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| Titel |
Interpolating an ice core depth-age relationship from sparse data using an inverse approach |
| VerfasserIn |
Jessica Lundin, Ed Waddington, Howard Conway, Edward Brook |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053750
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| Zusammenfassung |
| Often Antarctic ice cores can be dated at only a sparse number of discrete depths; however, it is desirable to have a physically based interpolation of the depth-age relationship between the sparse dated points. Interpolation schemes that do not properly account for the variation of dynamical strain with depth due to ice flow (for example piece-wise linear and spline interpolations) can introduce serious error, because these interpolations over-fit the data and are not physically based. We use an inverse method to determine an accumulation-rate history that reproduces the measured depth-age data to a tolerance specified by data uncertainty. The forward problem is a transient one-dimensional kinematic ice-flow model that produces a depth-age relationship, based on histories of ice thickness, divide migration and accumulation rate. The accumulation-rate history inferred in the inverse problem produces a more realistic interpolation of the measured depth-age data. The accumulation-rate history may be determined if the ice dynamics histories are known. Regardless of whether the unique accumulation history and ice dynamics pair can be determined, our depth-age interpolation is robust. |
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