Measuring Earthquake Strength

Question 1

Maya wants to study how the ground moves when a tremor happens. Which of the following devices would best match the definition of a seismometer?

Accepted Answer

A sensor that is fixed to the ground, moves with the shaking, and draws a line graph showing the speed and duration of the motion.

Answer

A machine that listens for underground animal sounds and tells you when the next earthquake will happen.

Answer

A video camera that watches the surface for cracks and snaps pictures whenever it sees one.

Answer

A thermometer that records temperature changes that occur when the Earth releases heat during an earthquake.

Question 2

Liam is helping his science club monitor whether the construction work at the new school wing is making the ground vibrate. He can pick one of these four instruments: A) A thermometer that shows the air temperature each hour. B) A motion‑alarm that flashes a light whenever the floor shakes, but it does not save any data. C) A seismometer that senses the ground’s shaking and stores a graph of the motion. D) A camera that takes pictures of the construction site every few minutes. Which instrument will let the club both detect that the ground is shaking and keep a record they can study later?

Accepted Answer

C) The seismometer

Answer

A) The thermometer

Answer

B) The motion‑alarm

Answer

D) The camera

Question 3

Earthquake X was measured at magnitude 5.0 and Earthquake Y was measured at magnitude 7.0. Which statement best describes what these magnitude numbers tell us?

Accepted Answer

Earthquake Y was much stronger than Earthquake X because a larger magnitude means stronger shaking.

Answer

Earthquake X was stronger because lower numbers indicate more energy released.

Answer

Both earthquakes had the same strength; the numbers are just different labels.

Answer

Earthquake Y lasted longer than Earthquake X because higher magnitudes last longer.

Try three questions

Maya wants to study how the ground moves when a tremor happens. Which of the following devices would best match the definition of a seismometer?

Earthquake X was measured at magnitude 5.0 and Earthquake Y was measured at magnitude 7.0. Which statement best describes what these magnitude numbers tell us?

Keep going on this shelf