What is the contour interval on this map?

It is reasonable to assume that nations with a low total fertility rate (tfr) and a modest amount of population growth are in

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

What structure on the south african coast has a range of 63 km and releases flashes every 30 seconds?