@article {6247, title = {A Multi-Frequency Investigation of the Influences of Groundwater Discharge on Hydrocarbon Emission and Transport in the Baltic Sea}, year = {2017}, month = {December 11-15}, pages = {New Orleans, LA}, abstract = {

In nearshore coastal regions submarine groundwater discharge is a major component of the hydro-geological cycle: transporting nutrients and pollutants to the ocean, producing up-welling currents through buoyancy effects, and acting as an erosional force at discharge sites. In nearshore regions where biogenic gas production is high, groundwater discharge could potentially act as a control on hydrocarbon emission and transport from the seafloor though the water-column.

In the southern Stockholm Archipelago of the Baltic Sea, terraces and semi-circular depressions on shallow (\<20 meters) seafloor have been linked to the discharge of ground water, traveling along the permeable layers in glacial clay deposits (S\öderberg and Flod\én 1995; Jakobsson et al., 2016). Sub-bottom profiles over the same region have identified widespread areas of subsurface blanking, commonly attributed to gas, as well as water-column seep features, both in spatial proximity to the groundwater discharge sites.

High-resolution multibeam bathymetry and chirp sub-bottom profiles were combined with water-column data sets collected at multiple frequencies (300 kHz, 45-90 kHz, 160-260 kHz) to map the spatial distribution of seeps and investigate their relationship to localized groundwater discharge as determined by seafloor and subsurface morphology. The spatial extent of seep sites appears closely tied to regions of suspected groundwater discharge, suggesting direct or indirect controls on gas emission pathways. Additionally, seep morphology in the broadband data hints at the possibility of groundwater and gas flow mixing.

}, url = {https://agu.confex.com/agu/fm17/meetingapp.cgi/Paper/230878}, author = {Elizabeth Weidner and Martin Jakobsson and Nycander, J and Larry A Mayer} } @article {, title = {The Early Miocene Onset of a Ventilated Circulation Regime in the Arctic Ocean}, volume = {447}, year = {2007}, pages = {986-990}, publisher = {Nature Publishing Group}, keywords = {Other}, author = {Martin Jakobsson and Backman, Jan and Rudels, J and Nycander, J and Frank, M and Larry A Mayer and Jokat, W and Sangiorgi, F and O{\textquoteright}Regan, M A and Brinkhuis, H and King, J W and Moran, K} }