Bermuda institute of Ocean Sciences
17 Biological Lane
St. George's GE 01
Bermuda
Tel: 441-297-1880 ext. 711
Fax: 441-297-8143
E-mail: peter.sedwick@bios.edu



Specialization:
Marine Biogeochemistry

Profile:
Dr. Sedwick received his Ph.D. in oceanography from the University of Hawaii in 1991, where he studied the geochemistry of hydrothermal vents on the summit of the submarine volcano Lo'ihi. Following postdoctoral work at the University of Hawaii and the University of Kiel (Germany), he was a research scientist at the Antarctic Cooperative Research Center, University of Tasmania, from 1993 until joining BIOS in 2001. Dr. Sedwick's current research interests include the marine biogeochemistry of trace metals, with an emphasis on iron and its role in regulating marine phytoplankton growth; the atmospheric transport of soil dust and the associated deposition of trace metals to the surface ocean; and the paleoenvironmental records contained in marine sediments and Antarctic ice cores. Dr. Sedwick is involved in field research programs in the Bermuda region of the North Atlantic and in the Ross Sea, Antarctica. He also manages the marine-atmospheric sampling facility (AEROCE tower) at Tudor Hill, on the southwest coast of Bermuda.

Current Research:

• Solubility of aerosol iron in seawater, and impact of atmospheric deposition on the distribution and speciation of iron in the upper ocean.
• Distribution and speciation of iron in the Ross Sea, Antarctica, and effects on phytoplankton growth and community composition.
• Iron requirements and physiology of Phaeocystis antarctica using laboratory culture experiments.
• Geochronology of Holocene sediment cores from the Antarctic continental shelf.
• Past atmospheric iron deposition from analysis of iron in glacial ice cores from Law Dome, East Antarctica.
• Origin of elevated marine deposits on Bermuda.

Educational Background:

• B.S. Chemistry (High Honors), University of Hawaii, 1983
• Ph.D. Oceanography, University of Hawaii, 1991

Selected Publications: 

• Sedwick, P.N., T.M. Church, A.R. Bowie, C.M. Marsay, S.J. Ussher, K.M. Achilles, P.J. Lethaby, R.J. Johnson, M.M. Sarin and D.J. McGillicuddy. 2005. Iron in the Sargasso Sea (Bermuda Atlantic Time-series Study region) during summer: Eolian imprint, spatiotemporal variability, and ecological implications. Global Biogeochemical Cycles, 19, doi:10.1029/2004GB002445.
• Sedwick, P.N., P.T. Harris, L.G. Robertson, G.M. McMurtry, M.D. Cremer and P. Robinson. 2001. Holocene sediment records from the continental shelf of Mac. Robertson Land, East Antarctica. Paleoceanography, 16:212-216.
• Sedwick, P.N. and G.R. DiTullio. 1997. Regulation of algal blooms in Antarctic shelf waters by the release of iron from melting sea ice. Geophysical Research Letters, 24:2515-2518.

Publications in Peer-reviewed Journals:

