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Project Summary Sheet

U.S. Geological Survey, Greater Everglades Science Program (Place-Based Studies Initiative)

Fiscal Year 2003 Project Summary Report


Project Title: Ground Water - Surface Water Seepage at Select TIME Sites

Project Start Date: July 14, 2003 Project End Date: Sept, 2004

Web Sites: TIME

Location (Subregions, Counties, Park or Refuge): ENP

Funding Source: USGS's Greater Everglades Science Initiative (PBS)

Principal Investigator(s): Peter Swarzenski

Project Personnel: Chris Reich

Supporting Organizations: ENP

Associated / Linked Projects: Dr. Langevin's GW work

Overview & Objective(s): The intent of this sub-Task is to provide continuous flux estimates across the sediment-water interface (i.e., groundwater-surface water exchange) at select sites within ENP in support of Dr Langevin's numerical models on GW-SW exchange. With Quantum Engineering, we have developed very robust and precise electro-magnetic seepmeters that can autonomously measure very fine flux rates across the sediment-water interface. We will calibrate and validate date from the EMS meters two-fold: 1) Dr Matt Charette (WHOI) is bringing his newly developed and tested Woods Hole Oceanographic Inst. seepmeter to our site for an intercalibration experiment. We will leave both types of autonomous seepmeters in the field for approximately 1-week. 2) We will also deploy a continuous 222Rn profiler that will provide a stream of radon-222 measurements from the water column adjacent to the seepmeters. Such an approach will allow for a detailed calibration of seepage against 222Rn measurements.

Status: Our two electromagnetic seepmeter prototypes are now complete and have been undergoing bench tests here in St. Petersburg. One of the hurdles we are currently overcoming is being able to provide enough portable electricity to power the computers and meters at the remote site in ENP. Our Rad-7 Aqua is now operational and will be able to continuously provide very precise 222Rn measurements to supplement our seepmeter data.

We will be in the field with these EM seepmeters starting August 19th with Drs Langevin and Charette and others. WHOI will join us in the fieldwork for intercalibration studies (see above) of our seepage meters. One successful field trip has been completed this year to collect interstitial waters for Ra isotopic measurements. A diffusive-advective flux estimate of GW-SW exchange can be derived from these profiles.

Recent & Planned Products: Field work is scheduled for the week of Aug 19th. From this field trip we plan to provide a 7-day time series of bi-directional flux across the sediment-water interface. Data from two very different seepage meter prototypes will be assessed along with the A longer termed assessment of the bidirectional flux across the sediment-water interface at select TIME sites. Time series metals/nutrient profiles should provide an estimate of the role of GW-SW exchange processes. Intercalibration results will be written up as follows.

Swarzenski, PW, Charette, M and Langevin, C. (2003) A new look at GW-SW exchange rates using autonomous seepage meters and continuous radon-222 measurements. USGS Open file report. IN PREP.

Swarzenski, PW, Charette, M and Langevin, C. (2003) A new look at GW-SW exchange rates using autonomous seepage meters and continuous radon-222 measurements. USGS Fact Sheet. IN PREP.

Swarzenski, PW, Charette, M and Langevin, C. (2003) A new look at GW-SW exchange rates using autonomous seepage meters and continuous radon-222 measurements. Limnology and Oceanography. IN PREP.

Relevance to Greater Everglades Restoration Information Needs: GW-SW exchange models and observations are essential for comprehensive ecosystem assessments and critical evaluations. We have now developed the technology to very precisely measure the bidirectional GW-SW exchange to support of Dr Chris Langevin's flow models.

Key Findings: Stay tuned for above mentioned products and findings.




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