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  • Abstract: We combine environmental magnetism, geochemical measurements and colour reflectance to study two late Quaternary sediment cores: GeoB 4905-4 at 2° 30 N off Cameroon and GeoB 4906-3 at 0° 44 N off Gabon. This area is suitable for investigating precipitation changes over Central and West Africa because of its potential to record input of aeolian and fluvial sediments. Three magnetozones representing low and high degree of alteration of the primary rock magnetic signals were identified. The magnetic signature is dominated by fine-grained magnetite, while residual haematite prevails in the reduced intervals, showing increase in concentration and fine grain size at wet intervals. Our records also show millennial-scale changes in climate during the last glacial and interglacial cycles. At the northern location, the past 5.5 ka are marked by high-frequency oscillations of Ti and colour reflectance, which suggests aeolian input and hence aridity. The southern location remains under the influence of the Intertropical Convergence Zone and thus did not register aeolian signals. The millennial-scale climatic signals indicate that drier and/or colder conditions persisted during the late Holocene and are synchronous with the 900 a climatic cycles observed in Northern Hemisphere ice core records. Category: geoscientificInformation Source: Supplement to: Itambi, Achakie C; von Dobeneck, Tilo; Adegbie, Adesina T (2010): Millennial-scale precipitation changes over Central Africa during the late Quaternary and Holocene: evidence in sediments from the Gulf of Guinea. Journal of Quaternary Science, 25(3), 267-279, https://doi.org/10.1002/jqs.1306 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 2.500000 * LONGITUDE: 9.390000 * DATE/TIME: 1998-03-01T06:48:00 * ELEVATION: -1328.0 m * Recovery: 12.18 m * LOCATION: off Cameroon * CAMPAIGN: M41/1 * BASIS: Meteor (1986) * METHOD/DEVICE: Gravity corer (Kiel type) EVENT LABEL: * LATITUDE: -0.690000 * LONGITUDE: 8.376667 * DATE/TIME: 1998-03-02T03:48:00 * ELEVATION: -1274.0 m * Recovery: 12.36 m * LOCATION: off Gabun * CAMPAIGN: M41/1 * BASIS: Meteor (1986) * METHOD/DEVICE: Gravity corer (Kiel type)
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  • Abstract: Selected multi-proxy and accurately dated marine and terrestrial records covering the past 2000 years in the Iberian Peninsula (IP) facilitated a comprehensive regional paleoclimate reconstruction for the Medieval Climate Anomaly (MCA: 900-1300 AD). The sequences enabled an integrated approach to land-sea comparisons and, despite local differences and some minor chronological inconsistencies, presented clear evidence that the MCA was a dry period in the Mediterranean IP. It was a period characterized by decreased lake levels, more xerophytic and heliophytic vegetation, a low frequency of floods, major Saharan eolian fluxes, and less fluvial input to marine basins. In contrast, reconstruction based on sequences from the Atlantic Ocean side of the peninsula indicated increased humidity. The data highlight the unique characteristics of the MCA relative to earlier (the Dark Ages, DA: ca. 500-900 years AD) and subsequent (the Little Ice Age, LIA: 1300-1850 years AD) colder periods. The reconstruction supports the hypothesis of Trouet et al. (2009, doi:10.1126/science.1166349), that a persistent positive mode of the North Atlantic Oscillation (NAO) dominated the MCA. Category: geoscientificInformation Source: Supplement to: Moreno, Ana; Pérez, Ana; Frigola, Jaime; Nieto-Moreno, Vanesa; Rodrigo-Gámiz, Marta; Martrat, Belén; González-Sampériz, Penélope; Morellón, Mario; Martín-Puertas, Celia; Corella, Juan Pablo; Belmonte, Ánchel; Sancho, Carlos; Cacho, Isabel; Herrera, Gemma; Canals, Miquel; Grimalt, Joan O; Jiménez-Espejo, Francisco J; Martinez-Ruiz, Francisca C; Vegas-Vilarrúbia, Teresa; Valero-Garcés, Blas L (2012): The Medieval Climate Anomaly in the Iberian Peninsula reconstructed from marine and lake records. Quaternary Science Reviews, 43, 16-32, https://doi.org/10.1016/j.quascirev.2012.04.007 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 36.383300 * LONGITUDE: -1.366700 * ELEVATION: -2512.0 m * Recovery: 0.4 m * LOCATION: Algerian-Balearic basin EVENT LABEL: * LATITUDE: 36.450000 * LONGITUDE: -1.183300 * ELEVATION: -2574.0 m * Recovery: 0.35 m * LOCATION: Algerian-Balearic basin EVENT LABEL: (Basa de la Mora lake) * LATITUDE: 42.550000 * LONGITUDE: -0.333300 * ELEVATION START: 1914.0 m * ELEVATION END: -3.0 m * LOCATION: Central Pyrenees * METHOD|DEVICE: Gravity corer EVENT LABEL: (Basa de la Mora lake) * LATITUDE: 42.550000 * LONGITUDE: -0.333300 * ELEVATION START: 1914.0 m * ELEVATION END: -3.0 m * LOCATION: Central Pyrenees * METHOD|DEVICE: Gravity corer EVENT LABEL: (MIN2400, MIN1) * LATITUDE: 40.494500 * LONGITUDE: 4.024800 * DATE/TIME: 2006-08-19T00:00:00 * ELEVATION: -2394.0 m * Recovery: 0.31 m * LOCATION: Minorca contourite * CAMPAIGN: HERM3 * BASIS: Thetys II * METHOD|DEVICE: MultiCorer EVENT LABEL: (MIN2400, MIN2) * LATITUDE: 40.496200 * LONGITUDE: 4.030200 * DATE/TIME: 2006-08-19T00:00:00 * ELEVATION: -2394.0 m * Recovery: 0.325 m * LOCATION: Minorca contourite * CAMPAIGN: HERM3 * BASIS: Thetys II * METHOD|DEVICE: MultiCorer
