WIKIARCHIVES.SPACE

Fire scars in Australia are featured in this image photographed by an Expedition 5 crewmember on the International Space Station (ISS). Bright orange fire scars show up the underlying dune sand in the Simpson Desert, 300 kilometers east of Alice Springs. The background is an intricate pattern of sand cordons that angles across the view from lower left to upper right. These cordons are now mostly green, showing that they have become generally static--“tied down” since they were formed by a vegetation mat of desert scrub. The fire scars were produced in a recent fire, probably within the last year. According to NASA scientists who are studying the Space Station photography, a time sequence of events can be interpreted. Fires first advanced into the view from the lower left--parallel with the major dune trend and dominant wind direction. Then the wind shifted direction by about 90 degrees so that fires advanced across the dunes in a series of frond-like tendrils. Each frond starts at some point on the earlier fire scar, and sharp tips of the fronds show where the fires burned out naturally at the end of the episode. The scientists added that the sharp edges of the fire scars are due to steady but probably weak southwesterly winds—weaker winds reduced sparking of additional fires in adjacent scrub on either side of the main fire pathways.