Earthquakes can happen any time and without warning. Did you know that earthquakes that occur near the surface of the earth are more destructive than the ones that happen deep within the earth’s crust? Or that the HYPOCENTER is where the shaking actually happens in the earth, and the point directly above the earthquake’s focus on the surface is known as the EPICENTER? Being educated about an earthquake may one day save your life, since understanding the terminology and properties of an earthquake can help you be better prepared if perchance you were ever to be in one. Following are three basic components that can help improve your knowledge of, and possibly help you escape the destruction of, an earthquake.
1. PLATE BOUNDARIES. The earth’s crust is divided into large moving plates called TECTONIC PLATES. The lines where these plates meet are called PLATE BOUNDARIES. Most of earthquakes occur along plate boundaries. The largest is the Pacific Plate that surrounds the Pacific Ocean. It is known as the RING OF FIRE and includes the majority (more than 75%) of volcanic eruptions. The Ring of Fire isn’t actually a complete ring, only forming a horseshoe shape beginning with the Tonga-Kormadec Trench that lies northeast of the New Zealand islands and wrapping around to the Peru-Chili Trench in South America and the South Sandwich Trench just east of the South Sandwich Islands. The earth’s plates are always moving, bumping into each other. Whenever these plates move towards each other with enough pressure, and slip past one another, an earthquake occurs.
2. MAGNITUDE. The magnitude is how the power or intensity of an earthquake is measured based on the motion recorded by an earthquake-detecting instrument called a SEISMOGRAPH. The higher the magnitude, the more intense an earthquake is. For instance, an earthquake with a magnitude of 8.1 is going to be much larger and, therefore, more destructive than one measuring at 2.1. The size of an earthquake can vary, depending on many factors including the geography and the depth of the quake. Usually a large earthquake also produces many smaller earthquakes following the larger sequence. These smaller quakes are called AFTERSHOCKS, and can continue for weeks, months, and even years after the main earthquake. The larger an earthquake measures, the more aftershocks can be produced and can linger for longer periods of time.
3. INJURY. The harm that can come from an earthquake is most often not from the initial earthquake itself but from natural and man-made structures that can collapse on people during the shaking. If you happen to be outside during an earthquake, move away from buildings,power lines, and anything else that could fall on you. If you are inside a building, get under a desk or table and protect your head from any falling debris. You can also stand against an interior wall for protection. Avoid exterior walls, windows, anything containing glass, fireplaces, and heavy furniture or appliances. If you are driving, pull off to the side of the road, out of traffic, and stop. Do not park under bridges or overpasses, and avoid trees, power lines, and any other potential hazards. If you are in the mountains, beware of the possibility of a landslide. If you are near an ocean, you may be in danger of a tsunami and should get to higher ground.
Earthquakes occur on a daily basis, yet most of them are rarely felt because they are so small. They can’t yet be predicted, which makes them all the more deadly in the case of larger earthquakes. If you live in an earthquake zone, where earthquakes occur often, it is a good idea to learn more and be prepared in case you were ever to experience one. It may be the difference between injury or even survival.