Matching Pairs Waves, Currents & TidesOnline version 5th Grade Science Unit by Julie Copeland 1 Wind 2 What are tides? 3 Crest 4 Trough 5 What are estuaries? 6 Current 7 What is a barrier island? 8 How often do tides occur? 9 Wave 10 What causes surface currents? 11 What are inlets? The regular rise and fall of the waters in oceans and seas. Flowing streams of water that move along a curved path through the ocean in a specific direction The highest part of a wave The cause of most waves to form The area where a river meets the ocean Pieces of land surrounded by water on all sides that protect the mainland. The repeated movement of water up and down Water-filled spaces between barrier islands The movement of Earth and the force and direction of wind. The lowest part of the wave This occurs about twice a day.