THE earthquakes are some of the most serious natural disasters. Fortunately they do occur large earthquakes, even on a global scale, only a few times a year and therefore occasional tourists are very unlikely to run into any of them. However, if you live one, there is a serious risk to life and health.
The earthquakes
Small earthquakes that are barely noticeable can occur anywhere in the world. The truly disastrous ones occur mainly in these regions:
- the area fromItaly to China southern (more or less along the Silk Road), also known as Alpide belt
- along the Pacific coasts (New Zeland , Indonesia , Philippines , Taiwan , Japan , Far East Russian and the west coast of the Americas from Alaska to Tierra del Fuego), also known as Ring of fire.
- in the Caribbean
These areas are known as converging tectonic boundaries. In these areas, the tectonic plates (which form the earth's crust) are pushed towards each other and when they become blocked, stress builds up. When they are released at some point, the sudden release of this stress becomes an earthquake.
In places where tectonic plates are moving away from each other (e.g. the Iceland) you will encounter other phenomena associated with tectonic boundaries, such as i volcanoes, but rarely large earthquakes.
Earthquakes can cause tsunami, which can wreak havoc on shores thousands of miles away and across the ocean.
Sometimes, earthquakes can also occur far from the boundaries of the tectonic plates. These are known as intra-plate earthquakes. Although they are much rarer and usually less intense than earthquakes that occur at the edge of the plates, they are often more devastating because the areas where they often occur are not prepared for the event. One of the most devastating examples of an intra-plate earthquake is the Tangshan of 1976 in China.
Large earthquakes can destroy buildings and other infrastructure. During a major earthquake, expect windows to break, trees to fall, and objects to be scattered around. However, the danger did not pass once the earthquake ended. Buildings that have been damaged by the earthquake can suddenly collapse and cut gas pipes and power lines can cause fires. Landslides and soil liquefaction can cause buildings and other infrastructure to move, sink or collapse. In addition to all this, roads, water, electricity (and therefore communications) and other service lines are often damaged, which makes communication and rescue operations more difficult. In addition, aftershocks can occur and cause further damage.
How they are measured
Earthquakes are measured using various scales. There magnitude of an earthquake is a single number that represents "how big" the earthquake is. The intensity represents "the degree of shaking", which varies according to the position; the places close to the epicenter will have a greater intensity than the very distant places.
Richter scale
The first scale to measure the magnitude of earthquakes was the Richter magnitude scale developed by Charles F. Richter in 1935. Since the 1980s the modern scale for large earthquakes (the ones worth reporting in the news) has been the "instant magnitude scale", but the press and much of the public continue to use the name "Richter scale" even if it is imprecise. Whatever the name, this is often how the magnitude of an earthquake is reported by governments, humanitarian organizations and the media.
Note that the Richter magnitude scale is logarithmic, so an earthquake M 7.0 has 10 times the energy of an earthquake M 6.0, 100 times the energy of an earthquake M 5.0, 1000 times the energy of an earthquake M 4.0.
The scale is measured like this:
- 1.0–1.9: small. These earthquakes are minimal in size and are often not felt by people. There is little ground movement. In areas most prone to earthquakes, these can be a daily occurrence.
- 2.0–3.9: minor. It is more likely to be felt by people, but it rarely causes harm. Some internal items may shake.
- 4.0–4.9: light. The agitation is felt by most of the people in the area. It can cause minor damage. Some internal items may fall out.
- 5.0–5.9: moderate. It can damage poorly constructed buildings. It can cause minor damage to other buildings. It is heard by everyone.
- 6.0–6.9: strong. More damage occurs, even to well-constructed buildings. Poorly constructed buildings can collapse. There is a strong and violent shaking of the ground that is felt hundreds of kilometers away from the epicenter. The energy released by the nuclear bomb dropped on Hiroshima in 1945 it is equivalent to that of a 6.0 magnitude earthquake. In most regions, a tsunami warning after submarine earthquakes of at least 6.5 magnitude.
- 7.0–7.9: greater. Widespread damage to most buildings, including collapse. Damage and violent shocks can be spread over large distances up to 250 km from the epicenter.
- 8.0–9.0 : great. Widespread and severe damage over a large area, possible total destruction. Violent shaking may be felt even in distant areas. There are permanent changes in the topography of the soil. 9.0 was the magnitude of the devastating 2011 earthquake Tōhoku, in Japan, while the most powerful earthquake ever recorded occurred at 9.5 on the a scale Valdivia, in Chile, in 1960.
