John Halfman's Web Site:

John D. Halfman
Emeritis Professor of Geolimnology & Hydrogeochemistry
Inaugural Finger Lakes Institute Endowed Chair in Environmental Studies
Department of Geoscience & Envirnmental Studies Program
Finger Lakes Institute
Master of Science in Management Program 
Hobart and William Smith Colleges
Geneva, New York 14456
halfman@hws.edu, (315) 781-3918, FAX (315) 781-3860

Current / Recent Courses

Energy - An introductory/interdisciplinary course for Env. Studies co-taught Tom Drennen, Econ.
Environmental Science - A environmental science core course for Environmental Studies
Remote Sensing - A natural science course for Environmental Studies majors and elective course for Physics majors
Environmental Geology - An introductory non-majors course on environmental geology.
Introductory Hydrogeology -An introductory course for Geoscience & Env. Studies majors.
Environmental Hydrology - An upper-level course on surface & groundwater hydrology for Geoscience & Env. Studies majors
Fundamentals of GIS -An upper-level course on Geographic Information Systems for Env. Studies majors
Spatial Management Decisions - A graduate level course designed to collect, organize, manipulate, ananlyze, and output GIS Data using AcrGIS Pro Business Analysis Tools to investigate and make dicisions on spatial business issues.
Limnology - An advanced for majors course on the hydrogeochemistry of lakes. Not taught for a few years.
An Excel Primer - A tutorial and example environmental problem(s) for beginning Excel users.

For Reprints and Reports see Recent Publications section below...

For information about the lake water quality / meteorological monitoring buoys, ask Lise Cleckner, Cleckner@hws.edu.

Seneca Lake Water Quality - Water Quality Report for Seneca Lake
Seneca Lake Major Ion Hydrogeochemistry - A Hydrogeochemistry Paper for Seneca Lake
Atrazine in Seneca Lake & Its Watershed - The Concentration and Source of Atrazine
Nitrates in the Seneca Lake Watershed - A honors project by Lindsey Bowser, WS '0
Seneca Lake Zebra Mussels - Zebra Mussels in Seneca Lake

Owasco Lake Water Quality - Owasco Lake Water Quality Study

Finger Lakes Limnology, Water Quality Comparisons - Finger Lakes Water Quality

Seneca Lake Water Quality Movie -YouTube version
Seneca Lake Watershed Quality Degradation - PC/Apple Computer, mov, hi-resolution, 200 MB, version - Summer 2012. Largre screen view but it takes a while to load.
Seneca Lake Watershed Quality Degradation - IPad, m4v, lo-resolution, 30 MB, version - Summer 2012. Loads faster but smaller screen.

Movie on Water Sampling - Summer, 2011 (smaller format)
Movie on Water Sampling - Summer, 2011 (larger format)
Movie on Water Sampling - Summer, 2011 (*.mov file for older computers)

Special Interests

Building an Energy Efficient House
Environmental Studies Summer Youth Institute - Their Environmental Data
Science on Seneca - A high school outreach program on Seneca Lake
++++++> Seneca Lake Chloride/Sodium Concentrations Power Point
++++++> Seneca Lake Zebra & Quagga Mussel Power Point
Seneca Lake Pure Waters Association - A revitalized citizen-based, environmental, watchdog group
Seneca Lake Area Partners in 5 Counties (SLAP-5) - A watershed plan development team
Horses Marie and Camille.

Recent Publications (*student co-authors)

