BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Early East Antarctic Ice Sheet Growth Recorded in the Landscape of
  the Gamburtsev Subglacial Mountains - Dr Kathryn Rose\, British Antarctic
  Survey
DTSTART:20130227T163000Z
DTEND:20130227T173000Z
UID:TALK40748@talks.cam.ac.uk
CONTACT:Steven Palmer
DESCRIPTION:The Gamburtsev Subglacial Mountains are regarded as a key nucl
 eation site for the Antarctic ice sheet and\, as such\, may retain a uniqu
 e long-term record of pre-glacial and early glacial landscape evolution. H
 ere\, we use a range of morphometric analyses to constrain the nature of e
 arly glaciation and subsequent ice sheet evolution in the interior of East
  Antarctica\, using a new digital elevation model of the Gamburtsev Subgla
 cial Mountains\, derived from an extensive airborne radar survey.  We find
  that an inherited fluvial landscape confirms the existence of the Gamburt
 sev Subglacial Mountains prior to the onset of glaciation at the Eocene-Ol
 igocene climate boundary (ca. 34 Ma).  Features characteristic of glaciati
 on\, at a range of scales\, are evident across the mountains.  High elevat
 ion alpine valley heads\, akin to cirques\, identified along the mountain 
 ridge\, are interpreted as evidence for early phases of glaciation in East
  Antarctica.  The equilibrium line altitudes associated with these feature
 s\, combined with information from fossil plant assemblages\, suggests tha
 t they formed at\, or prior to\, 34 Ma.  It cannot be ruled out that they 
 may have been eroded by ephemeral ice between the Late Cretaceous and the 
 Eocene (100-34 Ma). Hanging valleys\, overdeepenings\, truncated spurs and
  steep-sided\, linear valley networks are indicative of a more widespread 
 alpine glaciation in this region.  These features represent ice growth at 
 the latest 33.7 Ma and provide a minimum estimate for the scale of the Eas
 t Antarctic Ice Sheet between ca. 34-14 Ma\, when dynamic fluctuations in 
 ice extent are recorded at the coast of Antarctica.  The implications are 
 that the early East Antarctic Ice Sheet grew rapidly and developed a cold-
 based core that preserved the alpine landscape.  The patterns of landscape
  evolution identified provide the earliest evidence for the development of
  the East Antarctic Ice Sheet and can be used to test coupled ice-climate 
 evolution models.
LOCATION:Scott Polar Research Institute\, main lecture theatre
END:VEVENT
END:VCALENDAR