Some mountain peaks have the ability to cast shadows on the clouds, making it look like another inverted mountain appearing in the sky.
In some cases, this optical phenomenon is so amazing that it makes you believe in a volcanic eruption… even more so, when that inverted shadow comes directly from a volcano! This is exactly what happens regularly over Mount Rainier, located in Washington State, USA, which is considered one of the most endangered volcanoes in the world.
About the period of the winter solstice, and generally from the end of October to January, the sun rises far south in this region of the American northwest: the sun’s rays are then lower than the mountain and set at the exact angle make for a memorable sunrise, only when atmospheric conditions are met .
The sky must be cloudy for the shadow to be striking, ideally with clouds of medium altitude and fairly thick, like high clouds. The sun’s rays then contain enough matter (the droplets and ice crystals that make up the cloud) for the red, pink, or violet light to scatter.
As some rays strike directly at the top of the mountain, which rises to 4,392 metres, the upturned shadow of the mountain contrasts sharply with the brilliant colors of the clouds.
To achieve this effect, the mountain’s summit must rise significantly above the other surrounding mountains and, even better, not be surrounded by any other peaks, as is the case with Mount Rainier. The shadow is so intense that it can be confirmed by satellite imagery:
The same phenomenon occurs elsewhere on the planet, such as in the Alps, but not as spectacularly as on Mount Rainier.