• G. M. McMurtry, D. R. Tappin, P. N. Sedwick, I. Wilkinson, J. Fietzke, and B. Sellwood (2007), Reply to Mega-highstand or megatsunami? Discussion of McMurtry et al. "Elevated marine deposits in Bermuda record a late Quaternary megatsunami": Sedimentary Geology, 200, 155-165, 2007 (Aug. 07) by Paul J. Hearty and Storrs L. Olson, Sedimentary Geology, in press.
• P. N. Sedwick, E. R. Sholkovitz, and T. M. Church (2007), Impact of anthropogenic combustion emissions on the fractional solubility of aerosol iron: Evidence from the Sargasso Sea, Geochem. Geophys. Geosyst., 8, Q10Q06, doi:10.1029/2007GC001586. [This paper was featured as a Research Highlight in Nature Geoscience, published on-line as doi:10.1038/ngeo.2007.32]
• P. N. Sedwick, N. Garcia, S. F. Riseman, C. M. Marsay, and G. R. DiTullio (2007), High iron requirements of colonial Phaeocystis antarctica under low irradiance, Biogeochemistry, doi: 10.1007/s10533-007-9081-7.
• G. R. DiTullio, N. S. Garcia, S. F. Riseman, and P. N. Sedwick (2007), Effects of iron concentration on the pigment composition of Phaeocystis antarctica in the Ross Sea at low irradiance, Biogeochemistry, doi: 10.1007/s10533-007-9080-8.
• G. M. McMurtry, D. R. Tappin, P. N. Sedwick, I. Wilkinson, J. Fietzke, and B. Sellwood (2007), Elevated marine deposits in Bermuda record a late Quaternary megatsunami, Sedimentary Geology, doi: 10.1016/j.sedgeo.2006.10.009.
• C. E. Hare, G. R. DiTullio, S. F. Riseman, A. C. Crossley, L. C. Popels, P. N. Sedwick, and D. A. Hutchins (2007) Effects of changing continuous iron input rates on a Southern Ocean algal assemblage, Deep-Sea Research I, 54, 732-746.
• K. S. Johnson, E. Boyle, K. Bruland, K. Coale, C. Measures, J. Moffett, A. Aguilar-Islas, K. Barbeau, B. Bergquist, A. Bowie, K. Buck, Y. Cai, Z. Chase, J. Cullen, T. Doi, V. Elrod, S. Fitzwater, M. Gordon, A. King, P. Laan, L. Laglera-Baquer, W. Landing, M. Lohan, J. Mendez, A. Milne, H. Obata, L. Ossiander, J. Plant, G. Sarthou, P. Sedwick, G. Smith, B. Sohst, S. Tanner, S. Van den Berg, and J. Wu (2007), The SAFe iron intercomparison cruise: An international collaboration, Eos, 88, 131-132.
• R. Edwards, P. Sedwick, V. Morgan, and C. Boutron (2006), Iron in ice cores from Law Dome: A record of atmospheric iron deposition for maritime East Antarctica during the Holocene and Last Glacial Maximum, Geochemistry, Geophysics, Geosystems, 7, doi:10.1029/2006GC001307.
• E. R. Sholkovitz and P. N. Sedwick, Open-ocean deployment of a buoy-mounted aerosol sampler on the Bermuda Testbed Mooring: Aerosol iron and sea salt over the Sargasso Sea, Deep Sea Research Part I, 53, 547-560, 2006.
• P. N. Sedwick, T. M. Church, A. R. Bowie, C. M. Marsay, S. J. Ussher, K. M. Achilles, P. J. Lethaby, R. J. Johnson, M. M. Sarin, and D. J. McGillicuddy, Iron in the Sargasso Sea (Bermuda Atlantic Time-series Study region) during summer: Eolian imprint, spatiotemporal variability, and ecological implications, Global Biogeochemical Cycles, 19 , doi:10.1029/2004GB002445, 2005.
• A. R. Bowie, P. N. Sedwick and P. J Worsfold, Analytical intercomparison between flow injection-chemiluminescence and flow injection-spectrophotometry for the determination of picomolar concentrations of iron in seawater, Limnology and Oceanography Methods, 2, 42-54, 2004.
• A. R. Bowie, E. P. Achterberg, P. N. Sedwick, S. Ussher and P. J. Worsfold, Real-time monitoring of picomolar concentrations of iron(II) in marine waters using automated flow injection - chemiluminescence instrumentation, Environmental Science and Technology, 36, 4600-4607, 2002.
