TY - GEN A1 - Tofelde, Stefanie A1 - Bernhardt, Anne A1 - Guerit, Laure A1 - Romans, Brian W. T1 - Times Associated With Source-to-Sink Propagation of Environmental Signals During Landscape Transience T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Sediment archives in the terrestrial and marine realm are regularly analyzed to infer changes in climate, tectonic, or anthropogenic boundary conditions of the past. However, contradictory observations have been made regarding whether short period events are faithfully preserved in stratigraphic archives; for instance, in marine sediments offshore large river systems. On the one hand, short period events are hypothesized to be non-detectable in the signature of terrestrially derived sediments due to buffering during sediment transport along large river systems. On the other hand, several studies have detected signals of short period events in marine records offshore large river systems. We propose that this apparent discrepancy is related to the lack of a differentiation between different types of signals and the lack of distinction between river response times and signal propagation times. In this review, we (1) expand the definition of the term ‘signal’ and group signals in sub-categories related to hydraulic grain size characteristics, (2) clarify the different types of ‘times’ and suggest a precise and consistent terminology for future use, and (3) compile and discuss factors influencing the times of signal transfer along sediment routing systems and how those times vary with hydraulic grain size characteristics. Unraveling different types of signals and distinctive time periods related to signal propagation addresses the discrepancies mentioned above and allows a more comprehensive exploration of event preservation in stratigraphy – a prerequisite for reliable environmental reconstructions from terrestrially derived sedimentary records. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1230 KW - signal propagation KW - landscape transience KW - source-to-sink KW - stratigraphy KW - response time Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544431 SN - 1866-8372 SP - 1 EP - 26 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Tofelde, Stefanie A1 - Bernhardt, Anne A1 - Guerit, Laure A1 - Romans, Brian W. T1 - Times Associated With Source-to-Sink Propagation of Environmental Signals During Landscape Transience JF - Frontiers in Earth Science N2 - Sediment archives in the terrestrial and marine realm are regularly analyzed to infer changes in climate, tectonic, or anthropogenic boundary conditions of the past. However, contradictory observations have been made regarding whether short period events are faithfully preserved in stratigraphic archives; for instance, in marine sediments offshore large river systems. On the one hand, short period events are hypothesized to be non-detectable in the signature of terrestrially derived sediments due to buffering during sediment transport along large river systems. On the other hand, several studies have detected signals of short period events in marine records offshore large river systems. We propose that this apparent discrepancy is related to the lack of a differentiation between different types of signals and the lack of distinction between river response times and signal propagation times. In this review, we (1) expand the definition of the term ‘signal’ and group signals in sub-categories related to hydraulic grain size characteristics, (2) clarify the different types of ‘times’ and suggest a precise and consistent terminology for future use, and (3) compile and discuss factors influencing the times of signal transfer along sediment routing systems and how those times vary with hydraulic grain size characteristics. Unraveling different types of signals and distinctive time periods related to signal propagation addresses the discrepancies mentioned above and allows a more comprehensive exploration of event preservation in stratigraphy – a prerequisite for reliable environmental reconstructions from terrestrially derived sedimentary records. KW - signal propagation KW - landscape transience KW - source-to-sink KW - stratigraphy KW - response time Y1 - 2021 U6 - https://doi.org/10.3389/feart.2021.628315 SN - 2296-6463 VL - 9 SP - 1 EP - 26 PB - Frontiers Media CY - Lausanne, Schweiz ER - TY - JOUR A1 - Yuan, Xiaoping P. A1 - Braun, Jean A1 - Guerit, Laure A1 - Rouby, D. A1 - Cordonnier, G. T1 - A New Efficient Method to Solve the Stream Power Law Model Taking Into Account Sediment Deposition JF - Journal of geophysical research : Earth surface N2 - The stream power law model has been widely