Volcanic Sunrise at San Eduardo del Mar, Argentina

December 14, 2011

VolcanicsunriseIMG_5089 (2)

Photographer: Luis Argerich; Luis's Web site
Summary Author: Luis Argerich; Jim Foster

The photo above showing an arresting sunrise and a lone piece of eroded basalt (about 20 in or 0.5 m in diameter) on a sandy beach was taken at San Eduardo del Mar, Argentina. Puyehue Volcano in Chile has been belching ash, dust and sulfur dioxide into the atmosphere since June 2011, producing interesting sunrise and sunset effects across southern South America and elsewhere in the Southern Hemisphere. Particles injected into the atmosphere during volcanic eruptions, when combined with the longer path length of sunlight when the Sun is near the horizon, often create vivid twilight skies, but only if the volcanic plume reaches the stratosphere.

Additionally, the weather here has been quite chilly of late, likely due to the dirtier atmosphere as a result of the eruption. Since volcanic particles and gases, especially sulfur dioxide, act to attenuate solar radiation, surface temperatures are generally lower following major volcanic eruptions. On the mid-spring morning when I took this picture on November 5, the air temperature was about 28 F (-2 C) -- unusually cold for this time of the year.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 5D Mark II; Focal Length: 32mm; Focus Distance: 5.24m; Aperture: f/4.5; Exposure Time: 2.000 s; ISO equiv: 800; Exposure Bias: none; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); Exposure Mode: Manual; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop CS5 Windows.