1. Streamflow Monitoring in the McMurdo Dry Valleys USGS cooperative activities with the MCMLTER NSF-funded project

2. USGS hydrologist gauging Onyx River

3. Streamflow monitoring in McMurdo Dry Valleys Onyx River in Wright Valley- in 1970 by New Zealand Antarctic Research Program Streams in Fryxell basin in Taylor Valley-in 1990 by USGS program supported by NSF All major streams in Taylor Valley and Onyx River- in 1993 by MCMLTER with USGS (Wyoming District since 1997)

4. Glacial meltwater streams:climatic connection between the glaciers and the lakes

6. Creek Canada Glacier Commonwealth Glacier Crescent Glacier Howard Glacier Green Delta Stream Harnish Stream Von Guerard Stream Aiken Creek Huey Canada Creek Stream St r e a m S e a l L o s t McKnight Creek C r e s c e n t S t r e a m N 2 km Relict Channel

7. USGS-MCMLTER Streamflow Monitoring Activities USGS hydrologist (or hydrologic technician) in the field for 1 month, working with graduate students in water resources from MCMLTER Graduate students analyze stage data following USGS protocols (using ADAPS) with guidance from hydrologists at Wyoming District office

8. McMurdo Dry Valleys, Antarctica Polar desert: Dry (<10 cm precip. Annually) Cold (average air temp. = -20 o C) –Meltwater streams flow for 6 to 14 weeks –Streamflow is 0.01 to 5 cfs (ft 3 /s), water temperature is 0.1 to 14 o C –High flows (>20 cfs) occur at decadal intervals –Habitat for benthic algae mats –Source and control of solute input to the lakes

9. Parshall flume used to obtain accurate discharge at low flow

10. Santa Fe Creek on 12/21/00: 35 cfs

11. Filamentous cyanobacteria (blue- green algae): orange algal mats

12. USGS Expertise Maintains Record Quality for Difficult Measurements Challenge-Extreme range of flows and unstable substrate Parshall flumes with weirs in cutoff wall- compound rating Natural channel controls High sediment load during high flow Temporary sites near glaciers

13. Maintenance of gauges to maintain record Green Creek gauge moved due to lake level rise Santa Fe gauge pummeled by 100 cfs (cubic feet/sec)

14. Streamflow monitoring in McMurdo Dry Valleys Streamflow data managed in MCMLTER relational database (Oracle) and available on MCMLTER website Future plans- upgrade measurement technology (acoustic doppler) and telemeter data in real time via satellite

16. Fryxell basin: streamflow greater during 89-92 than during 93-present

17. Wright Valley: Onyx River flow has also been lower since 93

18. Hyporheic zone, wetted zone adjacent to stream, stores water and enhances evaporation

19. In cold summers, streams retain water and nutrients, limiting inputs to lakes

20. The Stream Team (USGS & University of Colorado) acknowledges logistical support by PHI, ASA and Raytheon, and field assistance from other MCMLTER investigators