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VERSION:2.0
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X-WR-CALNAME:EAS Seminar Series: Kristin Poinar - Physical models for mouli
 ns: conduits to the subglacial world
X-WR-TIMEZONE:Eastern Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20260811T153043Z
UID:tag:localist.com\,2008:EventInstance_37951318509681
DTSTART:20211006T194500Z
DTEND:20211006T204500Z
DESCRIPTION:Title\n\nPhysical models for moulins: conduits to the subglacia
 l world\n\nSpeaker\n\nKristin Poinar\, Assistant Profesor\, Department of 
 Geology\, University of Buffalo\n\nAbstract\n\nGlacier hydrology is a cruc
 ial factor in short-term (daily) and long-term (millennial) calculations o
 f glacier mass loss into the ocean.  This is because meltwater influences 
 the flow of glacier ice if it reaches the bed.   On the Greenland Ice Shee
 t\, meltwater can run over bare ice\, coalesce into streams\, and pool int
 o lakes on top of the ice.  From there\, the water is often -- but not alw
 ays -- directed into moulins\, near-vertical shafts that connect to the be
 d of the ice sheet hundreds of meters below.  Each individual moulin drain
 s a large catchment of surface meltwater -- typically 10-50 km2\, similar 
 to the 30 km2 Cascadilla Creek catchment -- and thus has a strong influenc
 e on local to regional basal hydrology.\n\nI am developing two models cent
 ered around moulins. (1) The Moulin Shape (MouSh) model predicts the radia
 l expansion and contraction of a moulin connected to a subglacial channel 
 and fed by hourly varying meltwater inputs.  We find that the moulin size 
 and shape changes daily by some 20% as it accommodates changing meltwater 
 fluxes.  (2) The Fracture Sites model (FraSM) predicts the likelihood of m
 oulin initiation in space and time.  We find that moulin formation sites a
 re strongly tied to drainages of neighboring supraglacial lakes\, and that
  new moulins can form ~3-5 km upstream of a draining lake.  A new\, upstre
 am moulin could then drain an upstream lake\, potentially inciting a chain
  reaction of lake drainage / moulin formation that steps its way upstream 
 toward the vulnerable interior of the ice sheet\, where changes to basal h
 ydrology would significantly speed ice flow.\n\nUltimately\, the moulin mo
 dels connect climate\, in the form of surface meltwater\, to sea-level ris
 e\, via basal hydrology and ice flow.  As Greenland's climate changes\, we
  need to be able to predict the sea-level rise that is coming as a consequ
 ence.\n\nBio\n\nKristin Poinar is an Assistant Professor in the Department
  of Geology and the RENEW Institute at the University at Buffalo\, New Yor
 k.  She has worked on glaciers in Greenland\, Antarctica\, Washington Stat
 e\, and Alaska.  She uses physically-based models and remote sensing to he
 lp constrain the likely fate of glaciers in Earth’s uncertain future.
LOCATION:Snee Hall\, 2146 
SUMMARY:EAS Seminar Series: Kristin Poinar - Physical models for moulins: c
 onduits to the subglacial world
URL;VALUE=URI:https://events.cornell.edu/event/eas_seminar_series_kristin_p
 oinar_-_physical_models_for_moulins_conduits_to_the_subglacial_world
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