Tides are caused by gravitational pull of the moon and the sun. The rise and fall of the tides play an important role in the natural world and can have a marked effect on maritime-related activities. The image aboves shows the NOAA San Francisco Tide Station, in operation for more than 150 years.
One query we ran across in our research was “What is the main reason why tides happen?”.
Tide changes proceed via the following stages: Sea level rises over several hours, covering the intertidal zone; flood tide. The water rises to its highest level, reaching high tide. Sea level falls over several hours, revealing the intertidal zone; ebb tide. The water stops falling, reaching low tide.
” They are simply the rise and fall of the sea levels mainly affected at the shores. Before we look into how tides occur, we must understand “ why do tides occur? ”, and the answer is “ Gravity ”. Any object which has mass possesses a gravitational field and the larger the mass the stronger the gravitational field is.
Why are tides diurnal?
Despite that being the case in most places (where semidiurnal tides occur), some areas only experience a single tidal cycle per day and are thus known for featuring a diurnal pattern. Diurnal tides occur due to a series of factors, among which continental interference and the Earth’s spin axis are the most important to be considered.
In general, most areas have two high tides and two low tides each day. When the two highs and the two lows are about the same height, the pattern is called a semi-daily or semidiurnal tide. If the high and low tides differ in height, the pattern is called a mixed semidiurnal tide.
So, what is a semidiurnal tide?
Some think that – Tides Chart What is a semidiurnal tide? There are three main tidal patterns: semidiurnal, diurnal, and mixed. Most shorelines on the planet experience semidiurnal tides (two high tides and two low tides per lunar day), making it so that each transition between low to high lasts approximately 12 hours and 25 minutes.
What are the different types of tidal patterns?
Three basic tidal patterns occur along the Earth’s major shorelines. In general, most areas have two high tides and two low tides each day. When the two highs and the two lows are about the same height, the pattern is called a semi-daily or semidiurnal tide. If the high and low tides differ in height, the pattern is called a mixed semidiurnal tide.