7th grade earth and rocks

Question 1

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

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

Question 2

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 4 earthquake than in a magnitude 3?

Answer 

Question 3

What instrument records earthquake waves?

• A. a seismometer
• B. a barometer
• C. an anemometer
• D. a thermometer

Question 4

Two plates move apart at about 2.5 cm per year. How far apart will they move in 100 000 years, in kilometres? (1 km = 100 000 cm)

Answer km

Question 5

Plate tectonics: which statement is NOT true?

• A. Mountains such as the Himalayas formed where plates collided.
• B. Scientists cannot yet predict exactly when an earthquake will happen.
• C. The Earth's crust is broken into large pieces called tectonic plates.
• D. Tectonic plates move several metres every day.

Question 6

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

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

Question 7

Which type of plate boundary is this: the San Andreas Fault in California?

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

Question 8

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. The point on the surface above an earthquake's origin is the epicentre.
• D. Undersea earthquakes can cause tsunamis.

Question 9

What makes metamorphic rock?

• A. sediment settling in water
• B. lava cooling quickly
• C. heat and pressure changing existing rock without melting it
• D. wind blowing sand

Question 10

Two plates move apart at about 5 cm per year. How far apart will they move in 10000 years, in metres?

Answer m

Question 11

What drives the slow movement of tectonic plates?

• A. convection currents in the mantle
• B. the wind
• C. ocean waves
• D. the Moon's light

Question 12

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 a few centimetres each year, about as fast as fingernails grow
• D. plates move only during earthquakes

Question 13

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 3?

Answer 

Question 14

What instrument records earthquake waves?

• A. a barometer
• B. a thermometer
• C. an anemometer
• D. a seismometer