Exploring the Earth's Inner and Outer Core

In 1906, British geologist Richard Oldham discovered the Earth's core by analyzing seismic waves from an earthquake. He found that the waves were deflected by a dense mass, which he identified as the Earth's outer core. In the 1930s, Danish seismologist Inge Lehmann furthered this understanding by discovering the Earth's inner core, noting a change in seismic wave velocity. Today, we know the inner core is solid iron due to immense pressure, while the outer core is liquid iron, generating Earth's magnetic field. Together, these cores form a massive structure larger than Mars, with temperatures exceeding 13,000°F.

Who discovered the Earth's core?

• Inge Lehmann

• Richard Oldham

• Albert Einstein

• Isaac Newton

What did Richard Oldham analyze to discover the Earth's core?

• Volcanic activity

• Seismic wave readings

• Magnetic field variations

• Gravitational forces

What did Oldham's discovery suggest about the Earth's interior?

• It is entirely solid

• It contains a liquid outer core

• It has a dense mass at its center

• It is homogeneous

Who challenged the then-accepted structure of the Earth's core?

• Marie Curie

• Charles Richter

• Inge Lehmann

• Richard Oldham

What did Lehmann discover about the Earth's core?

• It is made of molten lava

• It contains a large diamond

• It is entirely liquid

• It has a solid inner core

What did seismic wave analysis reveal about the Earth's core?

• It is uninhabitable

• It is cooling down

• It has multiple layers

• It is completely solid

How did Lehmann's discovery change our understanding of the Earth?

• By mapping the Earth's surface

• By proving the Earth is flat

• By identifying a solid inner core

• By discovering water under the surface

What is the Earth's inner core made of?

• Diamond

• Molten lava

• Solid iron

• Liquid iron

What generates the Earth's magnetic field?

• Solar winds

• The rotation of the Earth

• The inner core's solid iron

• The outer core's electric currents

How does the Earth's core compare in size to Mars?

• It is larger

• It is the same size

• It is half the size

• It is smaller