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