How it was formed: When the seafloor spreads, magma rises up and cools creating new crust, sediments then fall from the continental shelf and settle on the uneven surface, making it flat (Britannica).

Where it is located: Abyssal plains can be found all around the world, but they are the largest and most common in the Atlantic ocean (Britannica).

How it was formed: When two oceanic plates collide, the overridden oceanic plate is consumed within Earth's mantle. During that process, magma rises from the downgoing plate, leading to an eruption that can form seamounts and islands.

Where it is located: Generally found at mid-tectonic plate regions, called hotspots, and near the boundaries of tectonic plates (Clark).

Example: MacDonald Seamount in the austral group of the Pacific

Marine Ecosystems: They provide critical habitats for ocean life. Some ocean life who live by seamounts are Mollusks, Fish, Coral, Crustaceans, and Marine Mammals (Clark).

Natural Resources: Some metals can be found in seamounts that were deposited from sites of hypothermal activity. Seamounts are thick crusts made up of Cobalt-rich ferromanganese (Clark).

How it was formed: Guyots are seamounts whose tops were eroded away by waves and currents and now sit with a flat top underneath the ocean (utdallas)

Where it is located: They are found in every ocean except for the Arctic, but they are most common in the Pacific (utdallas).

How it was formed: The crust thins from the continent to the ocean. The thicker continental crust is less dense and sits above the mantle, while the thinner and more dense oceanic crust sits much lower forming continental margins (Hanif).

Where it is located: Located along coastlines between ocean basins and terrestrial continents (Hanif).

How it was formed: Sediment and Inorganic material carried by rivers to the ocean accumulates in layers near the edges of the continents (Britannica).

Where it is located: On any shoreline near the shore up until the shelf break (Britannica).

How it was formed: Gravitational slumping and currents wash away sediments at the top of the slope and cause the seafloor to decline past the continental break (Britannica).

Where it is located: Between the shelf break and the beginning of the ocean basin along coastlines (Britannica).

The first recorded use of the technique was in 1490 by Leonardo da Vinci.

(1918)

How it was formed: Ocean basins are formed and expanded through seafloor spreading and the movement of tectonic plates creating new crust which is then covered with water (World Land Forms).

Where it is located: Located all around the world anywhere beyond the continental rise.

How it was formed: Seawater gradually filters through fissures, narrow cracks, in the earth’s crust near seafloor spreading and subductions zones (National Geographic).

Where it is located: Located along mid ocean ridges typically near volcanically active areas.

Marine Ecosystem: Due to the warm circulation of mineral rich water hydrothermal vents are responsible for supporting whole ecosystems. Some organisms like yeti crabs and scaly foot gastropods can only live around hydrothermal vents. Vent mussels, eelpouts, and tubeworms are also commonly found around hydrothermal vents. The extreme temperatures inside and around hydrothermal vents make it an ideal habitat for extremophile bacteria who can convert the minerals in the water into energy (National Geographic).

Distribution of Natural Resources: The hydrothermal vents create sulfide deposits containing silver, gold, manganese, cobalt, and zinc in addition to the mineral rich water surrounding the hydrothermal vents (National Geographic).

How it was formed: Most volcanic islands originate from passive lava flows on the seafloor. These passive flows harden into rock and build up the height of the underwater mountain over millions of years.

How it was formed: Most volcanic islands originate from passive lava flows on the seafloor. These passive flows harden into rock and build up the height of the underwater mountain over millions of years (Clark).

Where it is located: Volcanic islands occur in ocean basins (such as the Hawaiian Islands) or on or near ocean ridges (e.g., St. Paul Rocks and Ascension Island in the Atlantic Ocean) (Clark).

How it was formed: Trenches are formed by subduction when two plates converge and the more dense plate gets pushed underneath creating a v shaped depression in the crust (Woods Hole).

Where it is located: Along subduction zones at a convergent plate boundary

Marine Ecosystem: The lack of sunlight, freezing temperatures, and intense pressure make for one of the most hostile, unique, and largely unexplored ecosystems in the ocean. Due to the lack of photosynthesis ability and sight animals get their nutrients from marine snow (animal excrement, organism remains, and detritus) and chemosynthesis where bacteria converts chemical compounds into organic nutrients. Very few animals are able to live at these depths but among the most common are angler fish, vampire squid, sea cucumbers, and various types of bacteria (Woods Hole).

Distribution of Natural Resources: Deep sea trenches have polymetallic nodules (mineral concentrates of iron and manganese) in addition to basalts, dolorites, and gabbros (Woods Hole).

How it was formed: As two plates diverge large amounts of magmas come up and solidify creating mid ocean ridges (AMNH).

Where it is located: Mid ocean ridges are found along divergent plate boundaries

Example: Mid-Atlantic Ridge

Marine Ecosystems: These fauna live on the flanks of the mid-ocean ridge, and are dominated by corals, gorgonians, sponges and fishes. Most of the species feed on particles suspended in the water (AMNH).

Natural Resources: As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt (AMNH).