Tag Archives: Waves

Sound in Water

Did you know that sound travels over four times faster through water than through air? Next time you poke your head underwater, notice how it is difficult to tell which direction sound is coming from – that’s because it’s traveling so fast that there is no time for you to notice which ear it hits first!

Sound travels so quickly through water because there is more “stuff” – or “medium” – to conduct the sound waves. Have you ever played the game “telephone”, where one person passes along a message to another, and so on? Think of five hikers standing one mile apart on a trail, versus a baseball stadium row full of people packed close together. If both groups try playing telephone, through which group will the secret message travel faster? Through the one with more members closer together – like water molecules!Phases of matterMolecules are more densely packed together in ocean water, a liquid, than in air, a gas. This allows sound waves to pass more quickly through water. “Ironically”, sound travels even faster through iron, a dense solid, than water!

Many marine animals like fish, dolphins, and whales communicate and navigate using sound. For example, fish make specific popping sounds to find members of their same species to school with. Dolphins use echolocation – bouncing sound waves off of objects to determine their shape and location – to navigate and hunt, while baleen whales sing elaborate songs to call to each other in complex communication rituals. There is even a “sound corridor” at the specific depth where the pressure, temperature, and salinity are perfect for conducting sound slowly over thousands of miles, from Australia to Bermuda, for example, which fin whales use to communicate with other fin whales far away.

Sound

Fin whales use the Deep Sound Channel to communicate with fin whales very far away. (Image credit: David Rothenberg, thousandmilesong.com)

Since so many marine organisms use sound to survive, they are also often very sensitive to it. A shark’s best sense, for instance, is not in fact its sense of smell but its hearing! As our oceans are absorbing the excess CO2 in the atmosphere and becoming more acidic, sound is actually amplified, so loud and persistent sounds such as military sonar are having harmful effects on animals that are sound-sensitive such as dolphins and whales.

A microphone that records sound underwater is called a hydrophone. This spring, scientists from Oregon State University and the National Oceanic and Atmospheric Administration placed a hydrophone at the deepest place in the ocean, the Mariana Trench, southwest of Guam. To listen to what they heard, visit http://www.npr.org/sections/thetwo-way/2016/03/04/469213580/unique-audio-recordings-find-a-noisy-mariana-trench-and-surprise-scientists.

Hydrophones

Scientists lower hydrophones into the water at a special mooring over the Marianas Trench (image credit: NOAA)

How Erosion Influences Toyon Bay

Here at Toyon Bay erosion is constantly taking place! Erosion, the process in which the earth’s surface is worn away, can be caused by a number of ways including wind, rain, crashing waves, and even humans.IMG_3489

As wind blows against the earth’s surface it slowly begins to wear the environment away as well as smoothes and polishes it down. Over time this wear and tear is carried from one surface to another. Here at Toyon wind can carry a number of substances including dust, sand, and soil.

Although rain is not a common sight to see on the island it is still an important factor that affects erosion. Rain will wash away bits and pieces of soil and rocks and carry them to new places. Water is also a huge contributing factor in how our coastline was even formed! As waves continue to crash against our shore they wear rocks down into smaller and smaller pieces until they are turned into grains of sand. Over time waves even contribute to pushing coastlines further and further inland.

IMG_3481Us humans are even contributing factors towards erosion! Human activity can sometimes speed up the natural process of erosion. As we continue to physically change landscapes we inadvertently cause erosion to take place. For examples the more trees and plants we cut down, the more soil we expose. As a result more and more soil begins to wash away, creating less stable land, and an increase in erosion.

Written by: Alex Feltes

Waves 101

Waves start far away from the beach, out in the open water. As wind brushes up along the ocean, friction is created between the wind and the water, transferring energy from the wind to the water molecules. As the wind continues to push against the water, it can force smaller wave energy together forming larger waves. When the wave energy reaches the coast, the water starts to run into the ocean floor and is slowed down by friction. The closer the water gets to shore, the more shallow it is, causing more water molecules to come in contact with the ocean floor and slow down. As the energy moves closer to shore, the surface water continues forward at the same speed while the deep water continues to slow down. Eventually the water at the surface crashes over itself forming waves we see on the beach.

Screen Shot 2015-06-09 at 7.45.24 PM

Photo Credit: http://www.geography.hunter.cuny.edu/~tbw/ncc/Notes/chap3.landforms/oceans
.coastal.processes.landforms/waves/wave.formation.breakers.htm

The size of the wave depends on many different factors. First which of is the speed of the wind, the faster the wind travels the bigger the wave will be. This is due to the greater force of which the wind places on the ripples of the ocean. The second factor is the fetch, or the amount of time wind is blowing over a certain area of water. Waves will continue to get larger the longer wind blows across the water.

Larger waves tend to be formed farther from shore than smaller waves which are created right offshore. Waves that start far offshore are typically called swell waves because they have much more time to build in the open water. Large storms have the perfect conditions for forming large waves due to the amount of wind and pressure that is pushing against the ocean.

Surfers monitor the weather conditions and patterns to determine if the surf will be large or small. Here on Catalina Island the best surf comes from the windward, or the open ocean side of the island. This is due to the open ocean swell that builds up over time reaching the island as large waves. On the leeward or the channel side of the island there are little to no waves. The island acts as a wind shadow, protecting the channel from wind and therefore preventing the formation of large waves. Here at CIMI we are on the leeward side of the island, which produces little to no waves. Can you figure out where we are surfing?

Waves 101

Happy Pi Day! 3/14/15 at 9:26:53 a.m.


We may not teach a course on geometry at CIMI, but that doesn’t mean we can’t appreciate the importance of pi (π). Pi is a mathematical constant that represents the ratio of a circle’s circumference to its diameter. Ancient Egyptians and Babylonians were the first to approximate the number, calculating it to within one percent of its true value. It is an irrational number, meaning it cannot be expressed as a simple fraction and exists as an infinite series of numbers that will never end. When rounded up, the number comes to approximately 3.14. Thus, March 14th is Pi Day.

Why does a marine science camp care about Pi? Pi has all kinds of everyday applications. Think of all the round or rounded things that exist in this world: wheels, gears, eyes, rainbows, round rays. Engineers use pi to build machines. Architects use pi to create their blueprints. Geneticists use pi to understand the structure of DNA. The Earth itself is a sphere, so when an oceanographer measures the movement of the tides or the length of waves in the sea, they need to use pi in their calculations. So go celebrate pi today. Ride a Ferris wheel, eat a slice of apple pie, watch Life of Pi and get inspired by that beautiful scene with the bioluminescence and the whale all over again. Take a moment to watch the sunset and think about how big and beautiful and round it is, then wait for the moon to rise and look at that too. From all of us at CIMI, we wish you a very happy Pi Day.

Written by: Megan Petkovic

WECOME TO THE CIMI BLOG

We would like to thank you for visiting our blog. Catalina Island Marine Institute is a hands-on marine science program with an emphasis on ocean exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and ocean happenings. This blog has been created by our staff who have at least a Bachelors Degree usually in marine science or related subjects. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science and ocean information. Feel free to leave comments, questions, or share our blog with others. Please visit www.cimi.org for additional information. Happy Reading!

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