What are examples of divergent plate boundaries?

In plate tectonics a divergent boundary is the boundary between two contiguous lithospheric plates that are separating. As the plates diverge, new material rises by magmatic processes from the Earth’s mantle, creating new lithosphere, so it is also called a constructive edge.

The most active divergent edges are responsible for mid-oceanic ridges, where the mid-oceanic rift axis marks the boundary between contiguous plates, and where new oceanic crust is formed and symmetrically incorporated into each of them. The extension that occurs in the rift produces normal or extensional faults, which delimit steps and grabens or tectonic trenches parallel to the direction of the ridge.

Like convergent ridges, divergent ridges are associated with volcanic and seismic activity. Most of the terrestrial volcanism and most of the lava pouring from the asthenosphere occurs at ridges, but it is fluid-type volcanism that also remains hidden beneath the ocean. Earthquakes occur in association with recent rift-defining normal faults, and also with transform faults, of which the plate boundary zones are mostly on the ridges themselves, and are the site of the largest earthquakes occurring in the ocean.

At divergent or constructive boundaries, tensional stresses (the drift directions of plates that are opposite each other) pull the plates apart, giving way to upwelling of material from the mantle. The Mid-Atlantic Ridge is an example of divergent plate boundaries. An example of such a boundary can be seen on the island of Iceland.

The spreading of the ocean floor creates stresses in the ridge zone that result in collapse faults and open fractures, forming a collapse trough in the middle of the ridge, called an oceanic rift. Magma (molten rock) produced by the partial melting of the mantle enters the rift faults and fractures. Some of this magma crystallizes in the lithosphere, while some is expelled to the ocean floor as lava and forms submarine volcanoes. It is this crystallized magma that forms new oceanic crust as the ocean floor spreads.

We know that there is a flow of heat from the center to the outside of the earth, a flow caused by the radioactive decay of certain chemical elements in the mantle and which generates convection cells in the plastic mantle (asthenosphere). Because of this convection, there is a concentration of heat in a zone where the heated material expands, which explains the uplift corresponding to the oceanic ridge. The concentration of heat leads to a partial melting of the mantle which produces magma. Convection produces tension forces in the rigid part of the earth’s envelope (lithosphere) that cause two plates to diverge; it is the engine of the conveyor belt, driving the oceanic lithosphere on either side of the ridge. Between these two diverging plates, the arrival of magma creates new oceanic crust.

What are some examples of divergent boundaries?

Examples

• Mid-Atlantic Ridge.
• Red Sea Rift.
• Baikal Rift Zone.
• East African Rift.
• East Pacific Rise.
• Gakkel Ridge.
• Galapagos Rise.
• Explorer Ridge.

What 2 types of plate boundaries are divergent?

There are two types of divergent boundaries, categorized by where they occur: continental rift zones and mid-ocean ridges.

What is real life example of divergent plate boundary?

The mid-Atlantic ridge lies mostly in the middle of the Atlantic Ocean and is the classic example of a divergent plate boundary. This tells us that a couple of large mantel plumes are at work below the Earth’s surface and these are gradually pulling the crust apart.

What are 3 examples of plate boundaries?

Most seismic activity occurs at three types of plate boundaries—divergent, convergent, and transform.

Where are most divergent plate boundaries found?

mid-ocean oceanic ridges

Most divergent boundaries are located along mid-ocean oceanic ridges (although some are on land). The mid-ocean ridge system is a giant undersea mountain range, and is the largest geological feature on Earth; at 65,000 km long and about 1000 km wide, it covers 23% of Earth’s surface (Figure 4.5. 1).

What is an example of a convergent plate boundary?

Examples. The collision between the Eurasian Plate and the Indian Plate that is forming the Himalayas. Subduction of the northern part of the Pacific Plate and the NW North American Plate that is forming the Aleutian Islands. Subduction of the Nazca Plate beneath the South American Plate to form the Andes.

What is a famous divergent boundary?

Perhaps the best known of the divergent boundaries is the Mid-Atlantic Ridge. This submerged mountain range, which extends from the Arctic Ocean to beyond the southern tip of Africa, is but one segment of the global mid-ocean ridge system that encircles the Earth.

Is the Nazca Plate convergent or divergent?

convergent boundaries

Examples of ocean-continent convergent boundaries are subduction of the Nazca Plate under South America (which has created the Andes Range) and subduction of the Juan de Fuca Plate under North America (creating the mountains Garibaldi, Baker, St.

