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Tsunami

 

A Tsunami is a series of gigantic water waves that causes a surge of water onto land. These surges can reach heights up to 100 feet. The massive height of the surges can lead to devastating effects when it crashes over land. It can occur in large lakes but mainly occurs in seas.

Here are some terms that are associated with tsunamis:

Tide: The term ‘tide’ refers to the alternate rising and falling of the sea level at shores.

Seismic waves: Seismic waves of energy that travel through the Earth’s crust layers or plates, and are a result of an earthquake or a volcano eruption which can lead to causing tsunamis.

Surge: A surge of water is a strong swelling volume of water.

Earthquake: A sudden and violent movement of a portion of the earth’s crust, and the series of vibrations that follow.

Earth’s crust: This is the solid thin layer that covers the outside of the earth. Is the solid layer upon which we live. To put it in perspective, think of it as the skin on the outside of an apple.

Plate: A plate is a section of the earths crust. Plates slide along either beside, over or under each other, causing friction and pressure between the plates.

Teletsunami: A tsunami which causes damage a long distance away from the source has been given the name ‘teletsunami’. These types of tsunamis are not produced by horizontal motions, but by vertical motions in the seabed.

Tsunami waves are caused by large underwater earthquakes where there are tectonic plate boundaries. They can also be caused by volcano eruption under the ocean or lake. Even giant landslides have been known to cause large tidal waves or tsunamis in the past.

Tectonic plates are sections of the earth’s crust that move against each other.

When the pressure of the tectonic plate at the ocean floor releases pressure, it causes the water above to create a series of rolling waves which will build up to cause more turbulent and fast moving waves. These waves will turn into one large wave and will eventually result in a tsunami.

Tsunamis do not appear as a breaking wave. Initially it may resemble a tide that is rising rapidly. Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in what can be called a “wave train”.

Tsunami Facts and information
Tsunami in Morocco

The Pacific Ring of Fire

Almost 80 percent of tsunamis occur within the Pacific Ocean’s ‘Ring of Fire’. This is due to the amount of earthquake and volcanic activity in the area, which occur due to the tectonic shifts in the earth’s plates.

Tsunamis can reach speeds up to 500 miles per hour, racing across the sea. That is about as fast as a jet plane! Tsunamis can travel the entire length of the Pacific Ocean in less than a day. There is virtually no energy lost along the way due to their extremely long wavelengths.

The formation of a Tsunami

When tsunamis begin to form, they only appear a foot of so high in the deep ocean. This makes them impossible to distinguish. The closer they get to the shoreline and enter shallower water, their energy and height grow to drastic measures. The speed and momentum increases due to the top of the waves moving faster that the bottom does.

The lowest point under the wave usually reaches the shore first. When it reaches the shore, it produces what is described as the ‘vacuum effect’, which sucks the coastal water into the sea and gives the opposite effect of a tsunami. When this occurs, the sea floor is left completely waterless and the seafloor is totally exposed. This is the first sign a tsunami is about to hit.

The next stage causes the most serious and devastating effects. About five to ten minutes after the water retreats, the tsunami will hit. This gives people little time to escape the wrath of the tsunami; however the warning can save lives. When a tsunami hits it is important for people to remember that the danger may not have passed with the first wave or two. The aftershock of earthquakes can cause more waves to occur, sometimes even hours after the initial wave hits. The best defense against any tsunami is early warning that allows people to seek higher ground.

Pacific coastal countries are some of the most Tsunami prone areas in the world. Here is a list of some of the countries who have been affected or that could be affected by tsunamis:

  • Japan
  • United States
  • Mexico
  • Philippines
  • Russia
  • Ecuador
  • China
  • Chile
  • Papua New Guinea
  • Maldives
  • Indonesia
  • Italy

Problems caused by Tsunamis

Tsunamis can cause great loss of life and a serious decrease in population. Drowning is the most popular cause of death when a tsunami hits. Here are some dangers it can cause to the environment.

  • Shipwrecks can be left ashore when tsunamis hit. This can cause major pollution and can take time and money to remove.
  • Animals can be washed up to shore and die.
  • They can also flood the lands near the shore. This leaves crops damaged and the community can suffer from a lack of food and work.
  • Some people might left be trapped under buildings for long periods of time while search and rescue teams attempt to get a hold on the situation. The damage can be so great that people often die while trapped.
  • Tsunamis can cause economic decline as they have to spend a lot of money rebuilding the houses and restoring the original landscape. As the devastation can occur in very poor countries, there is usually not be enough help or money to completely rebuild entire livelihoods.
Water wave facts
Tsunami Recreation

Strongest Tsunami in history

One of the most well known and recent incidence of a tsunami was in Indonesia, on the 26th of December 2004. A 9.3 magnitude earthquake triggered a series of giant tsunamis along the coasts of most landmasses that bordered the Indian Ocean. This was also one of the largest earthquakes recorded. It killed over 230,000 people in fourteen different countries. It was recorded as one was one of the worst natural disasters in history. Indonesia was hit the hardest and Sri Lanka, Thailand and India also suffered greatly.

Due to the distances involved, the disastrous tsunami took between fifteen minutes and seven hours to reach the all the different coastlines. The tsunami took seven hours to hit Somalia. Sumatra, and Indonesian island was hit very quickly especially in the northern regions. The east coast of India and Sri Lanka were hit somewhere between 90 minutes to two and a half hours later. Thailand was hit around two hours later despite the fact that it was closer to the epicentre The reason for this is because the water was more shallow in the Andaman Sea, which is off the western coast.

The earthquake which caused the tsunami affected many countries even beyond Southeast Asia. These other countries included Sri Lanka, India, Malaysia, Thailand, Myanmar, the Maldives, Seychelles, Somalia, Tanzania and South Africa. Australia and Europe had a large number of their citizens in the region at the time of the disaster, along with many other countries. There were 543 Swedish people and 539 German people lost in the disaster.

