Are you sure you want to remove campaign "Bedform of the Dover Strait seafloor"?
Bedform of the Dover Strait seafloor
Enigmatic linear groove-and-ridge bed-form imprinted in the Dover Strait seafloor.
During our investigations in the Dover Strait (Gupta et al., 2017), we discovered several sets of kilometer-long, parallel streamlined ridge-and-groove bedforms. Individual ridges and grooves are generally up to 30 m wide, with amplitudes ranging between 0.5 and 1.2 m. Their lengths are unknown, as sand dunes and other sedimentary bodies cover large parts of them. These features are oblique to Holocene sedimentary bodies. Hence, they are not in equilibrium with the current flow field of the Strait. They should thus have been formed prior to the Holocene marine transgression. Importantly, most of these features are located within the ~20-km-wide, NNE–SSW-oriented, bedrock incised palaeovalley known as the Lobourg Channel. Some of them are however located outside (and truncated by) this channel, indicating that the erosional/sedimentary process(es) that formed these features happened more than once. All ridge-and-groove bedforms have a consistent ENE–WSW alignment, sub-parallel to the axis of the Lobourg Channel.
The origin and age of these parallel linear features remain unknown due to the lack of sedimentary and geophysical data. Currently, we interpret them as bedrock-eroded longitudinal grooves carved by megaflood flow(s) generated in the southern North Sea – eastern English Channel during Middle and/or Late Pleistocene Glaciations. This interpretation is based on their similarities to longitudinal scours identified in megaflood-eroded terrains of Washington State (USA) and Australia (Baker and Nummedal, 1978; Wohl, 1993). It is also supported by the presence of several other erosional features carved within the Lobourg Channel typically found in megaflood-eroded terrains (Collier et al., 2015; Gupta et al., 2017). The objective of this geophysical investigation is therefore to collect very high-resolution bathymetric data, high-resolution seismic-reflection data, and sedimentary grabs from these features to confirm that they are not sedimentary features, but bedrock-incised bedforms. We also aim to unravel how and when these features formed to verify their relationship to the occurrence of megaflood events in the English Channel and southern North Sea during Middle and/or Late Pleistocene glaciations.