The plate boundaries at which lithospheric plates interact in the specified ways are called:
- a. Convergent boundaries for plates that move toward each other.
- b. Transform boundaries for plates that move past each other.
- c. Divergent boundaries for plates that move away from each other.
Understanding Plate Boundary Movements
The Earth's lithosphere is broken into large pieces called tectonic plates, which are constantly in motion. The interactions between these plates at their boundaries create distinct geological features and phenomena. According to Study.com's lesson on plate boundaries, these interactions are categorized into three main types based on the relative movement of the plates.
Here's a breakdown of each type of plate boundary:
| Characteristic | Convergent Boundary | Transform Boundary | Divergent Boundary |
|---|---|---|---|
| Movement of Plates | Towards each other | Past each other | Away from each other |
| Results | Subduction or collision | Earthquakes (due to plates grinding past each other) | Spreading |
| Landforms Created | Volcanos, mountains, islands, oceanic trenches | Fault lines, often associated with intense seismic activity | Volcanos, mountains, new crust |
| Example | Himalaya mountains | San Andreas Fault (not explicitly in provided ref table) | Mid Atlantic Ridge |
1. Convergent Boundaries (Plates Moving Towards Each Other)
At convergent boundaries, lithospheric plates move toward each other. This movement leads to intense geological activity, as one plate is often forced beneath the other in a process called subduction, or the plates collide. As described by Study.com, the results of this movement include "subduction or collision." The significant pressure and friction at these boundaries lead to the creation of various landforms, such as "volcanos, mountains, islands, [and] oceanic trenches." A notable example of a convergent boundary, cited in the reference, is the formation of the Himalaya mountains, where the Indian and Eurasian plates are colliding.
2. Transform Boundaries (Plates Moving Past Each Other)
Transform boundaries occur where lithospheric plates move past each other horizontally. While the provided reference explicitly lists "Convergent" and "Divergent" boundaries with detailed characteristics in its table, the lesson title and URL also refer to "Transform" boundaries. At these boundaries, plates slide horizontally alongside each other, often leading to significant friction and stress buildup. This stress is periodically released as earthquakes. Unlike convergent or divergent boundaries, transform boundaries typically do not create or destroy lithosphere, nor do they commonly result in volcanic activity or mountain ranges in the same way. The San Andreas Fault in California is a well-known example, though not specifically mentioned in the provided reference's table.
3. Divergent Boundaries (Plates Moving Away From Each Other)
At divergent boundaries, lithospheric plates move away from each other. This separation allows magma from the Earth's mantle to rise to the surface, creating new crustal material. According to Study.com, the primary result of this movement is "spreading." This process is responsible for forming new oceanic crust. The landforms created at divergent boundaries include "volcanos, mountains, [and] new crust." A classic example of a divergent boundary, as highlighted in the reference, is the Mid Atlantic Ridge, where the North American and Eurasian plates are pulling apart.
