As we all know, tides are bulges in the ocean caused by the gravitational pull of the moon and the sun. Tides are the most constant phenomena that occur just as day and night do. Tides start in the oceans and move towards the coastlines where we see them as the rise and fall of the water surface. The rise is called the crest or high tide and the fall is called the trough or the low tide.
Read on for some ‘tide’y facts about tides.
1. Did you know that a ‘spring tide’ has nothing to do with the season – spring? It actually implies ‘springing forth’ of the tides. Spring tides are a round-the-year phenomena, occurring twice every lunar month, irrespective of the season. Spring tides occur during full moons(when the earth is between the moon and the sun) and during the new moons(when the moon is between the sun and the earth), when the gravitational pull of the sun adds on to the gravitational pull of the moon causing the oceans to surge or cause a bulge that is more than the usual and hence the name.
2.Did you know there is something also called the “neap tide”? A week after every Spring tide, the moon moves into a position to form right angles with the sun. Due to this, the swelling of the ocean caused by the moon is to a little extent wiped out by the swelling caused by the sun. During such times, the high tides are lower than usual and the low tides are a little higher than usual, thus bringing about moderate tides called neap tides.
3.Did you know that the National Oceanic and Atmospheric Administration(NOAA) at San Francisco, California, has been in operation for more than a 150 years?
4. Did you know that tides move up and down, while currents move left and right?
5. Did you know that though tides are caused by the pull of both the sun and the moon, the gravitational pull of the moon is twice as much as that of the sun? This is because of the moon’s proximity to the earth than that of the sun’s.
6. You do know that the moon rotates around the earth? But, did you know that the moon takes not just 24 hours, but an extra 50 minutes every day? That’s the reason why the tides would not occur at the same time, at the same place every day.
7. Did you know that the highest tide in the world is at the Bay of Fundy in Canada? Did you also know that, sometimes these tides could rise as high as 15 meters – that is taller than a three-storey building??
8. Did you know that it is essential to monitor and measure tides? People who depend on the seas for their livelihood – fishermen need to know where they can have a big catch, commercial ships that carry cargoes are in need of information to navigate their ships from one place to another, engineers involved in coastal area engineering projects such as construction, demolition or transportation of large structures cannot do without information on tidal currents.
9. An example that gains merit to show the importance of Tidal monitoring is that of the 4 industrial cranes worth approximately $5 million transported from China to the Port of Oakland. These cranes had to be navigated under the Oakland Bridge and could only achieve the feat because of the knowledge of the tidal currents: they cleared the bottom of the bridge by just about 6 feet!!
10. Tidal study and monitoring is also imperative for beachgoers and surfers alike who wish to tide the tides!!