediment build up
• D. erosion carries the sediment to the sea

Question 2

Modern GPS stations can measure plate movement directly. What do they show?

• A. plates move several kilometres each year
• B. plates do not move at all
• C. plates move only during earthquakes
• D. plates move a few centimetres each year, about as fast as fingernails grow

Question 3

Some countries send phone alerts seconds before strong shaking arrives. How is this possible?

• A. They predict quakes days ahead
• B. Phones feel the earthquake first
• C. Sensors detect the faster, weaker first waves and send warnings before slower damaging waves arrive
• D. Radio waves are slower than seismic waves

Question 4

Earthquakes: which statement is NOT true?

• A. A magnitude 6 earthquake is twice as strong as a magnitude 3.
• B. Most earthquakes happen near plate boundaries.
• C. Each step up in magnitude releases about 32 times more energy.
• D. The point on the surface above an earthquake's origin is the epicentre.

Question 5

What turns sediment into sedimentary rock?

• A. burning
• B. compaction and cementation over a long time
• C. melting and cooling
• D. freezing

Question 6

Plate tectonics: which statement is NOT true?

• A. Plates move a few centimetres each year.
• B. The continents have always been where they are now.
• C. Mountains such as the Himalayas formed where plates collided.
• D. Scientists cannot yet predict exactly when an earthquake will happen.

Question 7

Where do most earthquakes and volcanoes happen?

• A. along the edges of tectonic plates
• B. randomly everywhere
• C. in the middle of every continent
• D. only at the North Pole

Question 8

On the magnitude scale, each whole number up means the ground shaking (wave amplitude) is 10 times larger. How many times larger is the shaking in a magnitude 5 earthquake than in a magnitude 4?

Answer 

Question 9

Which type of plate boundary is this: the East African Rift Valley?

• A. divergent (moving apart)
• B. convergent (moving together)
• C. transform (sliding past)

Question 10

Two plates move apart at about 3 cm per year. How far apart will they move in 1 000 000 years, in kilometres? (1 km = 100 000 cm)

Answer km

Question 11

Two plates move apart at about 2 cm per year. How far apart will they move in 100 years, in metres?

Answer m

Question 12

In the path from igneous to sedimentary rock, what comes straight after "weathering breaks it into pieces"?

• A. layers of sediment build up
• B. igneous rock at the surface
• C. compaction and cementation form sedimentary rock
• D. erosion carries the sediment to the sea

Question 13

Why are there volcanoes where an ocean plate meets a continental plate?

• A. The plates slide past each other
• B. Ocean water boils
• C. The plates move apart and cool
• D. The denser ocean plate sinks and melts, and the magma rises

Question 14

Why can scientists not predict the exact time of an earthquake?

• A. Seismometers do not work
• B. Stress builds up unpredictably along faults, so only long-term probabilities can be given
• C. Earthquakes only happen at night
• D. Earthquakes are random and have no causes

Question 15

Earthquakes: which statement is NOT true?

• A. Each step up in magnitude releases about 32 times more energy.
• B. Undersea earthquakes can cause tsunamis.
• C. A magnitude 6 earthquake is twice as strong as a magnitude 3.
• D. Most earthquakes happen near plate boundaries.