BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Turbulent convection in Antarctic Subglacial Lakes  -  Louis-Alexa
 ndre Couston (Laboratoire de Physique\, ENS de Lyon)
DTSTART:20210602T130000Z
DTEND:20210602T140000Z
UID:TALK156301@talks.cam.ac.uk
CONTACT:Dr Irena Vankova
DESCRIPTION:Trapped beneath the Antarctic ice sheet lie over 400 subglacia
 l lakes\, which are considered to be extreme\, isolated\, yet viable habit
 ats for microbial life. The physical conditions within subglacial lakes ar
 e critical to evaluating how and where life may best exist. In this talk\,
  I will demonstrate that Earth’s geothermal flux provides efficient stir
 ring of Antarctic subglacial lake water. I will show that most lakes are i
 n a regime of vigorous turbulent vertical convection\, enabling suspension
  of spherical particulates with diameters up to 36 micrometers. Thus\, dyn
 amic flows support efficient mixing of nutrient- and oxygen-enriched meltw
 ater derived from the overlying ice\, which is essential for biome support
  within the water column. I will show that a stable layer isolates the wel
 l-mixed bulk from the ice-water interface in lakes beneath a thin (<3.166 
 kilometers) ice cover\, because of the nonlinear equation of state of wate
 r. I will discuss how relaxing the approximations that the current theory 
 relies on (flat ice-water ceiling) might change the predictions\, as well 
 as the implications of this work for future lake exploration.
LOCATION:British Antarctic Survey\, Zoom
END:VEVENT
END:VCALENDAR