Where do earthquakes happen? Earthquakes happen at particular places under the ground where the Earth slips, usually along a fault. The place where the quake starts is called the focus. This may be many hundreds of kilometres deep in the Earth. The point on the Earth's surface directly above the focus is called the epicentre. Buildings near the epicentre are usually the most heavily damaged. How do you calculate how severe an earthquake is? The severity of an earthquake is calculated in several different ways. One early method, still used in some cases today, is measured on the Richter scale. This scale goes between 1 and 9. Each successive number is ten times greater than the previous number. So an earthquake measuring 5.0 is ten times more destructive than one measuring 4.0. There are two other scales commonly used as well.
When was the earliest earthquake? The earliest earthquake occurred in 1831 BC in the Shandong province of China, but there is a fairly complete record starting in 780 BC during the Zhou Dynasty in China.
Who discovered the earthquake? It was recognized as early as 350 BC by the Greek scientist Aristotle that soft ground shakes more than hard rock in an earthquake. The cause of earthquakes was stated correctly in 1760 by British engineer John Michell, one of the first fathers of seismology, in a memoir where he wrote that earthquakes and the waves of energy that they make are caused by “shifting masses of rock miles below the surface”.
How do we prove that earthquakes occur? There are several sources of evidence to support the theory of earthquakes occurring. Earthquakes are recorded using seismographs, which measures movement in the ground. The earliest seismograph was made in 132 AD by a Chinese astronomer, Chang Heng. This is the main source of evidence to support the earthquake theory as the ground is typically stable, and any unusual movement (especially around the tectonic plate region) will likely suggest an earthquake. How are tsunamis and earthquakes connected? More evidence of earthquakes occurring is the presence of a tsunami. Tsunamis are caused by an underwater earthquake, which occurs within the shifting of the tectonic plates.
Where do earthquakes occur? Earthquakes almost always occur in the regions of the boundaries between tectonic plates. Over 90% of earthquakes occur in these regions. Regions which are most affected by earthquakes are Hawaii, California and Japan, as they lie on the periphery of the tectonic boundaries.