Fuji Television captures video of on an interesting phenomenon known as the floating island (浮島, ukishima) in the city of Goto in Nagasaki Prefecture.

Goto comprises the south-west half of the Gotō Islands (140 in total with 5 main ones) in the East China Sea.

The camera catches the sun rising from what appears to be a floating island off in the distance (an actual island exists to the left of this). However, the floating island is just a mirage.

The phenomenon occurs due to the variations of temperature within the atmosphere. Cold air tends to be denser than hot air resulting in a higher refractive index. Mirages result when refracted light passes through these atmospheric layers and makes distant objects look closer, raised, inverted, or wavering.

In this floating island case, air close to the surface of the sea is colder than the air above it resultng in a temperature inversion in the atmosphere causing rays of light to bend down to the surface. This causes an image to appear above the real object (in this case, it might be another island located just over the horizon). This type of mirage is known as a superior mirage.