Bench Glacier Project

 

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Hydrology experiments 2002

 

Long length scale measurements of subglacial hydrology:

 

Ø      Installed 18 “Gophers” measuring water pressure, water conductivity, water turbidity, and water velocity. 

 

Ø      Each parameter sampled at 15 min intervals for a period of 1 year.

 

Ø      Gophers installed in boreholes extending 90-185 m to the glacier bed.  Data stored in surface data logger.  Gophers are retrievable by re-drilling boreholes with wire following drill.

 

Ø      Boreholes distributed in 9 evenly spaced sites along length of glacier; 2 holes per site.

 

 

 

 

 

Gopher and cable prior to installation.

 

90 days of gopher data (summer 2002).

 

 

Injecting a water slug into a borehole.

 

Oscillatory response of borehole water level to

slug

Slug tests:

 

Ø      80 l of water dumped into a borehole over a 20 second interval.

 

Ø      Slugs cause a response in holes adjacent to slugged hole.

 

Ø      Slug tests made in multiple boreholes and repeated over time.

 

Ø      Slug response changed over time and space.

 

 

 

 

More about slug tests…

 

Graduate student Jeremy Shaha calibrating pressure transducer.