Seismic waves as evidence for Earth's layers

Question 1

At a seismometer, the S waves arrive 15 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km

Question 2

Inside the Earth: which statement is NOT true?

• A. P waves can travel through solids and liquids.
• B. Studying seismic waves lets scientists "see" inside Earth.
• C. The mantle is mostly liquid magma.
• D. S waves can only travel through solids.

Question 3

S waves are not detected on the opposite side of Earth from an earthquake. What does this show?

• A. Part of the core is liquid, because S waves cannot travel through liquids
• B. The crust is liquid
• C. S waves are faster than P waves
• D. The core is hollow

Question 4

At a seismometer, the S waves arrive 45 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km

Question 5

Inside the Earth: which statement is NOT true?

• A. Studying seismic waves lets scientists "see" inside Earth.
• B. P waves can travel through solids and liquids.
• C. Earth's inner core is solid and the outer core is liquid.
• D. The mantle is mostly liquid magma.

Question 6

Which seismic waves arrive first at a seismometer?

• A. S waves (secondary, transverse)
• B. surface waves
• C. all arrive together
• D. P waves (primary, longitudinal)

Question 7

At a seismometer, the S waves arrive 15 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km

Question 8

Inside the Earth: which statement is NOT true?

• A. Earth's inner core is solid and the outer core is liquid.
• B. Studying seismic waves lets scientists "see" inside Earth.
• C. The mantle is mostly liquid magma.
• D. P waves can travel through solids and liquids.

Question 9

How do seismic waves show that the inner core is solid?

• A. No waves ever reach the inner core
• B. Waves get louder in the inner core
• C. P waves speed up when they enter the inner core
• D. S waves stop at the crust

Question 10

At a seismometer, the S waves arrive 45 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km

Question 11

Inside the Earth: which statement is NOT true?

• A. S waves can only travel through solids.
• B. The mantle is mostly liquid magma.
• C. P waves can travel through solids and liquids.
• D. Earth's inner core is solid and the outer core is liquid.

Question 12

Why do seismic waves travel in curved paths through the mantle?

• A. Their speed changes gradually with depth, so they refract
• B. The Moon pulls them
• C. They bounce off the surface
• D. Earth's gravity bends them

Question 13

At a seismometer, the S waves arrive 5 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km

Question 14

Inside the Earth: which statement is NOT true?

• A. Studying seismic waves lets scientists "see" inside Earth.
• B. P waves can travel through solids and liquids.
• C. The mantle is mostly liquid magma.
• D. Earth's inner core is solid and the outer core is liquid.

Question 15

Why do seismic waves travel in curved paths through the mantle?

• A. Their speed changes gradually with depth, so they refract
• B. The Moon pulls them
• C. They bounce off the surface
• D. Earth's gravity bends them

Question 16

At a seismometer, the S waves arrive 10 s after the P waves. Assume P waves travel at 8 km/s and S waves at 4 km/s. How far away was the earthquake, in km?

Answer km