Outgoing Tide (Ebb Tide): Mechanics & Coastal Impact

Outgoing tide (ebb tide) is the seaward flow of water as the tidal cycle falls from high to low water.

Drivers

• Lunar gravity – primary; creates bulge toward moon.
• Solar gravity – secondary; modulates (spring/neap cycles).
• Earth's rotation – moves coastlines through bulges.

Coastal Dynamics

• Water level drops; shoreline recedes; intertidal zone exposed.
• Ebb currents accelerate through inlets, around headlands—navigation hazard & sediment transporter.
• Eddies form at channel bends, junctions.

Ecological & Human Significance

• Feeding windows for shorebirds, fish.
• Shellfish harvesting, wading access.
• Flushing of estuaries—nutrient export, salinity reset.
• Boating: bars exposed, draft restrictions.

Spring vs. Neap Ebb

Spring tides (new/full moon) → larger range, stronger ebb currents. Neap tides (quarter moon) → weaker.

Understanding ebb is essential for coastal safety, ecology, and navigation.