HR: 0800h
AN: C51A-0267 [Abstracts]
TI: Quantitative Understanding of Fracture Patterns in Ice Shelves
AU: * Cruikshank, K M
EM: CruikshankK@pdx.edu
AF: Geology Department, Portland State University
PO Box 751, Portland, OR 97201-0751
United States
AU: Hulbe, C L
EM: CHulbe@pdx.edu
AF: Geology Department, Portland State University
PO Box 751, Portland, OR 97201-0751
United States
AU: Fahnestock, M A
EM: Mark.Fahnestock@unh.edu
AF: Institute for the Study of Earth, Oceans, and Space, University of New Hampshire
Morse Hall
39 College Road, Durham, NH 03824
United States
AU: LeDoux, C
C51A-0267
AF: Geology Department, Portland State University
PO Box 751, Portland, OR 97201-0751
United States
AU: Fines, A
C51A-0267
AF: Geology Department, Portland State University
PO Box 751, Portland, OR 97201-0751
United States
AB:
Recent advances in the use of satellite remote sensing data to image the surfaces of Antarctic ice shelves have revealed a
wide spectrum of fracture patterns in the floating ice. The stress field in which the fractures form may change in both time
and space, and fracture geometries may be distorted by shear within the flowing ice. In some ice shelves, the result is
simple, repetitive geometries while in others distinctly non-steady flow (and stress) histories yield more complicated
patterns.
Structural Geologists use fracture mechanics to quantitatively understand joint patterns in rocks. Joints are similar to
ice-shelf rifts in that they both behave as mode I fractures. Treating individual fractures or simple patterns as mode-I
fractures allows existing analytical solutions to be used to interpret the stress-field responsible for observed fracture
patterns. Numerical models using Boundary Element solutions allow for more complex patterns involving numerous fractures to
be modeled. We apply both analytical and numerical solutions in a set of case studies of complicated fracture sets observed
in the Ross Ice Shelf, to study fracture interaction in this dynamic environment and make quantitative statements about
current and past stress states within the ice shelf.
DE: 0728 Ice shelves
DE: 0730 Ice streams
DE: 0798 Modeling
SC: Cryosphere [C]
MN: Fall Meeting 2005