Titel: “High resolution seafloor evidence for glacial and post-glacial environments in the Irish Sea.”

Main types of data:

New high resolution multibeam echosounder data has been collected in the Irish Sea through the auspices of many different projects in the last 7 years. As part of the INTERREG IIIa funded habitat mapping project HabMap this data was pulled together to map the Irish seafloor topography. The objective of this research is to map and study the bedforms regarding their spatial distribution, geometry, growth/decay and internal structuren and as a function of sediment characteristics, bathymetry, tidal current forcing and the time history of the above processes.

The seafloor in some areas of the Irish Sea has been dramatically sculpted by ice during past glacial activity. A morphometric approach to glacial bedforms description is used to reconstruct the direction of ice flow and the nature of final deglaciation in that area.

Tidal bedforms have been observed all over the Irish Seabed with dimensions that vary from small sand waves less then half a meter high to very large gravel waves of up to 40 meters high.

Sediment wave distribution and dimensions are modelled using derivatives of existing datasets and outputs of existing models in the Irish Sea. These models are then compared with the detailed analyses of the observed bedforms. The large bedforms are linked to the palaeo-tidal current regime of an isostatically unstable Irish Sea Basin after final deglaciation. The present day dynamics of smaller subaqueous sediment waves are described by comparing sequential bathymetric profiles revealing bedload transport pathways and migration mechanisms.