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  • Abstract: Climatic changes are most pronounced in northern high latitude regions. Yet, there is a paucity of observational data, both spatially and temporally, such that regional-scale dynamics are not fully captured, limiting our ability to make reliable projections. In this study, a group of dynamical downscaling products were created for the period 1950 to 2100 to better understand climate change and its impacts on hydrology, permafrost, and ecosystems at a resolution suitable for northern Alaska. An ERA-interim reanalysis dataset and the Community Earth System Model (CESM) served as the forcing mechanisms in this dynamical downscaling framework, and the Weather Research & Forecast (WRF) model, embedded with an optimization for the Arctic (Polar WRF), served as the Regional Climate Model (RCM). This downscaled output consists of multiple climatic variables (precipitation, temperature, wind speed, dew point temperature, and surface air pressure) for a 10 km grid spacing at three-hour intervals. The modeling products were evaluated and calibrated using a bias-correction approach. The ERA-interim forced WRF (ERA-WRF) produced reasonable climatic variables as a result, yielding a more closely correlated temperature field than precipitation field when long-term monthly climatology was compared with its forcing and observational data. A linear scaling method then further corrected the bias, based on ERA-interim monthly climatology, and bias-corrected ERA-WRF fields were applied as a reference for calibration of both the historical and the projected CESM forced WRF (CESM-WRF) products. Biases, such as, a cold temperature bias during summer and a warm temperature bias during winter as well as a wet bias for annual precipitation that CESM holds over northern Alaska persisted in CESM-WRF runs. The linear scaling of CESM-WRF eventually produced high-resolution downscaling products for the Alaskan North Slope for hydrological and ecological research, together with the calibrated ERA-WRF run, and its capability extends far beyond that. Other climatic research has been proposed, including exploration of historical and projected climatic extreme events and their possible connections to low-frequency sea-atmospheric oscillations, as well as near-surface permafrost degradation and ice regime shifts of lakes. These dynamically downscaled, bias corrected climatic datasets provide improved spatial and temporal resolution data necessary for ongoing modeling efforts in northern Alaska focused on reconstructing and projecting hydrologic changes, ecosystem processes and responses, and permafrost thermal regimes. The dynamical downscaling methods presented in this study can also be used to create more suitable model input datasets for other sub-regions of the Arctic. Category: geoscientificInformation Source: Supplement to: Cai, Lei; Alexeev, Vladimir A; Arp, Chistopher D; Jones, Benjamin M; Liljedahl, Anna; Gädeke, Anne (2016): Dynamical downscaling data for studying climatic impacts on hydrology, permafrost, and ecosystems in Arctic Alaska. Earth System Science Data Discussions, 39 pp, https://doi.org/10.5194/essd-2016-31 Supplemental Information: This is the data set created by polar WRF version 3.5.1 forced by multiple forcings including a reanalysis data set (ERA-interim) and an Earth System Model (CESM1) over the domain of the Alaskan North Slope, with 10 km grid spacing and 3-hourly output interval. The available variables in this data set are temperature, precipitation, wind speed/direction, and humidity. This data set has been bias-corrected using linear scaling method. More surface or upper layer variables or completed WRF output can be obtained by contacting Lei Cai (mailto:lcai4@alaska.edu). Coverage: Not Available
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  • Abstract: A high-resolution sedimentary sequence recovered from the Tagus prodelta has been studied with the objective to reconstruct multi-decadal to centennial-scale climate variability on the western Iberian Margin and to discuss the observations in a wider oceanographic and climatic context. Between ca. 100 BC and AD 400 the foraminiferal fauna and high abundance of Globorotalia inflata indicate advection of subtropical waters via the Azores Current and the winter-time warm Portugal Coastal Current. Between ca. AD 400 and 1350, encompassing the Medieval Climate Anomaly (MCA), enhanced upwelling is indicated by the planktonic foraminiferal fauna, in particular by the high abundance of upwelling indicator species Globigerina bulloides. Relatively light d18O values and high sea surface temperature (SST) (reconstructed from foraminiferal assemblages) point to upwelling of subtropical Eastern North Atlantic Central Water. Between ca. AD 1350 and 1750, i.e. most of the Little Ice Age, relatively