Option 1 states that tsunamis have a very long wavelength. This statement is correct. Tsunamis have wavelengths that can span over hundreds of kilometers, making them different from other types of ocean waves.

Option 2 states that tsunamis have a slight swell of about twelve inches above the normal sea surface. This statement is incorrect. Tsunamis can cause a significant rise in sea level, often reaching heights of several meters or even tens of meters.

Option 3 states that tsunamis grow in height when they reach shallower water. This statement is correct. Tsunamis have a unique behavior where they tend to increase in height as they approach the shore and encounter shallower water. This increase in height is known as "run-up."

Option 4 states that tides also play an important role in the generation of tsunamis. This statement is incorrect. Tides and tsunamis are separate phenomena. Tsunamis are usually caused by underwater earthquakes, volcanic eruptions, or landslides, while tides are caused by the gravitational pull of the moon and the sun.

In conclusion, the correct answer is option 4. Tides do not play a role in the generation of tsunam