↑ There is no accepted technical definition of sea amongst oceanographers. One definition is that a sea is a sub-division of an ocean, which means that it must have oceanic basin crust on its floor. This definition accepts the Caspian as a sea because it was once part of an ancient ocean.[5] The Introduction to Marine Biology defines a sea as a "land-locked" body of water, adding that the term "sea" is only one of convenience.[6] The Glossary of Mapping Sciences similarly states that the boundaries between seas and other bodies of water are arbitrary.[7]
↑ Theo định nghĩa này, biển Caspian sẽ bị loại trừ vì nó được coi là một "hồ nước".[10]
↑ To help put a change of this magnitude into perspective, when the pH of human blood plasma is raised from its normal 7.4 to a value above 7.8, or lowered to a value below 6.8, death ensues.[32]
↑ "As the waves leave the region where they were generated, the longer ones outpace the shorter because their velocity is greater. Gradually, they fall in with other waves travelling at similar speed—-where different waves are in phase they reinforce each other, and where out of phase they are reduced. Eventually, a regular pattern of high and low waves (or swell) is developed that remains constant as it travels out across the ocean."[3](tr83–84)
