Gisasa River Fire

200551,018 acresAlaska

The Gisasa River Fire burned 51,018 acres, about 80 square miles, across Yukon-Koyukuk Census Area. It began on July 1, 2005.

Watch how it happened

Gisasa River Fire · 2005

How it happened

Watch it burn in the order satellites saw it, coloured by how severely each place burned.

About this replay

Date (UTC)—Historical replay

Burned so far—acres

High severity—of the area so far

Detections1,261satellite fire pixels

Fire milestones

Burn severityHigh, Moderate, Low, Unburned to low, Increased greenness

Burning nowAreas reached in the last half day of satellite passes

Washington, D.C., to scale61 square miles of land, drawn at the fire’s scale

Timing: NASA FIRMS satellite fire detections (1,261 MODIS) inside the final perimeter; each place takes the time of its nearest detection, so the order is satellite-observed but interpolated between passes, roughly every 12 hours. Severity: Monitoring Trends in Burn Severity (USGS, U.S. Forest Service), mapped from Landsat after the fire.

How severely it burned

Burn severity inside the final perimeter, classified from Landsat images taken before and after the fire.

Map of burn severity across the Gisasa River Fire

Burn severity by class
Severity	Share	Acres
Highmost vegetation consumed, soils altered	27%	13,623
Moderatemixed: many trees killed, some survive	22%	11,467
Lowsurface fire, most trees survive	9.7%	4,970
Unburned to lowislands inside the perimeter, little change	11%	5,718
Increased greennessvegetation greener after the fire than before	0.2%	82
Not mappedcloud, shadow or water in the satellite images	30%	15,158

27% of the area inside the perimeter burned at high severity, about 13,623 acres; 49% burned at moderate or high severity.

Monitoring Trends in Burn Severity (U.S. Geological Survey and USDA Forest Service). Classes come from the change in a Landsat burn index (dNBR) between images before and after the fire; acres are each class’s share of the fire’s mapped area.

Where it burned

Acres inside each county, measured from the satellite-mapped perimeter.

Acres burned by county

Yukon-Koyukuk Census Area	AK	51,057

Other large fires in Alaska in 2005

Salmon Fork Fire255,430 acres
Old Dummy Fire238,884 acres
Holtnatkatna Creek Fire204,464 acres
North Bonanza Fire190,620 acres
Little Mud 2 Fire187,905 acres
Beaver Creek Fire184,035 acres
Chapman Creek Fire165,363 acres
Kandik River Fire156,377 acres

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service). Type recorded: Wildfire.