How are high tide and low tide alike?
Tides are caused by the position of the moon relative to the earth. The pull of the moon caused a bulge of water to travel across the earth. The high tide is caused by the moon being overhead and low tide is caused by the moon being on the opposite side of the earth. The variation in the tides is caused the the shared orbit of the earth and the moon. The moon actually orbits a point below the earths surface but not at the center of the earth. Thus when it is overhead it can be closer on one pass than another.