heavy d18O values and low reconstructed SST, as well as high abundances of Neogloboquadrina incompta, indicate the advection of cold subpolar waters to the area and a southward deflection of the subpolar front in the North Atlantic, as well as changes in the mode of the North Atlantic Oscillation. In addition, the assemblage composition together with the other proxy data reveals less upwelling and stronger river input than during the MCA. Stronger Azores Current influence on the Iberian Margin and strong anthropogenic effect on the climate after AD 1750 is indicated by the foraminiferal fauna. The foraminiferal assemblage shows a significant change in surface water conditions at ca. AD 1900, including enhanced river runoff, a rapid increase in temperature and increased influence of the Azores Current. The Tagus record displays a high degree of similarity to other North Atlantic records, indicating that the site is influenced by atmospheric-oceanic processes operating throughout the North Atlantic, as well as by local changes. Category: geoscientificInformation Source: Supplement to: Bartels-Jonsdottir, Helga B; Voelker, Antje H L; Abrantes, Fatima F; Salgueiro, Emilia; Rodrigues, Teresa; Knudsen, Karen Luise (2015): High-frequency surface water changes in the Tagus prodelta off Lisbon, eastern North Atlantic, during the last two millennia. Marine Micropaleontology, 117, 13-24, https://doi.org/10.1016/j.marmicro.2015.03.001 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 38.554000 * LONGITUDE: -9.335500 * DATE/TIME: 2000-09-01T00:00:00 * ELEVATION: -90.0 m * Recovery: 6 m * LOCATION: Portuguese Margin * CAMPAIGN: D249 * BASIS: Discovery (1962) * METHOD|DEVICE: Piston corer EVENT LABEL: * LATITUDE: 38.558170 * LONGITUDE: -9.364000 * DATE/TIME: 2002-04-29T09:08:00 * ELEVATION: -96.0 m * Recovery: 0.32 m * LOCATION: Portuguese Margin * CAMPAIGN: POS287 * BASIS: Poseidon * METHOD|DEVICE: Box corer EVENT LABEL: * LATITUDE: 38.557670 * LONGITUDE: -9.364500 * DATE/TIME: 2002-04-29T10:08:00 * ELEVATION: -97.0 m * Recovery: 3.05 m * LOCATION: Portuguese Margin * CAMPAIGN: POS287 * BASIS: Poseidon * METHOD|DEVICE: Gravity corer
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  • Abstract: Seawater 187Os/188Os ratios for the Middle Miocene were reconstructed by measuring the 187Os/188Os ratios of metalliferous carbonates from the Pacific (DSDP 598) and Atlantic (DSDP 521) oceans. Atlantic and Pacific 187Os/188Os measurements are nearly indistinguishable and are consistent with previously published Os isotope records from Pacific cores. The Atlantic data reported here provide the first direct evidence that the long-term sedimentary 187Os/188Os record reflects whole-ocean changes in the Os isotopic composition of seawater. The Pacific and the Atlantic Os measurements confirm a long-term 0.01/Myr increase in marine 187Os/188Os ratios that began no later than 16 Ma. The beginning of the Os isotopic increase coincided with a decrease in the rate of increase of marine 87Sr/86Sr ratios at 16 Ma. A large increase of 1 per mil in benthic foraminiferal delta18O values, interpreted to reflect global cooling and ice sheet growth, began approximately 1 million years later at 14.8 Ma, and the long-term shift toward lower bulk carbonate delta13C values began more than 2 Myr later around 13.6 Ma. The post-16 Ma increase in marine 187Os/188Os ratios was most likely forced by weathering of radiogenic materials, either old sediments or sialic crust with a sedimentary protolith. We consider two possible Miocene-specific geologic events that can account for both this increase in marine 187Os/188Os ratios and also nearly constant 87Sr/86Sr ratios: (1) the first glacial erosion of sediment-covered cratons in the Northern Hemisphere; (2) the exhumation of the Australian passive margin-New Guinea arc system. The latter event offers a mechanism, via enhanced availability of soluble Ca and Mg silicates in the arc terrane, for the maintenance of assumed low CO2 levels after 15 Ma. The temporal resolution (three samples/Myr) of the 187Os/188Os record from Site 598, for which a stable isotope stratigraphy was also constructed, is significantly higher than that of previously published records. These high resolution data suggest oscillations with amplitudes of 0.01 to 0.02 and periods of around 1 Myr. Although variations in the 187Os/188Os record of this magnitude can be easily resolved analytically, this higher frequency signal must be verified at other sites before it can be safely interpreted as global in extent. However, the short-term 187Os/188Os variations may correlate inversely with short-term benthic foraminiferal delta18O and bulk carbonate delta13C variations that reflect glacioeustatic events. Category: geoscientificInformation Source: Supplement to: Reusch, Douglas N; Ravizza, Gregory E; Maasch, Kirk A; Wright, James D (1998): Miocene seawater 187Os/188Os ratios inferred from metalliferous carbonates. Earth and Planetary Science Letters, 160(1-2), 163-178, https://doi.org/10.1016/S0012-821X(98)00082-X Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: -26.073800 * LONGITUDE: -10.264500 * DATE/TIME: 1980-05-02T00:00:00 * ELEVATION: -4125.0 m * Penetration: 84 m * Recovery: 75.2 m * LOCATION: South Atlantic/HILL * CAMPAIGN: Leg73 * BASIS: Glomar Challenger * METHOD/DEVICE: Drilling/drill rig EVENT LABEL: * LATITUDE: -18.806300 * LONGITUDE: -129.770500 * DATE/TIME: 1983-03-02T00:00:00 * ELEVATION: -4166.0 m * Penetration: 54.7 m * Recovery: 41.8 m * LOCATION: South Pacific * CAMPAIGN: Leg92 * BASIS: Glomar Challenger * METHOD/DEVICE: Drilling/drill rig EVENT LABEL: * LATITUDE: -19.004700 * LONGITUDE: -124.676800 * DATE/TIME: 1983-03-17T00:00:00 * ELEVATION: -3699.0 m * Penetration: 52.4 m * Recovery: 41.2 m * LOCATION: South Pacific * CAMPAIGN: Leg92 * BASIS: Glomar Challenger * METHOD/DEVICE: Drilling/drill rig
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  • Abstract: Members of the calcareous nannofossil genus Discoaster have been used extensively to subdivide Tertiary deep-sea sediments into biostratigraphic zones or subzones (e.g., Martini, 1971; Bukry, 1973). Haq and Lohmann (1976) mapped biogeographic migrations of this group through time and over latitude. They suggested that expansions and contractions of Discoaster-dominated assemblages across latitudes reflect sea-surface temperature changes. Subsequently, late Pliocene Discoaster species were counted at closely spaced sample intervals from various Atlantic sites (Backman et al., 1986; Backman and Pestiaux, 1987; Chepstow-Lusty et al., 1989, 1991), and Indian Ocean as well as Pacific Ocean sites (Chepstow-Lusty, 1990). In addition to the biostratigraphic information revealing positions and the precision by which the different late Pliocene Discoaster species can be determined, these studies also demonstrated that discoasters strongly fluctuate in abundance as a function of time. These abundance variations occur in equatorial as well as temperate temperature regimes, and show periodicities that reflect orbital frequencies. Chepstow-Lusty et al. (1989, 1991) also suggested that the oscillating abundances partly represent productivity pressure, because discoasters tend to show low abundances under high productivity conditions and vice versa. In the Pacific Ocean, counts showing late Pliocene Discoaster abundances exist from three sites, namely Ocean Drilling Program (ODP) Site 677 in the eastern equatorial upwelling region, Core V28-179 from the central equatorial region, and Core V32-127 from the mid-latitude Hess Rise. The two Vema cores are condensed and show sedimentation rates below 0.5 cm/1000 yr, thus offering a poorly resolved stratigraphy. Hole 806C from the Ontong Java Plateau provided an opportunity to establish a highly resolved Discoaster record from the western extreme of the equatorial Pacific under an environmental setting that differed from ODP Site 677 by being less influenced by intense upwelling. The Discoaster counting technique is described by Backman and Shackleton (1983). Category: geoscientificInformation Source: Supplement to: Backman, Jan; Chepstow-Lusty, Alex J (1993): Data report: Late Pliocene discoaster abundances from Hole 806C. In: Berger, WH; Kroenke, LW; Mayer, LA; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 130, 755-759, https://doi.org/10.2973/odp.proc.sr.130.057.1993 Supplemental Information: Sediment depth is given in mbsf. One (1) counted specimen represents about 0.7 specimens per mm**2. Coverage: EVENT LABEL: * LATITUDE: 0.318500 * LONGITUDE: 159.361000 * DATE/TIME START: 1990-02-23T01:30:00 * DATE/TIME END: 1990-02-25T19:00:00 * ELEVATION: -2520.8 m * Penetration: 776.4 m * Recovery: 523.62 m * LOCATION: North Pacific Ocean * CAMPAIGN: Leg130 * BASIS: Joides Resolution * DEVICE: Drilling/drill rig
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  • Abstract: Abstract & Purpose of the cruise M114 At the so-called asphalt volcanoes in the southern Gulf of Mexico heavy oil is seeping at the seafloor where it remains as asphalt deposits. Discovered and preliminarily surveyed during SO174 and M67/2 expeditions, these sites are subject for detail studies during M114 focusing on mapping with autonomous underwater vehicle (AUV MARUM-SEAL), deep-towed sidescan sonar (DTS-1), sediment echosounder (Parasound), multibeam echosounder (EM122), and remotely operated vehicle MARUM-ROV Quest. The overarching objective is to better understand the impact, fate, and decay rates of oil in the deep-sea environment. Heavy oil and gas bubbles are emitted from the 1200 to 2900 m deep seafloor in the hy-drocarbon province Campeche Knolls in the southern Gulf of Mexico. The viscous heavy oil flows across the seafloor, loses volatile compounds, solidifies, and is converted to asphalt with time. Due to the fact that the heavy oil remains at the seafloor, these sites are natural laboratories to study the impact of oil on deep-sea ecosystems, and the time scales of oil and asphalt degradation. These subjects are very timely, and can help understanding effects of deep water oil spills as caused by the 2010 Deepwater Horizon accident