used to represent erosion by rivers but does not take into account the role played by sediment in modulating erosion and deposition rates. Davy and Lague (2009, ) provide an approach to address this issue, but it is computationally demanding because the local balance between erosion and deposition depends on sediment flux resulting from net upstream erosion. Here, we propose an efficient (i.e., O(N) and implicit) method to solve their equation. This means that, unlike other methods used to study the complete dynamics of fluvial systems (e.g., including the transition from detachment-limited to transport-limited behavior), our method is unconditionally stable even when large time steps are used. We demonstrate its applicability by performing a range of simulations based on a simple setup composed of an uplifting region adjacent to a stable foreland basin. As uplift and erosion progress, the mean elevations of the uplifting relief and the foreland increase, together with the average slope in the foreland. Sediments aggrade in the foreland and prograde to reach the base level where sediments are allowed to leave the system. We show how the topography of the uplifting relief and the stratigraphy of the foreland basin are controlled by the efficiency of river erosion and the efficiency of sediment transport by rivers. We observe the formation of a steady-state geometry in the uplifting region, and a dynamic steady state (i.e., autocyclic aggradation and incision) in the foreland, with aggradation and incision thicknesses up to tens of meters. KW - stream power law model KW - efficient method KW - sediment transport and deposition KW - river erosion KW - dynamic steady state KW - aggradation and incision cycles Y1 - 2019 U6 - https://doi.org/10.1029/2018JF004867 SN - 2169-9003 SN - 2169-9011 VL - 124 IS - 6 SP - 1346 EP - 1365 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Yuan, Xiaoping A1 - Braun, Jean A1 - Guerit, Laure A1 - Simon, Brendan A1 - Bovy, Benoît A1 - Rouby, Delphine A1 - Robin, Cécile A1 - Jiao, R. T1 - Linking continental erosion to marine sediment transport and deposition: A new implicit and O(N) method for inverse analysis JF - Earth & planetary science letters N2 - The marine sedimentary record contains unique information about the history of erosion, uplift and climate of the adjacent continent. Inverting this record has been the purpose of many numerical studies. However, limited attention has been given to linking continental erosion to marine sediment transport and deposition in large-scale surface process evolution models. Here we present a new numerical method for marine sediment transport and deposition that is directly coupled to a landscape evolution algorithm solving for the continental fluvial and hillslope erosion equations using implicit and O(N) algorithms. The new method takes into account the sorting of grain sizes (e.g., silt and sand) in the marine domain using a non-linear multiple grain-size diffusion equation and assumes that the sediment flux exported from the continental domain is proportional to the bathymetric slope. Specific transport coefficients and compaction factors are assumed for the two different grain sizes to simulate the stratigraphic architecture. The resulting set of equations is solved using an efficient (O(N) and implicit) algorithm. It can thus be used to invert stratigraphic geometries using a Bayesian approach that requires a large number of simulations. This new method is used to invert the sedimentary geometry of a natural example, the Ogooue Delta (Gabon), over the last similar to 5 Myr. The objective is to unravel the set of erosional histories of the adjacent continental domain compatible with the observed geometry of the offshore delta. For this, we use a Bayesian inversion scheme in which the misfit function is constructed by comparing four geometrical parameters between the natural and the simulated delta: the volume of sediments stored in the delta, the surface slope, the initial and the final shelf lengths. We find that the best-fit values of the transport coefficients for silt in the marine domain are in the range of 300 - 500 m(2)/yr, in agreement with previous studies on offshore diffusion. We also show that, in order to fit the sedimentary geometry, erosion rate on the continental domain must have increased by a factor of 6 to 8 since 5.3 Ma. (C) 2019 Elsevier B.V. All rights reserved. KW - river erosion KW - sediment-transport model KW - efficient method KW - inverse analysis KW - the Ogooue Delta Y1 - 2019 U6 - https://doi.org/10.1016/j.epsl.2019.115728 SN - 0012-821X SN - 1385-013X VL - 524 PB - Elsevier CY - Amsterdam ER -