 |
| Titel |
Estimations of the age of the ice beneath Dome A, Antarctica |
| VerfasserIn |
Thomas Zwinger, Bo Sun, Liyun Liyun, John C. Moore, Daniel Steinhage, Carlos Martin |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093662
|
| Publikation (Nr.) |
 EGU/EGU2014-8597.pdf |
|
|
|
|
|
| Zusammenfassung |
| The drilling of a deep ice core at the Chinese Kunlun station, Dome A, East Antarctica, is
about to start with high expectations on obtaining the oldest possible ice so far. The Alpine
type bedrock of the Gamburtsev mountains in combination with a largely undetermined
geothermal heat flux distribution raises questions on the basal thermal conditions that via the
melting rate have a strong feedback on the vertical flow velocity and in consequence
on the age/depth horizons. Additionally, the undetermined ice fabric introducing
anisotropic effects in rheology have to be taken into account. By deploying a full
Stokes ice sheet model (http://elmerice.elmerfem.org) we investigate the influence
of those parameters, namely anisotropy as well as geothermal heat flux values,
on the spatial distribution of the age close to the bedrock. Results are compared
with dated radar isochrones in the upper one third of the ice sheet. We find that a
non-unique combination of parameters is able to closely reproduce those measured
values, leading to the conclusion, that without additional information, the basal age
beneath Kunlun station remains undetermined. However, our simulations suggest
that vast spatial variation of basal melting rates and, in consequence, the age/depth
distribution over a relative small domain exists, increasing the motivation for ice coring,
obtaining both high resolution as well as possibly oldest ice from the same site. |
|
|
|
|
|
|