in the northern Gulf of Mexico. We propose to study the extent of oil emissions and asphalt deposits using sidescan sonar and to investigate them further employing ROV Quest. A further major topic of the proposed cruise addresses the question whether or not methane can reach the sea surface and may contribute to the pool of greenhouse gases. The fact that seepage of oil-coated gas bubbles leads to oil slicks at the sea surface and enhanced methane concentrations was recently shown in the north-ern Gulf. It can be assumed that similar efficient transport processes for methane exists in the area of the Campeche Knolls, where oil slicks have been observed in association with about ~30 individual seafloor structures. Category: geoscientificInformation Source: Not Available Supplemental Information: Description of the AUV platform and the payload: The company International Submarine Engineering (I.S.E.) built the AUV MARUM-SEAL in 2005-2006 as #5 of its Explorer-Class AUVs. It is nearly 5.75 m long, with a diameter of 0.73 m and a weight of 1.35 tons in air. The AUV consists of a modular atmospheric pressure hull, designed as two hull segments and a front and aft dome. Inside the pressure hull, the vehicle control computer (VCC), the payload control computer (PCC), eight lithium batteries and spare room for additional "dry" payload electronics are located. The inertial navigation system IXBlue PHINS and the KONGSBERG multibeam-processor (VxWorks computer) are located as dry payload here. The tail and the front section, built from GRP-material, are flooded wet bays. In the tail section the motor, beacons for USBL, RF-radio, Flashlight, IRIDIUM antenna and DGPS antenna are located. The Seabird SBE 49 CTD, the Sercel MATS 200 acoustic modem, the Doppler Velocity Log (DVL, 300kHz), KONGSBERG Pencil beam (675kHz) as obstacle avoidance, the KONGSBERG EM2040 (200,300, 400kHz) implemented in 2014, the PAROSCIENTIFIC pressure-sensor and the BENTHOS dual frequency (100/400kHz) side scan sonar can be mounted as optional payload in the custom made aluminium front section. The SEAL AUV has a capacity of approx. 15,4 KWh main energy, enabling the AUV to conduct approx. 65 km mission-track lengths. However, mission-track lengths had to be reduced during M114 due to water depths of about 4km and the more energy consuming EM2040 MBES, compared to former cruises. For security aspects, several hard- and software mechanisms are installed on the AUV to minimize the risk of malfunctioning, damage, and total loss. More basic features are dealing with fault response tables, including an emergency drop weight, either released by user or completely independent by AUV time-relays itself. MARUM put special emphasis on an open architecture in terms of hard- and software design of the AUV, in order to guarantee modular and flexible vehicle operations. Therefore, the VCC is based largely on industrial electronic components and compact-PCI industrial boards and only few proprietary hardware boards have been implemented. The software is completely built on QNX 4.25 - a licensed UNIX derivate, open to large extents for user modifications. The payload PC is built on comparable hardware components, but running either with OS Windows and/or OS Linux. On the support vessel, the counterpart to the VCC is located on the surface control computer (SCC). It is designed as an Intel based standard PC, also running with same QNX OS and a Graphic User Interface (GUI) to control and command the MARUM SEAL AUV. Payload during M114 CTD Seabird SBE49 Fastcat. Last calibration from 2010. KONGSBERG EM2040 setup (400kHz dive 67-70); Range of 150m (400kHz); recording of water column data was on during all dives. Acquisition of Multibeam-Echsounder (MBES) Data A MBES system on an AUV requires a number of auxiliary sensors for position, motion, sound velocity and depth of the vehicle. The INS PHINS delivers, based on complex Kalman filters, a position and attitude data for the AUV platform, while sound velocity (SV) is calculated utilizing an UNESCO SV equation on CTD sensor measurements. The pressure to depth calculation is based on a simplified equation, depending mainly on the latitude of the area of interest and an average water depth of the area investigated, and is used as static factor for the recalculation. Therefore, the recorded data could be enhanced by post-processing of the pressure data with the UNESCO pressure to depth equation. The EM2040 system itself is controlled by the VCC of the AUV and records data directly on the control unit of the EM2040 (VxWorks computer) as *.all files including the option to store water column data. The PAROSCIENTIFIC depth sensor presented a large number of noise spikes varying between +/- 1 meter. The CTD depth data was a lot smoother but presented a non-linear depth drift that generated some unreal long scale oscillations. Due to this the PARASCIENTIFC was preferred and re-processed. Description of data processing: The Seafloor-Imaging group of MARUM, responsible person Christian dos Santos Ferreira and CI Paul