Earthquakes Study the map of an earthquake in Italy and answer the following questions in your answer book: (i) What was the magnitude (strength) of the earthquake at the epicenter? (ii) At what time did the earthquake take place? (iii) How many towns reported deaths as a result of the earthquake? (iv) Explain in detail how earthquakes occur. - Leaving Cert Geography - Question B - 2010

The earthquake took place at 1:32 PM. This is an important detail for understanding the timing of emergency responses and subsequent aftershocks.

A total of 5 towns reported deaths as a result of the earthquake. This data highlights the impact the earthquake had on surrounding communities.

Earthquakes occur due to the sudden release of energy in the Earth's crust, which creates seismic waves. This energy buildup typically happens at fault lines, where tectonic plates collide, pull apart, or slide past each other. The point within the Earth where the earthquake originates is called the focus, while the point directly above it on the surface is the epicenter.

1. Tectonic Plates: The Earth's crust is divided into several large and small tectonic plates that float on the semi-fluid mantle below. Their movement can be caused by convection currents.

2. Stress Accumulation: As plates move, they can become stuck at their edges due to friction. Over time, stress builds up in the rocks until it exceeds the strength of the rocks.

3. Rupture and Release: Once the rocks can no longer withstand the accumulated stress, they rupture, causing a sudden release of energy that generates seismic waves. This rupture occurs along faults, which are fractures in the Earth's crust.

4. Seismic Waves: The energy release propagates outward in the form of waves, which are felt as tremors at the surface. They can be classified mainly into P-waves (primary waves) and S-waves (secondary waves), with P-waves being faster and arriving first.

5. Aftershocks: Following the main earthquake, the crust may continue to adjust, leading to aftershocks that can also cause damage.

By understanding the mechanics of earthquakes, we can better prepare for their impacts in earthquake-prone areas.