The earth is constantly changing and causing natural events such as volcanoes and earthquakes. Earthquakes are shaking the ground that causes tsunamis and causes volcanoes to erupt. Volcanoes are erupting and making massive explosives. This is all due to plate tectonics. Plate tectonics is the theory that Earth’s outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The evidence for plate tectonics is the age of rocks at mid ocean ridge, and subduction and trenches, , and shape of plates. Mid ocean ridge is a mountain system that was formed by plate tectonics. A mid ocean ridge demarcates the boundary between the two tectonic plates and consequently is termed a divergent plate boundary. The buoyant melt rises as magma at the linear weakness in the oceanic crust and emerges as lava creating a new crust upon cooling. tectonics plates converge and the older denser plate is pushed beneath the lighter plate and deep into the mantle causing the seafloor and outermost crust to bend and form a steep v shaped depression. Because of these processes, the ocean floor is renewed about every 200 million years. Mid ocean ridge is responsible for seafloor spreading which led for the plates moving. Shape of plate is when the plates was were together like a jigsaw puzzle, and then there was an earthquake that moved the plates. It wasn’t just a couple of days, it took 175 million years for the plates to move apart. Alfred Wegener is a originator of the scientific theory of continental drift and hypothesizing in 1912 that the continents are moving slowly drifting around the earth. The lithosphere has a greater mechanical strength than the asthenosphere so that the plates will move. Over the last 175 million years the plates that was moved is the same plates that we have it today. Subduction zones are circles that circle the pacific ocean that made up the ring of fire. Subduction zones is the biggest crash scene on earth. The boundaries mark the collision between two of the planets tectonic plates. The plates are pieces of crust that slowly move across the planet’s surface over millions of years. Trenches are formed by sunductions in which the plates are pushed beneath the lighter plate and deep into the mantle causing seafloor and the outermost crust to bend and form a steep v shaped depression. The three piece of evidence for plate tectonics are mid ocean ridge, subduction and trenches, and shape of plates. Plate tectonics is the theory earth outer shell is divided into several plates that glided over the mantle. Plates are pushed separately they create volcanoes in which plate tectonics spread apart from each other, hot magma rises up and fills the space between.