tombolo

Tombolo is a term used in coastal geography to describe a narrow strip of sand or shingle that connects an island to the mainland or to another island, creating a continuous land bridge between two bodies of water. It forms when sediment carried by longshore currents is deposited in the area between the island and the shore, building up an isthmus. Waves approaching at an angle drive sediment along the coast, and the sheltered area behind the island slows water flow, promoting deposition. The resulting tombolo can consist of sand, gravel, or a mixture of sediments, and its width can vary with tides, storms, and sediment supply. Tombolos may persist for long periods or be temporary features that change or disappear as coastal dynamics shift. They can alter local hydrology by reducing tidal exchange with adjacent waters and by creating sheltered lagoons or bays behind the bridge of land.

Tombolo lace is another, unrelated meaning of the term. Tombolo lace, or punto tombolo, is a traditional lace-making technique in which motifs are formed and then joined to a mesh ground on a pattern pillow. It typically involves arranging pins in a pattern and threading, wrapping, and interlacing to create raised motifs that connect to a surrounding net-like background. The craft has historical associations with southern Europe, particularly Italy and Madeira, and remains practiced by artisan communities in some regions.