Types of plate boundaries
Answers
Answer:
There are three types of tectonic plate boundaries:
Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes;
At a convergent plate boundary, one plate dives (“subducts”) beneath the other, resulting in a variety of earthquakes and a line of volcanoes on the overriding plate;
Explanation:
Answer:
The landscapes of our national parks, as well as geologic hazards such as earthquakes and volcanic eruptions, are due to the movement of the large plates of Earth’s outer shell.
There are three types of tectonic plate boundaries:
Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes;
At a convergent plate boundary, one plate dives (“subducts”) beneath the other, resulting in a variety of earthquakes and a line of volcanoes on the overriding plate;
Transform plate boundaries are where plates slide laterally past one another, producing shallow earthquakes but little or no volcanic activity.
Another large-scale feature is a hotspot, where a plate rides over a rising plume of hot mantle, creating a line of volcanoes on top of the plate. National Park Service lands contain not only active examples of all types of plate boundaries and hotspots, but also rock layers and landscapes that reveal plate-tectonic activity that occurred in the distant past.
Plate Boundaries and Hotspot Demonstration
Oreo® cookies are a fun way to demonstrate the three types of plate boundaries and a hotspot. (Modified from “Oregon's Island in the Sky: Geology Road Guide to Marys Peak, by Robert J. Lillie, Wells Creek Publishers, 75 pp., 2017, www.amazon.com/dp/1540611965).
Divergent Plate Boundary
Volcanic eruptions and shallow earthquakes are common where plates rip apart.
divergent plate block diagram and cookie demonstration
Convergent Plate Boundary
Where plates crash together, one dives (“subducts”) beneath the other, causing volcanoes (red triangles) to erupt on the overriding plate and earthquakes (black stars) at a variety of depths. The large white star represents the zone where plates lock together for centuries then suddenly let go, causing the largest earthquakes.
convergent boundary diagram and cookie demonstration
Transform Plate Boundary
Shallow earthquakes and little volcanism occur where one plate slides laterally past another.
transform boundary diagram and cookie demonstration
Hotspot
In places like Hawaii and Yellowstone, a plate rides over a rising plume of hot mantle, causing earthquakes and a chain of volcanoes.
Explanation: