Tides are the rise and fall of Earth's oceans in relation to the moon. The moment at which these tides occur is called high tide, while low tide occurs when there are no waves. The highest tides on Earth are found in the Bay of Fundy in Nova Scotia in, Canada. The Bay of Fundy has a "tidal range" of more than 50 feet high, meaning that the tide can rise and fall more than 50 feet. The tides are caused by the moon's gravitational effect, which is stronger on one side of Earth than on the other. This causes a bulge in the ocean on one side of Earth and a dip on the other.