Lesson 3- Our Changing Earth

The theory of ____________, proposed by Alfred Wegener, suggests that continents were once joined in a single landmass called ____________.

• Continental Drift

• Pangaea

Tectonic plates float on the Earth's ____________, a thick layer of hot, flowing rock.

The ____________ is the point within the Earth where an earthquake originates, while the ____________ is the point on the Earth's surface directly above it.

• Focus

• Epicenter

____________ volcanoes are those that have erupted recently or are expected to erupt again.

Earthquakes are measured using a ____________, and their magnitude is quantified using the ____________ scale.

• Seismograph

• Richter

Which theory explains the movement of the Earth's tectonic plates?

• Gravitational Theory

• Plate Tectonic Theory

• Theory of Evolution

• Continental Drift Theory

Which type of volcano is no longer expected to erupt?

• Active Volcano

• Dormant Volcano

• Extinct Volcano

• Shield Volcano

What is the most seismically active earthquake belt in the world?

• Mid-Atlantic Ridge

• Circum-Pacific Belt

• Himalayan Belt

• Alpide Belt

The ____________ measures the intensity of an earthquake's effects.

• Richter Scale

• Mercalli Scale

• Seismograph

• Epicentre

Which of the following waves is the fastest and travels through both solids and liquids?

• Surface waves

• Secondary waves (S-waves)

• Primary waves (P-waves)

• Tsunami waves