![]() (Image credit: Kate Ramsayer/AGU.)Īs the name suggests, divergent boundaries are tectonic boundaries where plates "diverge" or are tugged apart. Volcanic activity and earthquakes are common in the area. Visitors can walk down the rift between the North American plate and the Eurasian plate. Thingvellir Valley in Iceland is only place where the Mid-Atlantic Ridge is above sea level. Plate tectonics are responsible for the Mid-Atlantic Ridge. Erosion also hinders growth by wearing mountains down, but because mountains can grow at a relatively fast rate, erosion typically doesn’t win out, according to the University of Hawai’i at Manoa. However, when a mountain’s mass becomes too large to resist gravity, it will cease to grow. Geologists have discovered the Swiss Alps are being lifted faster than they are being lowered through erosion-and are thus growing every year, according to a 2020 study in the journal Earth-Science Reviews. As the mash-up continues, those mountains grow higher and higher. For example, India and Asia came together about 55 million years ago to create the Himalaya Mountains. Where those plates meet, Earth's crust crumbles and buckles into mountain ranges. There are three ways in which plate boundaries meet, and each one triggers a unique geological feature.Ĭonvergent boundaries occur where plates collide into one another. Related: The Alps are still growing faster than they're eroding They're thought to wrap around the Earth like seams on a baseball. Geologists refer to the places where segments meet and divide as plate boundaries. Meanwhile, geologists imagine the plates above this roiling mantle as bumper cars they repeatedly collide, stick together, then rip apart. "It's kind of like a pot boiling on a stove," Van der Elst said. Hot material near the Earth's core rises, and colder mantle rock sinks. The driving force behind plate tectonics is convection in the mantle. "Plate tectonics unified all these descriptions and said that you should be able to describe all geologic features as though driven by the relative motion of these tectonic plates." How plate tectonics works Plate boundary zones occur where the effects of the interactions are unclear, and the boundaries, usually occurring along a broad belt, are not well defined and may show various types of movements in different episodes."Before plate tectonics, people had to come up with explanations of the geologic features in their region that were unique to that particular region," said Van der Elst. ![]() Thus, crust is cracked and broken at transform margins, but is not created or destroyed. In contrast to convergent and divergent boundaries, no magma is formed. As the plates alternately jam and jump against each other, earthquakes rattle through a wide boundary zone. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. Two plates sliding past each other, Natural or human-made structures that cross a transform boundary are offset-split into pieces and carried in opposite directions. Transform boundaries (Conservative) Transform plate boundaries Thus at convergent boundaries, continental crust, made of granite, is created, and oceanic crust is destroyed. Magma formed from melting plates solidifies into granite, a light colored, low-density rock that makes up the continents. Magma rises into and through the other plate, solidifying into new crust. If one of the colliding plates is topped with oceanic crust, it is forced down into the mantle where it begins to melt. Plate Boundary Types Divergent boundary (Constructive)
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