Author: Jonny Lupsha, News Writer
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A web tool can show where your house was before 750 million years of continental drift, Science Alert reported. The interactive tool, called Ancient Earth Globe, makes use of a slider bar to show how Earth’s major plates shifted together and apart since prehistoric times. Drift divides continents.
Science Alert recently featured an interactive web tool that helps explain the geological theory of continental drift. “[Earth’s] land masses, once locked together in supercontinents, have cracked and broken and slid away from each other, and repeatedly come together again over the course of our planet’s 4.5-billion-year history,” the article said.
“In a sense, the location of your hometown has therefore done more globetrotting than you have. Thanks to a cool interactive website that’s been doing the rounds recently, you can even explore how much that location has shifted over the course of hundreds of millions of years.”
The interactive web tool, called Ancient Earth Globe, shows the drift of plate tectonics on a sliding scale, with any one location marked—similar to Google Earth or Maps—for perspective. Science Alert said it uses a combination of paleogeographic maps and data from an open-source repository of geoscience data in order to pinpoint where your location would have been on Earth over the last three-quarters of a billion years.
Continental drift makes mountains and separates continents.
According to Britannica, the lithosphere is the “rigid, rocky outer layer of the Earth, consisting of the crust and the solid outermost layer of the upper mantle.” The Earth’s lithosphere is broken into seven large plates and eight smaller plates. The movement of one plate underneath another involves the theory of plate tectonics, which ultimately causes the movement of continents.
For a land mass like a supercontinent to break apart, forces of tension rise up from underneath it, from hot spots called convection cells in the Earth’s mantle. The effect is similar to a pan of brownies rising in the middle and cracking. How does this process of intense pressure begin?
“Tensional forces are going to be generated within the crust, within the entire lithosphere, and the [tectonic plate] is going to break,” said Dr. John J. Renton, Professor of Geology at West Virginia University. “What you’re going to see from the very beginning are cracks starting to form from the bottom of the lithosphere, working their way toward the surface. Once they get to the surface, they’re going to line up; and so on the surface, what you’re going to see is a series of cracks opening up under tension.”
Dr. Renton said that as the cracks in the lithosphere open up, the tensional forces that pull the crust apart is called rifting. The location of the rifting is called a rift zone. Magma begins to flow deep underneath the rift zone, rising to the surface and becoming lava. The tensions under the surface can produce a phenomenon called a fire fountain, which involves a volcanic eruption of magma and leftover gases spitting molten rock up to 2,000 feet into the air.
“As the volcanic activity erupts into the air, the magma breaks into little pieces that solidify on the way down. Those little pieces then become what we call cinders,” Dr. Renton said. “The cinders accumulate around the point where all this activity is coming out, into what we call a cinder cone. So the point is that this zone, now, this rift zone, is volcanically active.”
A volcanically active rift zone is the perfect setting for continental plates to break apart.
Dr. John J. Renton contributed to this article. Dr. Renton is Professor of Geology at West Virginia University where he has been teaching for more than 40 years. He earned his bachelor’s degree in Chemistry from Waynesburg College and went on to earn his master’s degree and PhD in Geology from West Virginia University.