The Pacific Plate is the largest crustal plate on our planet. The plate is presently shrinking as the Atlantic Ocean increases in size pushing the North American Plate slowly westward. This movement has created subduction zones that cause volcanoes to erupt, large subduction zone earthquakes, and tsunamis.
The Pacific Ring of Fire is a horseshoe shaped area on the Pacific Plate that contains subduction zones and deep trenches. The andesite line is an imaginary line that follows the subduction zones and trenches that separates composite volcanoes and shield volcanoes.
On the continental side of the subduction zones a towering composite volcano erupts rhyolite, dacite and andesite lavas. These volcanoes can be extremely explosive and deadly. The volcanoes are fueled by the subducting plates.
The great eruption of Mount Pinatubo in 1992 is an example of a composite volcano. The seaward side of the andesite line forms shield volcanoes of basalt form. These volcanoes are fueled by hot spots and spreading ridges where molten rock from the upper mantle flows out on the ocean floors creating basalt rocks.
The Pacific Plate is surrounded by large and small crustal plates. These tectonic plate boundaries are the reason that of the 1,500 volcanoes that have been active in historic time and 90 percent of them occur in the Pacific Ocean.
Ninety percent of the world's earthquakes and 81 percent of the world's largest earthquakes occur in the region. Tsunamis are generated by large earthquakes and that is the reason ninety percent of the world's tsunamis also occur in the Pacific Ocean.
The Pacific Plate covers about 103,300,000 square kilometers of our planet. The Pacific Ocean, which is larger, covers about one-third of the Earth. The deepest point in the oceans is located where the Mariana Plate overrides the plate creating the Mariana Trench.
The Challenger Deep is at one end of the trench and is the deepest point on Earth. In June 2009 a ship found the depth to be 10,971 meters (35,994 feet) or about 6.8 miles. Jacques Picard and Navy Lieutenant Donald Walsh took the bathyscaphe Trieste to the bottom of the Challenger Deep in 1960. They stayed on a few minutes because of a crack in the glass of the bathyscaphe.
James Cameron spent 7 years preparing for his solo descent to the depths of the Challenger Deep. He took pictures documenting his dive on March 27, 2012. He plans to return in the future. Here is a link where you can view pictures of his dive. James Cameron Challenger Deep Dive.
Ocean Trenches Find out how plates diving beneath other crustal plates create trenches on the ocean floor that are deepest points on Earth.
S Waves Find out about S waves and how they are produced and travel through the Earth.
Plate Movements Moving plates on our planet converge, separate and slide past each other.
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.
Pacific Plate The Pacific Ocean Plate is the largest plate on Earth. Great earthquakes and towering volcanoes surround the plate along the Pacific Ring of Fire.
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.