 

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Blizzard

 

By definition, a blizzard is an extended, severe snowstorm. In order to qualify as a blizzard, winds have to be at least 35mph and rage for a longer period of time—at least three hours or more. The amount of snowfall has little to do with a storm qualifying as a snowstorm, but rather the intensity of the wind and length of time. There are two other classifications for blizzards:

–Severe blizzard: winds over 45mph, temperatures at 10 Fahrenheit or lower, near zero visibility.

–Ground blizzard: no falling snow, snow from the ground is blown by the strong winds.

A nor’easter gets it’s name from the direction of the oncoming winds. This occurs on the Atlantic side of Canada and East Coast of the USA. These storms can start as far south as the Gulf of Mexico or the North Atlantic Ocean. However, the most common usage of the name is in the coastal regions of Atlantic Canada and New England. These storms are similar to a hurricane. One of the deadliest blizzards in the USA—the Great Blizzard of 1888—was a nor’easter, killing 400 people after dumping 40-50 inches of snow.

What causes blizzards?

Blizzards are usually formed when the jet stream pitches very far south. This allows the cold air that comes from the north to collide with warm air coming from the south. This creates a strong storm system, usually developing on the northwest side of such storm systems.

Any area which is mostly flat is susceptible to blizzards, though there are some areas in the US, Australia, and the UK that suffer from blizzards more than others. However, the deadliest blizzard in recorded history occurred in Iran in 1972.

Dangers of blizzards

Blizzards are one of nature’s deadlier storms, as the conditions make travel and movement hazardous. Snowstorms disrupt traffic, but blizzards make any kind of travel nearly impossible. Almost every blizzard results in at least a few deaths, with some of the bigger ones resulting in hundreds of people dying.

Visibility is drastically reduced, in some cases to as little as 3 meters or what is called zero visibility.  In a ground blizzard, though no new snow is falling, the snow already on the ground is whipped up and around by the winds to where visibility is also close to zero.

Travel under these conditions is close to impossible. Cars have to come to a complete standstill as they can drive off the road. Because blizzards rage for so long, people can get trapped in their cars, freezing to death as they wait for it to clear. Once the storm is over, cars are often buried under mounds of snow, making it difficult for rescue teams to find them. Hypothermia sets in as people trapped outdoors try to find shelter and warmth.

Blizzards have been known to come suddenly and while it is possible to be warned in advance, it’s not always possible to be entirely prepared for the intensity of the blizzard. Clearing roads is not possible until after the blizzard has passed and then takes a long time due to the intensity of the build up. The aftermath of the blizzard can be almost as dangerous as the storm itself, as people trapped inside vehicles, unheated buildings, or outdoors take longer to be found and brought to warmth and safety.

blizzard facts and information
Snow covered car

History of blizzards

Though not as common as snowstorms, tornadoes, or even hurricanes, blizzards are deadly every time they hit. Not all blizzards are mentioned here, not even all of the most severe. This is just a sample of the havoc that blizzards can wreak.

–The white winter of 1880-1881 is one of the earliest blizzards mentioned in history books. This is considered the worst winter in US history. Because the first blizzard hit in October, before most farmers had the opportunity to bring in their crops. One after the other the blizzards continued to hit, making travel impossible, even by train. People were at the brink of starvation and train services stopped completely by January 1880 as no matter how often they cleared the tracks, another storm would come and cover them again. The snow never thawed and on February 2, 1881 a nine day blizzard hit again. By then, towns and farmers had to tunnel through the snow to get to livestock, wood for heating, and supplies.  Once the snow started melting, huge areas were flooded, washing away huge areas around the Missouri river. The town of Yankton, currently South Dakota, was nearly completely washed away by the overflowing river.

–The Iran Blizzard of 1972 is the deadliest recorded blizzard. Starting on February 3, until February 9, more than 10 feet of snow fell, the worst areas in Southern Iran getting up to 26 feet of snow. Whole villages died, one being completely buried beneath the snow. Approximately 4000 people died.

–The Armistice Day Blizzard in 1947 came somewhat unexpected, resulting in a lot of deaths. On the morning of the blizzard, the weather was warm, resulting in many hunters going out to take advantage of ideal conditions. Within a few hours, the blizzard hit, raging through the night and into the next day. 145 deaths were reported as a result of the 1,000 mile wide storm. Many hunters were not dressed warmly enough to withstand the wind and snow. Many were stranded on islands in the Mississippi, or drowned trying to get back to land.

–The Schoolhouse Blizzard in 1888 is different from the nor’easter and in some ways more heart breaking. Because the day started out relatively fair, people went about their lives, with children going to school and adults going to work. The storm hit early in the day, leaving thousands stranded; mostly children in their one-room schoolhouses. 235 people died; including children.

Although meteorologists are now able to more accurately predict blizzards, the storms still have the ability to cripple whole cities at a time, and deaths are almost always inevitable. Over the years, rescue missions during and after blizzards are becoming better and preparedness goes a long way towards preventing large amounts of casualties. It has also become considerably easier to notify people of oncoming storms, with more reliable predictions and getting the word out quickly and effectively.

Countries which are not used to large amounts of snow, extreme cold, and long periods of strong winds tend to have a harder time coping when the storms hit. Regardless of where the blizzards hit, there is never a way to be completely prepared. There is always a chance of power outages, communications systems breaking down, people going for long periods with little or no heat, and getting trapped outdoors or in a vehicle. During winter months, people are advised to pay close attention to weather warning coming over the radio or TV. There are weather websites set up to help people prepare for blizzards and post warnings when a snowstorm is being upgraded to a blizzard.

 

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