Hi everyone, welcome to my blog, I am new here so I appreciate you taking out time to read this article, I hope you enjoy it. It’s been a rainy few days in this part of the world, this is obviously due to the fact that the rainy season is here, do I hear you say yaaaay? That’s what I said too, I mean who wouldn’t love the smell of fresh air after an early morning rain, the natural cool breeze that comes along when the clouds graciously releases some of the water stored in it over time? Sadly the answer to that question is a sizeable amount of people. On my way out this morning, I came across some set of people complaining about the rain and the rainy season in general, the destruction that comes with it, the flood, the erosion, the destruction of crops and property, I just smiled and thought to myself, do these people really understand the treasure they have here? But of course they don’t, we are humans and we tend to appreciate certain things more when we lose them, thankfully we are not about to lose the rain or our earth's water but we should learn to appreciate it more, which is why I’m writing this article and for us to go through this journey of better appreciating the rain and our water in general, I would like to talk about where it comes from.
The question above is a fairly simple one, from the clouds right? Yes that is correct and when I ask how it got there I’m sure you will describe the hydrological cycle to me, yes the hydrological cycle, every person that has gone through elementary school knows what the hydrological cycle is, we have the Evaporation stage where water leaves the surface of the earth by changing from the liquid state to the gaseous state and then we move to the Condensation stage where those water vapor cools down and condenses to form clouds as a result of lifting of moist air and next is the Precipitation stage where the clouds gets too filled up and it then releases the water stored in it, then the water gets back to the surface of the earth where it seeps back into the soil and finds its way back to surface water through groundwater movement or it goes back into the atmosphere through Transpiration or it ends up as Surface runoff and still finds its way back into surface waters and then the cycle repeats itself again.
The above answer takes care of the question of how we get rainfall, what it doesn’t answer is where we got the “first water” from and by this, what I mean is the first water that began the hydrological cycle, our earth is covered with about 70% water, this means that we have more water than we have land, but where did all of this water come from in the first place, to fully answer this particular question we would need a very complex piece of equipment, a time traveling machine, yes you read that correctly. The elusive time traveling machine, this is because we would need to go back in time, 4.6 billion years back specifically, to a time when the earth was in its formative years but in the absence of this machine, the answer becomes more tricky. There has been 3 sources in which scientists have used in trying to explain the origin of water on earth, these are
- through the bombardment of the earth by water carrying meteorites
- through the bombardment of the earth by icy comets and
- the rocks that formed the bulk of the earth.
The first two was previously accepted as the major sources for the origin of earth’s water, this is due to the fact that the earth was assumed to have formed dry, as the sun which also formed at the same time as the earth should have stripped the earth of any water molecules present during its formation, so it made sense for the earth’s water to have come at a later time after its formation through the bombardment of the earth by water carrying meteorites and icy comets, the study of deuterium, which is a heavy hydrogen isotope found in water however disproves this theories, in studying the amount of deuterium present in our seawater, comets and meteorites, it is found that the amount of deuterium in comets and meteorites are significantly heavier than that found in our sea water. This therefore, rules out these theories as the major source for the origin of earth’s water, moreover, if the majority of our water came from meteorites the earth’s atmosphere would contain around 10 times more xenon (which is an inert gas) than it actually contains, as meteorites have been found to carry an excess amount of xenon, this therefore rules out meteorites as a major source of the origin of earth’s water.
On Baffin Island in the Canadian arctic, scientists studied some volcanic basalt rocks which have been preserved deep within the earth’s mantle and are said to be as old as the planet itself and therefore was part of the rocks that formed the earth, in studying the water molecules in these rocks, it was found that they contained very little deuterium which was even less than what we have in our seawaters today which suggest that the water came from a source with very little deuterium, so how did these water survive the harsh conditions present during the formation of the earth?
The earth was formed by small rock fragments called planetesimals which collided together over a long period, and from physics, we know moving objects has kinetic energy, the kinetic energy of each earth forming plantesimals would have been converted into thermal energy during this collision so the earth would have been really hot and along with the heat coming from the sun at this time, any water molecules present in these planetesimals should have been sucked dry but by now we should know that water always find a way, it is possible that water found a way to survive these condition by being buried deep in the earth’s mantle to later resurface after the earth's formation when the condition was right for its survival.
Water vapor helps propel volcanoes, so volcanoes would have helped in bringing water back to the surface of the earth, this water along with water delivered at a later time by comets is most likely responsible for the water we have in our seas today as this combination would have about the right amount of deuterium we have in our seawater today as the heavy deuterium present in water from comets would have been balanced out by water present in the rocks that formed the earth.
Ever witnessed a sculptor working on a piece of sculpture? If you have then you can appreciate what it takes to come up with such a beautiful work of art (if it is a beautiful sculpture), earth itself is one big sculpture and the sculptor behind this magnificent work of art is none other than water itself, water has been carving out the earth since the earth’s formation and it continues to do so till this very day and just like any sculptor, water has its own technique, a kind of process it goes through before coming up with its piece and these processes are 1. weathering 2. erosion 3. deposition, permit me to explain how these work.