Wintersteller (seafloor-imaging@marum.de), conducted postprocessing and products of the EM2040 data of AUV dives 67 to 70. The MB-system suite (Caress, D.W., and D.N. Chayes, MB-System Version 5, an open source software distributed from the MBARI and L-DEO web sites, 2000-2017) as well as QPS Fledermaus™ were utilized for this purpose. A tide correction was applied, based on the Oregon State University (OSU) tidal prediction software (OTPS) that is retrievable through MB-System. A pitch correction was not required other than a roll correction of 0.05°, observed in roll-calibration lines taken at the beginning of dive 67. Bathymetric data has been manually cleaned for existing artefacts with MB-System's mbeditviz tool. No SV profile correction was applied. MBnavadjust, an MB-system tool, allowed rectifying for position-shifts due to e.g. DVL drift. After receiving it's last DGPS signal when starting to dive, the DVL (Doppler Velocity Log) is next to the propeller rotation the only consecutive information the INS PHINS uses to calculate the absolute position of the AUV during mission-mode. Since the DVL delivers only velocity through water until 200m above sea floor, the AUVs position while diving down to the sea floor is rather relative and exposed to potential currents of the different water masses. Due to the high frequency noise in the PARASCIENTIFIC data (depth sensor) a despike filter was applied before the depth sensor got smoothed by a 4 seconds window. Without that the amount and vertical scale of the spikes would influence the depth sensor smoothing generating some short scale (1-2 seconds) false depth oscillations manifested as woobling and heave artifacts. The open source package "R" was utilized using the function called "despike" provided by package "oce" for analysis of oceanographic data (and time series). The MBnavadjust corrected navigation is therefore evaluated with respect to plausibility e.g. to avoid strong, unrealistic tying or bending of the navigation track. A two-three steps workflow has been established correcting thirst every AUV dive within itself (line by line ties) while the second step includes referencing to the shipside bathymetry and a potential third step the combination of different AUV dives next to each other. NetCDF (GMT) grids of the product and the statistics were created using mbgrid. No total propagated uncertainty (TPU) has been calculated to gather vertical or horizontal accuracy. The currently published bathymetric grid of the cruise has a resolution of 10 m. A higher resolution up to 1 m is achievable and used for current scientific investigations. The grid extended with _num represents a raster dataset with the statistical number of beams/depths taken into account to create the depth of the cell. The extended "_sd"-grid contains the standard deviation for each cell. Grid naming and explanation: Term1_Term2_Term3_Term4_Term5_Term6/optTerm7/optTerm8 e.g.: 2015_M114_EM2040_AUV_D70_A2F1C7E10m/_num/_sd Term1: Year of the survey Term2: Cruise Term3: MBES sensor Term4: Carrier e.g. AUV Term5: Dive# (carrier internal) Term6: MB-System syntax for A2 (Bathy), A3 (Amplitude), A4 (Beam Time Series); E10m for 10m grid cell resolution Term7: Grid showing the # of beams/points within a grid cell Term8: Grid showing the standard deviation for each grid cell Size/Amount of data: NetCDF Km of hydroacoustic survey - 34.85 km Storage <10MB for all the datasets Coverage: EVENT LABEL: (GeoB19312-1) * LATITUDE START: 21.910000 * LONGITUDE START: -93.454000 * LATITUDE END: 21.907000 * LONGITUDE END: -93.452000 * DATE/TIME START: 2015-02-25T02:20:00 * DATE/TIME END: 2015-02-25T13:20:00 * CAMPAIGN: M114/1 * BASIS: Meteor (1986) * METHOD/DEVICE: Autonomous underwater vehicle
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  • Abstract: This initial survey of pollen from 192 samples from Hole 794A, supplemented by 189 samples from Hole 795 and 797B, suggests that marine pollen assemblages from the southwestern Sea of Japan provide a consistent Neogene pollen stratigraphy and a solid basis for regional paleoenvironmental reconstructions. Late Miocene vegetation inferred from these pollen data, a mix of conifer and broad-leaf elements with now-extinct Tertiary types well represented, appears similar to Aniai-type floras of Japan. During the late Miocene through early Pliocene, as Tertiary types declined, conifers (including the Sequoia/Cryptomeria group) became more prominent than broad-leaf elements, and herbs played an increasing role in the vegetation. Middle Pliocene pollen assemblages imply significant changes in forest composition. In a 500,000-yr interval centered at ~4 m.y., Tertiary and warm-temperate deciduous types re-expanded and were comparable to or greater than middle-late Miocene levels. Temperate and cold-temperate conifers {Picea, Abies, Tsuga) were minimal. Subsequently, Tertiary and deciduous forest components (including Quercus) decreased, Picea, Tsuga, and Abies were again prominent, and herbs formed an increasingly larger part of the vegetation. Between ~3 