Chalkyitsik Complex

2019470,271 acresAlaska

The Chalkyitsik Complex burned 470,271 acres, about 735 square miles, across Yukon-Koyukuk Census Area. It began on July 9, 2019.

Watch how it happened

Chalkyitsik Complex · 2019

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

Detections31,579satellite fire pixels

Fire milestones

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

Burning nowAreas reached in the last half day of satellite passes

Houston, to scale640 square miles of land, drawn at the fire’s scale

Timing: NASA FIRMS satellite fire detections (25,404 VIIRS and 6,175 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 Chalkyitsik Complex

Burn severity by class
Severity	Share	Acres
Highmost vegetation consumed, soils altered	6.5%	30,536
Moderatemixed: many trees killed, some survive	27%	126,750
Lowsurface fire, most trees survive	44%	206,462
Unburned to lowislands inside the perimeter, little change	20%	94,988
Increased greennessvegetation greener after the fire than before	0.2%	1,094
Not mappedcloud, shadow or water in the satellite images	2.2%	10,440

6% of the area inside the perimeter burned at high severity, about 30,536 acres; 33% 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	470,521

Other large fires in Alaska in 2019

Hess Creek Fire181,319 acres
Old Grouch Top Fire173,850 acres
Swan Lake Fire164,759 acres
Hurst Creek Fire139,315 acres
North River Fire110,985 acres
Black River Fire103,354 acres
Little Mud River Fire98,159 acres
Little Crazy Mountain Fire78,237 acres

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