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 initial study area of the cruise MSM14/2 GeoNORM (Geophysik im noerdlichen Roten Meer) was the northern Red Sea. However, because of not given research permissions from Egypt and Saudi Arabia, the study area had to be changed to the alternative study area Eratosthenes Seamount (ESM), south of Cyprus. The ESM is supposed to represent a continental fragment of the former African-Arabian Plate that is entering the subduction zone south of Cyprus i.e. the subduction turns into collision in the area of the ESM. This changed the entire tectonic setting in the Eastern Mediterranean. Therefore, the tectonic evolution of the area is rather complex with phases of extension, subduction, compression, salt tectonics and gravitational processes and not comprehensively understood. Because of the isolation of the ESM as a continental fragment this region is an ideal spot to investigate the transition from regular subduction to continental collision and its associated tectonic processes i.e. faults were activated or reactivated, transform motion has to be compensated, the overriding plate has been elevated. This impacts the ongoing geological and tectonic processes in this region but also influences the social and economic life in the Eastern Mediterranean as earthquakes and submarine landslides are possible geohazards and the entering of the ESM to the subduction trench alters the thermal history of the adjacent sedimentary basins significantly what should have an influence on the maturity processes within the source rock sediments and new faults open new migration paths for hydrocarbon fluids or gases.

The expedition PS155/1 started on August 5th, 2018 in Tromsø (Norway) and ended in Longyearbyen (Spitsbergen) on September 3rd, 2018. In the course of BGR’s GREENMATE project the geological development of the European North Atlantic and the northern and north eastern Greenland shelf was analyzed using various marine geophysical methods (seismics, magnetics, gravity, heatflow measurements) and geological sampling (gravity corer, box corer, multi-corer, dredge). Sampling of marine Shelf sediments was undertaken in close correspondence with co-users from Geomar (add-on project ECHONEG), aiming to reconstruct Holocene paleo environmental and climatic evolution. Using the ship’s helicopters, marine sampling was complemented by onshore sampling operations to extract geological material at selected near coastal locations. Other scientific project groups used the cruise PS115.1 as an opportunity to quantify marine mammals and sea birds and their statistical distribution in our research area as part of the long-term project (add-on project Birds& Mammals) and to gather additional meteorological data via radiosondes (add-on Project YOPP). Against all expectations, outstanding ice conditions along the northern coast of Greenland enabled us to carry out reflection seismic surveys north of 84°N at the southern tip of Morris Jesup Rise with a 3 km long streamer. Structural data of this particular region of North Greenland is of special importance for BGR’s project GREENMATE for reconstructing the continental margin evolution. A 100 km long refraction seismic profile was measured to complement the reflection seismic data. After completing this, scientific work was concentrated on the northeastern Greenland shelf area between 76°N and 82.5°N. Over the time of the cruise a total of 2500 km of reflection seismic profiles (2250 km measured with 3km streamer length) and 100 km of refraction seismic profile (using nine ocean bottom seismometers) were measured, accompanied by gravity and magnetic surveys and seven heat flow measurement stations. Along the shelf and deep-sea area 21 geological sampling sites were chosen, with all together one dredge (around 200 kg of sample), 16 gravity cores (total core length 65 m), 12 box corers and 6 multi-corer stations. Onshore sediment sampling was done at 11 sampling sites. Beside sediment sampling hard rock from near coastal outcrops was collected in a total amount of 250 kg that will be used for age dating. The entire science program was carried out under consideration of the highest ecological standards to protect marine mammals and to meet all environmental requirements of the permitting authorities. In addition to external marine mammal observers (MMO) various acoustic monitoring systems and AWI’s on board infrared detection system AIMMS monitored any activity of marine mammals in the ships perimeter, especially during seismic operations.

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.

