Key Facts about Nazca Ridge

About Nazca Ridge:

• It is a submarine ridge located in the southeastern Pacific Ocean off the coast of South America.
• It is approximately 1,100 kilometers (684 miles) long and varies in width.
• The ridge extends from the Nazca Plate, off the coast of Peru, and runs southwest toward Easter Island, Chile.
• It was formed by volcanic activity associated with a hotspot in the Earth's mantle.
• The ridge is composed of abnormally thick basaltic ocean crust.
• The ridge is tectonically active and is being subducted beneath the South American Plate at the Peru-Chile Trench.

What is a Seamount?

• A seamount is an underwater mountain with steep sides rising from the seafloor.
• Most seamounts are remnants of extinct volcanoes. 
• Typically, they are cone-shaped but often have other prominent features such as craters and linear ridges, and some, called guyots, have large flat summits. 
• There is a broad size distribution for seamounts, but to be classified as a seamount, the feature must have a vertical relief of at least 1,000 meters (3,300 feet) above the surrounding seafloor.
• They are found in every world ocean basin.
• These are formed near mid-ocean ridges, where the earth’s tectonic plates are moving apart, allowing molten rock to rise to the seafloor.
• Some seamounts have also been found near intraplate hotspots– regions of heavy volcanic activity within a plate – and oceanic island chains with a volcanic and seismic activity called island arcs.