Plate tectonics is a theory regarding the creation of landforms and other natural movements on Earth. This theory, which was formed in the 1960s, suggests that the major landforms are created as a result of the earth’s subterranean movements. It also explains multiple movements like volcanoes and earthquakes. However, what is the best piece of evidence for plate tectonics? Is it the fact that we see plates moving on the surface of Earth? Or is it something else entirely? Keep reading to find out 6 evidences of plate tectonics and 2 fossil evidence that support plate movement.
1. What does Plate Tectonic Theory explain?
The plate tectonic theory is a scientific explanation for how major landforms are created due to Earth’s subterranean movements. This theory states that the Earth’s outermost layer comprises large, flat plates that move around on the planet’s surface. When these plates interact with each other, they can create mountains, earthquakes, and volcanoes. One of the most important pieces of evidence for plate tectonics is the presence of continents. For example, when you look at a map of North and South America, you can see that they fit almost perfectly (like a jigsaw puzzle). This is because they were once part of a single landmass called Pangaea. (See How many countries start with letter A?)
2. What are the 3 Theories of plate tectonic boundaries?
- Divergent: When both plates are pulled apart from each other.
- Convergent: Both the plates move towards each other
- Transform: They slip past each other.
3. Who gave the Plate Tectonic Theory?
Alfred Wegener is generally credited with first proposing the plate tectonic theory, in his 1912 book, The Origin of Continents and Oceans wherein he named it Continental Drift. However, his theory was not the first that proposed regarding the earth’s movements but what made Wegener’s proposal unique was its hypothesized mechanism for how continents could move – namely, that they were carried on giant slabs of rock (later called plates).
Wegener first developed his idea while working as a meteorologist in Greenland wherein he observed that the coastlines of Africa and South America seemed to fit together perfectly as if they had once been joined. He also noticed that the fossils of tropical plants and animals could be found in Arctic regions, suggesting that these areas had once been much warmer than they are today. To explain his observations, Wegener proposed that the continents had once been joined together in a supercontinent he called Pangaea. In the upcoming segments, we will discuss the best piece of evidence for plate tectonics, hence read on! (See What are some map distortion examples?)
4. How is the Plate Tectonic Theory formed?Image by arrpaleo from Pixabay
Plate tectonic theory is the scientific study of the movement and displacement of the Earth’s crust. The theory postulates that the Earth’s lithosphere is divided into several large, distinct plates that move independently on the planet’s surface. Earthquakes, volcanic eruptions, and mountain building are all said to be associated with plate tectonics.
German meteorologist Alfred Wegener first proposed the plate tectonic theory in the early 20th century. His work was initially met with skepticism from the scientific community but eventually came to be accepted as a valid explanation for many of the geological features observed on Earth. Today, plate tectonics is one of the most widely accepted theories in the Earth sciences. Must see Geographic Pattern Definition.
5. What is Importance of Plate Tectonic Theory?
Before going forward with learning the best piece of evidence for plate tectonics, let us first understand its importance. Plate tectonics is one of the most important geological theories, as it helps us to understand the movements of the Earth’s crust. Plate tectonics has also helped us to understand the volcanic activity, earthquakes, and the formation of mountains. Here are some reasons why plate tectonics is so important:
- It helps us to understand the Earth’s surface and its core
- Explains the physical and geological features of the Earth’s surface.
- Gives us a better understanding of how volcanoes form and erupt.
- This theory can also help us predict earthquakes.
6. What are the 4 Types of Plate Tectonics?
- Divergent Boundary: A divergent boundary is a type of plate boundary where two plates move apart from each other. This can create new land masses between the plates as they pull apart which is known as a rift zone. The Horn of Africa is an example of a divergent boundary.
- Convergent Boundaries: Convergent boundaries are places on Earth where two plates collide. The force of the collision creates mountains or trenches. The mountains are made of the solid rock that makes up the plates, and the trenches are made of the material that is forced down between the plates. Eg: Cape Fold Mountains.
- Transform Fault Boundaries: This takes place when 2 plates slip past each other which results in the formation of a fault or a boundary. The sudden release of this stress causes an earthquake. A large earthquake can happen if the plates get stuck and continue to build up stress. When the accumulated stress overcomes friction, the plates slip violently past each other, often producing a large earthquake.