 
1. Halfman, J.D., M. Horvath.  2024. Chloride Hydrogeochemistry of the Finger Lakes in Central and Western New York, USA.  Anthropocene 45 (2024) 100428, https://doi.org/10.1016/j.ancene.2024.100428  
2. Long, James P., John D. Halfman, and Nathan Hawley, 2024. Internal wave resonance, surges, and strong nonlinear damping differentiated in two elongated lakes with the aid of an original Green’s function. Limnology and Oceanography 9999, 2024, 1-13. http://doi.org/10.1002/lno.12537 
3. Halfman, J.D., 2024. Observations based on multi-decadal limnological monitoring of the Finger Lakes. Keynote Presentation. 2024 Finger Lakes Research Conference. 4-pgs.
4. Halfman, J.D.,   Shaw, I. Dumitriu, L. Cleckner, 2023. Meteorological and Limnological Precursors to Cyanobacteria (HABs) blooms in Seneca and Owasco Lakes, New York, USA. Water, 15, 2363. https://doi.org/10.3390/w15132363 - Supplementary Tables.
5. Halfman, J.D., M. Horvath, E. Swenson, M. Geiger, I. Dumitriu, T. Massey & L. Cleckner, 2023. The 2022 Water Quality Monitoring Report,  Owasco Lake, NY.  Finger Lakes Institute, Hobart & William Smith Colleges. 47 pg.  OLWMC Presentation-1-17-23.
6. Halfman, J.D., M. Horvath, E. Swenson, M. Geiger, I. Dumitriu, T. Massey & L. Cleckner, 2023. 2022 Nearshore Monitoring of Cyanobacteria (Blue-Green Algae) in Seneca & Owasco Lakes. The Final Report to the Seneca Lake Pure Waters Association, Fred L. Emerson Foundation and Cayuga County. Finger Lakes Institute, Hobart & William Smith Colleges. 76 pg.
7.  Halfman, J.D., J. Shaw*, I. Dumitriu,  Baillos, T. Massey, C. Brown*, & L. Cleckner, 2022. 2021 Nearshore Monitoring of Cyanobacteria (Blue-Green Algae) in Seneca & Owasco Lakes. The 2021 Report to the Seneca Lake Pure Waters Association, Fred L. Emerson Foundation and Cayuga County. Finger Lakes Institute, Hobart & William Smith Colleges. 70 pg.
8.  Halfman, J.D., et al., 2022. 2021 Nearshore Monitoring of Cyanobacteria (Blue-Green Algae) in Seneca & Owasco Lakes Data Repository.
9.  Halfman, J.D.,  I. Dumitriu, & L. Cleckner, 2022. The 2021 Water Quality Monitoring Report, Owasco Lake, NY. Finger Lakes Institute, Hobart & William Smith Colleges. 53pg.
10. Halfman, J.D., 2021. Cyanobacteria (Blue-green algae) in the Finger Lakes, Central, NY.         American Institute of Professional Geologists, Northeast Section Spring Newsletter.
11. Halfman, J.D., A. Shaw*, I. Dumitriu, & L. Cleckner, 2021.  The 2020 Water Quality Monitoring Report, Owasco Lake, NY.  Finger Lakes Institute, Hobart & William Smith Colleges. 48 pg.
12. Halfman, J.D., S. Stone*, I. Dumitriu, & L. Cleckner, 2021. 2020 Nearshore Monitoring of Cyanobacteria (Blue-Green Algae) in Seneca & Owasco Lakes. The 2020 Report to the Seneca Lake Pure Waters Association, Fred L. Emerson Foundation and Cayuga County.  Finger Lakes Institute, Hobart & William Smith Colleges. 62 pg.
13. Halfman, J.D., et al., 2021.  2020 Nearshore Monitoring of Cyanobacteria (Blue-Green Algae) in Seneca & Owasco Lakes Data Repository.
14. Halfman, J.D., B. Kharrazi*, E. Wilber*, A. Leavitt*, W. White*, E. Moore*, P. Spacher, I. Dumitriu, E. Helming, M. Kastan, T. Massey & L.B. Cleckner, 2020. Dockside monitoring of Blue-Green Algae in Seneca Lake. The 2019 FLI report to the Seneca Lake Pure Waters Association. Finger Lakes Institute, Hobart and William Smith Colleges. 40 pg.
15. Halfman, J.D., B. Kharrazi*, E. Wilber*, A. Leavitt*, J. Andrews*, W. White*, E. Moore*, P. Spacher, I. Dumitriu, M. Kastan, E. Rosser, T Massey & L.B. Cleckner, 2020. Blue-Green Algae in Owasco Lake, the 2019 Update. The 2019 Annual Report to the Fred L. Emerson Foundation. Finger Lakes Institute, Hobart and William Smith Colleges. 36 pg.
16. Halfman, J.D., B. Kharrazi*, E. Wilber*, A. Leavitt*, J. Andrews*, P. Spacher, I. Dumitriu & L.B. Cleckner, 2020. The 2019 Water Quality Monitoring Report, Owasco Lake, NY. Finger Lakes Institute, Hobart and William Smith Colleges. 48 pg.
17. Halfman, J.D., B. Kharrazi*, S. Johnson*, J. Francois*, K.E. Valicenti*, E. Wilber*, J. Andrews*, P. Spacher, I. Dumitriu, K. Amejecor*, T. Massey & L.B. Cleckner, 2018. Blue-Green Algae in Owasco Lake: The 2018 Update. The 2018 Annual Report to the Fred L. Emerson Foundation, Finger Lakes Institute, Hobart and William Smith Colleges. 37 pg.
18. Halfman, J.D., I. Dumitriu, & L.B. Cleckner, 2018. Final Report on the Owasco Lake HAB Inhibiting Technologies Assessment. Submitted to Owasco Watershed Lake Association. 57 pg.
19. Halfman, J.D., B. Kharrazi*, S. Johnson*, J. Francois*, K. E. Valicenti*, E. Wilber*, J. Andrews*, P. Spacher, I. Dumitriu & L.B. Cleckner, 2018. The 2018 Water Quality Monitoring Report, Owasco Lake, NY. Finger Lakes Institute, Hobart and William Smith Colleges. 47 pg.
20. Halfman, J.D., S. Bradt*, D. Doeblin*, K. Homet*, P. Spacher, I. Dumitriu, J. Andrews*, M. Gad*, T. Massey, D. Ryan*, N. Nguyen* & L. Cleckner, 2017. Blue-Green Algae in Owasco Lake. The 2017 Annual Report to the Fred L. Emerson Foundation. Finger Lakes Institute, Hobart and William Smith Colleges. 27 pg.
21. Halfman, J.D., S. Bradt*, D. Doeblin*, K. Homet*, J. Andrews*, M. Gad*, P. Spacher & I. Dumitriu, 2017. The 2017 Water Quality Report for Owasco Lake, NY. Finger Lakes Institute, Hobart and William Smith Colleges. 46 pg
22. Halfman, J.D., 2017. Decade-scale water quality variability in the eastern Finger Lakes, New York. Clear Waters. Fall 2017, v. 47, No. 3, pg. 20-32. http://nywea.org/clearwaters/uploads/Decade-ScaleWater7.pdf
23. Halfman, J.D., 2017. Water quality of the eight eastern Finger Lakes, New York: 2005-2016. Finger Lakes Institute, Hobart and William Smith Colleges. 51 pg.
