Boards, Advisory Committees, Professional Organizations


  • Operation IceBridge Science Team Member, NASA (2017 - Present)
  • Polar Meteorology and Oceanography Committee member, American Meteorological Society (2017 - Present)

Professional Education


  • Doctor of Philosophy, University of California San Diego (2015)
  • Master of Science, Dartmouth College (2010)
  • Bachelor of Arts, Dartmouth College (2008)

Stanford Advisors


All Publications


  • Ice flow dynamics forced by water pressure variations in subglacial granular beds GEOPHYSICAL RESEARCH LETTERS Damsgaard, A., Egholm, D. L., Beem, L. H., Tulaczyk, S., Larsen, N. K., Piotrowski, J. A., Siegfried, M. R. 2016; 43 (23): 12165-12173
  • Impacts of warm water on Antarctic ice shelf stability through basal channel formation NATURE GEOSCIENCE Alley, K. E., Scambos, T. A., Siegfried, M. R., Fricker, H. A. 2016; 9 (4): 290-?

    View details for DOI 10.1038/NGEO2675

    View details for Web of Science ID 000373374100013

  • Episodic ice velocity fluctuations triggered by a subglacial flood in West Antarctica GEOPHYSICAL RESEARCH LETTERS Siegfried, M. R., Fricker, H. A., Carter, S. P., Tulaczyk, S. 2016; 43 (6): 2640-2648
  • Subglacial Lake Whillans microbial biogeochemistry: a synthesis of current knowledge PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES Mikucki, J. A., Lee, P. A., Ghosh, D., Purcell, A. M., Mitchell, A. C., Mankoff, K. D., Fisher, A. T., Tulaczyk, S., Carter, S., Siegfried, M. R., Fricker, H. A., Hodson, T., Coenen, J., Powell, R., Scherer, R., Vick-Majors, T., Achberger, A. A., Christner, B. C., Tranter, M. 2016; 374 (2059)

    Abstract

    Liquid water occurs below glaciers and ice sheets globally, enabling the existence of an array of aquatic microbial ecosystems. In Antarctica, large subglacial lakes are present beneath hundreds to thousands of metres of ice, and scientific interest in exploring these environments has escalated over the past decade. After years of planning, the first team of scientists and engineers cleanly accessed and retrieved pristine samples from a West Antarctic subglacial lake ecosystem in January 2013. This paper reviews the findings to date on Subglacial Lake Whillans and presents new supporting data on the carbon and energy metabolism of resident microbes. The analysis of water and sediments from the lake revealed a diverse microbial community composed of bacteria and archaea that are close relatives of species known to use reduced N, S or Fe and CH4 as energy sources. The water chemistry of Subglacial Lake Whillans was dominated by weathering products from silicate minerals with a minor influence from seawater. Contributions to water chemistry from microbial sulfide oxidation and carbonation reactions were supported by genomic data. Collectively, these results provide unequivocal evidence that subglacial environments in this region of West Antarctica host active microbial ecosystems that participate in subglacial biogeochemical cycling.

    View details for DOI 10.1098/rsta.2014.0290

    View details for Web of Science ID 000367471500001

    View details for PubMedID 26667908

  • A decade of progress in observing and modelling Antarctic subglacial water systems PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES Fricker, H. A., Siegfried, M. R., Carter, S. P., Scambos, T. A. 2016; 374 (2059)

    Abstract

    In the decade since the discovery of active Antarctic subglacial water systems by detection of subtle surface displacements, much progress has been made in our understanding of these dynamic systems. Here, we present some of the key results of observations derived from ICESat laser altimetry, CryoSat-2 radar altimetry, Operation IceBridge airborne laser altimetry, satellite image differencing and ground-based continuous Global Positioning System (GPS) experiments deployed in hydrologically active regions. These observations provide us with an increased understanding of various lake systems in Antarctica: Whillans/Mercer Ice Streams, Crane Glacier, Recovery Ice Stream, Byrd Glacier and eastern Wilkes Land. In several cases, subglacial water systems are shown to control ice flux through the glacier system. For some lake systems, we have been able to construct more than a decade of continuous lake activity, revealing internal variability on time scales ranging from days to years. This variability indicates that continuous, accurate time series of altimetry data are critical to understanding these systems. On Whillans Ice Stream, our results from a 5-year continuous GPS record demonstrate that subglacial lake flood events significantly change the regional ice dynamics. We also show how models for subglacial water flow have evolved since the availability of observations of lake volume change, from regional-scale models of water routeing to process models of channels carved into the subglacial sediment instead of the overlying ice. We show that progress in understanding the processes governing lake drainage now allows us to create simulated lake volume time series that reproduce time series from satellite observations. This transformational decade in Antarctic subglacial water research has moved us significantly closer to understanding the processes of water transfer sufficiently for inclusion in continental-scale ice-sheet models.

