Interpolating accumulation rates by means of internal layering detected by airborne radio-echo sounding
Mass balance studies using the input-output method as well as modelling studies require reliable knowledge of the regional distribution of accumulation rates. Since for the dating of ice samples have to be taken in the field either in snow pits or by drilling firn, respectively ice cores, there are...
| Main Authors: | , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2013
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/33930/ https://hdl.handle.net/10013/epic.42255 |
| Summary: | Mass balance studies using the input-output method as well as modelling studies require reliable knowledge of the regional distribution of accumulation rates. Since for the dating of ice samples have to be taken in the field either in snow pits or by drilling firn, respectively ice cores, there are only few sampling sites and thus accumulation rate data available from the Greenland and Antarctic ice sheet. Among the time series used for dating of ice cores are measurements of the dielectric properties of the firn and ice cores. Since radar also detects changes in dielectric properties, it is possible to link radar soundings to ice cores. The internal layering thus shows how representative the ice core is and tracing isochrones between two drill sites not only allows to test the dating of the ice cores based on independent measurements, but also provide an insight on the regional variations of the accumulation rate between the drill sites. The latter can be used to extend the data base for compiling data sets of the accumulation rate considerably prior to applying statistical tools for inter- and extrapolating the data for areal data sets. The Alfred-Wegener-Institut (AWI) is operating amongst other instruments a high-frequency frequency modulated continuous wave radar system on board of its ski-equipped aircraft. Compared to ground-based measurements airborne soundings allow to map large areas in relatively short time. AWI mapped in 2010 and 2012 the internal structure of the Greenland ice sheet within the 2000 m contour line with a regional focus on the NEEM deep ice core drill site (N 77 30 / W 051 18). The flown profiles also reached the deep ice core drill site NGRIP and the shallow ice coring sites of AWI’s North Greenland Traverse. By linking the isochrones detected the airborne frequency radar to ice cores, new data sets of the regional distribution of accumulation rates will be derived. |
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