We all know that Earth did not always look like what it did today, but if this is new information to you then let me explain: Earth has been around for about 4.54 billion years and in the beginning the continents of Earth weren’t always where there are now (click here to see the evolution of Earth). Earth’s land masses has always been in constant motion, the plates under Earth’s crust and convection currents are the reasons for this.
As you can see, North America was not always separated or more scattered apart, we also did not always have all of our green land like we do today. In the very beginning of Earth’s time, our land was all close together and our planet experienced ice ages and extreme heat conditions (we still see that today, just not as severe or constant throughout the year).
To understand why Earth has been changing you must know the definition of convection current and how it works.
Convection occurs when colder, denser fluid falls and pushes up warmer, less dense fluid. You can visually see how this works in this video (and/or try the experiment out!):
Water that is warmer will have particles that move quickly and spread further apart, the water in the bottom bottle is more dense than the water at the top. Resulting in, the denser water (cold water) below the less dense, warmer water staying at the top and the two colours of water do not mix. Once the cold water is placed at the top we can see that the colours mix, since the cold water is more dense compared to the warmer water gravity pulls the denser water downward, while the less dense, hot water travels upward.
The second factor to understanding Earth’s constant changes, you must have an idea on plate tectonics.
If you watch this video, it will explain plate tectonics and how it relates with convection currents under Earth’s crust.
Once you have understood these two factors, I am sure that you must believe that the Earth has been and will always be constantly moving under us. It is interesting to see that many million years from now, Earth will look different again, to myself that is quite unbelievable that the lands will always be changing. This makes me think that a lot of things will change in the future, like travelling. Imagine if our lands we’re coming closer together and some continents started pushing up against each other… Imagine our world map, how different that would look, I think that this is fascinating and every day geologist are putting their research into amazing possibilities, sorting out satellite images for us and predicting what the future has in store, which is helping us learn about the amazing Earth that we are living on. If you are interested in this topic you can find more information about Ronald Blakey’s research, along with other geologists at this link.