During the period from 1974 to 2018 various cruises from BGR acquired seismic lines worldwide. The aim of these marine expeditions was a detailed survey of the geological structure.

The previous BGR-cruises with RV AURELIA in 2003 and 2004 and RV HEINCKE in 2005 and RV ALKOR in 2006 were designed to collect a grid of seismic MCS-data which should enable us to get a high-resolution overview over the upper 1-2 s TWT of the sediments of the German North Sea sector. The data format is Society of Exploration Geophysicists SEG Y. The aim of this cruise was a detailed survey in the north westernmost area of the German EEZ (exclusive economic zone), the so-called ‘Entenschnabel’ and additionally a mapping of special glacial structures off Sylt Island. The cruise was subdivided into two Legs. One outreaching additional aim was to extend the results from the previous cruises for the Late Tertiary and Quaternary sedimentary evolution into the ‘Entenschnabel’-area which was virtually unexplored by systematic shallow high-resolution seismics. During Leg 1 the BGR high-resolution multichannel seismic reflection system consisting of a GI-Gun (0.8 l) and a 500 m streamer with 36 channels and a shallow swath bathymetric system, type SIMRAD EM1200 by Kongsberg, Bergen, Norway were used. While the BGR-seismic system was used to observe the shallow subsurface down to 2 s TWT penetration depth, the swath bathymetric system was used to identify possible pockmark locations as well as sampling positions for the deployment of the BGR vibration corer during the succeeding Leg 2. All seismic records were processed onboard for the quality control and for a first interpretation loaded into GEOQUEST.

In the period from 22nd December, 1987 to 15th January, 1988 a geophysical reconnaissance survey has been carried out with S.V. EXPLORA on the Argentine Eastern continental margin. A total of 3,675 km of digital seismic reflection profiles in parallel with gravimetric and in part magnetic measurements, and 13 sonobuoy refraction profiles were recorded during this survey. The general aim of the survey was to search the Argentine eastern continental margin between 37°S and 47°S for evidence of continent-ocean boundary structures previously recognized by us off South Africa. The following preliminary results were obtained: (1) Five regional seismic markers/unconformities have been observed, named from bottom to top AR V to AR I. (2) Two units are recognizable on all reflection seismic records: A buried lower unit the top of which is marked by the distinct 'AR IV' unconformity of presumably Beriasian/Valangian age, and a tectonically undisturbed upper sedimentary unit. (3) The dominant feature of the lower unit is a 50 km to 100 km broad wedge-shaped body characterized by an internally divergent pattern of reflection horizons having seaward dip. The seismic characteristics and recent ODP drilling is consistent with the wedge being formed from extrusive basaltic rocks. (4) The more than 5000 m thick wedge is parallel with the shelf edge and can be traced continuously for 1200 km. Its landward pinchout coincides with the magnetic slope anomaly 'G'. (5) A giant contourite mound of Neogene age has been recognized in the southeastern part of the survey area. (6) Bottom simulating reflectors have been recognized. Their occurrence is associated with the contourite mound.

On the F.S. POLARSTERN cruise ANT-IV/3 (6th December, 1985 - 13th March, 1986) multichannel seismic measurements were carried out in parallel with magnetic and gravimetric measurements on 33 lines with a total length of 6,263 km. 3,350 km of the multichannel seismic lines have been processed aboard. The geophysical studies were designed to investigate the structure and geological development of the Weddell Sea continental margin from meridians zero to 60°W, and to define suitable and safe drilling locations for Leg 113 of the Ocean Drilling Program. The main results of the geophysical studies are: (1) The discovery of an approximately N50°E trending failed drift basin, following the trend of a negative magnetic anomaly and a positive gravity anomaly. (2) The discovery of two extensive wedge-shaped and symmetric basement units around a failed drift basin between longitudes 40°W and 20°W. The seismic characteristics, i.e. seismic velocities of 4 km/s and an internally divergent pattern of reflectors suggest that both wedges are formed from extrusive/intrusive volcanic rocks. (3) The confirmation of a major plate tectonic boundary trending approximately N80°E to N60°E, i.e. the EXPLORA-ANDENES escarpment. (4) The confirmation of a glaciogenic progradational wedge beneath the shelf of the Weddell Sea Embayment, made up of several thousand metres of sediments. (5) The definition of 13 suitable and safe drilling locations for ODP-Leg 113.