24. Halfman, J.D., H.A, Simbliaris, B.N. Swete, S. Bradt, M.C. Kowalski, P Spacher & I. Dumitriu. 2016. The 2016 Water Quality Report for Owasco Lake, NY. Finger Lakes Institute, Hobart and William Smith Colleges. 51 pg.
25. Halfman, J.D., K. Coughlin*, A. Dylag*, R Ratsep*, & N. Tanquary*. 2015. Owasco Lake, New York 2015 Annual Report:  Water Quality & Nutrient Source Monitoring, Detailed Dutch Hollow Nutrient Loads & Detailed Water Quality Buoy Data.  Finger Lakes Institute, Hobart and William Smith Colleges.  48 pg.
26. Halfman, J.D., G. Moralez, K. Coughlin, and N. Andrzejczyk, 2014. Owasco Lake, New York:  Water quality and Nutrient Sources, 2014 Findings.  Finger Lakes Institute, Hobart and William Smith Colleges.  43 pg.
27. Halfman, J.D., 2014. An 2014 update on the chloride hydrogeochemistry in Seneca Lake, New York. Finger Lakes Institute, Hobart and William Smith Colleges.  27 pg.
28. Halfman, J.D., 2014. Finger Lakes impacted by heavy mid-May rain/runoff. 12 pages.
29. Halfman, J.D., A Cole*, G Moralez* & T Goldstoff*, 2013.  Owasco Lake, New York:  Water quality and Nutrient Sources, 2013 Findings.  Finger Lakes Institute, Hobart and William Smith Colleges.  41 pg,
30. Brown, M.E., T.M. Curtin, C.J. Gallagher* and J.D. Halfman, 2012. Historic nutrient loading and recent species invasions cause shifts in zooplankton demography and water quality in two Finger Lakes (New York, USA).  J of Paleolimnology.  48: 623-639.
31. Halfman, J.D., Meyer, S., Cleckner, L., Robertson, C.M. & D. Zorn., et al., 2012. Seneca Lake Management Plan, Characterization and Subwatershed Evaluation. Hobart & William Smith Colleges, Finger Lakes Institute, Genesee/Finger Lakes Regional Planning Council, Southern Tier Central Regional Planning and Development Board. 155 pg.
32. Halfman, J.D., E. Black*, L. Carver Dionne*, C. Ellis* and P. Hackett*, 2012. Owasco Lake, New York: Water quality and nutrient sources, a 2012 update. Finger Lakes Institute, Hobart and William Smith Colleges. 42 pg.
33. Halfman, J.D., 2011. Water quality of Seneca Lake, New York: A 2011 Update (ver 2). Finger Lakes Institute, Hobart and William Smith Colleges.  41 pg
34. Halfman, J.D., E.G. Cummings* and M.M. Stewart*, 2011.  Owasco Lake, New York:  Water Quality and Nutrient Sources, A 2011 Update.  Finger Lakes Institute, Hobart and William Smith Colleges.  44 pg
35. Halfman, J.D., 2010. Owasco Lake: A 2010 Update. Finger Lakes Institute, Hobart and William Smith Colleges. 24 pg.
36. Halfman, J.D., and K.O. O’Neill*, 2010.  Water quality and nutrient sources in the Owasco Lake watershed:  A 2010 Update.  Finger Lakes Institute, Hobart and William Smith Colleges.  22 pg
37. Halfman, J.D., 2009. Wastewater Treatment: Where do Toilet & Sink Wastes Go?
38. Halfman, J.D., 2009. Landfills:  Where Does Our Trash Go? 
39. Burtch, N., 2009. Landfill and Wastewater Treatment Facilities in the Finger Lakes Region.
40. Halfman, J.D., and P. Basnet*, 2009.  Bottom-water phsophates and suspended sediments in southern Cayuga Lake, New York.  Finger Lakes Institute, Hobart and William Smith Colleges.  21 pg.
41. Halfman, J.D., and K. O’Neill*, 2009.  Water quality of the Finger Lakes, New York:  2005 – 2008.  Finger Lakes Institute, Hobart and William Smith Colleges.  33 pg.
42. Halfman, J.D., T.F. Ware*, and K.A. O’Neill*. 2008.  The 2007 Progress Report: Phosphate and suspended sediment distribution and potential sources to southern Cayuga Lake.  Finger Lakes Institute, Hobart and William Smith Colleges.  9 pg.
43. Halfman, J.D., E.S. Brown*, T.F. Ware*, K.A. O’Neill*, C.K. Franklin* and R.E. Dye*, 2008.  Owasco Lake, New York:  Water Quality and Nutrient Sources.  In: Halfman, J.D., M.E. Balyszak and S.A. Meyer (eds.), A 2007 Water Quality Study of Owasco Lake, New York.  Finger Lakes Institute, Hobart and William Smith Colleges.  37 pg.
44. Halfman, J.D., and C.K. Franklin*, 2008.  Water Quality of Seneca Lake, New York: A 2007 Update.  Finger Lakes Institute, Hobart and William Smith Colleges.
45. Halfman, J.D., B.L. Holler*, and H.M. Philip*, 2006.  A preliminary water quality study of Owasco Lake, NY, and its watershed. Finger Lakes Institute, Hobart and William Smith Colleges. 26 pg.
46. Halfman, J.D., C.M. Caiazza*, R.J. Stewart*, S.M. Opalka*, and C.K. Morgan*. 2006., Major ion hydrogeochemical budgets and elevated chloride concentrations in Seneca Lake, New York.  Northeastern Geology and Environmental Sciences, v. 28, p. 324-333.
47. Halfman, J.D., and K. F. Bush*, 2006. A Preliminary Water Quality Study of selected Finger Lakes, New York. Finger Lakes Institute Report, 15 pg.
48. Halfman, J.D., I West*, T.M. Hintz*, and B.A. Beckingham* and many other undergraduate students, 2006. Water Quality and Pollution Sources to the Keuka Outlet, 2003-2005. Report to the Torrey Ad-Hoc Water Quality Committee. 12 pg text, 13 pg data & figures.
49. Halfman, J.D., D.E. Dittman, R.W. Owens, and M.D. Etherington*, 2006. Storm induced redistribution of deepwater sediments in Lake Ontario. J of Great Lakes Research. 32: 348-360.
50. Riley*, T.C., T.A. Endreny, and J.D. Halfman, 2006, Monitoring soil moisture and water table height with a low-cost data logger. Computers and Geoscience. 32: 135-140.
51. Halfman, J.D., D. Wood*, and S. Strong*, 2004. Bathymetric Survey of Owasco Lake for the Institute for the Application of Geospatial Technology (IAGT), Auburn, New York. In-House Report, Finger Lakes Institute, Hobart and William Smith Colleges.
52. Eyles, N., M Doughty, J.I. Boyce, H.T. Mullins, J.D. Halfman and B. Koseogulu*, 2002, Acoustic architecture of ice-contacted glaciolacustrine sediments deformed during zonal stagnation of the Laurentide Ice Sheet; Mazinaw Lake, Ontario, Canada. Sedimentary Geology. 157: 133-151.
    
