Credit: Elspeth Robertson
This photograph, taken from a helicopter, is of the lava dome at Volcan de Colima volcano, Mexico in November 2009. Volcan de Colima has been active throughout history with over 40 eruptions since the sixteenth century. The last explosive Plinian eruption was in 1913 blasting out the summit crater. Nowadays, eruptions tend to be effusive with eruptions of lava flows and the gradual build up of the volcanic dome. The dome is formed through extrusion of viscous lava that builds up into the flat-topped dome seen in the photo. Over time, the dome increases in volume and will eventually start to spill over the volcanic edifice creating spectacular incandescent rock falls.
The wispy looking fog you can see surrounding the dome is steam emanating from the dome, which despite its cool exterior, reaches temperatures of 380 degrees Celsius.