In the frame of the Continental Margin Study Program of the Federal Institute for Geosciences and Natural Resources (BGR, Hannover) marine geophysical measurements (48-channel reflection seismic, sono-buoy refraction, gravity and magnetic) were conducted over the Atlantic continental margin of Canada from 23th July to 7th August 1979 with S.V. EXPLORA (BGR79 leg 2). The survey on the Canadian continental margin was planned in cooperation between the Federal Institute for Geosciences and Natural Resources (BGR) and the Atlantic Geoscience Centre of the Geological Survey of Canada (Bedford Institute of Oceanography, Dartmonth, N.S.) on the base of existing Canadian multichannel seismic lines. A main target of the cruise was to acquire data which allow a comparison of the deep sedimentary basins offshore Nova Scotia with the already known basins offshore Morocco. The eastern part of the survey imaged complex structural deformation due to salt diapirs. The western seismic lines allowed to investigate the structural relationship between the Scotian Basin and the Georges Bank.

A geophysical reconnaissance survey was carried out in the Labrador Sea and Davis Strait between July and September 1977 by BGR. The data format is Society of Exploration Geophysicists SEG Y. The survey was executed on the research vessel MS Explora. The seismic, magnetic and gravity data from 5931 line-kilometers on 21 lines were recorded on magnetic tape. A 24-fold coverage technique was used with 48 seismic channels (traces), with a 2400m streamer cable, and 23.45 l airgun array. A full integrated computerized satellite navigation system (INDAS III) served as positioning system. Based on a preliminary interpretation of the seismograms, the Labrador Sea was devided into an eastern (Greenland) and western (Canadian) area, seperated by the Mid Labrador Ridge. Within the eastern part of the Labrador Sea the Pre-Cenozoic sediments show three distinct layers, traceable over the entire Greenland area of the sea. In the Cenozoic layer olisthostromes occur. The highest apparent velocity determined from sonobuoy data was 9.26 km/sec. The calculated refractor lies at a depth of approximately 13 km. The seismic section from the sediments on the Canadian side of the Labrador Sea show a uniform series of thick sediments below the Cenozoic cover. The highly disturbed basement is often masked by the multiple reflections from the seafloor. Statements about the nature and structure of the basement can only be made after processing data.

SONNE cruise SO-85 was designed to study the variability of the oceanic crustal structure along flow-line profiles over Early Tertiary through Early Cretaceous old crust in the Cape and Argentine basins of the South Atlantic. Between 21th February and 20th April 1993 deep imaging seismic reflection data in parallel with magnetic, gravimetric and hydroacoustic measurements have been collected along a 1,405 km long flow-line traverse across the Cape basin, and along three flow-line traverses across the Argentine basin with a total length of 4,255 km. A special geophysical survey was carried out on the Argentine continental margin. Although bad weather hampered the geophysical measurements in the Argentine basin, some new and intriguing observations were made: (1) the presence of an elongated wedge of seaward dipping reflectors, often associated with the distinct magnetic anomaly 'G', was confirmed on both, the South African and Argentine continental margins; (2) the sequence of seaward-dipping reflectors consists of two wedges. The younger wedge rests partly on the older one; (3) the surface of the oceanic crust lies more deep in the Argentine basin than in the Cape basin; (4) the structure of the oceanic crust is more variable in time and space within the Argentine and Cape basins than within the Angola and Brazil basins; (5) despite this, it appears that the oceanic crust generated during the younger half of the Cretaceous magnetic quiet period up to C 33r is characterized by relative high reflectivity in lower crustal levels; (6) high-amplitude magnetic anomalies C 33 through C 34 are apparently correlatable with oceanic crustal segments characterized by common seismic features, e.g. a smooth and scarped surface of the oceanic crust; (7) an elongated, positive gravity anomaly exists at about 58°E between 43.5°E and 47°E.

