Saturday, 2 June 2012

What are the Warning Systems for Tsunamis? 

A tsunami is one of the world’s most dangerous natural disasters. They destroy, kill, and damage homes and humans lives. We cannot stop or prevent a tsunami from happening, so the big question is, how can we protect ourselves? And what are some of the warning systems? And in what way do they protect us?

I guess the first thing that we should know is what is a tsunami?  A Tsunami is a series of waves traveling across an ocean, and has giant waves that are caused by volcanoes and earthquakes, under the sea.  There are three stages of a tsunami, Generation, Propagation, and Inundation. Generation of the tsunami is when it starts. It is the disturbance, so that would then be a earthquake, volcano, and the tectonic plates. The second stage is the propagation that is when the water starts to move across the deep ocean, and spreads out into all different directions. So it can travel as fast as 950 kilometers per hour through deep water. Also there wavelengths are very long in the ocean. And the last step is inundation that is when near land the water starts to get higher, and flows onto the foreshore. A tsunami is different depending on the coastline and the sea of the sea floor. If a tsunami is moving into shallow water then the amplitude will increase, that is called shoaling. But it does not happen everywhere. But it is more likely for it to occur in a lagoon, bay, harbor etc. So as the tsunami starts to approach the land, the wave grows high but then the speed is slower.  The movement of the water does not matter as much but the energy moving through the water is what makes it dangerous. So when we think about it how exactly is a tsunami different from wind swell waves, which are the typical waves we have daily on the shore? The first thing is that the wavelength of a wind swell is much shorter than a tsunami, and they can normally cause depths of water of 150 meters. Tsunamis have wavelengths that can go up to hundreds of kilometers apart, even when they reach shallow water. The third and second wave can be from ten minutes to two hours apart from each other! The movement of the water goes all the way to the seafloor. This is how a tsunami works.

Second, what type of damage do tsunamis even cause? The tsunamis trough which is the lowest part of the waves crest usually reaches the shore first. But when it does, it is like a huge vacuum cleaner! It sucks in all the water, then letting us see all the harbor, and sea floors. And on the shore they do not appear as breaking waves, instead it is a powerful wave that covers the land. Tsunamis are one of the most terrible natural disasters in the world. They destroy land, all the houses, shops, cities and villages are destroyed and many people are killed. They can even take the sand away from beaches, which takes years to build up. Tsunamis have happened since the begging of time! On October 28th, Nankaido, Japan 1707, an earthquake hit and was estimated to have been at least the magnitude of 8.3. Then of course after a tsunami came along the coasts of Kii, Milkawa, Surugu, Izu, and Sagami. The waves were powerful enough to even make a split, which then later separated Lake Hamana from the sea. There homes and villages flooded, and a total of 31,000 people killed. Now two tsunamis that you many of heard of was, the 2004 Indian Ocean tsunami, and the most recent one in Japan 2011. On December 26th 2004, there was a big earthquake with the magnitude between 9.1. It was off the coast of Sumatra, and estimated at the depth of 30km. And the flat zone was around 1300 km long, which caused the tsunami. The tsunami hit other countries, Thailand, Malaysia, and India. And it killed over 300,000 people. On the coasts of South Asia, and South East Asia, India, Indonesia, Sri Lanka and Thailand suffering the most damage. Many of the towns and villages were completely destroyed or badly damaged. Many of those affected places are still trying to rebuild their homes. And lastly on March 11th, North Pacific coast of Japan 2011, and earth quake hit, with the magnitude of 9.0. It traveled 800 km per hour, with waves at the height of 10m, flowing over the east coast of Japan. More than 18,000 people were killed, and around 425,000 people were relocated to shelters, because of their destroyed homes. The earthquake also caused a nuclear emergency, in Fukushima Daiichi were the nuclear power plant began leaking radioactive steam. These are why we need warning systems because tsunamis can destroy countries, and kill lives.     

