Starship Asterisk*

Ash and Lightning above an Icelandic Volcano

Explanation: Why did a picturesque 2010 volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well-populated areas. The Eyjafjallajökull volcano in southern Iceland began erupting on 2010 March 20, with a second eruption starting under the center of a small glacier on 2010 April 14. Neither eruption was unusually powerful. The second eruption, however, melted a large amount of glacial ice which then cooled and fragmented lava into gritty glass particles that were carried up with the rising volcanic plume. Pictured above during the second eruption, lightning bolts illuminate ash pouring out of the Eyjafjallajökull volcano.

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The "wow factor" is off the scale with this image!

Great shot. Can anyone explain why the stars in the background have trails?

Jim Leff wrote:Great shot. Can anyone explain why the stars in the background have trails?

Yes, it really is a great shot.

To catch that much lightning a photographer would need an extended exposure time. The stars have trails because the Earth rotates.

Then how are the ash plumes so clear and non-blurred?

Jim Leff wrote:Then how are the ash plumes so clear and non-blurred?

They were only briefly illuminated by the lightning.

Jim Leff wrote:Then how are the ash plumes so clear and non-blurred?

There is some blurring of the ash, which is most noticeable on the right edge of the plume against the blue sky. The exposure time couldn't have been very long, or the star trails would have been longer. There are some APOD commenters that can estimate exposure times from the length of star trails, but I'm not one of them. Maybe someone else can tell us how long this exposure was.

The EXIF data suggests a 15 second exposure with a 120mm focal length at f/5.6.

A mesmerising image.

Awesome elemental energy. A very moving image, but I'm glad I wasn't standing there when the picture was taken.

It's a superb photo. It would have been a good choice to have been used as the APOD of March 5 2014 (Ash Wednesday).

DavidLeodis wrote:It's a superb photo. It would have been a good choice to have been used as the APOD of March 5 2014 (Ash Wednesday).

Or Wednesday February 18, 2015, for Western (Catholic and Protestant) churches. February 25 for Orthodox churches. Easter, and therefore Ash Wednesday, will come fairly early next year.

Let's not continue in this vein, David and Anthony; thanks.

LocalColor wrote:The "wow factor" is off the scale with this image!

Looks so amazing that it seems fake to me. Without inspecting the image carefully with photoshop, my first guess is that this is a composite of several lucky lightning strike shots.

-s

Here ya go, Spif: https://www.flickr.com/photos/stefnisso ... 892644702/