May 16 2019

Field Report: May 16th, 2019

Vertical scale bar measuring water level along the rock wall.

Vertical scale bar along the rock wall.

image of ice and water in a glacial basin

Recently exposed bedrock on the south side of the basin. 

a person rappels into an ice-filled basin.

Jamie Pierce, USGS hydrologist, installing the level gauges.

a basin filled with ice and some water

The basin looked relatively empty as of mid-April.

a person installs camera equipment on a rock face above an ice-filled basin

Jamie installing the Nupoint camera. We also installed two temperature sensors and two precipitation gauges.

equipment measuring ice melt on a glacier

We measured 2.4 m of ice melt since last September.

GPS equipment on the ice in suicide basin

GPS on top of the ice dam. Note the elevation drop into the basin.

We installed the non-telemetered water level gauges, webcam, temperature and precipitation gauges, and the on-ice GPS. We also measured ice melt. We didn’t fly the drone and weren’t able to access/survey the water surface this time.

Access to the basin has become challenging given the drastic glacier thinning. We found some freshly exposed bedrock on the south side of the basin (photos below), suggesting that the remaining ice in that immediate area must be thin. During our visit, the water level was several meters lower than at the same time last year. The level has been rising since (links to movies and figures below). It is currently (2019-05-28) at around 400 m a.s.l., which is 25 m higher than during our last site visit last year (21 September 2018, 375 m a.s.l.). For reference, the maximum (pre-GLOF) water level in 2018 was ~442 m and the post-GLOF water level was ~386 m a.s.l.

Using the drone-based elevations models from last year, I derived an approximate vertical scale for the rock face on the north side of the basin. This scale is plotted on top of the telemetered photos (links below) and gives an approximate idea about the ice/water elevation in absence of telemetered water level measurements.