The name "Pororoca" comes from the indigenous Tupi language, where it translates into "great destructive noise". The wave can be heard about 30 minutes before its arrival, and it's so powerful that it can destroy anything, including trees, local houses and all kind of animals.

During spring in Denmark, at approximately one half an hour before sunset, flocks of more than a million European starlings (sturnus vulgaris) gather from all corners to join in the incredible formations shown above. This phenomenon is called Black Sun (in Denmark), and can be witnessed in early spring throughout the marshlands of western Denmark, from March through to the middle of April. The starlings migrate from the south and spend the day in the meadows gathering food, sleeping in the reeds during the night.
 
7. Idaho's Fire Rainbow



The atmospheric phenomenon known as a circumhorizon(tal) arc, or "Fire rainbow", appears when the sun is high in the sky (i.e., higher than 58° above the horizon), and its light passes through diaphanous, high-altitude cirrus clouds made up of hexagonal plate crystals. Sunlight entering the crystals' vertical side faces and leaving through their bottom faces is refracted (as through a prism) and separated into an array of visible colors. When the plate crystals in cirrus clouds are aligned optimally (i.e., with their faces parallel to the ground), the resulting display is a brilliant spectrum of colors reminiscent of a rainbow. The example shown above was captured on camera as it hung for about an hour across a several-hundred square mile area of sky above northern Idaho (near the Washington border) on 3 June 2006.