Intensity scales
Intensity scales can be used to describe the potential damage in a particular area and it is possible to have a "contour map" showing how the intensity varied around the epicenter. Different but similar scales are used in different parts of the world.
There Modified Mercalli intensity scale is used in United States, in Australia and in New Zeland. The scale values range from I (Unheard) to IV (Light, perceived by many inside) to VIII (Severe, great damage in poorly constructed buildings) up to a maximum of XII (Extreme, total damage).
There European macroseismic scale it is used in Europe. The scale values range from I (not perceived) to IV (widely observed) to VIII (severely harmful) up to a maximum of XII (completely devastating).
In Japan the seismic intensity scale of the Japanese Meteorological Agency, also known as Shindo scale (震 度, "seismic intensity"). The values of the scale (Shindo number) range from 0 (not perceived) to 4 (minor damage to non-seismic buildings) to 7 (all buildings badly damaged). To make the scale more precise, 5 and 6 are divided into "weak" and "strong", resulting in 10 possible values.
Getting ready
In general, the inhabitants of earthquake-prone areas should know what to do if and when the tremors begin. Follow their advice and their example.
If you are in an earthquake area, always keep your travel documents (tickets, passport, etc.), money and important personal items in a place where you can easily pick them up if you need to escape, even if you shouldn't make them so visible to attract thieves. Keep a pair of shoes under the bed: If an earthquake strikes at night while you sleep, we recommend that you wear shoes in case there are broken glass. Also, you may want to consider some ways to get out in case the front door has collapsed or been blocked by debris or fire. If you are staying in a hotel, take a look at the map of the emergency exits inside the room door. Emergency exits are usually designed to better evacuate a building in the event of a fire; however, they can also provide a means of escaping a building that is feared to collapse due to seismic damage. At worst, you may have to go out the window and go down a downspout or even jump.
Do not place heavy objects in high places, especially above the bed.
Long stays
If you plan to stay longer in an earthquake-prone area, you may want to prepare a anti-seismic survival kit. This would at least include:
- 3-5 day food and water supplies (4 L / person / day), water purification tablets or a portable water filter
- First aid kit, gloves, goggles, dust mask and personal toiletries
- Copies of the documents important documents (passport, driver's license, insurance documents, etc.) and photos of all group members (to help emergency personnel search for missing persons)
- Emergency contact information about your person, so that authorities can contact family / friends if should you be found
- Cash (at least $ 100), in small denominations, preferably in local currency or a widely accepted "hard currency"
- Spare batteries, flashlights and a battery-powered radio
Also, if applicable, you would also like to make your dwelling place safer against earthquakes (do not keep many free objects in high places, make sure the shelves are well fixed to the walls, etc.) and learn to shut off gas, electricity and water. . Self you are traveling with children, teach them what to do during an earthquake and do exercises. It's okay even if you're an expert in first aid. Locals will probably be happy to give you advice on what to do in the event of an earthquake.
During an earthquake
Earthquakes are unpredictable - they will often begin without any warning signs. However, an earthquake will extend from the epicenter with a speed of about 7 km / s, and in Japan this was used to develop an early warning system for earthquakes, giving people further away a warning on TV, radio and the cell phone of people in the affected area a few seconds before the earthquake arrives. If it starts shaking or you get a warning, take shelter immediately! However, if you have open fires (gas stoves, candles, etc.), put them out immediately, if possible, before taking shelter.
Don't move during the earthquake! Standing up, walking and especially running are things that you should avoid as you could fall and therefore injure yourself. Crawling may be the only way to get around if it's absolutely necessary.
The main earthquake of usual it won't persist more than a minute or two (although Japan's exceptionally powerful 2011 earthquake lasted six minutes), but that's more than enough to cause damage. It will often be followed by aftershocks. Don't let your guard down after an earthquake seems to have ended: make yourself safe!
Try not to never lose your temper by avoiding panic. Panic leads to senseless and generally harmful actions.
If you are inside a building
There US FEMA and the New Zealand civil defense give advice "throw yourself, cover yourself and attack yourself" in case of an earthquake.
If you are in home, stay: lie on the floor on your knees and bow, cover your head and neck and take cover under a table or some other sturdy piece of furniture, if possible. Take cover under a door if necessary. Hold on and don't let the shaking scare you. If possible, take cover close to interior walls away from windows and tall furniture such as cabinets that could tip over and trap you. You are much safer though stay at home: falling tiles and masonry outside usually represents a mortal danger.
