Burntcoat Head, Nova Scotia flow back out. Each day the tides times will change approximately by one hour. The reason why the tides fills and empties the Bay of Fundy each day is due to gravitational pull of the moon and the sun on the earth, as well as earths rotation. Spring tides happen twice a month when the sun, moon, and earth are aligned. During this alignment the tides rise higher than average. Neap tides occur during the first and third quarter moon. During this time the high tides heights are lower than average. At low tide the ocean floor becomes exposed allowing
Moon to persist as ice on the surface since they are shielded from the sun. The gravitational field of the Moon has been measured through tracking the Doppler shift of radio signals emitted by orbiting spacecraft. The main lunar gravity features are mascons, large positive gravitational anomalies associated with some of the giant impact basins, partly caused by the dense mare basaltic lava flows that fill those basins. The anomalies greatly influence the orbit of spacecraft about the Moon. There are some puzzles: lava flows by themselves cannot explain all of the gravitational signature, and some mascons exist that are not