Sand is a result of the breakdown of Earth’s crust. Sand is formed over a long period of time by water, wind, gravity, and tectonics, among other forces. Water provides movement of sediment from the beginning of streams and inland areas down through the land. As sediment is transported it becomes more worn. While heavier sediment settles along river banks and streams, lighter sediment gets carried to the ocean. Gravity assists the motion of material down streams, rivers, and cliff sides. The smashing of rocks together causes fragmentation of rocks. Like gravity, wind contributes to the movement of materials in powering waves, currents, and the eroding of surfaces. Fine sand is also transported to various locations by the wind. Plate tectonics work together with gravity and water to push rocks upward and then wear them down. These are some common causes that construct sand but depending on location others may exists, such as animal involvement.
These forces cause decomposition of the Earth’s crust to make fine sediment we refer to as sand. Depending on where you are located sand can look different. Different region’s sands are composed of various materials. California for example has many beaches composed of quartz grains. Quartz grains are minerals found in many different kinds of sedimentary rocks and igneous rocks found in Earth’s crust. Once the sedimentary and igneous rock is weathered away, quartz grains are what remains due to ability to resist weathering. Other locations such as the Hawaiian Islands have beaches that are composed of parrotfish poop. Parrotfish consume coral when biting and scraping algae off dead coral, this coral is then passed through their intestines and excreted. Other beaches in New Zealand are referred to as black sand beaches because of their black color which is a result of being composed of volcanic lava fragments. Yet others are made entirely of shells like those in West Australia. Thus, every beach with its abundant sand always has a story of how it came to be formed.
Echolocation is the emittance of sound and the reflection of vibrations off of an object back to the sender. This is commonly used by bats and dolphins! Dolphins release a high pitch click or snap sound that travels through the ocean in an effort to locate their food source. However some scientists do not agree about where the sound comes from. “Some scientists suggest that sound is emitted from a nasal plug and that the shape of the melon is altered by muscles to focus sound. Other scientists believe that the larynx emits sound and argue that echolocation focusing is achieved by bouncing sound off various parts of the skull.” (http://www.afsc.noaa.gov/nmml/education/cetaceans/cetaceaechol.php). The time it takes for a dolphin to send and receive this information varies depending on how far the vibrations have to travel back to the dolphin.
Here at CIMI we teach echolocation to students a few different fun ways. Jacque, a Toyon Bay CIMI Instructor, is seen teaching her students how echolocation works through the use of props such as the sample dolphin skull she is seen holding. Her students also participate in a fun game of echolocation! Four students are split up into dolphins and fish. The dolphins are blindfolded and will emit a sound, a clip or snap, and the fish will repeat that sound. It is the dolphins job to find the fish using “echolocation” or the repetition of their sound. Our students find out that it is a bit harder than they realized!
When swimming in salt water you can make observations on more than just the salty taste. An observation you may have made is that you are more buoyant, or you float more, in salt water than in fresh water. This is a result of the oceans salinity, the amount of salt in the water. Density is the amount of matter in a given space or area. When a volume of water is replaced by an item of greater density than the water, the object will sink. Likewise, if a volume of water is replaced with an object that is less dense than the water, it will float towards the surface.
This physical happening can be observed when pouring fresh water into a pitcher of salt water. The fresh water, when poured slowly, will remain on the top of the salt water. A small layer forms where the two bodies of water meet, called a Halocline. You can also observe the difference in density by using an egg. Place an egg in fresh water and watch as it sinks to the bottom. When placed in salt water it will float. The egg was denser than the space it replaced in the fresh water causing it to sink and was less dense than the salt water causing it to float. When placing the egg into the pitcher that had the fresh and salt water the egg floated right at the Halocline.
We would like to thank you for visiting our blog. Catalina Sea Camp 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 minimum a Bachelors Degree in Marine Science or related subject. 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.catalinaseacamp.org for additional information. Happy Reading!