The MSM67 SEGMENT research cruise was carried out between August 31st and October 4th 2017 aboard the research vessel MARIA S. MERIAN. Survey MSM67 SEGMENT it is intended to study the architecture of the rifted continental margin off East Greenland around the Jan Mayen fracture zone. Key issues to be addressed are margin segmentation and the location of the continent-ocean transition (COT). Both subjects are highly debated. Symmetric segmentation of conjugate margins has significant implications on our general understanding of continental rifting processes, and a margin-parallel COT off East Greenland would indicate an N-S opening in the Norwegian/Greenland Sea. The latter challenging most publications on the early evolution of the North Atlantic. A major open question is also the timing, duration and distribution of magmatism that resulted in the formation of the North Atlantic large igneous province. Previous suggestions of very short (~3 Myr) periods of intense magmatism have been challenged and a much longer duration and/or a post-breakup origin are under discussion. Here, we want to establish the amount of post-breakup magmatism as evident in high-velocity lower crust and test the dependence of magmatism with distance from the proposed hot-spot under Iceland and the influence of major fracture zones on volcanism.

As recommended by the Joint CCOP-IOC Working Group on Post-IDOE Studies on East Asia Tectonics and Resources and the proposal of the Bureau of Mines and Geosciences of the Philippines to extend the research of the previous R/V SONNE survey SO-23, the Federal Institute of Geosciences and Natural Resources (BGR) carried out a geophysical survey in the southeastern part of the South China Sea (Dangerous Grounds) and in the northwestern part of the Sulu Sea in two legs from 29th April to 29th June 1983 on SONNE cruise SO-27. Multichannel reflection seismic measurements were carried out in parallel with magnetic, gravimetric, Sea-Beam, and 3.5 kHz subbottom profiler measurements on 34 lines with a total length of 7,204 km. In addition, 26 lines with a total length of 2,800 km were surveyed with only the last four named methods. SONNE cruise SO-27 was financed by the Federal Ministry of Research and Technology (BMFT). Six seismic sequences (DG-1 to DG-6) (DG = Dangerous Grounds) could be distinguished in the surveyed part of the South China Sea. The oldest recognizable sequence is the sequence DG-6, an equivalent of the Pre-Nido Formation of the northwest shelf of Palawan. Seismic unconformity Violet marks the top of the DG-6 sequence, which consists of a complex system of tilted horsts and half-grabens. The half-grabens are presumably filled with clastic sediments of Eocene age (seismic sequence DG-5). The top of seismic sequence DG-5 is bounded by unconformity Blue, which is interpreted as representing the end of the rift phase and the onset of seafloor spreading in the South China Sea about 32 m.y. ago. The overlying seismic sequence DG-4 is characterized by an internal reflection pattern with low frequencies. Lithologically, this sequence consists of shallow-water carbonates with reef complexes of Oligocene to Early Miocene age and has to be regarded as equivalent to the oil-containing Nido Formation of the Palawan shelf. A rapid subsidence of large parts of the survey area during the late (?) Early Miocene ended the growth of the shallow water carbonate platform, indicated by the unconformity Blue. The overlying seismic sequence DG-3 is interpreted as consisting of a transitional facies between a shallow water and a bathyal depositional environment. The top of this sequence is marked by unconformity Red, which most probably represents the end of the drifting phase (seafloor spreading) in the South China Sea during the Middle Miocene. The most prominent structural feature of the shelf and slope of central and southern Palawan is a thick sedimentary wedge originally interpreted as a melange. Our data show that the Oligocene to Early Miocene carbonate platform of the Dangerous Grounds extends beneath the Palawan Trough, as well as beneath the central and southern Palawan shelf, underlying the melange. Based on the finding that i) Rhaeto-Liassic rocks are present in the Dangerous Grounds, ii) the Oligocene to Early Miocene carbonate platform continues from the Dangerous Grounds through the Palawan Trough to the central and southern Palawan shelf, and iii) there is thinned continental crust 20 km thick below the continental slope of southern Palawan, we believe the Dangerous Grounds, together with Palawan and the Caiman Islands belong to a uniform continental fragment which separated from the proto-chinese continental margin when the South China Sea opened during the Oligocene. Previously, the melange of central and southern Palawan, which contains ophiolites, was interpreted as being autochthonous. In our opinion, the melange is an allochthonous mass which has been overthrusted onto the eastern margin of the Dangerous Grounds-Palawan-Caiman microcontinent from the Northwest Sulu Basin. The Ulugan Bay fault is interpreted as the northeastern front of this allochthonous mass. The area of prospective carbonate plays is considerably enlarged by the discovery that the Oligocene to Early Miocene carbonate platform with Nido-type reef structures extends below the allochthonous sediments of central and southern Palawan. We expect that hydrocarbon-bearing structures of the Sabah-type, i. e. thick, folded Neogene sediments, will be found in the western part of the northwestern Sulu basin. If our interpretation is correct, a new chapter of hydrocarbon exploration may be about to begin around Palawan in the Philippines.

