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The Beauty and Science of Volcanic Sunrises and Sunsets

Updated: Feb 14, 2021

Twilight glow over Lake Isabelle, Indian Peaks Wilderness, Colorado
Twilight glow over Lake Isabelle, Indian Peaks Wilderness, Colorado

On August 27, 2019, I got up at 2:15 a.m., drove an hour and a quarter to the Long Lake trailhead in the Indian Peaks Wilderness, and hiked three miles to a location I last photographed in 1996 using a 4x5 field camera. My subject was a small stream that flows into Lake Isabelle. I planned to use the stream as foreground and shoot looking east as the sun rose over the lake. I was eager to learn the best way to use a digital camera to handle a difficult exposure challenge: shooting a constantly moving, reflective subject (the stream) lit by moment-of-sunrise light, with the sun in the frame. I had used a three-stop graduated neutral-density filter during my 4x5 shoot. This time I planned to shoot a heavily bracketed set of images and use Lightroom and Photoshop to produce the image I had in mind.

To my surprise, the best image of the morning proved to be the one I shot about 20 minutes before sunrise, when a strong golden glow developed along the eastern horizon. As I processed the image, I noticed that the sky above the golden band had an unusual purplish cast. The purplish color was even more pronounced in the water. Then I read Dr. Tony Phillips’ article in that day’s edition of the newsletter and the light dawned.

According to Dr. Phillips, about 60 volcanoes erupt every year, worldwide. Only a few eruptions, however, are powerful enough to pump plumes of sulfur dioxide gas into the stratosphere, where a series of chemical reactions eventually create tiny droplets of sulfuric acid and water. These droplets, called aerosols, can then spread around the globe. Two powerful eruptions occurred recently. Raikoke Volcano, in the Kirul Islands off the southern tip of the Kamchatka Peninsula, in far eastern Russia, erupted on June 22nd. Ulawun Volcano in Papua New Guinea, off the northeastern coast of Australia, erupted on August 3rd.