If you are in an elevator, "throw yourself, cover yourself and attack yourself" as you would anywhere else. When the shaking stops, leave the elevator on the nearest available floor, if possible, even if the elevator is on a high floor.
If you are a bed, cover yourself by putting yourself under, if it is not possible cover your head and neck with a pillow.
While it is extremely important to put out all flames (burners, candles, etc.) immediately if you have time, the immediate danger is falling objects and furniture overturning.
Try to open the door or window as soon as possible and keep it open using something like a doorstop in case it gets jammed due to possible deformation or because a possible shock wave from the outside (explosion or collapse) could cause it to explode. the glasses hurting you.
If you are outdoors
Self outdoors, move away from buildings, trees, power lines, or anything that could fall on you. Here too it is important to get away as soon as possible, cover up and resist. If you are near a cliff or on a mountain or other high natural formations, landslides or avalanches can occur during and after the earthquake.
Stay away from brick walls, glass panels and vending machines and watch out for falling objects - the tiles on older, traditional buildings are particularly dangerous, as they can fall long after the earthquake ends.
Self guided, pull over as soon as possible, preferably in an open area away from any structure, and stay in the car until the earthquake ends. If you are on an elevated road such as a bridge or highway, be aware that they may break or even collapse.
After the earthquake
After the shaking is over, you can move again. Remember that earthquakes are often followed by small earthquakes called aftershocks which can occur minutes, hours, or even days or months after the initial earthquake. In the event of an aftershock, follow the same procedures as above.
Walk out
If you are in home, get out. In the worst case, the building has been damaged and could collapse. Move with caution as the light may not work and there may be broken glass, other debris and live wires. Small fires should be put out and dangerous chemicals cleaned up if it can be done safely. If you are staying in a building that you are responsible for (vacation rental house, etc.), check for damaged utilities and, if necessary, turn off the gas and electricity from the meter - again, only if you can do so safely and if you know what you are doing.
If the worst happened and you stayed trapped inside a building, avoid lighting matches, picking yourself up or inhaling dust. Touch the walls or pipes so the rescue teams know you are there.
In built-up areas, if you move on the outside on foot, beware of potholes in roads and the fact that buildings, bridges, lampposts, trees and the like may not be as firmly standing as before the earthquake. If you move in the desert, beware of cracks in the ground. If you are in a mountainous area, there is also a risk of landslides or avalanches.
If you find yourself near the coast, you should immediately move inland due to the aforementioned risk of tsunami. Remember that the tsunami waves are several floors high and in some cases have the power to travel several kilometers inland.
If you are in a vehicle, it can be safe to drive carefully once the earthquake is over. However, you should avoid bridges and similar constructions: the earthquake may have damaged them and made them unstable. Furthermore, the road could also be damaged or, in the worst case, divided by the movement and no longer usable.
If you are on a train, it may have stopped automatically once the sensors have detected the earthquake. In that case, it is usually best to stay on the train and wait for instructions. If the train is derailed, you should get off and help others. Windows can often provide an additional way to escape after being smashed, pulled out, or both, depending on the design of the train. Look before you jump, as the fall from a train window can be noticeable.
To help
Help hurt people if you can, or at least ask for help. Avoid using the telephone unless it's an emergency because the telephone network will be under a huge load to handle everyone's emergency calls. If your phone has internet capabilities, disable it, as this will only cause more stress on the network. You may want to contact family and friends and tell them what happened and what condition you are in, but keep in mind that a SMS (text message) will use far less bandwidth and battery than a call or internet connection.
Follow the advice and warnings provided by the authorities on radio, TV, Internet and by rescue teams, police and military on site. Help them if explicitly requested, but do not disturb them unnecessarily or otherwise hinder them to stare or take pictures or go around just for "sightseeing"; let them do their job. Be aware that there is usually a separate organization that manages missing persons; for example, in United States, is the Red Cross.
If you are not a local, it is probably best to try to get out of the affected area if possible, unless you want to volunteer to help rescue, in which case you should ask if your presence is helpful. If you have special skills, such as a doctor, you could help save lives in the aftermath of a disaster. In the event of major disasters such as earthquakes, embassies often want to get in touch with "their" citizens traveling to the affected area to find out if they are okay or not.
See also
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