In July 1998, Donjek Glacier, Yukon Territory, Canada, produced a large
outburst flood. Unlike most such floods the source of water appears to
have been entirely subglacial. The flood must have been intense because
flood waters covered much of the broad valley of Donjek River, as
evidenced by the countless stranded icebergs. The ice canyon that formed
during the flood appears to have resulted from collapse of the ice roof
that enclosed the subglacial water tunnel.
|To enlarge any photo, click on it.
||The headwaters of Donjek River looking toward the terminal moraine
and stagnating terminus of Donjek Glacier. Note the stranded ice blocks
that were deposited during the subglacial outburst from Donjek Glacier.|
||The source of the flood waters. Water emerges from a subglacial
tunnel and enters the subaerial ice canyon. Evidently the ice canyon
was formed by collapse of a subglacial tunnel. During a subglacial
outburst flood the conduit area increases with time. Eventually the
conduit becomes too large to support the ice roof and collapse of the
roof occurs. Most of the icebergs strewn across the Donjek River valley
probably were associated with this unroofing.|
||As for Photo 1 but nearer the glacier terminus and showing the
hydrologic left bank of Donjek River. The white ice of lower Donjek
Glacier is more clearly revealed.|
||An ice-walled canyon cut into Donjek Glacier. The canyon was formed
during the outburst flood. The canyon walls are clearly unstable as
evidenced by ice that has collapsed into the canyon and the crevasses (white lines
trace the crevasses which cut across debris-covered ice) that are
forming near the canyon edges.|
||The hydrologic right bank of Donjek River looking toward the terminus
of Donjek Glacier. Regions that were inundated by the outburst flood
are indicated by stranded icebergs.|
||Looking downglacier through the ice canyon. The canyon walls are
roughly 30 m high and the channel width roughly 50 m.|
||The ice canyon (looking downflow) near the point at which subglacial
water emerges. The channel is cluttered with ice that has recently calved from the
canyon walls. |
||Ice calving from the canyon walls and cluttering the water channel.|
||The ice canyon terminates as a "blind" canyon. The water source is a
subglacial tunnel. (Looking up the moraine-covered Donjek Glacier.)|
||Icebergs stranded on gravel bars of Donjek Glacier.|
Satellite photos of the neighborhood of Donjek Glacier
The nearest settlement to Donjek Glacier is Burwash Landing, Yukon.
Below is a photo (from Google maps) centered at Burwash Landing.
The left edge and the ocean front is Alaska.
The bottom right edge is British Columbia.
All else is Yukon Territory (population 30,129).
Along the lowland on
the back side of the ice is the Alaska Highway.
You'll have fun if you zoom in.
To zoom in, point your browser to
and search for
"Burwash Landing, Yukon, Canada".
Then click "satellite" in the upper right corner of the screen.
Then fly around to your heart's content in your google/maps machine.
An easy picture-postcard goal is the merging of glaciers
directly south of Burwash Landing, "Kuskawulsh Glacier".
Another goal is to look for the Donjek glacier.