• P. N. Sedwick, S. Blain, B. Quéguiner, F. B. Griffiths, M. Fiala, E. Bucciarelli and M. Denis, Chemical limitations on phytoplankton production in the Crozet Basin, Subantarctic Southern Ocean, Deep-Sea Research II, 49, 3327-3349, 2002.
• S. Blain, P. N. Sedwick, F. B. Griffiths, B. Quéguiner, E. Bucciarelli, M. Fiala, P. Pondaven, and P. Tréguer, Quantification of algal iron requirements in the Subantarctic Southern Ocean, Deep-Sea Research II, 49, 3255-3273, 2002.
• T. W., Trull, P. N. Sedwick, F. B. Griffiths, and S. R. Rintoul, S. R., Introduction to special section: SAZ Project, Journal of Geophysical Research 106, 31,425-31,431, 2001.
• P. W. Boyd, A. C. Crossley, G. R. DiTullio , F. B. Griffiths, D. A. Hutchins, B. Queguiner, P. N. Sedwick, and T. W. Trull, Control of phytoplankton growth by iron supply and irradiance in the subantarctic Southern Ocean:  Experimental results from the SAZ Project, Journal of Geophysical Research 106, 31,573-31,585, 2001.
• DiTullio, G. R., P. N. Sedwick, D. R. Jones, P. Boyd, A. C. Crossley, and D. A. Hutchins, Effects of iron, silicate and light on dimethylsulfoniopropionate production in the Australian Subantarctic Zone, Journal of Geophysical Research 106 , 31,585-31,597, 2001.
• D. A. Hutchins, P. N. Sedwick , G. R. DiTullio, P. W. Boyd, B. Quéguiner, F. B. Griffiths, A. C. Crossley, Control of phytoplankton growth by iron and silicic acid availability in the Subantarctic Southern Ocean:  Experimental results from the SAZ project, Journal of Geophysical Research 106, 31,559-31,573, 2001.
• R. Edwards, and P. Sedwick, Iron in East Antarctic snow:  Implications for atmospheric iron deposition and algal production in Antarctic waters, Geophysical Research Letters 28, 3907-3910, 2001.
• P. N. Sedwick, P. T. Harris, L. G. Robertson, G. M. McMurtry, M. D. Cremer and P. Robinson, Holocene sediment records from the continental shelf of Mac. Robertson Land, East Antarctica, Paleoceanography 16, 212-226, 2001.
• P. N. Sedwick, G. R. DiTullio, and D. J. Mackey, Iron and manganese in the Ross Sea, Antarctica:  Seasonal iron limitation in Antarctic shelf waters, Journal of Geophysical Research, 105 (C5), 11,321-11,336, 2000.
• P. N. Sedwick, G. R. DiTullio, D. A. Hutchins, P. W. Boyd, F. B. Griffiths, A. C. Crossley, T. W. Trull, and B. Quéguiner, Limitation of algal growth by iron deficiency in the Australian Subantarctic region, Geophysical Research Letters,  26 , 2865-2868, 1999.
• P.T. Harris, W. Howard, P. E. O'Brien, P. N. Sedwick, and E. L. Sikes, Quaternary Antarctic ice-sheet fluctuations and Southern Ocean palaeoceanography: natural variability studies at the Antarctic CRC, AGSO Journal of Australian Geology & Geophysics, 17, 105-119, 1999.
• P. N. Sedwick, P. T. Harris, L. G. Robertson, G. M. McMurtry, M. D. Cremer, and P. Robinson (1998) A geochemical study of marine sediments from the Mac. Robertson Shelf, East Antarctica:  Initial results and paleoenvironmental implications.  Annals of Glaciology 27, 268-274, 1998.
• P. R. Edwards, P. N. Sedwick, V. I. Morgan, C. F. Boutron, and S. Hong, Iron in ice cores from Law Dome, East Antarctica:  Implications for past deposition of aerosol iron,  Annals of Glaciology 27, 365-370, 1998.
• K. J. R. Rosman, W. Chisolm, C. F. Boutron, S. Hong, R. Edwards, V. I. Morgan, and P. Sedwick (1998) Lead isotopes and selected metals in snow and ice cores from Law Dome, Antarctica.  Annals of Glaciology 27, 349-354, 1998.
• P. N. Sedwick, and G. R. DiTullio, Regulation of algal blooms in Antarctic shelf waters by the release of iron from melting sea ice, Geophysical Research Letters 24, 2515-2518, 1997.
