My parents live near the sea and my daughters love going to visit Granny and Grandad, especially when they get to spend an afternoon on the beach hunting for crabs and fish in the rockpools.
The sea is a fascinating natural beauty but how was it formed? Where did all the water come from? How heavy is it? And how can you hear the sea in a shell?
On Earth, water can be found in lots of places: from rivers and streams to lakes, seas and oceans; to glaciers, ice caps and snow; and the clouds in the sky.
Where did the Earth’s water come from?
Scientists think there are two possible places it might have come from. One theory is that when our solar system was born, there was ice in the gas and dust that formed the Sun and the planets, and some of this ice stayed with the Earth as it was created. The other theory is that ice was brought to the Earth by asteroids that smashed into the Earth millions of years ago. Either way, about 72% of the Earth’s surface is covered in water and most of it is the salty kind found in seas and oceans.
How heavy is the sea?
The total volume of water on the Earth is estimated as 362 million cubic miles. And 97% of this water is found in seas and oceans.
The estimated weight of all Earth’s water is 1,450,000,000,000,000,000 short tons. Multiplying that number by 97%, we can estimate the weight of the seas and oceans as 1,400,000,000,000,000,000 short tons. But this is an impossibly big number to imagine!
So, I tried to compare it to something else here on Earth: Mount Everest (the tallest mountain), which is estimated to weigh about 3 trillion short tons. By using simple division, I estimate that the sea weighs about 42,000 times more than Mount Everest! (Which is still too big a number for me to imagine!)
How can you hear the sea in a shell?
Some people say that if you hold a conch shell to your ear, you can hear a noise that sounds a bit like the rushing and swooshing of waves on the sea. But you’re not really hearing the sea – you’re actually hearing the sounds of the world around you!