What type of plate boundary is Mt Everest?

Convergent boundaries

Convergent boundaries are responsible for producing the deepest and tallest structures on Earth. Among those that have formed due to convergent plate boundaries are K2 and Mount Everest, the tallest peaks in the world. They formed when the Indian plate got subducted underneath the Eurasian plate.

What type of boundary is Iceland on?

divergent plate boundary

Iceland lies on the Mid Atlantic Ridge, a divergent plate boundary where the North American Plate and the Eurasian Plate are moving away from each other.

What kind of boundary is the San Andreas fault?

transform fault

The 1,200-kilometer-long San Andreas fault zone is part of the boundary between the Pacific and North American plates, and thus is known as a transform fault.

What type of plate boundary is Mariana trench?

convergent boundary

In the case of a convergent boundary between two oceanic plates, one is usually subducted under the other, and in the process a trench is formed. “The Marianas Trench (paralleling the Mariana Islands), for example, marks where the fast-moving Pacific Plate converges against the slower moving Philippine Plate.

Is the San Andreas fault convergent or divergent?

The San Andreas Fault is where the Pacific plate collides with the North American plate. this is a convergent boundary. The two plates hit an angle in California. This forms a transverse fault in stead of the subduction zone usually found where an Ocean Plate and a Continatial plate meet.

What type of boundary is Mid-Atlantic Ridge?

divergent

The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world.

What type of boundary is the Aleutian Islands?

convergent plate boundary

The Aleutian Trench (or Aleutian Trough) is an oceanic trench along a convergent plate boundary which runs along the southern coastline of Alaska and the Aleutian islands.

What type of plate boundary is Mt St Helens?

convergent plate boundary

Mt. St. Helens is a volcano in Washington, near the Oregon border, in the Cascade Range. The Cascade Volcanoes, which stretch all from British Columbia through Northern California, are stratovolcanoes that have formed inland from a convergent plate boundary, where ocean crust is subducting below the continent.

What type of plate boundary formed Hawaii?

The Hawaiian Islands were formed by such a hot spot occurring in the middle of the Pacific Plate. While the hot spot itself is fixed, the plate is moving. So, as the plate moved over the hot spot, the string of islands that make up the Hawaiian Island chain were formed.

What plate boundary is Alaska?

Living with Earthquakes in Alaska

The southern edge of our state is an active tectonic plate boundary where the Pacific plate subducts (i.e., dives beneath) the North American plate along the great Alaska-Aleutian Megathrust.

What type of boundary is south of Australia?

The southerly side is a divergent boundary with the Antarctic Plate called the Southeast Indian Ridge (SEIR).

What type of plate boundary is California?

San Andreas Transform Plate Boundary

The transform plate boundary between the Pacific and North American Plates in western California formed fairly recently.

What plate boundary is Brazil?

The plate motions cause a great amount of energy to accumulate on the surface of the Earth, causing it to tremble. Brazil, however, is not located on the edge of any tectonic plate. The country actually sits right in on top of the South American plate.

What tectonic plate is Australia on?

the Indo-Australian plate

Australia doesn’t sit on the edge of a tectonic plate. However, the Indo-Australian plate, at the centre of which our continent lies, is being pushed to the north-east at about 7cm per year. It’s colliding with the Eurasian, Philippine and Pacific plates, causing stress to build up in the 25km-thick upper crust.

What type of boundary is North American Plate?

transform boundary

The movement of the hot mantle below the lithosphere drives the plate motion. The North American Plate has a transform boundary with the Pacific Plate, dividing California at the San Andreas Fault.

What type of plate boundary is Antarctic and South American Plate?

sinistral strike-slip boundaries

The two longest boundaries—those with the Antarctic and South American plates—are both sinistral strike-slip boundaries (Thomas et al., 2003). The southern border with the Antarctic plate, known as the South Scotia Ridge, moves with a rate of 7.5-9.5 mm/yr.

Is the South American Plate convergent or divergent?

The South American Plate is the smallest major plate

But the eastern edge lies in the Atlantic Ocean at a divergent plate boundary. Along the African Plate boundary, these two plate boundaries pull apart from each other. This diverging plate motion creates some of the youngest oceanic crust on the planet.

What type of plate boundaries is North American and Eurasian Plates?

The Mid Atlantic Ridge, like other ocean ridge systems, has developed as a consequence of the divergent motion between the Eurasian and North American, and African and South American Plates.