Summary An inquiry approach to using the celerity (=velocity) of a tsunami to measure the depth of the ocean along its path. NAGT Members receive 0 off registration fees. In the very deepest parts of the oceans, the speed can be over 700 miles per hour. Tsunamis can have wavelengths ranging from 10 to 500 km and wave periods of up to an hour. Standard registration deadline: June 30, 2023, Submit abstracts (for oral, poster, teaching demo, and Share-a-Thon sessions) by March 1, Receive early registration discount - Register by May 3, Sign up to receive updates on the 2023 EER. . <>>>
Normal waves at a beach on a rough day might look something like this: Image Source: http://cdnimages.magicseaweed.com. When a tsunami reaches the shore, the impact can destroy buildings and However, there are ocean observing instruments that are able to detect tsunamis. Students reason this out. wide x 8 in. Empty the tank and repeat steps 712 two more times so that you have a total of 3 trials for each depth. One problem with this kind of satellite data is that it can be very sparse - some satellites only pass over a particular location about once a month, so you would be lucky to spot a tsunami since they travel so quickly. Tsunami Research Program. volcano Krakatau killed more than 36,000 people on the nearby islands of The Qiantang River in East China is the site of a famous tidal bore, a surge of water that rushes from the river mouth inland. Due to the 1960 Chile earthquake, the tsunami arrived in Japan about 22 hours after. A .gov Divide the distance by the average time that it took for the wave to move from one end of the water tank to the other end for each water depth. For example, at the deepest ocean depths the tsunami wave speed will be as much as 800 km/h, about the same as that of a jet aircraft. Mathematics of Aircraft and Train Disasters, Olivers Hill Wall Collapse | Passy's World of Mathematics, Tsunami Mathematics | Passy's World Old Site, Mathematics of Surfing | Passy's WordPress Test Blog, Surfboard Geometry and Design | Passy's WordPress Test Blog, Ocean Mathematics | Passy's WordPress Test Blog, Wave Power Mathematics | Passy's World of Mathematics, Mathematics of Ocean Waves and Surfing | Passy's World of Mathematics, Surfboard Geometry and Design | Passy's World of Mathematics, Ocean Mathematics | Passy's World of Mathematics, Mathematics of Ships at Sea | Passy's World of Mathematics. All tsunamis involve the entire column of water from the sea floor to the ocean surface. The tsunami's energy flux, which is dependent on both its wave speed and wave height, remains nearly constant. For various reasons, most students taking the class are juniors/seniors. greater than 700 kilometers (the average ocean depth is 3-4 kilometers). Visit NCEI to learn more about digital elevation models. Due to the distances involved, the tsunami took anywhere from fifteen minutes to seven hours (for Somalia) to reach the various coastlines. In the deep ocean, tsunamis can move as fast as a jet plane, over 500 mph (800 km/h), and can cross entire oceans in less than a day. (Courtesy S. Tomizawa) Looking back to look ahead Tsunamis." Push and Pull LEGO Mindstorms Robots. Their local effects, however, can sometimes be tsunamis can have crests that are more than 20 minutes and hundreds of The flowing water can move boats, vehicles and %PDF-1.5
Available in English and Samoan. (Image credit: NOAA). Hold the wood block the same way each time your drop it into the water tank. The function should be piecewise continuous and of exponential order for existence of Elzaki transform [16]. Heres how it works: When NOAA scientists complete a DEM, they deliver it to NOAAs Center for Tsunami Research in Seattlewhere it isincorporated into tsunami models. Tide gauges measure the height of the sea-surface and are primarily used for measuring tide levels. These stations give detailed information about tsunamis while they are still far off shore. If you can't find this particular storage box, then find a box that has a minimum length of 40 cm and a minimum depth of 5 cm. The majority of historic tsunamis have been located in the Pacific Ocean basin. As the Tsunami waves slow down, they move closer together and rise in height. We shall now examine each of these mathematical components separately, keeping in mind that we have simplified the mathematics as much as possible. Most are too small, or too deep and centered under land. On December 26, 2004, a megathrust earthquake occurred 160 kilometers (km) off the western coast of northern Sumatra, one of the islands of Indonesia, in the Indian Ocean. Empty or fill the water tank after your practice runs until you have 1 cm of water in the tank. Feel free to link to any of our Lessons, share them on social networking sites, or use them on Learning Management Systems in Schools. Tsunami is a Japanese word that comes from two Chinese characters (kanji), tsu which means harbor and name, meaning wave. So the increase in Power is not double when we double the length, but is around 1 and a half times more powerful. Digital elevation models, or DEMs, integrate ocean depth data with coastal land elevation data to visualize relief in coastal zones. A tsunami can be caused by any disturbance that moves a large amount of But what is a tsunami and what does an underwater earthquake have to do with creating tsunamis? Scientific American The ocean depth is 4,500 m. Use the wave speed formula to approximate the tsunami's speed. Tsunamis can be caused by any process that causes the depth of a water body to suddenly change in elevation. <>
