Answer:
JUST COPY AND PASTE THE ARTICLE FOR 100
Step-by-step explanation:
A Planet in Constant Motion
Have you ever studied a map of what Earth looked like millions of years ago? The continents were positioned very differently than they are today. How is that possible?
Earth's outer layer, called the lithosphere, is broken into 15 large slabs called tectonic plates. These plates are slowly yet constantly moving. Some of the plates are under ocean water, and those are called oceanic crust. Plates under continents are called continental crust. Continental crust is thicker and usually older than oceanic crust.
The space between the tectonic plates, called the boundaries, is where the geological action happens. These boundaries are where we will discover earthquakes striking, volcanoes erupting, and mountain ranges expanding.
Colliding Plates: A Convergent Boundary
A convergent boundary occurs where two plates push against each other. When an oceanic plate collides with a continental plate, the oceanic plate gets pulled under the continental crust, creating a deep trench where high heat and pressure form magma. This is called a subduction zone. The magma eventually rises up through a vent, creating a volcano that erupts. When oceanic plates collide, they can form chains of islands such as the Hawaiian Islands. Colliding plates can also create earthquakes and tsunamis. A tsunami is a huge ocean wave caused by a sudden shift of oceanic plates.
When two continental plates collide, the rock crunches and folds at the boundary, lifting it higher, resulting in the development of mountains ranges. For example, the Himalayan Mountain range in Asia was formed when the Indian and the Eurasian plates collided, about 40–50 million years ago. The Himalayas continue to grow about one centimeter per year.
Spreading Plates: A Divergent Boundary
A divergent boundary marks two plates that are moving apart from each other. But what happens in the space in between?
When two oceanic plates diverge, a rift valley can form. In these new valleys, magma rises up to create ocean ridges. It also spreads outward to create new oceanic crust. On land, when two continental plates diverge, a similar valley rift can develop. Streams and rivers flow through the valley, or lakes or inlets are developed. Over long periods of time, even millions of years, the rift between the two plates can become so thin that continents drift apart.
The mid-ocean ridge system is an example of a divergent boundary. At 40,390 miles long and 932 miles wide, this is Earth’s longest mountain range, but it is 90 percent underwater in the deep ocean.