## 5 Conclusions  
A multidisciplinary survey consisting of high-resolution geophysical means and geochemical analyses provides new insights into the Patras Gulf pockmarks field. This survey has not only revealed the existence of new pockmarks, but it has brought new knowledge regarding their spatial distribution and the level of activity, their link with the structural framework of the area, the fluid escape structures, the fluid pathways used, and finally the origin of the fluids. High-resolution marine remote sensing techniques, including MBES, sub-bottom profilers, side-scan sonars and ROV, together with laboratory techniques, enabled us to record in detail the active pockmark field, which developed in Patras Gulf. In the past, the field showed co-seismic activation, while over the last 26 years, the field has been partially covered by the Patras city harbour. The acquired data sets showed that:  
* The main mechanisms for the development of the field are the local tectonism and the internal characteristics of the sedimentary layers. * The local faulting appears to be the main contributor to the arrangement of the field, as it was shown to regulate the density, spatial distribution and geometry of the pockmark shapes in the field. All these morphometric characteristics are in line with the direction of the main active faults and the associated tectonic failures recorded in the region. * The lithological parameters and the thickness of the upper sedimentary deposits in the examined area also contributed to the formation of the field. Thick, muddy deposits enhance the development of pockmarks in terms of quantity (high number of pockmarks) and sizes (large sizes) of pockmarks. * Pockmarks recorded have steep sidewalls (up to 40\({}^{\circ}\)), suggesting recent activation. Steep slopes (at least \(>\)20\({}^{\circ}\)) seem to promote slumping events in the pockmarks. No acoustical or optical evidence of benthic ecosystems linked with gas seepages was recorded. * The combined acoustic data sets detected, in detail, the migrated gas in marine sediments and the water column. The sediments provide evidence for the presence of gas by the recordings of Acoustic Turbidity Zones (ATZs), Enhanced Reflectors (ER) and, to a lesser extent, Intracellular Gas Plumes (IGP). Evidence for the gas in the water column was revealed by the gas flare recordings. * Geochemical analysis showed that CH\({}_{4}\) is the dominant component of the released fluid, and its isotopic analysis showed a microbial origin, which is common in shallow marine environments. * Although the source of the gas flare pockmarks changes through time, the fact that gas flares are always recorded above the field denotes an ongoing pockmark activity. * Through time, local and regional, active tectonic processes and possibly recent anthropogenic activities (construction of the harbour) alter the migration paths of the escaping gas and cause modifications in the growth of the field. The field serves as a living underwater landscape, which has the potential to respond directly to seismic activity, even as a precursory response to earthquakes. * This study showed that multidisciplinary surveying, incorporating marine geophysical and laboratory investigations, can illuminate aspects of a pockmark field in relation to configuration, structure, activity and triggering mechanisms. Conceptualisation, D.C., G.P. and M.G. ; methodology, D.C. and G.P. ; formal analysis, D.C. and N.G. ([PERSON]); investigation, D.C., X.D., S.S., E.F., N.G. ([PERSON]), G.E., E.S., G.F., M.G. and G.P. ; data curation, D.C. and G.P. ; writing--original draft preparation, D.C., G.P., M.G. and S.K. ; writing--review and editing, D.C., G.P., M.G., S.K., X.D., G.F.  
and G.E. ; visualisation, D.C. and N.G. ([PERSON]); supervision, G.P. ; project administration, G.P. ; funding acquisition, G.P. All authors have read and agreed to the published version of the manuscript. This research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the \"First Call for H.F.R.I.