landslide and pond

Water backs up behind a natural dam on the Black Rapids Glacier. This dam formed from one of 3 enormous landslides that cover the entire width of the glacier. The landslides occurred in 2002 after a 7.9 earthquake on the Denali Fault that runs along the length of the Black Rapids Glacier. While the debris cover itself is not very thick, a few meters at most, the rock insulates the ice beneath it so there is less melt in the summer months compared to the surrounding ice. The height difference between the top of the debris here and the ice surface I took this photo from is due almost entirely to the difference in the amount of melt of insulated and non-insulated ice over the previous 11 years.

Andy drills a new hole for the antenna at the continuous (year-round) GPS station on the Loket tributary.

The continuous GPS station on the Loket tributary.

Recording pole heights adds to the seasonal melt record and lets us know when we need to re-drill poles.

After doing some GPS maintenance we hiked down to the landslide. One of the main channels kept getting deeper as we hiked downstream.

The channel was a little over six feet deep where it finally disappeared.

Hiking along a small supraglacial channel on a large tributary to the Black Rapids Glacier.

Surface stream flowing toward one of the landslides. This one dropped into a moulin under the snow here.

Slow-moving and ponding water at the edge of the landslide debris.

Andy next to the pond and landslide for scale