Mid-ocean ridges form when tectonic plates meet beneath the ocean and ridge-push, slab-pull or do both to create a subduction zone. Over time, one plate raises up. This, along with the simultaneous magma buildup, creates a submarine mountain range, or ocean ridge.Continue Reading
When tectonic plates meet, they are essentially unstoppable forces, which means something must give. Usually, one plate slides beneath the other, lifting the edge of the second plate, creating a subduction zone. As the subduction zone grows, magma seeps in through the cracks and edges of the plate, quickly cooling as it hits the surface. These underwater actions have raised tall mountain range systems totalling about 37,000 miles in length altogether.
Around the ridge, the cracks and gaps that allow magma to escape also allow ocean water to seep in. When it meets the deep-earth magma, it picks up heavy metals conveyed up from the earth's core, such as gold and iron. The super-heated, mineral-rich water then returns through hydrothermal vents at temperatures up to 700 degrees Fahrenheit. The sudden shock of hitting cold ocean water causes minerals to precipitate out quickly, creating rich ore deposits and supporting the habitats of deep-ocean microbes. These microbes, in turn, provide a food source for tubeworms, shrimp and mussels, creating a strange ecosystem that could not exist without the mid-ocean ridge's hydrothermal vents.Learn more about Earth Science
Encyclopædia Britannica states that many pieces of evidence support the sea floor spreading theory of plate tectonics, including increased heat flow along mid-ocean ridges, geomagnetic anomalies near ocean ridges, thickness of marine sediments and age of sediments. Sea floor spreading was first proposed by geophysicist Harry Hess in 1960 after reviewing submarine data. The theory is the basis for modern plate tectonics that states plates in the Earth's crust move.Full Answer >
Eskers are narrow ridges of fine sediment and gravel formed by subglacial rivers. Eskers remain long after glaciers retreat, sometimes running for several miles and standing over hundreds of feet tall.Full Answer >
Seafloor spreading is an oceanic process involving the formation of new oceanic crust through the solidification of basaltic magma at mid-ocean ridges. This process is a partial explanation for the process of Continental Drift.Full Answer >
The tropical zone is an area located around the Earth's axis at the equator. It is limited to the Tropic of Cancer in the northern hemisphere and the Tropic of Capricorn in the southern hemisphere.Full Answer >