m.y. and -2.5 m.y., conifers, except for Cryptomeria types, were prominent, Quercus continued to decline, and other broad-leaf trees were minor. Over the last 2 Ma, the very large and frequent changes in forest composition inferred from pollen in the Sea of Japan correspond to forest dynamics inferred from changes in pollen and floral assemblages throughout Japan. Given present vegetation/climate relationships, broad trends in Neogene climate inferred from these preliminary pollen data include decreasing temperatures, increasing seasonality in temperatures and precipitation, and increasing amplitude and frequency of climatic change. Two significant events, centered at ~9 m.y. and ~4 m.y., punctuate the gradual deterioration of the equable warm, humid subtropical/warm temperate late Miocene and early Pliocene climates. The first indication of cold-temperate conditions comparable to those of Pleistocene glacial intervals occurs ~3 m.y. Subsequently, regional climates oscillated rapidly between temperate and cold-temperate regimes that supported conifer and mixed broad-leaf forests; however, climatic extremes were apparently never great enough to displace warm-temperate and temperate forests from Honshu nor to produce arctic climates on the west coast of Japan. Category: geoscientificInformation Source: Supplement to: Heusser, Linda E (1992): Neogene palynology of Holes 794A, 795A, and 797B in the Sea of Japan: stratigraphic and paleoenvironmental implications of the preliminary results. In: Pisciotto, KA; Ingle, JCJr.; von Breymann, MT; Barron, J; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 127/128(1), 325-339, https://doi.org/10.2973/odp.proc.sr.127128-1.139.1992 Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 40.190000 * LONGITUDE: 138.231000 * DATE/TIME START: 1989-06-26T00:00:00 * DATE/TIME END: 1989-07-11T00:00:00 * ELEVATION: -2821.3 m * Penetration: 1554 m * Recovery: 422.8 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Composite Core EVENT LABEL: * LATITUDE: 40.190000 * LONGITUDE: 138.231000 * DATE/TIME START: 1989-06-26T15:15:00 * DATE/TIME END: 1989-06-30T12:15:00 * ELEVATION: -2822.0 m * Penetration: 351.3 m * Recovery: 302.17 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Drilling/drill rig EVENT LABEL: * LATITUDE: 43.987000 * LONGITUDE: 138.966000 * DATE/TIME START: 1989-07-12T00:00:00 * DATE/TIME END: 1989-07-22T00:00:00 * ELEVATION: -3310.5 m * Penetration: 1128.1 m * Recovery: 447.2 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Composite Core EVENT LABEL: * LATITUDE: 43.987000 * LONGITUDE: 138.967000 * DATE/TIME START: 1989-07-12T20:15:00 * DATE/TIME END: 1989-07-16T00:00:00 * ELEVATION: -3311.0 m * Penetration: 365.9 m * Recovery: 258.26 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Drilling/drill rig EVENT LABEL: * LATITUDE: 38.616000 * LONGITUDE: 134.536000 * DATE/TIME START: 1989-07-31T00:00:00 * DATE/TIME END: 1989-08-18T00:00:00 * ELEVATION: -2874.7 m * Penetration: 1408.7 m * Recovery: 544.6 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Composite Core EVENT LABEL: * LATITUDE: 38.616000 * LONGITUDE: 134.536000 * DATE/TIME START: 1989-07-31T20:00:00 * DATE/TIME END: 1989-08-04T17:00:00 * ELEVATION: -2874.0 m * Penetration: 495.7 m * Recovery: 370.69 m * LOCATION: Japan Sea * CAMPAIGN: Leg127 * BASIS: Joides Resolution * METHOD|DEVICE: Drilling/drill rig
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  • Abstract: Purpose of the cruise M114 At the so-called asphalt volcanoes in the southern Gulf of Mexico heavy oil is seeping at the seafloor where it remains as asphalt deposits. Discovered and preliminarily surveyed during SO174 and M67/2 expeditions, these sites are subject for detail studies during M114 focusing on mapping with autonomous underwater vehicle (AUV MARUM-SEAL), deep-towed sidescan sonar (DTS-1), sediment echosounder (Parasound), multibeam echosounder (EM122), and remotely operated vehicle MARUM-ROV Quest. The overarching objective is to better understand the impact, fate, and decay rates of oil in the deep-sea environment. Heavy oil and gas bubbles are emitted from the 1200 to 2900 m deep seafloor in the hy-drocarbon province Campeche Knolls in the southern Gulf of Mexico. The viscous heavy oil flows across the seafloor, loses volatile compounds, solidifies, and is converted to asphalt with time. Due to the fact that the heavy oil remains at the seafloor, these sites are natural laboratories to study the impact of oil on deep-sea ecosystems, and the time scales of oil and asphalt degradation. These subjects are very timely, and can help understanding effects of deep water oil spills as caused by the 2010 Deepwater Horizon accident in the northern Gulf of Mexico. We propose to study the extent of oil emissions and asphalt deposits using sidescan sonar and to investigate them further employing ROV Quest. A further major topic of the proposed cruise addresses the question whether or not methane can reach the sea surface and may contribute to the pool of greenhouse gases. The fact that seepage of oil-coated gas bubbles leads