Rift Zone
. an area of deep cracks that forms between two tectonic plates that are pulling away from each other.
When two tectonic plates pull apart what is the area between them called?
When two continental plates diverge,
a valleylike rift
develops. This rift is a dropped zone where the plates are pulling apart. As the crust widens and thins, valleys form in and around the area, as do volcanoes, which may become increasingly active.
What are the cracks between plates called?
Faults
are cracks in the earth’s crust along which there is movement. These can be massive (the boundaries between the tectonic plates themselves) or very small. If tension builds up along a fault and then is suddenly released, the result is an earthquake.
What is the largest lithospheric plate?
There are seven major plates: African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American. The Hawaiian Islands were created by
the Pacific Plate
, which is the world’s largest plate at 39,768,522 square miles.
What are the 3 fault types?
There are three main types of fault which can cause earthquakes:
normal, reverse (thrust) and strike-slip
. Figure 1 shows the types of faults that can cause earthquakes. Figures 2 and 3 show the location of large earthquakes over the past few decades.
What are the 4 types of plate tectonics?
- Divergent: extensional; the plates move apart. Spreading ridges, basin-range.
- Convergent: compressional; plates move toward each other. Includes: Subduction zones and mountain building.
- Transform: shearing; plates slide past each other. Strike-slip motion.
What happens when two tectonic plates move apart?
A divergent boundary
occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries.
What causes the tectonic plates to move?
The heat from radioactive processes within the planet’s interior
causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.
Which is the smallest lithospheric plate?
| Juan de Fuca Plate | Features Pacific Ocean | 1 Relative to the African Plate |
|---|
What is the difference between the crust and a plate?
The crust is the surface of the Earth. It is a rock layer forming the upper part of the lithosphere . The lithosphere is
split into tectonic plates
.
How thick are tectonic plates?
Plate thickness also varies greatly, ranging from
less than 15 km for young oceanic lithosphere
to about 200 km or more for ancient continental lithosphere (for example, the interior parts of North and South America). How do these massive slabs of solid rock float despite their tremendous weight?
What are the 4 major types of faults?
There are four types of faulting
— normal, reverse, strike-slip, and oblique
. A normal fault is one in which the rocks above the fault plane, or hanging wall, move down relative to the rocks below the fault plane, or footwall. A reverse fault is one in which the hanging wall moves up relative to the footwall.
What is type of fault?
There are three different types of faults:
Normal, Reverse, and Transcurrent (Strike-Slip)
. Normal faults form when the hanging wall drops down. … Reverse faults form when the hanging wall moves up. The forces creating reverse faults are compressional, pushing the sides together.
What is tensional stress?
Tensional stress is
the stress that tends to pull something apart
. It is the stress component perpendicular to a given surface, such as a fault plane, that results from forces applied perpendicular to the surface or from remote forces transmitted through the surrounding rock.
What are the two main types of tectonic plates?
The two types of tectonic plates are
continental and oceanic tectonic plates
. Continental tectonic plates are those that are situated below land…
What are the 3 theories of plate tectonics?
The three types of plate boundaries are
divergent, convergent, and transform
. They are described in the following three concepts. Most geological activity takes place at plate boundaries.