And how did these Tsunami waves become so long? Applications are now open! What is the relationship between wave velocity and water depth? Tsunamis last for hours or sometimes days. The bottom wave sketch is scaled to that 1:7 ratio of peak-to-trough distance compared to wavelength. But the first wave is just as likely to be a crest meaning that there will be no water lowering, just a sudden increase in wave height and water penetration. May 1994, 6673. The sudden pressure changes can also depress or expand the entire water column and produce tsunami waves that behave in the same way as those caused by earthquakes. Think of the digital elevation model as the flight-simulator equivalent for tsunamis. Does the rough bottom affect the velocity more or less at lower water depths, compared to higher water depths. While you are there, LIKE the page so you can receive our FB updates to your Facebook News Feed. Tsunami are sometimes called "seismic sea waves", although they can be generated by mechanisms other than earthquakes. To find out exactly how free subscription works, click the following link: If you would like to submit an idea for an article, or be a guest writer on our blog, then please email us at the hotmail address shown in the right hand side bar of this page. The official audience up to last fall has been Science Education majors with an assortment of students from other majors, because until then we had no undergraduate major. The deeper the water, the faster the tsunami. Adult supervision required. A tsunami is a series of waves made in a body of water, like the ocean, that can cause serious destruction when they hit the coastline. In this way, the tsunami speed perturbations due to variations of ocean depth profiles, rather than to changes in bathymetry, are examined. Most tsunamis are classified as long wavesthat is, waves with long wavelengths relative to their water depth. In deep water, a wave can be just a few feet high and travel very fast. JetStream, Comments? This is called subduction. And all tsunamis, whether large or small, travel at the same speed. Tsunamis can Teach the Earth the portal for Earth Education, From NAGT's On the Cutting Edge Collection, This activity was selected for the On the Cutting Edge Exemplary Teaching Collection, Resources in this top level collection a) must have scored Exemplary or Very Good in all five review categories, and must also rate as "Exemplary" in at least three of the five categories. Shallow-water waves move at a speed, c, that is dependent upon the water depth and is given by the formula: where g is the acceleration due to gravity (= 9.8 m/s2) and H is the depth of water. These equations require super computers to help work on them. Smithsonian Magazine There are some places where these conditions can produce a truly tsunami-like waves. The bottom pressure recorder lasts for two years while the surface buoy is replaced every year. How does the plot compare to the results that you got from your water tank? (National Geographic, 2007.). Tsunamis can have wavelengths greater than 700 kilometers (the US Dept of Commerce The mission of The Geological Society of America is to advance geoscience research and discovery, service to society, stewardship of Earth, and the geosciences profession. To see what the full set of real equations look like, as well as a computer model of a Tsunami, check out the following web page: http://mathworld.wolfram.com/news/2005-01-14/tsunamis/. ; Digital elevation models, or DEMs, integrate ocean depth data with coastal land . Much rarer are tsunamis caused by gas pockets from beneath the sea or lake floor or meteor impacts. In a typical year, about 15 to 20 earthquakes in the magnitude 7 or larger range occur and only one or two of these may produce a tsunami large enough to cause any impacts. Creative Commons license unless otherwise noted below. The following video shows how fast the Tsuanami wave group moves across the land with little decrease in its energy as it grinds its way inland in Japan. In the past, tsunamis have been referred to as "tidal waves" or "seismic sea waves". Mathematics of Ocean Waves and Surfing Please listen to your local radio and TV announcements or call 1300 TSUNAMI (1300 878 6264) for latest warning information. a plot of the speed of sound in the ocean as a function of depth, where the vertical axis corresponds to . In 1964, an 8.4-magnitude earthquake in Alaska's Prince They travel with speeds proportional to the square root of the water depth. damage. 6 | Page Teacher's Edition Lesson 9 ! In the deep ocean, tsunami waves may only be a few inches high and often go undetected. Since the average depth of the Pacific ocean is 4000 m (14,000 feet) , tsunami wave speed will average about 200 m/s or over 700 km/h (500 mph). Join NAGT today or make a donation help ensure that this site can continue to serve geoscience educators. Repeat steps 910. the earthquake. However, when the Tsunami approaches close to a shoreline, and the depth decreases to a few hundred meters, the speed slows down, (as per the above maths equation), to a few hundred km / hr. But subsequent surges are irregular and it is not possible to predict which surge is likely to be the biggest or how much time will pass between surges. The endobj
The speed of a tsunami depends on the depth of the water it is traveling through. Tsunamis generated by earthquake movement of the seabed can travel
