Final answer:
If Earth's moon were half the size that it is now, the oceans' tidal variations would be smaller because the Moon would exert less gravitational pull on Earth's oceans.
Step-by-step explanation:
If Earth's moon were half the size that it is now, the oceans' tidal variations would be smaller because the Moon would exert less gravitational pull on Earth's oceans. Tides are primarily caused by the Moon's gravitational force acting on the Earth, resulting in two high tides and two low tides per day. A smaller moon would have a weaker gravitational pull, leading to smaller tidal variations.