Question

Which of the following best expresses the differences between a semi-diurnal and diurnal tide?

Answer 1

C A diurnal tide is a single high and low tide in a 25 hour period and a semi-diurnal tide is two high tides and two low tides in a single day is correct.

Answer 2

Diurnal comes from the Latin diurnus, meaning daily.

A diurnal tide is a single high and low tide per day (actually the tidal period is 24hrs 50mins because of the Moon's orbit)

A semi-diurnal tide is two high and two low tides per day (24hrs 50mins as above