Earthquakes: Causes, Effects and Prediction

Most recently on 8th  March 2010

The magnitude 6.0 quake struck in the early hours of the morning, there have been at least 40 aftershocks in the 12 hours since the quake. There are currently 57 reported dead with 100’s injured. The earthquake hit at 4:32 a.m. in Elazig province, about 340 miles  east of Ankara, the capital of Turkey, it is known to have damaged at least 10 villages and left numerous people homeless.

27th February 2010

The magnitude 8.8 quake, struck at 12:40 p.m., it shook the Chilean capital 780 miles to the south of the epicenter, and was felt as far away as the other side of the continent – in Sao Paulo, Brazil, over 1,400 miles to the east. The U.S.G.S. calculated the magnitude at 7.7. It has been followed by several aftershocks, including three larger than magnitude 5. 100’s have been killed by the quake and the resulting tsunami.

12th January 2010:

The magnitude 7.0 quake struck 16 kilometres from the Haitian capital city of Port-au-Prince. There have been numerous aftershocks. The earthquake which has also brought down the presidential palace was the strongest to hit the country in 200 years and was felt as far away as Cuba. The UN peacekeeping headquarters in Haiti has collapsed under the strain of a massive earthquake and everyone inside is expected to have died.

What are they?

Earthquakes are caused when two of the massive tectonic plates that make up the solid surface of our Earth rub together violently. These tectonic plates normally move past each other, relatively easily, but from time-to-time they get stuck. This is when strain builds up in the faults (rocks) that haven’t moved, eventually the pressure is overcome and the tectonic plates move violently – causing the earthquake. If you think about pushing your hands together very tightly and then trying to move one forward, you get a big movement and heat generated when your hand does move – this is similar to the two tectonic plates finally slipping.

Earthquakes are mainly caused by the movement of geological faults, but can also be caused by:

• volcanic activity
• landslides
• mine blasts
• nuclear experiments

The epicenter of an earthquake is the point at ground level that is directly about the initial point of rupture. This initial point of rupture is called the focus or hypocenter.