The aim of the cruise was to explore gas emissions using the echosounders of the ship along the slope of the Barents Sea up to Svalbard to find more evidence for dynamic changes of gas hydrates and emissions of free gas. CI Citation: Paul Wintersteller (seafloor-imaging@marum.de) as responsible party for bathymetry post-processing and its products. Description of processed data sources: During the cruise HE450 the Kongsberg EM710 shallow multibeam echosounder with a nominal sounding frequency of 70-100 kHz was utilized. 256 beams (and up to 800 soundings with equidistant and dual swath mode) are formed for each ping with a 1°(Tx)/2°(Rx) footprint while the seafloor is detected using amplitude and phase information for each beam sounding. For further information consult: http://epic.awi.de/26726/1/Kon2007b.pdf. During the surveys the EM710 experienced a few crashes (acquisition software and/or processing unit) but was otherwise stable during the cruise. The wobbling problem detected during the HE387 cruise (Sahling, 2012) is still present over the EM710 data. Responsible person during this cruise / PI: Christian dos Santos Ferreira (cferreira@marum.de) and Paul Wintersteller (pwintersteller@marum.de). Chief Scientist: G. Bohrmann (gbohrmann@marum.de) CR: not available CSR: https://www2.bsh.de/aktdat/dod/fahrtergebnis/2015/20150037.htm A special thanks goes to the watchkeeper during HE450: Chieh-Wie Hsu & Markus Loher

Data acquisition was performed using a multibeam sonar system Simrad EM710 from Kongsberg. Raw data are delivered in current Simrad multibeam vendor format. SIMRAD raw data can be processed e.g. with the software packages CARIS HIPS/SIPS, Caraibes or with the open source software package MB-System (http://www.ldeo.columbia.edu/res/pi/MB-System/).