What makes a zigzag pattern on the seafloor?
Most such faults are found in oceanic crust where they accommodate the lateral offset between segments of divergent boundaries forming a zigzag pattern. This is a result of oblique seafloor spreading where the direction of motion is not perpendicular to the trend of the overall divergent boundary.
What is the name of the Zig Zag feature running down the middle of the South Atlantic ocean?
Called the global mid-ocean ridge, this immense submarine mountain chain — more than 50,000 kilometers (km) long and, in places, more than 800 km across — zig-zags between the continents, winding its way around the globe like the seam on a baseball.
How magnetic patterns develop on the seafloor?
The striped magnetic pattern develops because, as oceanic crust pulls apart, magma rises to the surface at mid-ocean ridges and spills out to create new bands of ocean floor.
What causes magnetic stripes on the seafloor such as those shown here?
At the mid-ocean ridge spreading axis, these flips in the direction of the Earth's magnetic field are recorded in the magnetization of the lava. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges.
Why does the mid-ocean ridge have a zigzag appearance?
The reason the mid-ocean ridge has a zigzag appearance is because: it accommodates spreading of a linear ridge system on a spherical Earth. Turbidity currents are highly erosive and are thought to be responsible for the creation of deep-sea trenches.
Which of the following supports the theory of seafloor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
What type of plate boundary formed the Mid-Atlantic Ridge?
divergent plate boundaries The Mid-Atlantic Ridge is an example of divergent plate boundaries. When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench.
What does this pattern suggest about how the seafloor forms?
Distance from Oceanic Ridge (km) VGP Latitude (deg.) 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.
What type of plate boundary creates seafloor spreading?
divergent plate boundaries 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 creates magnetic stripes on the seafloor quizlet?
The rock of the ocean floor contains iron. As molten material cooled and hardenend, the iron bits inside lined up in the direction of Earth's magnetic poles, creating a pattern of magnetized stripes.
How does the pattern of magnetic stripes give evidence for seafloor spreading?
When the Earth's magnetic field reverses, a new stripe, with the new polarity, begins. Such magnetic patterns led to recognition of the occurrence of sea-floor spreading, and they remain some of the strongest evidence for the theory of plate tectonics. The figure below includes two images of the ocean floor.
How are mid-ocean ridges formed?
It formed and evolves as a result of spreading in Earth's lithosphere—the crust and upper mantle—at the divergent boundaries between tectonic plates. The vast majority of volcanic activity on the planet occurs along the mid-ocean ridge, and it is the place where the crust of the Earth is born.
Which plate boundary and movement commonly create ridges like the Mid Atlantic oceanic ridge explain how ridges can be created by plate tectonics?
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 are the features of seafloor spreading?
Seafloor spreading produces major characteristics of the seafloor – 1) the age of the seafloor is progressively older away from midocean ridges, 2) the elevation of the seafloor is progressively lower away from midocean ridges, 3) the magnetic history of the seafloor bears the striped-pattern of the Earth's magnetic …
What are the main features of the seafloor?
There are nine main features of the ocean floor which include (1) continental shelf, (2) continental slope, (3) continental rise, (4) abyssal plains, (5) abyssal hill, (6) mid-ocean ridges, (7) seamounts, (8) deep ocean trenches, and (9) volcanic islands.
How are Mid-Atlantic ridges formed?
The Mid-Atlantic Ridge is a giant rift valley that runs along the Atlantic Ocean floor from north to south. It was formed by tectonic forces and diverging plates. As the Eurasian and North American plates move apart, rising magma solidifies and creates new oceanic crust along the rift valley.
What is the shape of the Mid-Atlantic Ridge?
2. Bathymetric map of Mid-Atlantic Ridge that shows how relatively straight sections are offset from each other. Instead of a continuous curvy line of mountains, the shape of the Mid-Atlantic Ridge is formed of shorter straight sections that are staggered.
How does the pattern of magnetic stripes give evidence for seafloor spreading quizlet?
How do strips of magnetized rock on the ocean floor provide evidence of sea-floor spreading? Strips of ocean-floor basalt record the polarity of Earth's magnetic field at the time the rock formed. These strips form a pattern that is the same on both sides of the mid-ocean ridge.
Why does the crust in the ocean have magnetic patterns quizlet?
Magnetic patterns are symmetrical on each side of the mid-ocean ridge, which would indicate that the seafloor is spreading apart like the tectonic plate theory claims.
What does magnetic stripes pattern represent?
This represents periodic reversals in the direction of the Earth's magnetic field.
What plates formed the mid-ocean ridge?
This ridge is formed as the North American and Eurasian plates, as well as the South American and African plates, move away from each other. The Mid-Atlantic Ridge is considered a slow-spreading center, with 2 to 5 centimeters, or 0.8 to 2 inches, of new ocean floor formed each year.
How seafloor spreading occurs in the mid-ocean ridge and the formation of the new oceanic crust?
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. Eventually, the crust cracks.
What plates make up the Mid-Atlantic Ridge?
The MAR separates the North American Plate from the Eurasian Plate in the North Atlantic, and the South American Plate from the African Plate in the South Atlantic. These plates are still moving apart, so the Atlantic is growing at the ridge, at a rate of about 2.5 cm per year in an east-west direction.
What is the pattern of seafloor age in the ocean basins?
The age pattern is symmetric. Youngest ages are at the middle of the pattern (on the oceanic ridges) and the seafloor grows older moving outwards to each side of the middle. 4.
Which feature of the seafloor is a tectonic plate boundary?
Deep ocean trenches, volcanoes, island arcs, submarine mountain ranges, and fault lines are examples of features that can form along plate tectonic boundaries.
What are the features of seafloor quizlet?
What are the eight main features of the ocean floor? Continental shelf, continental slope, continental rise, abyssal plain, mid-ocean ridge, ocean trench, seamount, and volcanic island.
Which map shows how the seafloor looks like?
Contour maps for land are called topographic maps. Contour maps for ocean depths are called bathymetric maps or charts.
Where is the southern Mid-Atlantic Ridge?
The Mid-Atlantic Ridge (MAR) is a mostly underwater mountain range in the Atlantic Ocean that runs from 87°N -about 333km south of the North Pole- to subantarctic Bourvet island at 54°S.
How does the new seafloor form at the mid-ocean ridge?
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.
Where is the Southern Mid-Atlantic Ridge?
The Mid-Atlantic Ridge (MAR) is a mostly underwater mountain range in the Atlantic Ocean that runs from 87°N -about 333km south of the North Pole- to subantarctic Bourvet island at 54°S.