التفاصيل البيبلوغرافية
| العنوان: |
Preservation of the Climatic Signal in the Old Ice Layers at the Dome B Area (Antarctica). |
| المؤلفون: |
Ekaykin, A. A., Lipenkov, V. Ya., Tchikhatchev, K. B. |
| المصدر: |
Izvestiya, Atmospheric & Oceanic Physics; 2023 Suppl1, Vol. 59, pS1-S7, 7p |
| مصطلحات موضوعية: |
ICE, ICE cores, GLACIAL Epoch, MELTING points, TEMPERATURE distribution, SQUEEZED light |
| مصطلحات جغرافية: |
ANTARCTICA |
| مستخلص: |
In this work we present the results of numerical modeling of the age and temperature distribution in ice layers at the Dome B site (79.02° S, 93.69° E, altitude 3807 m a.s.l., ice thickness about 2.5 km), located 300 km west of the Russian Antarctic station Vostok. Dome B is situated on the onset of the ice flow line passing through the deep 5G borehole, and it is considered one of the most promising places to search for and study the earth's oldest ice (with an age reaching 1.5 Ma). According to our calculations, all realistic scenarios show the ice age at 60 m above the ice base to be considerably older than 1 Ma, and the glacier base temperature is well below the pressure melting point (–1.8°С for pressure = 23 MPa). For the most likely scenario (accumulation rate 1.8 g/(cm2 year), effective ice surface temperature –64°С, and geothermal heat flux 60 mW/m2), the ice age is 1.4 Ma and the basal temperature is about –13°С, which is close to the earlier predictions from a 2D model. The maximum estimate of the diffusion length in the old ice (for the scenario in which the basal temperature reaches the melting point and in which 30% of excess diffusion is taken into account) is 5.2 cm. In 1.4-Ma-old ice, a 40-ka climatic cycle is squeezed into a 290-cm-thick ice layer. For this ratio of wavelength and diffusion length, the climatic signal attenuation (ratio between the signal amplitude after and before diffusive smoothing) is 0.6%. Thus, due to the relatively low ice temperature here, we may expect a nearly undisturbed climatic curve in the old ice core that will be drilled one day at Dome B. At the same time, shorter oscillations with wavelengths of <1500 years will be totally erased by diffusion. [ABSTRACT FROM AUTHOR] |
|
Copyright of Izvestiya, Atmospheric & Oceanic Physics is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| قاعدة البيانات: |
Complementary Index |
