 |
| Titel |
Assessing soil fluxes using meteoric 10Be: development and application of the Be2D model |
| VerfasserIn |
Benjamin Campforts, Gerard Govers, Veerle Vanacker, Stijn Baken, Erik Smolders, Jan Vanderborght |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110741
|
| Publikation (Nr.) |
 EGU/EGU2015-10768.pdf |
|
|
|
|
|
| Zusammenfassung |
| Meteoric 10Be is a promising and increasingly popular tool to better understand soil fluxes at
different timescales. Unlike other, more classical, methods such as the study of sedimentary
archives it enables a direct coupling between eroding and deposition sites. However,
meteoric 10Be can be mobilized within the soil. Therefore, spatial variations in
meteoric 10Be inventories cannot directly be translated into spatial variations in
erosion and sedimentation rates: a correct interpretation of measured 10Be inventories
requires that both lateral and vertical movement of meteoric 10Be are accounted for.
Here, we present a spatially explicit 2D model that allows to simulate the behaviour
of meteoric 10Be in the soil system over timescales of up to 1 million year and
use the model to investigate the impact of accelerated erosion on meteoric 10Be
inventories.
The model consists of two parts. A first component deals with advective and diffusive
mobility within the soil profile, whereas a second component describes lateral soil (and
meteoric 10Be) fluxes over the hillslope. Soil depth is calculated dynamically, accounting for
soil production through weathering and lateral soil fluxes. Different types of erosion such as
creep, water and tillage erosion are supported. Model runs show that natural soil fluxes can be
well reconstructed based on meteoric 10Be inventories, and this for a wide range of
geomorphological and pedological conditions. However, extracting signals of human impact
and distinguishing them from natural soil fluxes is only feasible when the soil has
a rather high retention capacity so that meteoric 10Be is retained in the top soil
layer. Application of the Be2D model to an existing data set in the Appalachian
Mountains [West et al.,2013] using realistic parameter values for the soil retention
capacity as well as for vertical advection resulted in a good agreement between
simulated and observed 10Be inventories. This confirms the robustness of the model. We
therefore conclude that the Be2D model is a useful tool to develop more solid and
quantitative interpretations of the spatial variation of meteoric 10Be inventories in eroding
landscapes.
West, N., E. Kirby, P. Bierman, R. Slingerland, L. Ma, D. Rood, and S. Brantley (2013),
Regolith production and transport at the Susquehanna Shale Hills Critical Zone Observatory,
Part 2: Insights from meteoric 10 Be, J. Geophys. Res. Earth Surf., 118(3), 1877–1896. |
|
|
|
|
|
|