A complex tidal cycle, usually with two high tides and two low tides of unequal height per day.

• A. Slack Tide
• B. Semidiurnal Tide
• C. Mixed Tide
• D. Stand

Answer: (C)

In a mixed tide, you get two high tides and two low tides each day, but their heights are not the same. The irregular coastline and varying seabed depths cause the tidal wave to interact with the shore differently on successive highs and lows, so the amplitudes differ from one cycle to the next. This contrasts with a semidiurnal tide, where the two highs and two lows are about equal in height. Slack tide is the brief period of minimal current around the changeover between flood and ebb, not the overall pattern of tides. Stand isn’t a standard term for tide types. The described cycle is a mixed tide.