Divergent Plate Boundaries Flashcards

Divergent plate boundaries occur when two tectonic plates separate, leading to the formation of new land, primarily in oceanic regions.
The Mid Atlantic Ridge is a prominent example of a divergent plate boundary located in the ocean.
The Great Rift Valley in Africa represents a land-based divergent boundary that is anticipated to eventually fill with water and create a new sea.

Mid ocean ridges are where tectonic plates pull apart, resulting in the formation of a rift valley between the separating plates.

One form of evidence for tectonic plates moving apart is the symmetrical age of the sea floor on either side of mid-ocean ridges.
Another form of evidence involves magnetic pole reversal, indicating changes in Earth's magnetic field over time.

Continental crust is significantly older than oceanic crust, illustrating the different geological histories of these landforms.

A rift valley is specifically the area within a mid-ocean ridge where tectonic plates are actively separating and new crust is forming.

The youngest rocks are located in the rift valley of mid-ocean ridges, while the oldest rocks are found furthest from the ridges, on the Atlantic coasts of North America and Africa.

The age similarity of rocks on the Atlantic coast of North America and the west coast of Africa supports Wegener's theory of continental drift, indicating that these landmasses were once joined.

Hot spots are locations of superheated magma plumes rising from the mantle and are not associated with plate boundaries; they are stationary while tectonic plates move over them.
Hot spots provide indicators of the speed and direction at which tectonic plates are shifting.

Notable hot spots include the Galapagos Islands, Hawaiian Islands, Yellowstone National Park, and Iceland.

Iceland is currently being shaped by two main forces: the Mid Ocean Ridge and the presence of hot spots.

A plume refers to an upwelling column of magma from the Earth's mantle.
Convection currents are cycles of heating, rising, cooling, and sinking that drive plate movement.
Convection describes the process where heated fluid rises while cooler fluid sinks, facilitating energy transfer within molten rock.
Density is defined as mass per unit volume, which influences the behavior of materials within the Earth's layers.
Tectonic plates are sections of the Earth's lithosphere that shift due to underlying convection currents.

Magnetic reversal occurs when the outer core's flow changes, which alters Earth's magnetic field direction, providing evidence of tectonic plate movement through the differing orientations of magnetized rocks found symmetrically along ocean floors.