10) Ocean currents can be generated by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes. Currents are cohesive streams of seawater that circulate through the ocean.
11) because of the rapid evaporation by the hot sun so the salt is left behind
12) they follow a circular path as the wave passes by
14) 10 to 12 seconds
15) water with different densities
16) Waves that pass from deep water into shallower water slow down, causing shorter wavelengths and greater wave heights. Waves tend to approach a coastline at an angle, but become more parallel the closer they get to the beach. ... Longshore currents are shallow water currents that mostly move parallel to the shore.
17) a gravel beach would be wider because gravel is larger than fine sand
