This is one of the nature that God's made

 This is one of the nature that God's made. Actually, you can find anywhere in the parts of the world but not in the ocean. When you taking a bath near the mouth of the river, wherein the sea. The above and below sea level were not mixed because of different density and God designed for it. These two bodies of water were merging in the middle of The Gulf of Alaska and there was a foam developing only at their junction. It is a result of the melting glaciers being composed of fresh water and the ocean has a higher percentage of salt causing the two bodies of water to have different densities and therefore makes it more difficult to mix