Earthquakes!
Earthquakes are one of the planet’s many natural disasters and they display signs that the Earth is relieving built up stress. Pressures from extreme temperatures and gasses within the Earth’s core are the cause of this stress condition. When enough pressure builds in the plates and is released, the plates move and grind against one another which result in earthquakes. Certain areas on the planet are much more prone to frequent, and in some cases, very severe earthquakes. Since history is one of the best teachers, the construction of buildings has improved in areas where earthquakes are common, in an effort to effectively withstand the effects of an earthquake and its aftershocks.
Earthquakes primarily occur along faults and on boundaries between oceanic and continental plates. Faults are cracks or breaks in a plate, where the pieces are moving in opposite directions from each other. All of the Earth’s plates are literally floating on a sea of molten hot magma that is found within the planet’s mantel. When plates collide or grind, earthquakes occur as a result. Japan and California are both hot spots for earthquake activity and this is due to their relative location to the plate activity and fault lines. Japan is the meeting place for multiple continental and oceanic plates and California has the infamous San Andreas Fault that runs the length of the state. Many scientists struggle over the issue of whether or not an earthquake can be accurately predicted. There is a small team of experts who has predicted general time frames and locations with a good amount of success, by developing algorithms for predicting future events based on past patterns and history. The ability to accurately predict earthquakes, weeks or even months ahead of time will save lives and allow the affected area to prepare ahead of time.
The exact science of predicting earthquakes has not been perfected yet, but precautionary measures can be taken into consideration when building new structures. It is wise to prepare for the inevitable in locations like California and Japan because it is known that it is just a matter of time until the next disaster strikes. Buildings can be built to withstand a heavy side load of swaying, by tying the walls, floor, roof, and foundation into a strong, rigid box. This may have once been the exception in places with high seismic activity, but modern, strict building codes have made it the rule. Areas of the world with concrete or brick and mortar construction will crumble and fall over in the swaying motions that earthquakes are known for. Earthquakes, like other powerful forces of nature, can’t possibly be stopped by man so it’s a futile effort to even try. Its still pays to be prepared with basic emergency supplies, like food, water, flashlights, radios, and blankets in case disaster strikes.
Records of earthquakes date back hundreds of thousands of years and will continue as long as the planet is here. They can’t all be predicted at this point in time, but some areas of the world are known to be very active places for the quakes. Whether people are vacationing in Japan or California, the danger is always clear and present, and the disaster may come without warning. Some of the worst earthquakes in recorded history are as follows:
- December 22, 856 – Damghan, Iran – 200,000 casualties
- January 23, 1556 – Shanghai, China – 830,000 casualties
- November 1, 1755 – Lisborn, Portugal – 70,000 casualties
- September 1, 1923 - Kwanto, Japan – 143,000 casualties
- April 18, 1906 – San Francisco, California – 700 dead