to oil slicks at the sea surface and enhanced methane concentrations was recently shown in the north-ern Gulf. It can be assumed that similar efficient transport processes for methane exists in the area of the Campeche Knolls, where oil slicks have been observed in association with about ~30 individual seafloor structures. Category: geoscientificInformation Source: Not Available Supplemental Information: Description of the AUV platform and the payload: The company International Submarine Engineering (I.S.E.) built the AUV MARUM-SEAL in 2005-2006 as #5 of its Explorer-Class AUVs. It is nearly 5.75 m long, with a diameter of 0.73 m and a weight of 1.35 tons in air. The AUV consists of a modular atmospheric pressure hull, designed as two hull segments and a front and aft dome. Inside the pressure hull, the vehicle control computer (VCC), the payload control computer (PCC), eight lithium batteries and spare room for additional "dry" payload electronics are located. The inertial navigation system IXBlue PHINS and the KONGSBERG multibeam-processor (VxWorks computer) are located as dry payload here. The tail and the front section, built from GRP-material, are flooded wet bays. In the tail section the motor, beacons for USBL, RF-radio, Flashlight, IRIDIUM antenna and DGPS antenna are located. The Seabird SBE 49 CTD, the Sercel MATS 200 acoustic modem, the Doppler Velocity Log (DVL, 300kHz), KONGSBERG Pencil beam (675kHz) as obstacle avoidance, the KONGSBERG EM2040 (200,300, 400kHz) implemented in 2014, the PAROSCIENTIFIC pressure-sensor and the BENTHOS dual frequency (100/400kHz) side scan sonar can be mounted as optional payload in the custom made aluminium front section. The SEAL AUV has a capacity of approx. 15,4 KWh main energy, enabling the AUV to conduct approx. 65 km mission-track lengths. However, mission-track lengths had to be reduced during M114 due to water depths of about 4km and the more energy consuming EM2040 MBES, compared to former cruises. For security aspects, several hard- and software mechanisms are installed on the AUV to minimize the risk of malfunctioning, damage, and total loss. More basic features are dealing with fault response tables, including an emergency drop weight, either released by user or completely independent by AUV time-relays itself. MARUM put special emphasis on an open architecture in terms of hard- and software design of the AUV, in order to guarantee modular and flexible vehicle operations. Therefore, the VCC is based largely on industrial electronic components and compact-PCI industrial boards and only few proprietary hardware boards have been implemented. The software is completely built on QNX 4.25 - a licensed UNIX derivate, open to large extents for user modifications. The payload PC is built on comparable hardware components, but running either with OS Windows and/or OS Linux. On the support vessel, the counterpart to the VCC is located on the surface control computer (SCC). It is designed as an Intel based standard PC, also running with same QNX OS and a Graphic User Interface (GUI) to control and command the MARUM SEAL AUV. Payload during M114 CTD Seabird SBE49 Fastcat. Last calibration from 2010. KONGSBERG EM2040 setup (400kHz dive 67-70); Range of 150m (400kHz); recording of water column data was on during all dives. Acquisition of Multibeam-Echsounder (MBES) Data A MBES system on an AUV requires a number of auxiliary sensors for position, motion, sound velocity and depth of the vehicle. The INS PHINS delivers, based on complex Kalman filters, a position and attitude data for the AUV platform, while sound velocity (SV) is calculated utilizing an UNESCO SV equation on CTD sensor measurements. The pressure to depth calculation is based on a simplified equation, depending mainly on the latitude of the area of interest and an average water depth of the area investigated, and is used as static factor for the recalculation. Therefore, the recorded data could be enhanced by post-processing of the pressure data with the UNESCO pressure to depth equation. The EM2040 system itself is controlled by the VCC of the AUV and records data directly on the control unit of the EM2040 (VxWorks computer) as *.all files including the option to store water column data. The PAROSCIENTIFIC depth sensor presented a large number of noise spikes varying between +/- 1 meter. The CTD depth data was a lot smoother but presented a non-linear depth drift that generated some unreal long scale oscillations. Due to this the PARASCIENTIFC was preferred and re-processed. Size/Amount of data: (incl. Water Column Data) - 50.37 size in GB # of recorded lines (incl. turns), 26 GB Storage (about 47) Km of hydroacoustic survey - 34.85 km Coverage: EVENT LABEL: (GeoB19312-1) * LATITUDE START: 21.910000 * LONGITUDE START: -93.454000 * LATITUDE END: 21.907000 * LONGITUDE END: -93.452000 * DATE/TIME START: 2015-02-25T02:20:00 * DATE/TIME END: 2015-02-25T13:20:00 * CAMPAIGN: M114/1 * BASIS: Meteor (1986) * METHOD/DEVICE: Autonomous underwater vehicle
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