keskiselänteinä

Keskiselänteinä refers to mid-ocean ridges, which are underwater mountain ranges formed by plate tectonics. They are the longest mountain ranges on Earth, stretching over 65,000 kilometers (40,000 miles) across the ocean floors. These ridges are a key feature of the Earth's seafloor and are sites of active volcanic and seismic activity.

The formation of keskiselänteinä occurs at divergent plate boundaries, where the Earth's oceanic crust is pulled apart. As the plates separate, magma from the Earth's mantle rises to fill the gap. This magma cools and solidifies, creating new oceanic crust. This continuous process of seafloor spreading is responsible for the growth and widening of the ocean basins.

Keskiselänteinä are characterized by a rift valley running along their crest, which is where the most intense volcanic activity takes place. Hydrothermal vents, also known as black smokers, are common in these rift valleys, releasing superheated, mineral-rich water into the ocean. These vents support unique ecosystems of chemosynthetic organisms.

The most prominent example of a keskiselänne is the Mid-Atlantic Ridge, which runs down the center of the Atlantic Ocean. Other significant mid-ocean ridges include the East Pacific Rise and the Indian Ocean Ridge. The study of keskiselänteinä has been crucial for understanding plate tectonics, seafloor spreading, and the Earth's geological history.