- Plate Boundary Zones: Plate Boundary Zones are areas where the boundaries are not well defined because the plate movement that takes place here, extends over a broad belt. Eg: The Mediterranean-Alpine region.
7. What are 2 Fossil Evidence that support Plate Movement?Photo by Lisa Yount on Unsplash
Two main types of fossil evidence support the theory of plate tectonics and serve as the best evidence for plate tectonics: the presence of identical or closely related species on different continents and the existence of ancient mountains that are now submerged.
The discovery of similar fossils on the coasts of various continents supports the belief that these land masses were once connected. For example, fossils of Mesosaurus, a freshwater animal, have been recovered in both Brazil and western Africa. This indicates that these two landmasses used to be part of the same supercontinent before they separated and drifted to their current locations.
Similarly, the existence of ancient mountains that are now submerged can be explained by plate tectonics. For example, the Appalachian Mountains in North America were once as tall as the Rocky Mountains, but today they are much lower due to millions of years of erosion. However, if you look at a map of the Atlantic Ocean floor, you can see an underwater mountain range that closely resembles the Appalachian. (See Date of oldest fossils)
8. What are the 6 Evidences of Plate Tectonics?
Before we choose the best piece of evidence for plate tectonics, let us look at its 6 evidences:
- Seismic activity: This is caused by the movement of the lithospheric plates as they interact at plate boundaries. Earthquakes happen when plates either collide or slide past each other, causing stress on the rocks and resulting in an earthquake.
- Volcanoes: These are also caused by the movement of lithospheric plates. When plates move apart, the mantle’s molten rock (magma) can rise to the surface and erupt, forming volcanoes.
- Plate boundaries: The edges of lithospheric plates are marked by distinct geological features. For example, the Mid-Atlantic Ridge is a long, raised area where the North American and Eurasian plates are moving apart.
- Fossils: Fossils can be used to study the movement of plates over time. For example, identical fossils have been found on different continents, which shows that these continents were once joined together before plate tectonics caused them to move apart.
- Rock types and ages: The types of rocks found in an area can tell us a lot about the history of that area. For example, older rocks are typically found nearer the center of a continent, while younger rocks are found near the edges. This is because the edges of continents are constantly being eroded and renewed by the movement of plates.
- Earth’s magnetic field: The Earth’s magnetic field is caused by the movement of molten iron in the outer core. This movement is thought to be influenced by the motion of the lithospheric plates. As plates move, they change the orientation of the Earth’s magnetic field, which can be seen in the fossil record.
9. What is the Best Piece of Evidence for Plate Tectonics?
There is no single best piece of evidence for plate tectonics. However, one strong line of evidence supporting the theory is that many geological features on Earth appear to be best explained by the movement of the continents over a relatively thin, weak layer of mantle material which is also known as the lithosphere. This evidence includes the presence of mountain ranges and ocean trenches around the edges of the continents, as well as the orientation and direction of continental drift.
Additionally while establishing the best piece of evidence for plate tectonics, several laboratory experiments have demonstrated the physical properties of this weak layer (the lithosphere) and how it behaves under stress. Taken together, these lines of evidence provide strong support for plate tectonics theory. (See What is the Difference between Oceanic Crust and Continental Crust?)
10. Are Earthquakes Evident of Plate Tectonics?Photo by Jens Aber on Unsplash
There is ample evidence to support the theory and the best piece of evidence for plate tectonics is that earthquakes are caused by plate tectonics. Plate tectonics is the scientific study of the movement and behavior of Earth’s crustal plates. The theory holds that the Earth’s outermost layer is divided into several large, rigid plates that move around on the planet’s surface. Earthquakes occur when these plates collide or grind against each other. The force of the collision creates an earthquake. Earthquakes can also be triggered by other geological events, such as volcanoes or landslides. However, most earthquakes are caused by plate tectonics.
So what is the best piece of evidence for plate tectonics? The answer to that question may not be as straightforward as you think. There are many lines of evidence that support plate tectonics, and no one piece of evidence can be considered definitive. However, when taken together with 2 theories of fossils and seismic activity which support plate movement, it is convincing and supports the theory of plate tectonics. (See How are earthquakes distributed on the map?)