lstevens

Primary tabs

Profile

Postdoctoral Research Fellow
Earth and Environmental Sciences
Marine Geology and Geophysics
109A Oceanography
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
United States
Phone: 
(845)365-8397

linebreak

Fields of interest: 
Glaciology, Geophysics, Physical processes driving ice-sheet flow.

Understanding ice sheet dynamics is critical for the prediction of past and future global ice volumes, which have direct implications for global sea level. My research seeks to disentangle the physical mechanisms of Greenland and Antarctic ice sheet disintegration as temperatures rise during the 21st century with both field observations and numerical modeling. 

To determine the physical processes driving ice flow, my main research questions are:

  1. How does meltwater access the ice-bed interface and drive ice flow?
  2. How will meltwater abundance and access to the ice-bed interface change over the 21st century?

To approach these questions, I pair geophysical observations (e.g., Global Positioning System (GPS) measurements of ice motion, surface mass balance estimates) with inverse methods and numerical modeling. 

During my PhD in the MIT/WHOI Joint Program, I investigated a range of meltwater processes acting on the Greenland Ice Sheet ablation zone including: (1) the mechanisms triggering hydro-fracture and rapid (~2 hours) drainage of supraglacial lakes [Stevens et al., 2015]; (2) the structure of glacially modified waters at a marine-terminating outlet glacier margin [Stevens et al., 2016a]; (3) drivers of ice sheet flow variability on a decadal scale [Stevens et al., 2016b]; and (4) the relationship between regional ice flow patterns and modeled subglacial hydrology [Stevens et al., In review].

For my postdoctoral research at LDEO, I am continuing work on ice sheet dynamics in Greenland and Antarctica with specific projects on: (1) the effect of tidal forcing on flow at the termini of major Greenland marine-terminating outlet glaciers; (2) rheology of Antarctic ice rises as constrained by phase-sensitive radar echo sounder (pRES); and (3) the mechanisms of Antarctic ice shelf melt pond drainage. 

Publications:

  1. Stevens, L. A., M. D. Behn, J. J. McGuire, S. B. Das, I. Joughin, T. Herring, D. E. Shean, and M. A. King (2015), Greenland supraglacial lake drainages triggered by hydrologically induced basal slip, Nature, 522, 73–76, doi:10.1038/nature14480.
  2. Carmichael, J.D., Joughin, I., Behn, M.D., Das, S.B., King, M.A., Stevens, L.A., and D. Lizarralde (2015), Seismicity on the Western Greenland Ice Sheet: Surface Fracture in the Vicinity of Active Moulins. Journal of Geophysical Research Earth Surface, 120:1082–1106, doi:10.1002/2014JF003398.
  3. Stevens, L. A., M. D. Behn, S. B. Das, I. Joughin, B. P. Y. Noël, M. R. van den Broeke, and T. Herring (2016a), Greenland Ice Sheet flow response to runoff variability, Geophysical Research Letters, 43, 1–9, doi:10.1002/2016GL070414.
  4. Stevens, L. A., F. Straneo, S. B. Das, A. J. Plueddemann, and A. L. Kukulya (2016b), Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations, Cryosphere, 10, 417–432, doi:10.5194/tc-10-417-2016.
  5. Stevens, L.A., I. Hewitt, S. B. Das, M. D. Behn (2018), Relationship between Greenland Ice Sheet surface speed and modeled effective pressure, Journal of Geophysical Research Earth Surface, doi:10.1029/2017JF004581. Model code and output available on GitHub.
  6. Wagner, T. J. W., Straneo, F., Rickards, C. G., Slater, D., Stevens, L. A., Das, S. B., Singh, H. (2018), Large spatial variations in the frontal mass budget of a Greenland tidewater glacier. In review. 
Education
List of degrees from highest to lowest:
PhD
Massachusetts Institute of Technology/Woods Hole Oceanographic Institution
09/2017
BA
Wellesley College
05/2011
Honors & Awards: 
2017 - Lamont-Doherty Earth Observatory Postdoctoral Fellowship
2015 - Horton Research Grant, American Geophysical Union Hydrology Section
2012 - Graduate Research Fellowship Program (GRFP), National Science Foundation
2011 - cum laude, Phi Beta Kappa, and Sigma Xi, Wellesley College
2011 - Margret D. Thompson Award for Scholarship in the Geosciences, Wellesley College
2010 - Sara F. Langer Memorial Award in Geology, Wellesley College
2009 - American Mineralogist Undergraduate Award, Mineralogical Society of America
frontpage image: