Tectonic Plates and Earth's Layers

Miss K introduces fourth graders to geology, focusing on key vocabulary like seismic waves and plate tectonics. The lesson covers Alfred Wegener's continental drift hypothesis, seismic waves, and Earth's layers. It explains seafloor spreading, plate tectonics, and different types of plate interactions, such as colliding and subduction. The video concludes with a grammar review on commas, adjectives, and similes.

What is a seismic wave?

• A layer of the Earth

• A type of rock

• A type of volcanic eruption

• A surge of energy from an earthquake

What did Alfred Wegener's hypothesis fail to explain?

• How oceanic crust is formed

• Why continents have similar fossils

• Why earthquakes occur

• How continents could move across the Earth's surface

Which layer of the Earth is composed of very hot metal and is solid?

• Crust

• Inner core

• Mantle

• Outer core

What is the main difference between oceanic and continental crust?

• Oceanic crust is thicker

• Continental crust is made of basalt

• Continental crust is heavier

• Oceanic crust is thinner but heavier

What process describes the creation of new oceanic crust at mid-ocean ridges?

• Subduction

• Seafloor spreading

• Plate collision

• Continental drift

What happens to old crust as new crust forms at mid-ocean ridges?

• It remains unchanged

• It becomes part of the mantle

• It is pushed outward and eventually destroyed

• It forms new continents

What is subduction?

• When two plates slide past each other

• When two plates collide and form mountains

• When a heavier plate slides under a lighter one

• When two plates move apart

How do tectonic plates move?

• Because of ocean currents

• Due to the rotation of the Earth

• Due to gravitational pull from the moon

• Because of heat and pressure in the mantle

What geological feature is created when two tectonic plates collide?

• A volcanic island

• A mountain range

• A deep ocean trench

• A mid-ocean ridge

What is the result of tectonic plates sliding sideways past each other?

• Earthquakes

• Subduction zones

• Creation of mountains

• Formation of new crust