Jun 7 2019

Field Report: June 7th, 2019

Image from a timelapse camera in the basin, with a scale to measure water level.

Image from a timelapse camera in the basin from June 7, 2019, with a scale to measure water level.

image of ice and water in a glacial basin

The water level in the basin from June 2019 and May 2018.

GPS equipment on ice near a rock wall

GPS equipment measuring the low point in the ice dam for June 2019.

a chart containing values of lake volumes for Suicide Basin

Potential lake volumes for different Pre-GLOF and Post-GLOF water level combinations.

ice in a basin with steep rock walls

Photos from the June 7, 2019, field visit.

ice flowing from mendenhall glacier in to a basin

Photos from the June 7, 2019, field visit.

aerial image of a glacier

Photos from the June 7, 2019, field visit.

ice in suicide basin

Photos from the June 7, 2019 field visit.

ice and water in suicide basin

Photos from the June 7, 2019 field visit.

a person stands on rock above a glacier with scientific equipment

 Eran Hood during the June 7, 2019 field visit.

mountains and ice at mendenhall glacier

Photos from the June 7, 2019, field visit.

aerial image of ice in suicide basin

Photos from the June 7, 2019, field visit.

We drilled in a new melt wire at the basin entrance (to continue the ice melt measurements we started last spring), deployed the drone (for DEMs and orthoimages), surveyed the lowest point in the dam (to constrain the maximum water level), and deployed additional air temperature sensors higher up in the basin (to facilitate melt modeling across the entire Suicide Basin watershed).

The lake level has risen by approximately 15 m since our last site visit on 16 May. While we still couldn’t access/survey the waterline, our drone data indicated the water was at 406.5 m, which is close to the water level read from the scale bar in the Nupoint timelapse images (within 1–2 m).

Comparing Friday’s photo to last year’s photos confirms a water level between 406 and 407 m (next figure). The dates on the photos compared also indicate that the lake level is approximately one week delayed compared to last year.     

The lowest point in the dam (and thus the highest possible water level) is currently at 439 m a.s.l. and will keep dropping during the melt season. The low point was at 442 m last year when the lake overtopped the dam.

Based on a DEM from last fall (taken at low water levels), I compiled a lake volume lookup table that provides lake volume estimates for different pre-GLOF and post-GLOF water level combinations:

For reference, last year’s post-GLOF water level is marked in orange color. The current water level can be estimated from the scale in the time-lapse images. This morning, the water level was at approximately 408 m a.s.l.