Lastly, what are the warning systems? And how do they protect us? Tsunamis are danger to humans, animals, cities, countries etc. They can do so much damage and cause many deaths. So we want to find a way were humans know and can be warned when a tsunami is coming, to have a chance to get away, and be safe. The West Coast/ Alaska Tsunami Warning Center (WC/ATWC) are responsible for the warning systems, for California, Oregon, Washington, British Columbia, and Alaska. They also have the Pacific Tsunami Warning Center (PTWC) that is then responsible to warn other countries such as Hawaii and the U.S, countries within the Pacific basin. They both work together to warn countries if a tsunami is coming. But how do these warning systems work? So there are two types of sources, a distance source and a local source. A local source is when there is an earthquake and you feel violent shaking for around a few minutes you should head for higher ground. Because when there is an earthquake there will usually be a tsunami following afterward. But you should only do this when there is an earthquake near the water, because say if there was an earthquake right in the middle if Asia, it would not really affect the water. But then if there was an earthquake, near the bottom of Asia then that would maybe cause a tsunami. Especially when the earthquake will have a high magnitude, for example 9.0, which actually was the magnitude of the earthquake in 2004, Ocean Basin tsunami. Now for the distance source, there is a big tectonic plate, and all of its edges are the perimeter around the Pacific Ocean, we even have a nick name for it, The Ring of Fire! This plate causes many earthquakes, some that can have the magnitude of 7.0 and greater. Both of the tsunami warning centers use these certain buoys to help them with their tsunami warnings. Six of these buoys are put around the epicenter of the North Pacific to help scientist detect any signs of a tsunami. Depending on the water and how it might move across the Pacific and passing the buoy, the scientists can tell if a tsunami is approaching. One of the inventions that they also have is a warning toolbox buoys just to help avoid any false alarms, and provide backup if there are any outages. Once the scientists have found out that a tsunami is approaching, they will activate the Emergency Alert System. They will inform broadcasters, tv, radio, homes, businesses, schools, health care facilities etc. What is also good is that when there is a big earthquake when it causes a tsunami, it can take around 10 hours for it to get there, so you would have more time to prepare. But it depends because that I not always the case, after the earthquake in Japan 2011, the tsunami hit shortly after around 20 minutes later. You must always be prepared for a tsunami so some of the things you should do and consider, always have a disaster plan and a escape route, to get to higher ground. Always have a first aid kit for your home and car (This is also good for other natural disasters). And you should know how to turn off electricity, gas, and water.  So these are the warning systems, and how they work.  

In conclusion, tsunamis are very dangerous and we always need to be alert for when they will happen. And we have warning systems to protect humans, to help us be prepared for when a tsunami might be coming. Today I think we have pretty good warning system, but scientists are always trying to come up with new ideas to help and protect us more.

(Some tips on how to protect you, and be ready for a tsunami)

-Safety tips
-When you are on the beach in coastal areas, always be alert for tsunami warnings
-Have always an evacuation route that leads you to a higher ground
-Know the warning signs, the rumble of an earthquake, or the waters being pulled in
-Do not stay near the shore, to watch a tsunami
-Do not return to an affected or destroyed place, until authorities say it’s safe, because a tsunami is a series of waves
-Plan for a tsunami
-Always have a disaster plan
-Know that you are at risk for danger
-have a supplies kit, for home and car
-First aid kit, canned food and opener, bottled water, battery operated radio, flashlight, protective clothing, and instructions on how to turn off electricity, gas, water
-During Tsunami
-Follow instructions by local authorities
-Evacuate immediately
-Get to higher ground as fast as you can
-After tsunami
-Help injured or trapped people
-stay out of buildings if water remains around it
-Waters can cause buildings to sink, or floors to crack, and walls to collapse
-check for gas leaks
-open windows and doors to help dry things out
-look for fire hazards 

Bibliograhy

"How Do Tsunami Work?" How Do Tsunami Work? Web. 02 June 2012. <http://beachsafe.org.au/tsunami/ema/pages/03_workings.html>.

"The 10 Most Destructive Tsunamis in History - Australian Geographic." The 10 Most Destructive Tsunamis in History - Australian Geographic. Web. 02 June 2012. <http://www.australiangeographic.com.au/journal/the-10-biggest-tsunamis-in-history.htm>.

"History's Biggest Tsunamis." LiveScience.com. Web. 02 June 2012. <http://www.livescience.com/13176-history-biggest-tsunamis-earthquakes.html>.

"Tsunami Safety Tips." National Geographic. Web. 02 June 2012. <http://environment.nationalgeographic.com/environment/natural-disasters/tsunami-safety-tips/>.

"Tsunami Safety Tips." Tsunami Safety Tips. Web. 02 June 2012. <http://www.nilesema.com/tsunamitips.htm>.

"Weather Wiz Kids Weather Information for Kids." Weather Wiz Kids Weather Information for Kids. Web. 02 June 2012. <http://www.weatherwizkids.com/weather-safety-tsunami.htm>.

"NOAA Tsunami - How Does the Tsunami Warning System Work?" NOAA Tsunami - How Does the Tsunami Warning System Work? Web. 02 June 2012. <http://www.tsunami.noaa.gov/warning_system_works.html>.

"Children of Tsunami - Asians Affected by Tsunami Tell Their Own Story on Video." Children of Tsunami - Asians Affected by Tsunami Tell Their Own Story on Video. Web. 02 June 2012. <http://www.childrenoftsunami.info/tsunami/what.htm>.

1 comment:

  1. Excellent resources used Hannah! Good information and a logical flow as well. You included all aspects of the assignment effectively!

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