When lava gets erupted at the mid-ocean ridge axis it cools and turns into hard rock. As it cools it becomes permanently magnetized in the direction of the Earth’s magnetic field. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges.

Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.

Magnetic stripes are the result of reversals of the Earth’s field and seafloor spreading. New oceanic crust is magnetized as it forms and then it moves away from the ridge in both directions.

How to form magnetic striping: new oceanic crust forms continuously at the mid-ocean ridges. While it cools down, it records the magnetic field during its formation. The two parts of the oceanic plate are pulled apart, and magnetic stripes become older as they move away from the mid-ocean ridge.

When lava is extruded at any mid-ocean ridge, the rock it forms becomes magnetized and acquires the magnetic polarity that exists at the time the lava cools. As the crust moves away from mid-ocean ridges, it contains a continuous record of the Earth’s changing magnetic polarity.

When scientists plotted the points of normal and reversed polarity on a seafloor map they made an astonishing discovery: the normal and reversed magnetic polarity of seafloor basalts creates a pattern. Stripes of normal polarity and reversed polarity alternate across the ocean bottom.

Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples.

The continual process of seafloor spreading separated the stripes in an orderly pattern. Oceanic crust slowly moves away from mid-ocean ridges and sites of seafloor spreading. As it moves, it becomes cooler, more dense, and more thick.

The north pole becomes the south pole, and the south pole becomes the north pole. Rocks of normal and reversed polarity are found in stripes symmetrically about the mid-ocean ridge axis. The seafloor is youngest at the ridge crest and oldest far away from the ridge crest.

Magnetic stripes in the Pacific Ocean are wider because the seafloor spreads more rapidly there than in the Atlantic Ocean. Seafloor sediment increases in thickness away from the mid-ocean ridge because the oceanic crust is older farther away from the ridge.

mid-ocean ridges

Scientists discovered that the rock that makes up the ocean floor lies in a pattern of magnetized “stripes.” These stripes hold a record of reversals in Earth’s magnetic field. The rock of the ocean floor contains iron. The rock began as molten material that cooled and hardened.

Hess envisaged that oceans grew from their centres, with molten material (basalt) oozing up from the Earth’s mantle along the mid ocean ridges. This created new seafloor which then spread away from the ridge in both directions.

The stripes are symmetric across the Oceanic Ridge. They create a mirror image. It suggests that new seafloor is formed in the middle (at the Ridge) and some of the new seafloor moves to each side of the Ridge forming a symmetric pattern.

The first step of seafloor spreading is when a crack forms in the oceanic crust. Explanation: Seafloor spreading occurs in ocean waters. The force behind its formation is the convection currents in the mantle beneath it.

Which information did the Glomar Challenger study in 1968? the age of rocks of various places in the ocean.

Features of the ocean floor include the continental shelf and slope, abyssal plain, trenches, seamounts, and the mid-ocean ridge. The ocean floor is rich in resources. Living things on the ocean floor are used for food or medicines.

The Indian Ocean has the fewest trenches of any of the world’s oceans. The narrow (50 miles [80 km]),… Both types of subduction zones are associated with large earthquakes that originate at a depth of as much as 700 km (435 miles).

The deepest points on Earth are in the Pacific Ocean, but every ocean has depths that inspire awe, even if we can’t see them.

• The Philippine Trench.
• The Tonga Trench.
• The South Sandwich Trench.
• The Puerto Rico Trench.
• The Eurasian Basin and Molloy Deep.
• The Diamantina Trench.
• The Mariana Trench and the Challenger Deep.

The Mariana Trench was formed through a process called subduction. Today, the majority of the Mariana Trench is a U.S. protected zone as part of the Marianas Trench Marine National Monument, established in 2009.

Why are most oceanic trenches found in the Pacific Ocean? The Pacific Ocean is shrinking and plates are descending below surrounding plates along its edges, hence the creation of trenches.

Which best describes an ocean trench? A deep, curved depression near the margin of a continent or chain of volcanic islands. Lava erupts from the mid-ocean ridge and is carried away as the floor of the ocean spreads apart.

Some well-known examples of island arcs are Japan, Aleutian Islands of Alaska, Mariana Islands, all of which are in the Pacific, and the Lesser Antilles in the Caribbean. The abundance of volcanic rocks around the Pacific Ocean has led to the designation of the Pacific margin as a “Ring of Fire”.

The three most common organisms at the bottom of the Mariana Trench are xenophyophores, amphipods and small sea cucumbers (holothurians), Gallo said. The single-celled xenophyophores resemble giant amoebas, and they eat by surrounding and absorbing their food.

• Life In the Shadowy Depths. (Image credit: U.S. Antarctic Program Photo Library)
• Alien-like Anglerfish. (Image credit: Theodore W.
• “Spaghetti Monster” (Image credit: Screenshot, Live Science/SERPENT Project Youtube video)
• “Ghost Fish”
• Vampire Squid.
• Eerie Anglerfish.
• Giant Crustaceans.
• Monstrous Megamouth Shark.

The average depth of the Atlantic Ocean is 3,900 meters, or just over 2 miles. If we can reach a depth of 4,000 meters, we can explore 63% of the world’s ocean floor.