9781422269534

CHAPTER

WHAT MAKES AN EARTHQUAKE

Our planet consists of 20 tectonic plates that are constantly moving. As the plates shift, pressure increases and causes the Earth’s crust to break. The breaks allow stress to be released as energy. Earthquakes are natural phenomena that occur when there is a sudden release of energy in the Earth’s crust, resulting in seismic waves. This release of energy is typically caused by the movement of tectonic plates, the large sections of the Earth’s crust that float on the semifluid layer below. Several tectonic plates form the Earth’s crust. The plates constantly move, but very slowly, due to the convective currents in the underlying mantle . The boundaries where these plates meet and interact are called fault lines. There are three types of plate boundaries. Convergent boundaries are created when two tectonic plates collide or move toward each other. When one plate is

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