TY - JOUR

T1 - The role of biophysical cohesion on subaqueous bed form size

AU - Parsons, D.R.

AU - Schindler, R.J.

AU - Hope, J.A.

AU - Malarkey, J.

AU - Baas, J.H.

AU - Peakall, J.

AU - Manning, A.L.

AU - Ye, L.

AU - Simmons, S.

AU - Paterson, D.M.

AU - Aspden, R.J.

AU - Bass, S.J.

AU - Davies, A.G.

AU - Lichtman, I.D.

AU - Thorne, P.D.

PY - 2016/1/28

Y1 - 2016/1/28

N2 - Biologically active, fine-grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud-sand dominates many coasts, deltas, and estuaries. Our predictions of sediment transport and bed roughness in these environments presently rely on empirically based bed form predictors that are based exclusively on biologically inactive cohesionless silt, sand, and gravel. This approach underpins many paleoenvironmental reconstructions of sedimentary successions, which rely on analysis of cross-stratification and bounding surfaces produced by migrating bed forms. Here we present controlled laboratory experiments that identify and quantify the influence of physical and biological cohesion on equilibrium bed form morphology. The results show the profound influence of biological cohesion on bed form size and identify how cohesive bonding mechanisms in different sediment mixtures govern the relationships. The findings highlight that existing bed form predictors require reformulation for combined biophysical cohesive effects in order to improve morphodynamic model predictions and to enhance the interpretations of these environments in the geological record.

AB - Biologically active, fine-grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud-sand dominates many coasts, deltas, and estuaries. Our predictions of sediment transport and bed roughness in these environments presently rely on empirically based bed form predictors that are based exclusively on biologically inactive cohesionless silt, sand, and gravel. This approach underpins many paleoenvironmental reconstructions of sedimentary successions, which rely on analysis of cross-stratification and bounding surfaces produced by migrating bed forms. Here we present controlled laboratory experiments that identify and quantify the influence of physical and biological cohesion on equilibrium bed form morphology. The results show the profound influence of biological cohesion on bed form size and identify how cohesive bonding mechanisms in different sediment mixtures govern the relationships. The findings highlight that existing bed form predictors require reformulation for combined biophysical cohesive effects in order to improve morphodynamic model predictions and to enhance the interpretations of these environments in the geological record.

UR - https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2F2016GL067667&file=grl53987-sup-0001-supplementary.pdf

U2 - 10.1002/2016GL067667

DO - 10.1002/2016GL067667

M3 - Article

VL - 43

SP - 1566

EP - 1573

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

ER -