EVERYDAY SCIENCE

SCIENCE

EARTH SCIENCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
How do scientists know that Earth’s outer core is a liquid?
A
The Earth does not have a magnetic field.
B
S-waves do not reach seismic stations that are opposite an earthquake’s epicenter.
C
P-waves do not reach seismic stations that are opposite an earthquake’s epicenter.
D
Scientists have dug to the outer core to extract the liquid.
Explanation: 

Detailed explanation-1: -Scientists figured out that the outer core must be liquid because S waves do not pass through it, but P waves do. The behavior of P and S waves also indicates that the inner core is solid. The speed of seismic waves also depends on the density of the material through which they are traveling.

Detailed explanation-2: -Scientist learned that the outer core is liquid by analyzing earthquake waves. The inner core is a dense ball of solid iron crystals.

Detailed explanation-3: -Shear waves cannot travel in liquids or gases–so, for example, S waves don’t travel through the ocean or through the outer core.

Detailed explanation-4: -S waves cannot pass through the liquid outer core, but P waves can. The waves are refracted as they travel through the Earth due to a change in density of the medium.

There is 1 question to complete.