The mean high water spring tide is the average height of high waters during spring tides, which occur approximately twice a month.
Understanding Mean High Water Springs (MHWS)
According to provided information, the height of mean high water springs is:
the average of the heights of two successive high waters during those periods of 24 hrs (approximately once a fortnight) when the range of the tide is greatest.
In simpler terms, it's the average high tide level observed when tides are at their highest and lowest points within a tidal cycle. Spring tides happen around the time of the new and full moon when the gravitational pull of the sun and moon align, resulting in larger tidal ranges.
Key Aspects of MHWS
- Averaging: MHWS is determined by averaging the heights of two consecutive high tides during spring tide periods.
- Frequency: Spring tides (and consequently, MHWS) occur roughly every two weeks (fortnightly).
- Range: The defining characteristic of spring tides is their significantly greater tidal range compared to neap tides.
Why is MHWS Important?
Understanding MHWS is crucial for:
- Coastal Planning: Helps in determining building setbacks and infrastructure placement to avoid flooding.
- Navigation: Provides critical information for safe passage of vessels in coastal waters.
- Ecological Studies: Affects the distribution of intertidal habitats and species.
- Recreational Activities: Influences activities like surfing, swimming, and beach access.
Example
Imagine two successive high tides during a spring tide reach heights of 4.5 meters and 4.7 meters. The MHWS for that location would be the average of these two heights:
(4.5 meters + 4.7 meters) / 2 = 4.6 meters