53. Halfman, J.D., S.M. Baldwin*, J.P. Rumpf* and M.B. Giancarlo*, 2001, The impact of the zebra mussel (Dreissena polymorpha) on the limnology, geochemistry and sedimentology of Seneca Lake, New York. Wagenet, L.P., D.A. Eckhardt, N.G. Hairston, D.E. Karig, and R. Yager, eds., A Symposium on the Environmental Research in the Cayuga Lake Watershed. October 12, 1999. Natural Resource, Agriculture and Engineering Service (NRAES), Cooperative Extension, Cornell University. P. 154-166.
54. Mullins, H.T. and J.D. Halfman, 2001. High-resolution deglacial and post glacial seismic stratigraphy of Owasco Lake, New York. Quaternary Research, v. 55, p. 322-331.
55. Dedrick*, R.R., J.D. Halfman & D.B. McKinney, 2000. An inexpensive, microprocessor-based, data logging system. Computers and Geosciences, v. 26, p. 1059-1066.
56. Eyles, N., J.I. Boyce*, J.D. Halfman and B. Koseogulu*, 2000, Seismic-stratigraphy of Waterton Lake, a sediment starved glaciated basin in the Rocky Mountains of Alberta, Canada and Montana, USA. Sedimentary Geology. v. 130, p. 283-311.
57. Halfman, J.D., 2000, Stratigraphy, sedimentology, and geochemistry of Seneca Lake, New York. New York State Geological Association Annual Meeting. NYSGA Field Trip Guidebook. p. 27-38.
58. Halfman, J.D., and many undergraduate students*, 1999. Limnology and Water Quality. Chapter 6A. Setting the Course for Seneca Lake - The State of the Seneca Lake Watershed, 1999. Chap 6A, 28 p.
59. Halfman, J.D., and many undergraduate students*, 1999, Seneca Lake Stream Water Quality. Chapter 6B, Setting the Course for Seneca Lake - The State of the Seneca Lake Watershed, 1999. Chap 6B, 16 p.
60. Halfman, J.D., and D.T. Herrick*, 1998, Mass-movement and reworking of late glacial and postglacial sediments in northern Seneca Lake, New York. Northeastern Geology and Environmental Sciences, 20: 227-241.

