Plate tectonics is the scientific theory that describes the movements and changes in the Earth’s outer shell, or mantle. These movements are described as plates that float on a liquid layer below the Earth’s crust.
These plates are made of solid rock, and they weigh tons! Over time, these plates move around the planet due to forces such as earthquakes, volcanoes, and melting ice.
The trouble is that scientists cannot see these plates moving. They can only observe how landmasses shift and where new volcanoes form to determine plate movement. How do they then measure how much work must be done to pull the plates apart to where the distance between them is 2.0 mm?
This article will explain how scientists determined this number by observing changes in oceanic crusts over time via marine fossils found on them.
Calculate the distance between the plates
Once the stress is calculated, you can determine the deformation of the plate by calculating how much the plate is pulled apart.
The greater the compressive stress, or force pushing down on the plates, the more deformation will occur. As mentioned before, this is because there is less room for the atoms to rearrange themselves to accommodate the stress.
You can use a formula that takes into account the thickness of the plates, as well as the compressive stress within them. By doing this, you can determine how far apart the plates will be pulled by tectonic activity.
Determine how much work must be done to pull the plates apart
To determine how much work must be done to pull the plates apart, you need to know two things:
The distance the plates must be pulled apart The force that must be applied to pull the plates apart
You can think of work as how much energy is needed to perform a task. For example, walking takes little energy, while running takes more energy.
In this case, we need to figure out how much energy it would take to pull the Earth’s crust apart at the MID-OCEAN RIDGES where it is thinnest. This is a pretty difficult task, so we’re going to be extra careful here.
The first thing we need to do is figure out the distance the plates must be pulled apart.
Calculate how much energy is in the space between the plates
The next step is to calculate how much energy is in the space between the plates. This energy is called vacuum energy, and it’s a part of quantum physics that scientists are still trying to understand.
According to Encyclopaedia Britannica, vacuum energy is the intrinsic energy of a vacuum — that is, the energy of the virtual particles that constantly arise and vanish in every point of space.
Vacuum energy is theorized to be caused by virtual particles such as photons, gluons, and gravitons moving back and forth between existence and non-existence. The constant creation and destruction of these particles causes a sort of friction, which releases energy.
Scientists have calculated how much vacuum energy exists in a cubic meter of empty space, and it’s approximately 10−14 joule (10−7 erg).
Compare this to an atomic separation
Although this is much smaller than the diameter of an atom, it is still quite impressive. The diameter of a hydrogen atom is around 1.6 nanometers, or 160 billionths of a meter!
Atoms are also not very thick – only a few billionths of a meter thick. So you can see that 2 millimeters is quite impressive when it comes to pulling continents apart.
The process took around 100 million years, which is quite a long time compared to the time it takes tectonic plates to move – around six months on average. This means that the plates moved quite slowly in relation to each other, which helped facilitate the separation process.
There you have it: Two million years ago, Africa parted ways with South America, thanks in part to some help from internal pressure within the Earth.
Conclude whether or not this is possible
While it is possible to separate the plates by 2 mm, the amount of work that would have to be done is far greater than the available energy in the system.
The best analogy for this situation is trying to lift yourself off the ground using only the force of gravity. Because gravity is a downward force, you would have to work hard to pull yourself up, but you could not do it.
You would have to find some other source of energy to pull yourself up, and then you could lift yourself off the ground. The same goes for separating the tectonic plates by 2 mm – there is not enough energy in the system to do so.
There are other things that influence plate movements, like rock deformation and stress buildup, but they are not taken into account when calculating whether or not we can move the plates 2 mm apart.
Provide a reference
Prior work referenced in the paper includes a paper by Ngeze and a book by Davies. The paper by Ngeze was used as a reference for some of the observations made in this paper, and the book by Davies was used to describe some of the processes involved in plate tectonics.
The connection between these sources is that they both describe parts of the theory behind what happens when plates pull apart. This makes it easier to build upon their work to develop more complete theories about plate separation.
The authors also mention other sources that contributed to their understanding of what happens when plates pull apart, which shows how many people are working on this topic and contributing their own findings. This helps ensure that all of the necessary information is gathered so that new researchers can understand what needs to be done to pull the plates apart.
