Measuring the Power of an Earthquake
The magnitude of an earthquake is a measure of its size and is given a value which does not change regardless of your location.
The intensity of an earthquake has to do with measuring the effect of the shaking, and this value does vary with location.
We always hear the word 'Magnitude' when an earthquake is reported.
Here are some links to give you some information on what is called the Richter Scale, what it is and how it works.
1. USGS – The Richter Magnitude Scale
2. Wikipedia - Richter Magnitude Scale
Are Earthquakes on the Increase?
Not according to the United States Geological Survey. The fact is that as they place more seismograph stations across the world along with improvements in global communications they can monitor more earthquakes. Earthquakes of magnitude 7.0 or greater have remained fairly constant according to their findings. What we need to remember is that out of the great number of earthquakes recorded every year, there are approximately 17 major earthquakes of magnitude 7.0 - 7.9 and one great earthquake of magnitude 8.0 or other in any given year. Have a look here for a report found on AccuWeather about this.
The USGS estimates that approximately several million earthquakes occur every year but that many go undetected because they occur in remote locations. Have a look at their Earthquakes Facts and Statistics page for more information. The USGS locates approximately 50 earthquakes each day making that 20,000 per year.
The predictability of earthquakes seem to vary from not easily predictable to not predictable. Geologists and other professionals measure the pressure on the tectonic plates along the faults which may give them a clue as to if and when an earthquake is likely. Also, scientists are able to 'expect' if not 'predict' an earthquake by studying records that they have of the diverse areas where earthquakes have happened. From what I have read on the USGS site, a magnitude 6.5+ is expected in the Nephi segment of the Wasatch Range in Utah.
Earthquakes cannot be predicted with great accuracy, and the best that scientists can do is make educated guesses based on current and past data, but it remains that its a guess.
Earthquakes themselves rarely cause injuries, in that it is the falling debris from buildings and other structures as well as road accidents that are the main causes and areas where injuries occur.
There are many earthquakes that happen yearly around the globe. The location of the epicenter, the depth and types of land surface features or geological conditions that are affected will determine the extent of the damage caused by the earthquake.
Many are relatively harmless and do little or no damage. In all of the recorded instances of earthquakes happening yearly, the larger more destructive ones are rare in comparison to the whole.
The fact that there is media coverage when a larger earthquake happens may lead us to believe that they are not rare.
Earthquakes may cause the ground to shake for several seconds to several minutes, during which time significant damage may occur to buildings and other structures such as dams and towers.
I would like to add a few things that aren't mentioned in the information below.
1. During an earthquake the majority of injuries and deaths occur as people move around in their homes and try to leave the building during the quake. By doing so they expose themselves to falling furniture and other things within the home, as well as falling brick, glass and other debris if they try to exit the building.
2. Locate before an earthquake any potential troublespots in your locality such as chemical factories, railroads, overpasses and other bridges, power line installations, gas stations and in fine anything else that may pose a threat to your well being.
In the information below it mentions that if it is safe to do so, you may re-enter your home.
However it may be a good idea to check with your insurance company if you plan on getting earthquake insurance, to see what the rules are should the disaster strike.
The insurance company may want to send someone to assess the damages and take photos. Take your own as well but but do not disturb the area if it can be avoided.
Here are some links to help you learn more about earthquakes.
1. USGS - Earthquake Facts
2. USGS - Earthquake Notification Service
3. List of Links: Preparedness Information and Response Agencies
4. BBC Home - Animated Earthquake Guide
5. USGS – FAQ
6. CBC - Earthquakes
The following information is from the Get Prepared site of the Government of Canada.
For more info on earthquakes
Canadian Hazard Information Service - Earthquakes Canada
In Canada, the coast of British Columbia is the region most at risk from a major earthquake. Other areas prone to earthquakes are the St. Lawrence and Ottawa River valleys, as well as parts of the three northern territories. Approximately 5,000 mostly small earthquakes are recorded in Canada each year. In the past 100 years, at least nine earthquakes in or near Canada have registered a magnitude greater than 7. A few have caused extensive damage. Even a magnitude 6 earthquake could do extensive damage in a built-up area. In fact, a strong quake near one of Canada's major urban areas would likely be the most destructive natural disaster this country could experience.
Small or moderate earthquakes
Know what to do before, during, and after an earthquake
Wherever you are when an earthquake starts, take cover immediately. Move a few steps to a nearby safe place if need be. Stay there until the shaking stops.
If you are indoors: "DROP, COVER, HOLD"
If you are outdoors
If you are in a vehicle
AVOID the following in an earthquake
Stay calm. Help others if you are able.