Tidal waves, also known as ocean tides, are primarily caused by the gravitational interaction between the Earth, Moon, and Sun. The gravitational pull of the Moon is the dominant force behind tidal formation, while the Sun's gravitational pull also contributes to a lesser extent.
The Moon's gravitational force creates two tidal bulges on opposite sides of the Earth, one facing the Moon and the other on the opposite side. These bulges are the high tides. As the Earth rotates within the tidal bulges, different locations experience high tides as they pass through the bulges, resulting in a cyclic pattern of two high tides and two low tides each day.
The Sun's gravitational force also affects tidal patterns, although its influence is about half as strong as the Moon's. When the Moon, Sun, and Earth align during full and new moon phases, their combined gravitational forces produce higher high tides, known as spring tides. Conversely, when the Moon and Sun are at right angles to each other during the first and third quarter moon phases, their gravitational forces partially cancel out, resulting in lower high tides, known as neap tides.
It's important to note that tidal waves can also refer to large ocean waves caused by seismic activity, such as earthquakes or volcanic eruptions. These are not directly related to the astronomical tides caused by gravitational forces.