Searching for the birth of the Glow
The eerie glow emanating from the crater
of the Mount St.
Helens volcano at night was first noticed on the images streaming from
US Forest Service Volcanocam
on the
night of 11
October 2004. On 12 October, the USGS/CVO
reported that thermal imaging of the expanding new lava dome had
revealed temperatures of 500-600 degrees C on a "...large pinkish-gray
fin of rock and in nearby fumaroles and cracks", and concluded that
these observations were "...consistent with new lava having reached the
surface of the uplift." But, it is not known exactly when the new lava
reached the surface.
The immediate area around the mountain had been closed on 26 September, and the closest observatory (Johnston Ridge) was closed due to safety concerns on 2 October 2004. So, while USGS scientists were able to make observations from helicopters when weather permitted, the Volcanocam was the only near real-time view of what was happening in the crater.
This opens the intriguing possibility of using archived images from the Volcanocam to try and give a clearer indication of when the lava broke through to the surface for the first time.
To check for the first appearance of the glow, the nightly images from the beginning of October were added and combined in a way that recorded the brightest pixels from each image (using a program called Image Stacker). So any hotspot would be highlighted in the final image and by looking at different dates the first appearance of the glow could be estimated.
The two images below are examples of the result from this process. The first image shows the result of combining all of the night time images from 5 October to the morning of 11 October 2004. The second picture combines all the images from 05 October to the morning of 12 October 2004.
Clearly no glow is visible in the images prior to the morning of the 11 October. So it seems that the first appearance of the glow on the Volcanocam images did occur on the night of 11/12 October. To see whether the glow was present from the beginning of the night or appeared during the course of the night the images from sunset to sunrise were assembled into a Macromedia Flash movie (see below). Viewing the movie it appears the glow first made its appearance at around on the frame taken at 20:29. The movie has controls to enable frame-by-frame viewing, so feel free to have a look and judge for yourself when you think the glow first appears.
Watch the movie of the birth of the glow on the evening of 11/12 October 2004 (size 233 kB)
On the 12th August 2005 USGS photographer Elliot Endo captured a sequence of images of the lavadome following the sunset from the Johnston Ridge Observatory. Just for fun I have combined these images into a short animation - hopefully to give a sense of watching the incandescent glow appear as the night falls. After all, its interesting to see the details of that make up the diffuse brightness we see on the Volcanocam images each night. Flash movie of the glow appearing (size 452 kB)
Volcanocam Hall of Fame Image Archive: http://www.fs.fed.us/gpnf/volcanocams/msh/archive/hall-of-fame/index.shtml
USGS Crater, Dome, and Eruption Images: http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/
USGS/PNSN Mount St Helens Update 12 October 2004 (7:00am): http://vulcan.wr.usgs.gov/Volcanoes/Cascades/CurrentActivity/2004/current_updates_20041012.html
Tawbaware Image Stacker program: http://www.tawbaware.com/imgstack.htm
The immediate area around the mountain had been closed on 26 September, and the closest observatory (Johnston Ridge) was closed due to safety concerns on 2 October 2004. So, while USGS scientists were able to make observations from helicopters when weather permitted, the Volcanocam was the only near real-time view of what was happening in the crater.
This opens the intriguing possibility of using archived images from the Volcanocam to try and give a clearer indication of when the lava broke through to the surface for the first time.
To check for the first appearance of the glow, the nightly images from the beginning of October were added and combined in a way that recorded the brightest pixels from each image (using a program called Image Stacker). So any hotspot would be highlighted in the final image and by looking at different dates the first appearance of the glow could be estimated.
The two images below are examples of the result from this process. The first image shows the result of combining all of the night time images from 5 October to the morning of 11 October 2004. The second picture combines all the images from 05 October to the morning of 12 October 2004.
 Stacked night time images from 05 Oct. to morning of 11 Oct |
 Stacked night time images from 05 to morning of 12 October |
Clearly no glow is visible in the images prior to the morning of the 11 October. So it seems that the first appearance of the glow on the Volcanocam images did occur on the night of 11/12 October. To see whether the glow was present from the beginning of the night or appeared during the course of the night the images from sunset to sunrise were assembled into a Macromedia Flash movie (see below). Viewing the movie it appears the glow first made its appearance at around on the frame taken at 20:29. The movie has controls to enable frame-by-frame viewing, so feel free to have a look and judge for yourself when you think the glow first appears.
Watch the movie of the birth of the glow on the evening of 11/12 October 2004 (size 233 kB)
On the 12th August 2005 USGS photographer Elliot Endo captured a sequence of images of the lavadome following the sunset from the Johnston Ridge Observatory. Just for fun I have combined these images into a short animation - hopefully to give a sense of watching the incandescent glow appear as the night falls. After all, its interesting to see the details of that make up the diffuse brightness we see on the Volcanocam images each night. Flash movie of the glow appearing (size 452 kB)
References
Volcanocam: http://www.fs.fed.us/gpnf/volcanocams/msh/Volcanocam Hall of Fame Image Archive: http://www.fs.fed.us/gpnf/volcanocams/msh/archive/hall-of-fame/index.shtml
USGS Crater, Dome, and Eruption Images: http://vulcan.wr.usgs.gov/Volcanoes/MSH/Images/MSH04/
USGS/PNSN Mount St Helens Update 12 October 2004 (7:00am): http://vulcan.wr.usgs.gov/Volcanoes/Cascades/CurrentActivity/2004/current_updates_20041012.html
Tawbaware Image Stacker program: http://www.tawbaware.com/imgstack.htm