This photograph has two different meanings in today’s post. Being posted on the last day of December 2017, the sunset itself represents the end of another year full of events large and small, some small events that were over-blown into large events, and large events ignored so as to make them seem like small events. As the sun sets and the Earth completes another trip around it, it’s natural to look back at past events, as well as entertain expectations of the year to come.
But resolutions and predictions about the future hold little interest to me, so as is my usual focus, I’m going to share a couple of scientific phenomena that are embodied in today’s photo. The first relates to my previous blog about the color of sunsets. You can see how the sunlight has taken on a decidedly yellow coloration as it travels a longer distance through the atmosphere. But notice how the blue sky shines through above the clouds that are blocking the heavily filtered rays of the sun.
The other phenomenon in today’s photo are the geological processes that shape the planet we inhabit. The mountains behind which the sun is sinking are part of the Ritter Range located on the eastern edge of the Sierra Nevada Mountains in California. The jagged saw-tooth fingers to the left of the distant ridge are the Minarets. Beneath the main bank of clouds just to the left of the setting sun are Banner Peak (12,942 ft., 3,945 m) and to its left, conical Mount Ritter (13,143 ft., 4,006 m).
The Ritter Range began forming about 140 million years ago, before the Sierra Nevada existed, as part of the formation of the ancestral Sierra Nevada. As a tectonic plate of oceanic crust dove under the North American plate, the pressure and friction caused the land to crumple and mountains formed to the east. All of this pressure and heat also caused the existing rock to metamorphose, producing the dark green rocks that can today be seen in the Ritter Range. This rock is highly resistant to erosion, and thus has remained intact during a period starting 65 million years ago, while much of the surrounding granite has eroded. The Sierra Nevada as we know it today began rising quite rapidly only about two million years ago. But that is a story for another post.
This photo was taken at Minaret Summit near Mammoth Lakes, California, USA with a Canon EF17-40 mm f/4L USM lens at focal length 37 mm on a Canon EOS 5D Mk III. The exposure was set to 1/125 sec at f/11 and ISO 400.