�WHY ARE EARTHQUAKES PRODUCED?

¿WHY ARE EARTHQUAKES PRODUCED? Seismic activity is measured on the Richter Scale. Earthquakes, their definition, characteristics, secondary effects. Tectonic plates, Alfred Wegener. Summary. INTRODUCTION - Earthquakes cause many deaths and have contributed to the configuration of our planet’s landscape. - Seismic intensity is measured with the help of the Richter Scale. - Scientific investigation helps us to understand with more precision the natural phenomena which go around us. THE EARTHQUAKES - Definition of an earthquake - Behaviour of earthquakes - Hypocentre and epicentre - Number of earthquakes that are produced each year in the Earth, their strength and consequences. - Consequences of the San Francisco Earthquake disaster (1906) - Definition of a Tsunami - The Lisbon earthquake (1755) - How are earthquakes detected? The Origin of the earthquakes. - Relationship between earthquakes and the tectonic fractures that take place on the Earth’s crust. TECTONIC PLATES - The six large Tectonic plates, known as the “Continental Drift”. - Alfred Wegener and his theory about the continuous drift of the continents. - The forming of mid-oceanic backbones. - “Subduction areas”. Definition and consequences - Submerged volcanos can rise above the ocean’s surface and form islands, such as Iceland, for example - Description and extention of the San Andreas Fault. - Seismic activity produces lateral displacements. - Why are there seismic zones? SEISMIC ZONES a. Percentage of earthquakes on islands b. Location of seismic zones in the Earth c. Images of the last earthquakes in Sicily and in the former Soviet Union. Why were they produced? d. Risk earthquake areas: Himalaya and Pakistan e. Earthquakes release a tremendous amount of energy. This reminds us that the Earth is a living planet. SUMMARY