11 - Heat Transfer & Geophysics | Earth’s Inner Core Slowdown RQ

What recent discovery about Earth's inner core was confirmed by scientists?

• It has started to melt.

• It is rotating faster than before.

• It has slowed down and is moving backward.

• It has stopped rotating.

Answer explanation

The recent discovery confirmed by scientists is that Earth's inner core has slowed down and is moving backward.

Who discovered Earth's inner core?

• Marie Curie

• Inge Lehmann

• Isaac Newton

• Albert Einstein

Answer explanation

Inge Lehmann discovered Earth's inner core.

What method do seismologists use to study the inner core's motion?

• Satellite imaging

• Using magnetic field data

• Examining seismic waves from large earthquakes

• Drilling into the core

Answer explanation

Seismologists study the inner core's motion by examining seismic waves from large earthquakes.

What is the estimated temperature of Earth's inner core?

• 1,000 degrees Fahrenheit

• 5,400 degrees Fahrenheit

• 9,800 degrees Fahrenheit

• 15,000 degrees Fahrenheit

Answer explanation

The estimated temperature of Earth's inner core is 9,800 degrees Fahrenheit, making the correct answer choice 9,800 degrees Fahrenheit.

What generates Earth's magnetic field?

• The sloshing of metal-rich fluid in the outer core

• The movement of tectonic plates

• The rotation of the inner core

• The heat from the sun

Answer explanation

The sloshing of metal-rich fluid in the outer core generates Earth's magnetic field.

What did the 2023 study propose about the inner core's rotation?

• It has never rotated.

• It used to spin faster than Earth but is now moving slower.

• It is spinning faster than ever before.

• It has always rotated at the same speed as Earth.

Answer explanation

The 2023 study proposed that the inner core used to spin faster than Earth but is now moving slower, indicating a change in rotation speed over time.

What is the significance of the 70-year cycle mentioned in the study?

• It indicates the core's rotation speed changes every 70 years.

• It shows the core stops rotating every 70 years.

• It marks the time it takes for the core to complete one full rotation.

• It is the time taken for seismic waves to travel through the core.

Answer explanation

The significance of the 70-year cycle mentioned in the study is that it indicates the core's rotation speed changes every 70 years.

What is one potential effect of the inner core's slowdown?

• Longer days

• Changes in Earth's magnetic field

• Higher global temperatures

• Increased volcanic activity

Answer explanation

One potential effect of the inner core's slowdown is changes in Earth's magnetic field.

What did seismologists in the 1880s conclude about Earth's core?

• It was made of gas.

• It was molten.

• It was solid.

• It was hollow.

Answer explanation

Seismologists in the 1880s concluded that Earth's core was molten, not gas, solid, or hollow.

What is the main composition of Earth's inner core?

• Magnesium and aluminum

• Silicon and oxygen

• Iron and nickel

• Carbon and hydrogen

Answer explanation

The main composition of Earth's inner core is iron and nickel, which are responsible for its solid state due to high pressure and temperature.