Mapping the Inner Earth

Question 1

how do scientists inferred the different layers of the earth?

Answer 1

-by analyzing seismic waves created by earthquakes, volcanic eruptions, and other tectonic processes.

Question 2

knowledge of how seismic waves has allowed scientists to learn…

Answer 2

the composition, density, and properties of earth’s layers.

Question 3

what are these highly sensitive instruments to detect and record seismic waves?

Answer 3

-seismometer (detection)
-seismographs (recording)

Question 4

2 types of seismic waves

Answer 4

body waves & surface waves

Question 5

what are body waves?

Answer 5

it travels through the inner layers of the planet.

Question 6

what are surface waves?

Answer 6

-it travels through, but only on the surface.
-they don’t provide information about earth’s interior.

Question 7

during an earthquake, what are the 2 types of waves that radiate in all directions?

Answer 7

primary waves & secondary waves

Question 8

primary wave’s description?
travelling speed?

Answer 8

-first to be felt on earth’s surface, they shake the ground back and forth in the same direction the wave is moving (compressional waves), and pass through solid and liquid sections of earth but refract as they pass through liquids.
-1.5 to 8 km/s

Question 9

secondary wave’s description?
percentage of speed (how fast or how slow)?

Answer 9

-are felt in an up-and-down motion perpendicular to the direction of the wave (transverse wave), they do not travel through liquids, and the outer core was discovered to be liquid using this principle.
-60% to 70% more slowly than P waves

Question 10

the PHIVOLCS director

Answer 10

Renato Solidum