Volcanoes under high surveillance

This image shows the eruption of the Tungurahua Volcano in Ecuador in August 2006.

This false colour image was created by combining ASTER's recordings in shortwave infrared, near-infrared and green wavelengths of light.

The glowing red dot at the summit indicates an area of intense heat.

The ash cloud appears bright purple, whereas clouds would appear white.

The scars of earlier eruptions are also visible: deep purple rivulets of rock result from previous lava flows that later solidified.