• P. N. Sedwick, P. R. Edwards, D. J. Mackey, F. B. Griffiths, and J. S. Parslow, Iron and manganese in surface waters of the Australian subantarctic region, Deep-Sea Research I 44, 1239-1253, 1997.
• P. Sedwick, G. DiTullio, and D. Mackey, Dissolved iron and manganese in surface waters of the Ross Sea, austral summer 1995-1996, Antarctic Journal of the United States 31, 127-128, 1996.
• P. Sedwick, and D. Stüben, Chemistry of shallow submarine warm springs in an arc-volcanic setting:  Vulcano Island, Aeolian Archipelago, Italy, Marine Chemistry 53, 147-161, 1996.
• D. Stüben, P. Sedwick, and P. Colantoni, Geochemistry of submarine warm springs in the limestone cavern of Grotta Azzurra, Capo Palinuro, Italy:  Evidence for mixing-zone dolomitisation, Chemical Geology 131, 113-125, 1996.
• P. T. Harris, P. E. O'Brien, P. Sedwick, and E. M. Truswell, Late Quaternary history of sedimentation on the Mac. Robertson Shelf, East Antarctica:  Problems with 14C-dating of marine sediment cores, Papers and Proceedings of the Royal Society of Tasmania 130, 47-53, 1996.
• P. Sedwick, G. DiTullio, and D. Mackey, Iron and manganese in surface waters of the Ross Sea during the spring bloom 1994, Antarctic Journal of the United States 30, 199-201, 1995.
• P. N. Sedwick, G. M. McMurtry, D. R. Hilton, and F. Goff, Carbon dioxide and helium in hydrothermal fluids from Loihi Seamount, Hawaii, USA:  Temporal variability and implications for the release of mantle volatiles, Geochimica et Cosmochimica Acta 58, 1219- 1227, 1994.
• G. M. McMurtry, P. N. Sedwick, P. Fryer, D. L. Vonderhaar, and H.-W. Yeh, Unusual geochemistry of hydrothermal vents on submarine arc volcanoes:  Kasuga Seamounts, northern Mariana Arc, Earth and Planetary Science Letters 114, 517-528, 1993.
• P. N. Sedwick, G. M. McMurtry, and J. D. Macdougall, Chemistry of hydrothermal solutions from Pele's Vents, Loihi Seamount, Hawaii, Geochimica et Cosmochimica Acta 56, 3643-3667, 1992.
• P. N. Sedwick, G. M. McMurtry, and G. W. Tribble, Chemical alteration of seawater by lava from Kilauea Volcano, Hawaii, Marine Geology 96, 151-158, 1991.
• J.-L. Cheminée, P. Stoffers, G. M. McMurtry, H. Richnow, D. Puteanus, and P. Sedwick, Gas-rich submarine exhalations during the 1989 eruption of Macdonald Seamount, Earth and Planetary Science Letters 107, 318-327, 1991.
• F. J. Sansone, J. A. Resing, G. W. Tribble, P. N. Sedwick, K. M. Kelly, and K. Hon, Lava seawater interactions at shallow-water submarine lava flows, Geophysical Research Letters 18, 1731-1734, 1991.
• P. N. Sedwick , T. Gamo, and G. M. McMurtry, Manganese and methane anomalies in the North Fiji Basin, Deep-Sea Research  5, 891-896, 1990.
• P. Stoffers, R. Hékinian, D. Ackermand, N. Binard, R. Botz, D. Hansen, R. Hodkinson, G. Jeschke, J. Lange, E. vd Perre, J. Scholten, M. Schmitt, P. Sedwick, and J. D. Woodhead, Active Pitcairn hotspot found, Marine Geology 95, 51-55, 1990.
• P. N. Sedwick, D. W. Shinn, and H. Zeitlin, The separation of metals from treated deep-sea ferromanganese nodules by adsorptive bubble techniques using salicylaldoxime and sodium diethyldithiocarbamate as organic precipitating reagents, Separation Science and Technology 2 & 3, 183-190, 1984.
• D. W. Shinn, P. N. Sedwick, and H. Zeitlin, The hydrometallurgical behavior of sulfated ferromanganese nodules, Marine Mining 1, 57-73, 1984.
• D. W. Shinn, P. N. Sedwick, and H. Zeitlin, Controlling factors in the high-temperature sulfation of deep-ocean ferromanganese nodules, Marine Mining 1, 33-55, 1984.