Crustal Plate Movements

Introduction
Plate movements were first studied using seismographs to study earthquake patterns. They recorded earthquakes caused by the crustal plates moving around the Earth. Scientists found the earthquakes occur along narrow bands on the Earth's surface. These narrow bands of earthquakes outline the major and minor plates here on Earth.

Earthquakes outlining crustal plates, USGS

Earthquakes outlining crustal plates, USGS

Tracking moving plates
Today scientists use GPS to track moving plates. GPS sensors are placed around the Earth and are tracked by satellites. Sensors on both sides of the San Andreas Fault give precise measurements of movement by the North American Plate and the Pacific Plate.

Stress on San Andreas Fault
Scientists are concerned about the build up in stress on the rocks in the southern section of the San Andreas Fault and are hoping to use the GPS tracking devices and seismographs to help predict major earthquakes before they occur.

Iceland on Mid-Atlantic Ridge
Iceland sits atop the Mid Atlantic Ridge offering a perfect place for scientists to study a plate movements on a divergent plate boundary. Near the Iceland volcano Krafta fissures form as the island is splitting apart because the North American Plate and the Eurasian Plate are separating.

Rift valleys on Iceland
A rift valley is located right through the center of Iceland. Rifting is when the land is pulling apart and the ground rises and cracks as molten rock moves upward toward a volcano vent.

Eruptions on the island
The ground above molten rock will drop down as a volcanic eruption begins and lava flows out the volcano's vent creating new basalt rocks on the island. Rifting between 1975 and 1984 caused the land to pull apart more than 21 feet (7 meters) in Iceland.

More Plate Tectonic Links

Nazca Plate This plate converges with the Pacific Plate producing very large earthquakes off the coast of Chile.

Thrust Faults These faults occur where large blocks of land can be forced over the top of another block of land at a low angle.

Divergent Boundary These boundaries form the global mid-ocean ridge system which is the largest mountain chain on Earth.

Crustal Plates There are large and small plates that cover the Earth. Subduction zones form where these plates are recycled.


Mid Ocean Ridge The global mid-ocean-ridge system is the longest chain of mountains on Earth and was not discovered until the 20th Century.

Plate Movements Moving plates on our planet converge, separate and slide past each other.

Plate Tectonics Find out lots of fascinating facts and interesting trivia on plate tectonics.

Kids Fun Science The links on our home page include information about volcanoes, science activities, plate tectonics, the rock cycle and much more.

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