    View details for DOI 10.1098/rsta.2014.0294

    View details for Web of Science ID 000367471500005

    View details for PubMedID 26667904

  • High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica GEOPHYSICAL RESEARCH LETTERS Marsh, O. J., Fricker, H. A., Siegfried, M. R., Christianson, K., Nicholls, K. W., Corr, H. F., Catania, G. 2016; 43 (1): 250-255
  • The structural and dynamic responses of Stange Ice Shelf to recent environmental change ANTARCTIC SCIENCE Holt, T. O., Glasser, N. F., Fricker, H. A., Padman, L., Luckman, A., King, O., Quincey, D. J., Siegfried, M. R. 2014; 26 (6): 646-660
  • A decade ofWest Antarctic subglacial lake interactions from combined ICESat and CryoSat-2altimetry GEOPHYSICAL RESEARCH LETTERS Siegfried, M. R., Fricker, H. A., Roberts, M., Scambos, T. A., Tulaczyk, S. 2014; 41 (3): 891-898
  • WISSARD at Subglacial Lake Whillans, West Antarctica: scientific operations and initial observations ANNALS OF GLACIOLOGY Tulaczyk, S., Mikucki, J. A., Siegfried, M. R., Priscu, J. C., Barcheck, C. G., Beem, L. H., Behar, A., Burnett, J., Christner, B. C., Fisher, A. T., Fricker, H. A., Mankoff, K. D., Powell, R. D., Rack, F., Sampson, D., Scherer, R. P., Schwartz, S. Y. 2014; 55 (65): 51-58
  • Estuaries beneath ice sheets GEOLOGY Horgan, H. J., Alley, R. B., Christianson, K., Jacobel, R. W., Anandakrishnan, S., Muto, A., Beem, L. H., Siegfried, M. R. 2013; 41 (11): 1159-1162

    View details for DOI 10.1130/G34654.1

    View details for Web of Science ID 000327392200006

  • A microbiologically clean strategy for access to the Whillans Ice Stream subglacial environment ANTARCTIC SCIENCE Priscu, J. C., Achberger, A. M., Cahoon, J. E., Christner, B. C., Edwards, R. L., Jones, W. L., Michaud, A. B., Siegfried, M. R., Skidmore, M. L., Spigel, R. H., Switzer, G. W., Tulaczyk, S., Vick-Majors, T. J. 2013; 25 (5): 637-647
  • Evidence of rapid subglacial water piracy under Whillans Ice Stream, West Antarctica JOURNAL OF GLACIOLOGY Carter, S. P., Fricker, H. A., Siegfried, M. R. 2013; 59 (218): 1147-1162
  • Speedup and fracturing of George VI Ice Shelf, Antarctic Peninsula CRYOSPHERE Holt, T. O., Glasser, N. F., Quincey, D. J., Siegfried, M. R. 2013; 7 (3): 797-816
  • Arsenic speciation in food chains from mid-Atlantic hydrothermal vents ENVIRONMENTAL CHEMISTRY Taylor, V. F., Jackson, B. P., Siegfried, M. R., Navratilova, J., Francesconi, K. A., Kirshtein, J., Voytek, M. 2012; 9 (2): 130-138

    Abstract

    Arsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata, the vent chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus, and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ(13)C and δ(15)N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata, whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate, and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the vent chimneys, covered with microbial mat, which is a presumed food source for many vent organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of vent origin, suggests that organic arsenicals can occur in a food web without algae or other photosynthetic life.

    View details for DOI 10.1071/EN11134

    View details for Web of Science ID 000303509300007

    View details for PubMedID 23741175

  • High-Resolution Ground-Based GPS Measurements Show Intercampaign Bias in ICESat Elevation Data Near Summit, Greenland IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING Siegfried, M. R., Hawley, R. L., Burkhart, J. F. 2011; 49 (9): 3393-3400