It may not always be noticeable but everything on earth is under pressure. Above the ocean’s surface everything is subject to the air pressure of our atmosphere, which equals about fourteen and a half pounds per square inch, or one atmosphere of pressure.
If that doesn’t seem like much then consider the fact that it is pressing down on every single part of your body at all times. You’ve probably opened a brand new bottle of soda before and noticed how when the seal is cracked there is a familiar hissing sound and the bottle becomes more flexible. This is because sodas are stored under a few atmospheres of pressure to help keep them carbonated or “fizzy”.
That’s only one example of pressure though. Now, consider water weighs a lot more than air. The amount of pressure that most animals in the ocean have to live with is a lot greater than the amount that surface dwellers have to live with. At a depth of only thirty-three feet, the surrounding water pressure is now two atmospheres or double the amount of air pressure at the surface. At this depth there is no need to worry about the pressure being strong enough to do any physical harm but for fish that use a swim bladder, which is a gas filled organ used to maintain buoyancy, the increase in density of their bodies becomes an issue. The deeper you go, the denser you become. The denser you become, the faster you will sink without being able to stop it. Luckily most fish have the ability to deal with this issue before a problem occurs, but for others like the chambered nautilus, maintaining the right depth is crucial for survival. The nautilus uses chambers of gas inside its hard shell and water exchange for buoyancy so unlike many fish, it cannot raise or lower its buoyancy level very quickly if need be. To witness how pressure exists all around us you can do an experiment for yourself. Try cracking an egg under water and notice how the surrounding water pressure keeps the egg round instead of it falling apart.
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.
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!