Variability in fluvially‐dominated, fine‐grained, shallow‐water deltas

Fluvially-dominated, fine-grained, shallow-water deltas are more variable than is generally recognized. Studies of the Mississippi River imply rather persistent river-mouth jet dynamics, resulting in either progressive channel bifurcation around middle-ground mouth bars on lobate deltas, or steady progradation to form elongate akin modern Delta. By contrast, satellite imagery and historical maps less well-known fluvially-dominated show diverse deposits, with plan-form shapes ranging from fans, through splay, triangular, frond tongue-shaped bars, channels prominent subaqueous levées. Critically, such deposits may vary along individual across between lobes suggesting that variability can be normal, a spectrum jets forms suite stable deposits. Channel elongation also common. In addition high-inertia delta-head backwater-mediated avulsion, two further mechanisms recognized channels. Following splitting, dominant splits shoulder aside so subordinate wither extend parent channel. Alternatively, distributary networks abandoned, rejuvenated by receiving an increase discharge, allowing continue. Individual real-world expected characterized range both laterally over time. However, different modes elongation, not considered models – omissions have significant impact for land remediation projects descriptions subsurface constructed aid resource extraction.