 |
| Titel |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
| VerfasserIn |
C. Martin, G. H. Gudmundsson |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 6, no. 5 ; Nr. 6, no. 5 (2012-10-30), S.1221-1229 |
| Datensatznummer |
250003798
|
| Publikation (Nr.) |
 copernicus.org/tc-6-1221-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Ice flow in divide areas is strongly anisotropic. The evolution of
ice fabric, from the onset of divide flow towards steady state with
a fully developed fabric, has been shown to profoundly affect both
the stratigraphy and surface topography of ice divides. Here, we
investigate the effects of ice flow on the age-versus-depth
relationship at ice divides by using a full Stokes thermomechanical
model with a non-linear anisotropic constitutive relation between
stress and strain rates. We compare our results with analytical
approximations commonly employed in age–depth predictions, such as
the Dansgaard and Lliboutry approximations. We show that these
approximations systematically underestimate the age of ice at
fully developed divides by as much as one order of magnitude. We
also show that divides with fully developed fabric are ideal
locations for ice-core extraction because ice under them can be up
to one order of magnitude older than ice at the same depth at the
flanks. In addition, these divides have a distinctive morphological
structure that allows them to be clearly identified from satellite
imagery or ground-penetrating radar data. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|