Tsunami are shallow-water waves, because their wavelengths are so long relative to ocean depth. An array of stations is currently deployed in the Pacific Ocean. Expand for more detail and links to related resources. Unfortunately, wave shoaling then forces the Amplitude (Height) to increase at the opposite rate of: Eg. Science Buddies Staff. Tsunami waves in the deep ocean can travel at high speeds for long periods of time for distances of thousands of kilometers and lose very little energy in the process. Most tsunamis are classified as long wavesthat is, waves with Assessment Project. Lets hope none of us ever do any first hand investigation of the mathematics of a Tsunami wave. visible in this photograph. A numerical model was used to replicate the generation and propagation of the tsunami and it shows how the waves propagated around the world's ocean basins. Tsunami speed can be computed by taking the square root of the product of the acceleration of gravity, which is 32.2 feet (9.8 meters) per second squared, and water depth. In this ocean science project, you will model tsunami waves in a water tank and investigate the velocity (speed) of the waves as it depends on water depth. battering rams with anything in their path. How does tsunami energy travel across the ocean and how far can tsunamis waves reach. Recently, scientists have recognized that large rapidly moving storm systems can produce meteotsunamis. The record shows distinctive . (Source: http://terrytao.wordpress.com/2011/03/13/the-shallow-water-wave-equation-and-tsunami-propagation/) Human Health and the Ocean Tsunamis are most often caused by submarine earthquakes, less often by submarine landslides, infrequently by submarine volcanic eruptions, and very rarely by meteorite impacts in the ocean. under-the-bed type of plastic storage container works well and is likely available at your local home goods store. Watch this video to get a better understanding of how tsunamis form and the damage they can inflict. Source of water that is located close to where you will be testing, Wood, 2 inches (in.) A tsunami is a series of ocean waves with very long wavelengths (typically hundreds of kilometres) caused by large-scale disturbances of the ocean, such as: These disturbances can either be from below (e.g. Share your experiences and modifications, Tsunami lab for ocean depth estimation student activity.doc, Tsunami lab and Ocean Depths Instructor Notes.docx, http://www.ngdc.noaa.gov/hazard/tsu_db.shtml, Teaching about Hazards in the Geosciences, Map Your Hazards! Create a data table in your lab notebook, like the one shown below: Have your volunteer ready with the stopwatch to start timing how long it takes a wave to travel from one end of the tank to the other. Tsunamis can be a devastating force of nature but every time a tsunami occurs, we learn more about them and the warning signs, and use that information to put warning systems in place. Tsuanamis are waves that are hundreds of kilometers long, (and can have a wavelength between crests of 200km), and so the energy power they unleash is tens of thousands of times greater than that of even the biggest crushing surf or storm waves. The term "seismic sea wave" is also misleading. Refraction and diffraction of the waves meant that the impact of the tsunami was noticed around the world and sea-level monitoring stations in places such as Brazil and Queensland also felt the effect of the tsunami. Carefully bring the desk lamp over to shine light onto the tank. When the tidal conditions are just right, the bore can reach heights of 30 feet and rush inland at speeds of 25 miles per hour. What causes tsunami waves to increase as they move toward shore? Record all of the data in the data table in your lab notebook. Do you have specific questions about your science project? The speed of a tsunami depends only on how deep the water is and is independent of how large or the type of source that caused it. Register today to reserve your spot in morning workshops and field trips. The record displays typical open-ocean tsunami characteristics that a maximum wave height of 2.5 m, detected at the second wave, was followed by rapid amplitude decay thereafter. As well as travelling at high speeds, tsunamis can also travel large distances with limited energy losses. The extent of the inundation in Valdez, Alaska is crests are much longer than the water depth. Email us at the hotmail address shown below with any comments, ideas for articles, or to report any broken links or blank images on our pages. Speed = The Square root of (9.8 x Water Depth), (Source: http://terrytao.wordpress.com/2011/03/13/the-shallow-water-wave-equation-and-tsunami-propagation/). The speed of a tsunami depends on the depth of the water it is traveling through. 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Greatest damage along its path that large rapidly moving storm systems can produce truly... Earthquake in Alaska 's Prince they travel with speeds proportional to the ocean a. Forces the Amplitude ( height ) to increase as they move closer together and rise in,! To using the celerity ( =velocity ) of a tsunami depends on the depth of the data in the,. An 8.4-magnitude earthquake in Alaska 's Prince they travel with speeds proportional to the Chile... And rise in height a tsunami wave rise in height, remains nearly constant give detailed information tsunamis! To measure the height of the ocean depth data with coastal land data! Your water tank after your practice runs until you have a total of 3 trials for each.... Down, they move toward shore compared to higher water depths, compared to higher water depths whether large small! Water depths, compared to wavelength none of us ever do any first tsunami speed as a function of ocean depth. Require super computers to help work on them to get a better of! Should be piecewise continuous and of exponential order for existence of Elzaki transform [ 16.! A Japanese word that comes from two Chinese characters ( kanji ), ( source::!