Continuing the systematic work which was started during a previous BGR expedition with RV AURELIA in Sept./Oct. 2003 the late Tertiary and Quaternary development of the German EEZ was further investigated by seismic profiling. The data format is Society of Exploration Geophysicists SEG Y. Again the research vessel AURELIA was chartered for a period of 21 days from 31st of May to 19th of June 2004. During the cruise the grid of seismic profiles which was aquired in 2003 was completed and data gaps were closed. A total of 2618km of high quality MCS lines were surveyed.

The area of the 1st leg of METEOR cruise no. 67 lies off the Moroccan coast between longitudes 32.5°N and 35°N and latitude 12°W. Within this continental margin segment multichannel reflection seismic measurements were carried out in parallel with magnetic and gravimetric measurements on 22 lines with a total length of 4,378 km during the period from January 20th to February 13th 1984, with the research objectives: i) to collect new geophysical data for a better understanding of magmatic-volcanic and tectonic processes during the initial drifting phase, and ii) to search for suitable positions for deep drilling sites of the "Ocean Drilling Programme" in the transition zone between continental and oceanic crust. A distinct and sharp reflection seismic boundary running from about 31°30'N/11°W in the south to 34°30'N/10°25'W in the north separates flat-lying Mesozoic sediments overlying slightly structured basement of the Jurassic "Magnetic Quiet Zone" from the complex Moroccan piercement zone in the east. A prominent magnetic anomaly, called S1, is nearly coincident with the sharp reflection seismic boundary, and is thought to represent most probably the initial drifting zone. The Moroccan piercement zone is interpreted to represent the eastern part of a pre-Jurassic rift-basin which conjugated western part lies off Nova Scotia/Canada. Subsidence associated with small-scale rotational block-faulting was time-transgressive in the Moroccan piercement zone, e.g. it started in Triassic time in the central part of the rift-basin and affected successively its landward parts apparently due to successively cooling of the stretched and thinned crust. Weak magnetic anomalies trending approximately NE-SW were recorded within the Jurassic "Magnetic Quiet Zone" lying west of magnetic anomaly S1. These anomalies can be correlated over distances of up to 300 km. They are interpreted to represent either variations of the geomagnetic field intensity or field reversals during a time of weak geomagnetic field.

The research cruise PANORAMA-1 onboard the Italian vessel OGS Explora was carried out within 2 legs in the period August, 16th – September 17th 2013. The designated survey area was located in a sector of the European Arctic north of Svalbard covering an area north of 80°N between 15°E and 35°E. Main objectives were to acquire new geophysical data and extract near surface sediment samples in an underexplored area of the European Arctic with special focus on the transition zone from the North Barents shelf towards the oceanic Nansen basin. During leg 1 of the cruise a 20 days geophysical survey 1056 km of multi-channel seismic data was acquired supplemented by a 221 km long sonobuoy profile. Additionally, magnetic and sediment echosounding data was acquired along these profiles. During all operations within the survey area gravity and multibeam echosounding data was continuously acquired. After a 1 day stopover in Longyearbyen in order to exchange part of the scientific crew OGS Explora returned to the survey area to continue survey operations during leg 2. Within these 10 days period near surface sediments were extracted by means of a gravity corer at 12 locations and heat flow soundings were conducted at 7 locations. Gravity, sediment and multibeam echosounding data was continuously acquired along all transit lines within the survey area during leg 2. Total line length of magnetic data was 2658.7 km. Over all track lines with bathymetric and gravity data amount to 5665.8 km in total.

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.