As tectonic plates move away from one another at mid-ocean ridges, molten rock from the mantle may well up and harden as it contacts the frigid sea, forming new oceanic crust at the bottom of the rift valley.
What’s the difference between rifts and ridges?
The two words are nearly opposites. A rift is a break, crack, split, or fissure. If you imagine a glacier breaking into two pieces with a long narrow crevice between the two halves, you are imagining a rift. A ridge is high narrow elevation, such as an extended narrow hilltop or a mountain range.
What is the difference between ridge and rift and trenches?
So the ridge is a ridge, not a trench, but the rift valley along its length is not a trench either, but a graben: it has been formed by tectonic plates moving away from each other and parts of the separating ridge breaking off its edge and sinking into the rift.
What is an oceanic ridge and rift valley?
Mid-oceanic ridges. The mid-oceanic ridge is the place where two oceanic plates diverge, at the point where rising convection currents within the earth’s mantle spread sideways, forcing the plates apart and creating a rift, through which molten basalt comes to the surface along fissure eruptions and through volcanoes.
Which is the rift valley?
A rift valley is a lowland region that forms where Earth’s tectonic plates move apart, or rift. Rift valleys are found both on land and at the bottom of the ocean, where they are created by the process of seafloor spreading.
How is a valley similar to an ocean trench?
Answer: A rift valley is elongate depression that develops at a divergent plate boundary (ie. A trench is a long, narrow, steep-sided depression of the seafloor formed where a sub ducting oceanic plate sinks into the mantle causing the seafloor to bend downward like a flexed diving board(Earth, pg316).
Is the Mid-Atlantic Ridge A rift valley?
The Mid-Atlantic Ridge includes a deep rift valley that runs along the axis of the ridge for nearly its entire length. This rift marks the actual boundary between adjacent tectonic plates, where magma from the mantle reaches the seafloor, erupting as lava and producing new crustal material for the plates.
Is a rift valley convergent or divergent?
Areas where plates are colliding form convergent boundaries, and areas where plates are expanding create divergent boundaries. Rift valleys are formed by divergent boundaries that involve continental plates.
Why are mid-ocean ridges higher than the rest of the ocean floor?
Since hot rocks are in a more expanded state and then contract as they cool (as they spread away from the ridge), the midocean ridges stand up high above the surrounding seafloor. The seafloor depth increases with distance away from the midocean ridges.
Is mid-ocean ridge and ocean ridge the same?
The mid-ocean ridges of the world are connected and form the Ocean Ridge, a single global mid-oceanic ridge system that is part of every ocean, making it the longest mountain range in the world.
What is the difference between mid-ocean ridges and subduction zones?
(2) How is the shape of volcanoes at mid-ocean ridges different from the shape of volcanoes at subduction zones? Mid-ocean ridge volcanoes tend to be linear and look like long, low ridges, while volca- noes at subduction zones tend to be cone- shaped and isolated.
How are mid-ocean ridges and ocean trenches alike?
Mid ocean ridges occur at constructive plate boundaries where 2 oceanic plates are moving apart. Ocean trenches occur in front of subduction zones, also known as destructive boundaries. This is where one plate is sinking beneath another.
Where are the 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.
Where are rift valley located in India?
In India on the southern slopes of the Vindhyachal mountain ranges, at the Malwa plateau escarpment boundary is formed, under which the rift valley is formed and Narmada river flows in this valley in west direction.
Which is characteristic of mid-oceanic ridges?
A mid-ocean ridge (or mid-oceanic ridge) is an underwater mountain range, typically having a valley known as a rift running along its axis, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading center.
Why is rift valley important?
The system of rift valleys that characterizes the African continent represents a perfect environment to understand the evolution of mankind; for the important paleoanthropological discoveries in Ethiopia, Kenya, Tanzania, Uganda and Zaire, the African rift valleys are indeed considered the “cradle of mankind”, that is
How does the rift valley look like?
A rift valley is a linear shaped lowland between several highlands or mountain ranges created by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear depression may subsequently be further deepened by the forces of erosion.
In which two continents is the Great Rift Valley?
The Great Rift Valley is a series of contiguous geographic trenches, approximately 7,000 kilometres (4,300 mi) in total length, that runs from Lebanon in Asia to Mozambique in Southeast Africa.