Weathering simply put, is the breaking down of bigger rocks into smaller sized rocks when they are exposed to water or other organic fluids, weathering can either be mechanical or chemical, mechanical weathering occurs when a piece of rock is broken down into smaller sizes when its put under stress, an example is when water occupying space or cracks in a rock freezes over, when water freezes, it tends to expand and if its fully occupying the space then it pushes the rock further out till it breaks it into smaller pieces, chemical weathering on the other hand occurs when water and soil are in constant contact, the water combines with the carbon dioxide in the soil to form carbonic acid which then dissolves the minerals in rocks, when chemical weathering takes place, the rock is changed into new minerals, but when mechanical weathering takes place the rock minerals are unchanged, either way, water plays an important role in weathering.
Erosion is the removal of soil from the land's surface by running water including runoff from melted snow and ice, there are different types of water erosion, depending on the magnitude of their soil removal they are splash erosion, sheet erosion, rill erosion, gully erosion. Erosion gradually starts as splash erosion when rainwater hits the soil and detaches soil particles from their initial position then with more rain it could develop into sheet erosion where thin layers of the soil are washed away by running water and then the more the rain, the more the runoff and the more energy the water has to erode the soil and then we can have rill erosions whereby the soil is removed by water from small but well defined channels, if not checked, rill erosions would develop into gully erosions over time which are channels larger than rills and would carry lots of water during and after rainfall. The rate at which the soil is eroded generally depends on the amount of runoff, velocity of the flowing water and the soil characteristics.
Deposition is simply the transportation of soil sediments from one place to another with the help of water, sediments can be transported in water either by suspension, saltation or bed load movement, when they are transported through suspension, they remain suspended in the flowing water for a long period of time without touching the stream bed, this occurs when the sediments are less dense than the water, when they are transported through saltation they simply just bounce along the stream bed and when they are transported through bed load movement they move in constant contact with the stream bed by being dragged by the sheer force of the flowing water.
Water employs these techniques in sculpting the earth, landforms such as caves, valleys, hills canyons and deltas are created in this way, when rain water falls, the water infiltrates into the soil till the infiltration capacity of the soil is reached, then the excess water becomes runoff which leads to erosion of the soil, the water then begins transporting the eroded particles and in doing this, the soil grinds down on other rocks leading to weathering of these rocks, over time, large amount of materials eroded gets deposited in new areas when the water stops moving, usually larger pieces of materials gets deposited first when the velocity of the moving water reduces, these deposited materials forms layers of sediments, more layers of different materials are deposited over time and these layers then form new rocks.
Did you know?
The Grand Canyon is made up of layers of different rocks formed overtime through erosion, weathering and deposition of rocks at different time and some of the rocks are at least 2 billion years old.
It is no secret that when there is water, there’d always be life, the properties of water makes it very important to sustaining life on earth, we know without water plants won’t grow and then there is no food but even when there is food and no water, the human body can only survive for about three to four days, this is because the human body is about 65% water, this water is needed by our cells to function it’s also used to transport many essential molecules needed in the body and helps in disposing waste but humans loses water through sweating, respiration and waste disposal so we need to replenish the lost water by drinking more water every now and then, without water our cells would simply shrivel and stop functioning and death comes very quick. This is what happens when a human is deprived of water but what happens if earth loses its water?
They say a picture is worth a thousand words, I hope the picture to the right speaks as much, but in case it doesn’t, the picture is that of planet mars, a planet that has lost its water, when you compare this to the blue and green picture you see when you look at earth, it puts things into perspective, planet earth would look something similar to this without its water, no blue means no green cause without its water, plants would die but would that be all? Think again, without water there is no hydrological cycle which means no clouds and without clouds the earth is more exposed to the sun which means more heat, way more heat than we currently experience, how about what happens to the air, without moisture in the air there would simply be dry air, similar to what happens during harmattan season in West Africa, just more pronounced, the human nose would shrivel, no more moisture to carry sweet scents, where would the sweet scent come from anyway? Every plant would be dead, there would be more pronounced volcanoes, more pronounced earthquakes but it wouldn’t matter, humans wouldn’t be there to witness it, but thankfully the chances of this ever happening for now is almost zero but still, it’s scary thinking about it.
Although its destructive tendencies is well known and publicized thanks to flooding, tsunamis, hurricanes and other natural disasters associated with it, Water is simply the most important natural resource we have on earth, it’s quite unique being the only substance that could exist in three phases which enables it to sustain life on earth.
its origin on earth hasn't been fully explained by science but one thing for certain is that it went through a lot to be here whether its through comets, the rocks that formed our planet or a combination of both. it gives us life simply by being here and it makes the earth more beautiful. it could be destructive at times, but it gives more than it takes, without its existence life wouldn’t exist as we know it and the earth would not be the beautiful place it is today.