ALBERT

Description: Upper-ocean velocities along the cruise track of RV MARIA S. MERIAN cruise MSM103 were continuously collected by a vessel-mounted Teledyne RD Instruments 38 kHz Ocean Surveyor ADCP. The transducer was located at 6.0 m below the water line. The instrument was operated in narrowband mode with 32 m bins and a blanking distance of 16.0 m, while 50 bins were recorded using a pulse of 2.87 s. The ship's velocity was calculated from position fixes obtained by the Global Positioning System (GPS). Heading, pitch and roll data from the ship's gyro platforms and the navigation data were used by the data acquisition software VmDas internally to convert ADCP velocities into earth coordinates. Accuracy of the ADCP velocities mainly depends on the quality of the position fixes and the ship's heading data. Further errors stem from a misalignment of the transducer with the ship's centerline. Data post-processing included water track calibration of the misalignment angle (0.50° +/- 0.7353°) and scale factor (1.0006 +/- 0.0160) of the Ocean Surveyor signal. The average interval was set to 120 s.

Description: Upper-ocean velocities along the cruise track of RV MARIA S. MERIAN cruise MSM103 were continuously collected by a vessel-mounted Teledyne RD Instruments 75 kHz Ocean Surveyor ADCP. The transducer was located at 6.0 m below the water line. The instrument was operated in narrowband mode with 8 m bins and a blanking distance of 8.0 m, while 100 bins were recorded using a pulse of 1.43 s. The ship's velocity was calculated from position fixes obtained by the Global Positioning System (GPS). Heading, pitch and roll data from the ship's gyro platforms and the navigation data were used by the data acquisition software VmDas internally to convert ADCP velocities into earth coordinates. Accuracy of the ADCP velocities mainly depends on the quality of the position fixes and the ship's heading data. Further errors stem from a misalignment of the transducer with the ship's centerline. Data post-processing included water track calibration of the misalignment angle (0.73° +/- 0.5865°) and scale factor (1.0041 +/- 0.0095) of the Ocean Surveyor signal. The average interval was set to 120 s.

Description: Underway temperature and salinity data was collected along the cruise track with two autonomous measurement systems. Usually, the systems are changed after 6 hours. While temperature is taken at the water inlet in about 6.5 m depth, salinity is estimated within the interior measurement container from conductivity and interior temperature. Salinity was calibrated independently for both measurement containers (MCs). No correction was done for temperature. For details to all processing steps see Data Processing Report.

Description: The main objective of cruise POS524 to the Grimsey Vent Field (GVF), to the North of Iceland, was to study the suitability of electromagnetic (EM) systems for the characterization of an active hydrothermal system. As part of the EM measurements, a Microcat CTD sensor (Seabird) was attached to the mobile EM transmitter (MARTEMIS system), which was operated at an altitude of 5 - 10m above the seafloor. CTD measurements were collected alongside the EM measurements to serve as indicators for hydrothermal activity. CTD measurements with the Microcat CTD Sensor recorded conductivity [mS/cm], temperature [°C] and pressure [dbar] at a sampling rate of 4s, from which sound velocity [m/s] and salinity [psu] were derived using standard formulas (Chen and Millero formula; UNESCO Technical papers in Marine Science #44). Measurements were taken along profiles with a total length of about 18.5km crossing the GVF and surrounding areas during 24h of the 2nd deployment of the MARTEMIS system (station POS524_22-1) between 13.6.2018 6:00h - 14.6.2018 6:00h (UTC). The data are stored in an xls-file. Please note that on-deck measurements were cut from file. Details of the measurements and the cruise can be found in the cruise report (DOI 10.3289/CR_POS524)

Description: Raw data acquired by position sensors on board RV MERIAN during expedition MSM103 were processed to receive a validated master track which can be used as reference of further expedition data. During MSM103 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and the GPS receivers Trimble SPS855 and SAAB R4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track.

Description: Raw data acquired by position sensors on board RV MERIAN during expedition MSM103 were processed to receive a validated master track which can be used as reference of further expedition data. During MSM103 the motion reference unit Kongsberg SeaTex AS MRU-5 combined with Kongsberg SeaTex AS Seapath 320 and the GPS receivers Trimble SPS855 and SAAB R4 were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.bsh.de) with a resolution of 1 sec. Processing and evaluation of the data is outlined in the data processing report. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track.

Description: Multibeam bathymetry raw data was recorded in the North Atlantic during cruise MSM103 that took place between and 2021-09-12 and 2021-11-15. The data was collected using the ship's own Kongsberg EM 122. Sound velocity profiles (SVP) were applied on the data for calibration. Please see environmental data (zip file) and the cruise report for details.

Description: The endorheic Gaxun Nur Basin (GNB, local name: Ejina basin), which is located north of the Tibetan Plateau between the tectonic stress fields of the Qilian Shan and the Gobi-Tienshan, has evolved as a large inland basin filled with deltaic sediments during the past 250 ka. Here we present selected examples of geomorphological, sedimentological and geophysical evidence of tectonic activity and discuss a possible time frame of selected occurrences.We used medium-scale geomorphological mapping supported by analyses of Landsat ETM images, Corona images and an Aster Digital Terrain Model (Aster-DTM), combined with field surveys, dated sediment sections, and geophysical investigations using electromagnetic methods.The spatio-temporal distribution of radiocarbon-dated lake sediments within the northern GNB indicates a non-even distribution of neotectonic activity with west–east increasing amplitude of subsidence rates from 0.8–1.1 m/ka in the western part and more than three times higher rates in the eastern part.Our data indicate that tectonic has strongly amplified climate-induced environmental changes and may be regarded as an example of non-climatic pulses affecting lake-hydrology and basin development.

Description: Electromagnetic methods are commonly employed in exploration for land-based mineral deposits. A suite of airborne, land, and borehole electromagnetic techniques consisting of different coil and dipole configurations have been developed over the last few decades for this purpose. In contrast, although the commercial value of marine mineral deposits has been recognized for decades, the development of suitable marine electromagnetic methods for mineral exploration at sea is still in its infancy. One particularly interesting electromagnetic method, which could be used to image a mineral deposit on the ocean floor, is the central loop configuration. Central loop systems consist of concentric transmitting and receiving loops of wire. While these types of systems are frequently used in land-based or airborne surveys, to our knowledge neither system has been used for marine mineral exploration. The advantages of using central loop systems at sea are twofold: (1) simplified navigation, because the transmitter and receiver are concentric, and (2) simplified operation because only one compact unit must be deployed. We produced layered seafloor type curves for two particular types of central loop methods: the in-loop and coincident loop configurations. In particular, we consider models inspired by real marine mineral exploration scenarios consisting of overburdens 0 to 5 m thick overlying a conductive ore body 5 to 30 m thick. Modeling and resolution analyses showed that, using a 50  m2 transmitting loop with 20 A of current, these two configurations are useful tools to determine the overburden depth to a conductive ore deposit and its thickness. In the most extreme case, absolute voltage errors on the order of 10 nV are required to resolve the base of a 30 m thick ore deposit. Whether such noise floors can be achieved in real marine environments remains to be seen.