FOURTH QUARTER

FOURTH QUARTER

UNIT 7: NATURAL DISASTERS

II. UNIT 7: Natural Disasters

Time: Entire quarter

a. Unit Introduction:

b. Objectives:

Describe how seismic waves carry energy from an earthquake away from the focus, through Earth’s interior and across the surface and the damage they cause.
Describe how volcanoes form when magma erupts through the crust and reaches the surface.

c. Essential Questions:

How does the energy of an earthquake travel through Earth?
How can earthquake safety be increased and earthquake damage reduced?
How does the change in pressure and expansion of gases inside affect the magma inside a volcano?
How does the silica content of magma affect the type of landform that is formed?
How do volcanic belts form along plate boundaries?

d. Essential Concepts

Energy from an earthquake travels in waves. The waves can produce severe movement in the Earth’s crust and surface.
Scientists use level of damage, size of waves and amount of energy released to rate the magnitude of an earthquake.
Scientists use seismic waves to locate an earthquake’s epicenter.
Data collected from seismographs and fault-monitoring devices is used to monitor active faults and predict earthquakes.
When a volcano erupts, the force created by the expanding gases drives the magma to either flow out or explode out of the volcano.
Scientists classify eruptions according to the amount of silica found in the magma. Different types of landforms are created by different types of eruptions.
Earth’s crust often fractures along plate boundaries allowing magma to reach the surface.