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SUMMARY:From icequakes to earthquakes: Using seismology across the scales 
 to understand Antarctica’s glacial and subglacial environment - Aisling 
 Dunn (BAS) 
DTSTART:20260218T140000Z
DTEND:20260218T150000Z
UID:TALK243151@talks.cam.ac.uk
CONTACT:ChuanChuan Lu
DESCRIPTION:Seismic waves\, generated both within the ice and by distant e
 arthquakes\, provide a unique window into some of the most inaccessible en
 vironments on Earth. In this way\, cryoseismology\, a rapidly evolving bra
 nch of seismology\, offers a wide and exciting range of opportunities to s
 tudy the glacial and subglacial environments of polar and mountain regions
 . Such observations are invaluable to our understanding of the cryosphere 
 and for constraining how ice sheets will respond to a warming world. In th
 is talk\, I will present results from two studies that demonstrate how cry
 oseismology can be used to improve our understandings of the Antarctic Ice
  Sheet.\nStarting small\, an array of accelerometers and geophones deploye
 d on the Larsen C Ice Shelf in 2022 detected 108 icequakes originating fro
 m within the ice shelf. Correlations between icequake explosivity and tida
 l phase suggest that this micro-seismicity is predominantly driven by tida
 l infiltration and circulation of seawater in the ice. In combination with
  radar data\, this novel observation provides new insight into how rifting
 \, which eventually leads to the calving of large tabular icebergs such as
  A68\, can be controlled by the internal structure of ice shelves\, with i
 mportant implications for their long-term stability.\nAt the other end of 
 the scale\, the growing number of seismic deployments across Antarctica ha
 s enabled the use of teleseismic earthquakes to investigate the continent
 ’s lithospheric structure. These data\, however\, also record informatio
 n about the basal conditions of the Antarctic Ice Sheet. By building on es
 tablished receiver function and P-wave coda autocorrelation methods\, both
  the extent of subglacial sediment and the presence of subglacial till can
  be constrained. Rutford Ice Stream provides an ideal natural laboratory f
 or testing this approach\, with complementary radar\, active-source seismi
 c\, and drilling data allowing the seismic signatures of subglacial till t
 o be robustly validated. This proof of concept is then extended across Ant
 arctica\, where mapping the distribution of this deformable till can infor
 m ice sheet models and reduce uncertainties in the consequent sea-level ri
 se predictions.
LOCATION:Wolfson Lecture Theatre
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