Tombolo

• Longshore drift is the lateral movement of the waves. Swash is where waves push material up the beach at an angle due to the prevaling wind. The returning backwash is draged back down the beach at right angles due to gravity.
• Tombolos form where there is a change in the direction on a coastline, which allows a sheltered area for deposition. Material slowly builds up to appear above the water. The tombolo develops as long as the suply of deposits is greater than the amount of erosion
• A tombolo forms when a spit connects the mainland coast to an island leaving a long, thin strip of beach deposits.
• An example is the isle of Portland, Dorset