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What is the definition of the word Ridge?

What is the definition of the word Ridge?

(Entry 1 of 2) 1 : an elevated body part or structure. 2a : a range of hills or mountains. b : an elongate elevation on an ocean bottom.

What is a ridge in anatomy?

anatomy any elongated raised margin or border on a bone, tooth, tissue membrane, etc. the top of a roof at the junction of two sloping sides. (as modifier)a ridge tile.

Is a fissure a depression or opening?

Complete list of bone markings

Parts of a bone Head (epiphysis) Neck (metaphysis) Body (diaphysis) Articular surface
Openings and depressions Foramen and fissure Meatus Fossa and fovea Incisure and sulcus Sinus

What is the definition of mid ocean ridge?

: an elevated region with a central valley on an ocean floor at the boundary between two diverging tectonic plates where new crust forms from upwelling magma.

Why is the Mid-Ocean Ridge unique?

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.

What is an example of mid-ocean ridge?

Prominent examples of such mid-ocean ridge formations are along Africa, the Red Sea, in the USA where mid-ocean ridges have started to alter and newer ones have begun to form on account of the excessive heat.

Why are rocks next to the Mid-Ocean Ridge younger than those farther away from the ridges?

Compare the sea floor spreading with the formation of mid-ocean ridges? The scientists found that the farther the rocks the older the rocks were,so the youngest rocks were found near the mid-ocean ridge.

Is the crust near a divergent boundary older or younger than the crust farther away from the boundary?

Over millions of years, tectonic plates may move many hundreds of kilometers away from both sides of a divergent plate boundary. Because of this, rocks closest to a boundary are younger than rocks further away on the same plate.

Who discovered seafloor spreading?

Harry Hess

What causes seafloor spreading?

Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor.

What are the 4 steps of seafloor spreading?

What are the 4 steps of seafloor spreading?

  • Magma comes out of the rift valley.
  • Magma cools to rock and hardens.
  • Rock is pushed away as new rock is formed at MOR.
  • Oceanic crust and continental crust meet at the trench.
  • Oceanic crust bends down under the continental crust.
  • Gravity pulls rock towards mantle.
  • Rock melts to mantle.

What is the theory of seafloor spreading?

Seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them. …

What are three pieces of evidence that support seafloor spreading?

Look at Figure 19 to see the process of sea-floor spreading. Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.

What is the first step of seafloor spreading?

A crack forms in oceanic crust. Molten rock rises up through oceanic crust. Molten rock solidifies at the center of the ridge.

Is Earth’s current polarity normal or reversed?

Scientists have concluded that the Earth’s magnetic field has reversed itself again and again throughout the ages. When the field points toward the north magnetic pole, as it does today, the field and the rocks that record it have “normal” polarity.

What information did the Glomar Challenger study in 1968?

ANSWER: Glomar Challenger studies about the “age of rocks in various places in the ocean” in 1968. EXPLANATION: Glomar Challenger was a “deep sea research vessel” for marine geology and oceanography studies.

What is the theory of seafloor spreading quizlet?

Seafloor Spreading Theory. gradual addition of new oceanic crust in the ocean floor through a volcanic activity while moving older rocks away from the mid ocean ridge.

Where does seafloor spreading occur quizlet?

Where does seafloor spreading occur? This process occurs along divergent plate boundaries at areas called mid-ocean ridges.

Does the data support the theory of seafloor spreading How?

Modern plate tectonic theory. By the 1960s, the theories of continental drift and sea floor spreading were supported by reliable scientific data and combined to develop modern‐day plate tectonic theory.

What is the importance of seafloor spreading in understanding the origin of the plate?

Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.

What are formed when two plates collide?

If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary.

What is the seafloor made of?

Oceanic crust is about 6 km (4 miles) thick. It is composed of several layers, not including the overlying sediment. The topmost layer, about 500 metres (1,650 feet) thick, includes lavas made of basalt (that is, rock material consisting largely of plagioclase [feldspar] and pyroxene).

What does bathymetry mean?

Bathymetry is the study of the “beds” or “floors” of water bodies, including the ocean, rivers, streams, and lakes. The term “bathymetry” originally referred to the ocean’s depth relative to sea level, although it has come to mean “submarine topography,” or the depths and shapes of underwater terrain.