100+ Oceanic Terms

December 7, 2023

From shallow continental shelves to deep, dark ocean trenches, we’re set to navigate through a range of oceanic terms! Along the way, we’ll help you better understand some of the features and treasures of the sea

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Table of Contents

Continental Shelf

Imagine you’re at the beach, stepping into the water—instantly, you’re on the continental shelf!

You can think of a continental shelf as a giant extension of land underwater. It’s the part of the ocean floor that is right next to the land, and it’s pretty shallow compared to the rest of the ocean.

The ocean floor at these very shallow depths slopes slowly downward, and there are all sorts of marine life here, where the sun still shines through.

Just off the East Coast of the United States is an example of a continental shelf that extends along the coast from Maine’s northern shores down to Florida.

Coral Reef

If you explore a coral reef, you’ll find a bustling underwater city full of colorful formations that provide homes for all kinds of sea creatures.

These reefs are living structures that have been built over thousands of years by coral polyps, which are tiny marine animals related to jellyfish. These little polyps secrete calcium carbonate and create a protective enclosure called a calyx.

When polyps group together and keep building over time, they form a coral reef. These reefs are a safe haven for the coral polyps but also sustain whole ecosystems. An excellent example is the Great Barrier Reef off the coast of Australia, which stretches more than 2,300 kilometers (about 1429 miles). That’s the work of a lot of little polyps!

Abyssal

Ready to plunge into the abyss? Or maybe, more accurately, the abyssal zone. It’s where the ocean is very, very deep. Imagine being in the ocean’s deepest parts, where you’re shrouded in darkness. In these super cold, intensely pressurized depths, unusual and often bizarre creatures flourish because they have adapted to the extreme conditions.

If you are wondering what the low point of Abyssalzones is, it’s the Mariana Trench in the western Pacific Ocean, which reaches a depth of approximately 36,000 feet.

Trench

A trench is something that you can also find on land, but here we’re talking about oceanic terms. Exploring ocean trenches is like uncovering the secrets of deep, narrow underwater canyons. Often, these trenches take you into the abyssal zone (see above). Trenches can be massive and extend for many miles. They are formed by the collision and subduction of tectonic plates—one plate gets pulled below the other to create the trench.

As noted above, the Mariana Trench is a perfect example, descending deeper than the height of Mount Everest! These trenches are the ocean’s majestic landscapes, inverted and hidden in darkness.

Salinity

This is not solely an oceanic term, but here we’re talking about the salt of the sea! Salinity refers to the concentration of salt dissolved in water.

Have you ever been swimming in the ocean or hit by sea spray on a windy day, then licked your lips and noticed a salty taste? That’s salinity. On average, salt in ocean water is about 3.5%, or 35 grams of salt in every kilogram of seawater. It may be easier to picture this as nearly six teaspoons of salt in every quart of water. It’s a lot, and high salinity is one of the reasons water from the ocean is not safe to drink.

Littoral Zone

When you’re strolling along an ocean beach, you’re in the littoral zone—it’s where the land meets the sea.

The littoral zone is a unique habitat that supports many plant and animal species in a blended environment of both land and sea. The next time you’re at the beach, notice which creatures are enjoying the best of both worlds!

Exclusive Economic Zone (EEZ)

The EEZ is a country’s territory that extends into the ocean. This area might cover up to 200 nautical miles outward from a country’s coastline. The EEZ is where the country has full authority over oceanic exploration and sole rights to the many resources that may be found there—things like fish, oil, gas, minerals, and even renewable energy through the power of waves and tides or offshore wind.

Intertropical Convergence Zone (ITCZ)

The ITCZ is a major factor in tropical climates—those places with lush green landscapes and warm, humid air. Imagine a belt encircling Earth where winds from the northern and southern hemispheres meet. This collision creates low atmospheric pressure that leads to cloud formation and lots of rainfall.

Near the equator, the ITCZ moves throughout the year and brings the tropics to their rainy seasons. If you’re planning a trip to a tropical destination, keep an eye on the predicted location of the ITCZ and, if needed, bring your raincoat or plan to be wet. Either way, at least you’ll be warm!