Various earlier papers on paleoclimate and lake studies:

1. Vollmer, M.K, H.A. Bootsma, R.E. Hecky, G. Patterson, J.D. Halfman, J.M. Edmond, D.H. Eccles, & R.F. Weiss, 2005, Deep-Water Warming Trend in Lake Malawi, East Africa.  Limnology & Oceanography.  50: 727-732.
2. Halfman, J.D., T.C. Johnson and B.P. Finney, 1994, New AMS dates, stratigraphic correlations and decadal climatic cycles for the past 4 ka at Lake Turkana, Kenya.  Palaeogeography, Palaeoclimatology, Palaeoecology, 111: 83-98.
3. Halfman, J.D., 1993, Water column characteristics from modern CTD data, Lake Malawi, Africa.  Journal of Great Lakes Research, 19: 512-520.
4. Halfman, J.D. and C.A. Scholz, 1993, Suspended sediments in Lake Malawi, Africa: A reconnaissance study.  Journal of Great Lakes Research, 19: 449-511.
5. Halfman, J.D., D.F. Jacobson, C.M Cannella, K.A. Haberyan & BP Finney, 1992, Fossil Diatoms and the mid to late Holocene paleolimnology of Lake Turkana, Kenya: A reconnaisance study. J Paleolimnology, 7: 23-35.
6. Halfman, J.D. and T.C. Johnson, 1988, High-resolution record of cyclic climatic change during the past 4 Ka from Lake Turkana, Kenya.  Geology, 16: 496-500.
7. Johnson, T.C., J.D. Halfman, W.H. Busch and R.D. Flood, 1984, Effects of bottom currents and fish on sedimentation in a deep-water, lacustrine environment.  Geological Society of America, Bulletin, 95: 1425-1436.
8. Halfman, J.D., and T.C. Johnson, 1984, Enhanced atmospheric circulation over North America during the Early Holocene: Evidence from Lake Superior. Science, 224, 61-63.