The POLARSTERN cruise ANTVIII/6 from 14. March to 30. April 1990 incorporated an integrated geophysical reconnaissance survey consisting of multichannel seismic measurements in parallel with gravimetric and magnetic measurements. The survey covered the plateaus Maud Rise, Astrid Ridge and Gunnerus Ridge off Queen Maud Land and the oceanic crust in their vicinity. Severe ice and weather conditions allowed seismic work only on the Gunnerus Ridge and on the oceanic crust. Together with previous BGR lines on the Astrid Ridge and the Maud Rise the new data improve considerably the understanding of the area. The main results are: 1. The oldest identified sea-floor spreading anomaly was M11 before the cruise, now it is M24. Thus spreading has begun not only 135 mill. years B.P., but at least 160 mill. years B.P. 2. The Gunnerus Ridge is strongly asymmetric. The mainly weak magnetic anomalies indicate that in contrast to the Astrid Ridge volcanism was not important during its development. 3. The magnetic anomalies are much stronger on the Astrid Ridge and west of it than east of the Astrid Ridge and on the Gunnerus Ridge. 4. The roughness of the basement surface of the oceanic crust varies in a wide range.

In the southwestern part of the Sulu Sea and in the southeastern part of the South China Sea, between NW Palawan and the northwestern part of the Reed Bank the Federal Institute for Geosciences and Natural Resources (BGR), Hannover carried out the geophysical survey BGR84 from 11th October, 1984 to 23rd November, 1984. This work was done in close cooperation with the Bureau of Mines and Geosciences (BMG), Manila, using the German seismic vessel EXPLORA chartered from PRAKLA-SEISMOS GmbH, Hannover. Multichannel reflection seismic measurements were carried out on 40 lines with a total length of 4,467 km simultaneously with magnetic measurements on 19 lines with a total length of 3,047 km. The Oligocene to lower Miocene Nido-carbonates of the South China Sea that have been proven during the SONNE cruises SO-23 and SO-27 beneath the allochthonous and chaotically deformed complex which was overthrusted from the Sulu Sea terrane, could be correlated up to the Balabac Straits. The three major unconformities of the Sulu Sea, unconformity A (Early Pliocene), unconformity B (mid Middle Miocene) and unconformity C (lower Middle Miocene) have been correlated over extensive areas by tying into the Sulu Sea well Coral-1. In the Sulu Sea reflection horizon C forms the top of a chaotic bedded rock complex and presumably represents an equivalent to the unconformity "Red" of the South China Sea, in the west of Palawan. There, the unconformity "Red" forms the surface of a highly deformed rock complex which has been interpreted as an allochthonous mass accumulation (HINZ, 1983; HINZ & SCHLÜTER, 1985). It is assumed that pronounced magnetic anomalies, approximately 140 - 160 km off NW Palawan as well as a change in the reflection seismic pattern of the acoustic basement, associated with diapiric structures which are interpreted as intrusions represent the ocean-continent boundary in this part of the South China Sea. In the Reed Bank area the basement type which is interpreted as continental crust (transitional crust?) extends as far as 160 km to the northwest, towards the South China Sea Basin. The northern part of the Reed Bank is characterized by intense downfaulting and rotated fault blocks with reef complexes ontop. In contrast to results from the Dangerous Grounds of the previous SONNE cruises, the deeper lying coherent reflections could be recognized in the monitor records off the northwestern Reed Bank area. It might be that these parts of the Reed Bank block consists of metamorphized and/or highly consolidated rocks of pre-Tertiary age which originally formed part of the Chinese back country, and which was effected by previous orogenies prior to the rifting of the proto-China continental margin.

From 17th April to 6th June 2003 BGR conducted a marine geophysical cruise between 30°S and 38°S off the Atlantic coast of South Africa. The main research objective was to contribute to a better understanding of the initial breakup and the early opening of the South Atlantic. In continuation of our former work on the South Atlantic continental margins off Argentina, Brazil, Uruguay and Namibia marine geophysical research (multi-channel seismics, wide-angle refraction seismics, magnetics and gravity) was performed in cooperation with the Petroleum Agency South Africa (PASA). Multi-channel lines with a total lenght of 3,260 km, and additional 1,365km, with the other geophysical methods were acquired. Combined onshore/offshore refraction seismic work in cooperation with GeoForschungsZentrum Potsdam (Germany) and the Council for Geoscience (South Africa) was also part of the program.