Understanding the response of Alaska's ecosystems to a changing climate to support resource managers and sustainable communities

 

photo of the water level of Suicide Basin

Figure one from field site visit on July 10th, 2018.

Current situation

As of 6:00 pm today, the water level in Suicide Basin was still rising. According to our estimates, current water volumes in Suicide Basin are in the ballpark of the 2016 flood. Today at noon, the median of our Monte Carlo simulations yielded 0.0325 km3, while the volume of the 2016 flood was approximately 0.035 km3.

ice from a glacier in a basin

Photo from site visit on July 24th, 2019

We completed our post-drainage site visit on 24 July, roughly one week after completion of the lake drainage. We surveyed the basin with the drone, measured ice melt at the melt wires, and also installed a new melt wire up on Suicide Glacier. This new melt wire at 950 m above sea level complements the temperature sensor deployed next to Suicide Glacier and allows for a melt model calibration across the entire Suicide Basin watershed.    

View across the overflowing portion of the lake. The water runs along the glacier boundary towards Mendenhall Lake visible in the far distance.

View across the overflowing portion of the lake. The water runs along the glacier boundary towards Mendenhall Lake visible in the far distance. Photo by Christian Kienholz.

As smoke from distant wildfires clouds the skies above Southeast Alaska, Juneau residents have a much closer hazard on their minds. Warm weather sped up water collection in Suicide Basin, a glacier-dammed lake adjoining Mendenhall Glacier that has generated outburst floods regularly over the last decade. On Sunday, July 7th, the basin water level reached a point where it began to overtop the Mendenhall Glacier ice dam, flowing along the side of the glacier towards Mendenhall Lake. Almost one week later, on July 13th, the basin began draining beneath the glacier.

ice from a glacier in a basin

Photo from site visit on July 8th, 2019

The lake started overtopping the dam on Sunday 7 July in the morning and reached its maximum level shortly thereafter. The water level in the basin has been slowly dropping since due to erosion of the overflowing water at the ice dam. Subglacial drainage has not begun as of Monday afternoon. In 2018, the lake started draining subglacially within ~24 hours of dam overtopping. The timeline will be different this season, however, accurate predictions are not possible. We suspect subglacial drainage will happen within the next few days.

ice from a glacier in Suicide Basin

Photo from site visit on July 5th, 2019

The water in Suicide Basin has gone up by 8.25 m over the last week. On Friday afternoon, the lake level was at 436 m, which is within 1.5 to 2.0 m of the lowest point of the dam.

Dam overtopping will likely start between Saturday 6 July and Sunday 7 July. The lake may start draining subglacially before or after overtopping. In 2018, the lake started draining subglacially within ~24 hours of dam overtopping, however, the timeline may be different this season.

Suicide Basin

Photo from site visit on June 28th, 2019

The water in Suicide Basin has gone up by 7 m (~1 m per day) since our last site visit on 21 June. On Friday afternoon, the surveyed lake level was at 427.75 m, which is ~10 m below the lowest point of the dam. Given the very warm weather and thus increasing filling rates over recent days, dam overtopping may start in early July. This is only a rough estimate for the timing of the subglacial lake drainage, since the lake may drain before or after overtopping.

People at desks take notes

Participants learned tools for communicating their science from media experts. Photo by Heather McFarland.

Scientists with the AK CASC and International Arctic Research Center (IARC) learned skills in interacting with the media and communicating their work clearly during the day-long training.

ice from a glacier in a basin

Photo from field visit on June 21st, 2019

The water in Suicide Basin has gone up by 14 m (~1 m per day) since our last site visit on 7 June. On Friday afternoon, the surveyed lake level was at 420.35 m and thus ~18 m below the lowest point of the dam. Based on filling rates from previous years, dam overtopping may start around 12 July (see graph on the new NOAA website https://www.weather.gov/ajk/suicideBasin). This is only a rough estimate, since the lake may drain before overtopping and since filling rates may change from day to day.

Women with backpack and paddle stands near sign in mountains

Image courtesy of Amy Macpherson

Amy Macpherson joins us as the SNAP and AK CASC Data Manager and Analyst. Macpherson will be assisting with assisting researchers with metadata creation and maintenance and in keeping data organized and accessible for all users.

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.

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).

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Research Highlight

Eran Hood is an Associate Professor at the University of Alaska Southeast (UAS) where he teaches undergraduate courses in environmental science, hydrology, and biogeochemistry. We talked about some of his projects and the upcoming field season.

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