Category: 

What Is Tectonics?

Volcanic islands have been formed due to plate tectonic movement.
Tectonic shifting is the main cause of earthquakes.
Continental drift, a forerunner of plate tectonics, explained how the current continents once likely fit together.
The surface of the Earth is constantly shifting.
The Earth's tectonic plates may rise together, drop downward as they pull apart, shear, or overlap at their point of contact.
Article Details
  • Written By: Jacob Queen
  • Edited By: A. Joseph
  • Last Modified Date: 08 December 2014
  • Copyright Protected:
    2003-2014
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog
A red blood cell can pass through a person's entire body in 20 seconds.  more...

December 19 ,  1998 :  President Bill Clinton was formally impeached by the House of Representatives.  more...

Tectonics, also known as plate tectonics, is the theoretical understanding of how the surface of the earth is constantly shifting. According to the best understanding of science, giant tectonic plates are always moving very slowly as the Earth generates new crust and reclaims old crust. The effect has often been compared to a giant conveyor belt. There are certain points under the ocean where crust is generated, and these look like mountains, while other areas which look like trenches are the spots where the older crust segments are reclaimed. The understanding of plate tectonics is generally used to explain many geological occurrences on Earth, including earthquakes and volcanoes.

There are three main kinds of boundaries between different plates around the Earth. Some are moving toward each other, some are moving apart, and some are moving sideways next to each other. At the edges of these boundaries, things such as volcanoes and earthquakes are more common because the Earth is moving, leaving openings for magma to rise up and because the movement between the plates generates friction. A lot of the boundary areas are near the shoreline of the ocean, which is one reason why those areas are often more prone to geological activity. Studies have shown that the continents move at a speed roughly equivalent to 4 inches (about 10 cm) per year.

Ad

The whole idea of plate tectonics is a more advanced version of an idea developed in the early 1900s called continental drift. During that time, a scientist named Alfred Wegener decided to investigate some obvious facts that he found curious about the way the Earth was put together. There were certain similarities between the edges of continents where it looked as though they had broken apart at some point. Wegener started looking into the fossil records in these areas and discovered that there were surprising similarities, and he thought they warranted further investigation. For example, he found fossils of ancient plants and animals that were identical in areas that were separated by ocean.

Wegener started to believe that continents were moving around very slowly on the Earth's surface, and he even theorized that nearly all the land on Earth was once part of a giant single continent. Wegener's problem was that he could not explain how it was happening, and other scientists were very skeptical. In 1929, a scientist named Arthur Holmes came up with the basic idea for the currently accepted mechanism, but most scientists didn't really adopt the theory until the 1960s. Since that time, much evidence has been gathered to support the theory, and it is widely considered to be a fact.

Ad

More from Wisegeek

You might also Like

Discuss this Article

Wisedly33
Post 3

I was in west Tennessee when an earthquake hit. It was about 4.5 or so, I think, and the epicenter was New Madrid. I was walking to class from my dorm, and suddenly, it sounded like a big engine rumbled to life under the ground. I stood still, shocked, and the rumbling went on for maybe 10 seconds, and then it just stopped, like cutting off an engine. We saw it actually had been an earthquake on the noon news.

I've felt a couple of minor tremors that rattled the windows, but nothing like that one in Tennessee. We were all a little scared that it was just a precursor, but thank the Lord, nothing else happened.

Scrbblchick
Post 2

When I took earth science in college, the chapter on plate tectonics was my favorite. I thought it was fascinating about how earthquakes happen, and we saw some great films about it, produced, I think, by National Geographic.

There have been some small tremors in my area, but we're about 300 miles from the nearest fault line in New Madrid, Missouri, so we're not apt to feel too many big quakes. I have heard scientists theorize that "the big one" will hit that area in the next few decades, and it will rival the one in 1812 in that area.

Post your comments

Post Anonymously

Login

username
password
forgot password?

Register

username
password
confirm
email