Spits and Bars: When Coasts Get Creative
Spits are like nature's pointing fingers - these narrow strips of land stick out into the sea, often with a distinctive hooked end. They form when longshore drift keeps moving sediment along the coast until it hits a bend or change in direction.
Here's the clever bit: the prevailing wind pushes waves at an angle to the shore, creating that zigzag movement of sediment. The swash carries material up the beach diagonally, but gravity pulls the backwash straight back down. This creates the characteristic sideways drift of sand and pebbles.
When the coastline changes direction, all that moving sediment gets deposited offshore, gradually building the spit. Behind this new landform, you'll often find salt marshes forming in the calm, sheltered water where fine mud settles.
Bars work similarly to spits but they stretch right across bays or river mouths, sometimes creating enclosed lagoons behind them. The hook shape at the end of spits happens when tidal movements and changing wind directions curve the tip back towards the shore.
Geography Gold: Fast-flowing water from estuaries often prevents spits from growing further - it's like a liquid barrier that sweeps away the sediment!