Dinosaurs and the Water Cycle
What is it with the English and their weather? The UK is essentially a “maritime climate”, this is what comes from being a small island at one side of the Atlantic ocean with a large continent (Europe) adjacent to us. We do seem to get some very peculiar weather and June was no exception. With the cricket season in full swing and Wimbledon tennis underway, last month proved to be one of the wettest on record, July has not started too well either. Many parts of the UK have suffered from flash floods. South Yorkshire seems to have been hit the worst with many villages and towns still underwater.
With all this rain everywhere, you might think that planet Earth has suddenly started to produce more water, but this is not the case. The amount of water we have on this planet is just about fixed, water may change its state but this planet only has a finite amount. If you pour yourself a glass of water and sit it on the table in front of you, that water in your glass could have been part of an ocean a little over a week ago. It may have fallen as rain, just a couple of days before it found its way into your glass, but the water itself is virtually as old as the planet. The same water that you see before you could have made up part of a shallow rock pool that stranded Trilobites in the Ordovician 500 mya. It may have formed part of a thunderstorm that caused a herd of Plateosaurs to stampede in the late Triassic, it might even have been drunk by a Tyrannosaurus rex.
The water we have gets recycled, this is what we call the “Water Cycle”, water is evaporated (or transpirated by plants as they lose water) and forms water vapour. The water vapour in the air gets cold and forms clouds – this is called condensation. You can see condensation on windows in the morning when the water vapour hits the cold window glass and turns back into liquid.
The clouds become saturated with water, so that they cannot hold any more and the water falls out back down to earth as rain, sleet, hail of snow. The water may fall into or run off into oceans, lakes or rivers or get absorbed by the land into the “groundwater”, to be drunk by plants and trees or it will eventually under several natural processes, mainly gravity, find its way back to the sea – and the process starts all over again.