Sea Level Shift is a phenomenon that occurs when the average sea level rises or falls due to changes in the Earth's climate. Tides are a natural occurrence that is caused by the gravitational pull of the moon and sun on the Earth's oceans. The tides cause the sea level to rise and fall twice a day, creating a regular pattern of high and low tides. Sea Level Shift is a more drastic change in the sea level that can be caused by a variety of factors, such as melting glaciers, changes in ocean currents, and extreme weather events.