Marine Geoscience Research Articles

A deep-towed multichannel seismic streamer for very high-resolution surveys in full ocean depth

Monika Breitzke and Jorg Bialas, research scientists at the GEOMAR Research Centre for Marine Geosciences, Kiel, Germany describe the latest testing of a deep-towed multichannel streamer combined with a sidescan sonar system to achieve improved resolution in deep water with gas hydrates the main interest.

World Data Center for Marine Environmental Sciences provides lessons in marine geosciences data management

World Data Centers (WDCs) provide scientific data and information systems that help transfer comprehensive knowledge among researchers in a straightforward manner and under a sensitive data policy. However, use and acceptance of a WDC within the scientific community depends on respective knowledge and individual scientific needs. For that reason, the staff of the World Data Center for Marine Environmental Sciences (WDC‐MARE) (www.wdc‐mare.org) is providing lessons in information and data management in marine geosciences at the University of Bremen in Germany Recently, WDC‐MARE expanded this service to scientific programs outside of Germany.

Three-dimensional seismic refraction tomography of the crustal structure at the ION site on the Ninetyeast Ridge, Indian Ocean

SUMMARY We have performed a 3-D seismic refraction tomography of a 48 × 48 km2 area surrounding ODP site 757, which is planned to host an International Ocean Network (ION) permanent seismological observatory, called the Ninetyeast Ridge Observatory (NERO). The study area is located in the southern part of the Ninetyeast Ridge, the trail left by the Kerguelen hotspot on the Indian plate. The GEOMAR Research Centre for Marine Geosciences and the Federal Institute for Geosciences and Natural Resources acquired 18 wide-angle profiles recorded by 23 ocean bottom hydrophones during cruise SO131 of R/V Sonne in spring 1998. We apply a first arrival traveltime tomography technique using regularized inversion to recover the 3-D velocity structure relative to a 1-D background model that was constructed from a priori information and averaged traveltime data. The final velocity model revealed the crustal structure down to approximately 8 km depth. Resolution tests showed that structures with approximately 6 km horizontal extent can reliably be resolved down to that depth. The survey imaged the extrusive layer of the upper crust of the Ninetyeast Ridge, which varies in thickness between 3 and 4 km. A high-velocity anomaly coinciding with a positive magnetic anomaly represents a volcanic centre from which crust in this area is thought to have formed. A pronounced low-velocity anomaly is located underneath a thick sedimentary cover in a bathymetric depression. However, poor ray coverage of the uppermost kilometre of the crust in this area resulted in smearing of the shallow structure to a larger depth. Tests explicitly including the shallow low-velocity layer confirmed the existence of the deeper structure. The heterogeneity of the upper crust as observed by our study will have consequences for the waveforms of earthquake signals to be recorded by the future seismic observatory.

Ocean bottom seismometers deployed in Tyrrhenian Sea

The Institute for Geophysics (IfG) at Hamburg University and the Research Center for Marine Geoscience (GEOMAR) of Kiel University have developed new, wideband ocean bottom seismic stations (OBS) for long‐term, deep‐sea deployments of up to 1 year. A first long‐term pilot experiment of these stations was conducted in the Tyrrhenian Sea north of Sicily, in‐cooperation with the first long‐term, deep‐sea test of the European Ocean Bottom Observatory GEOSTAR [Beranzoli et al., 2000] by Istituto Nazionale di Geofisica e Vulcanologia (INGV). The seismic data retrieved prove that the new OBSs are useful for seismological studies. A large number of tele‐seismic earthquakes have been recorded in good quality; waves originating from such events pass the mantle and crust below the network, and thus provide important constraints on their structure.

Expected effect of climate change on Sylt island: results from a multidisciplinary German project

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 18:141-146 (2001) - doi:10.3354/cr018141 Expected effect of climate change on Sylt island: results from a multidisciplinary German project Kai Ahrendt* GEOMAR Research Center for Marine Geosciences, Wischhofstraße 1-3, 24148 Kiel, Germany Fig. 1. Overview of study area ABSTRACT: Climate change (i.e. increasing mean sea level and storm activity) will influence the coastal development of sandy islands such as Sylt. To estimate the influence of climate change, a numerical model was used to predict the development of the coastline of Sylt island. Data for coastal retreat are available from 1876 to 1997 and were measured every 500 m longshore (~70 profiles). Wave data are available from 1986 to 1997. The model was calibrated and verified with these data. Coastal retreat was calculated to the year 2050 under the following scenarios (IPCC 1990): mean sea level +25 cm; tidal range +25 cm; wave height +10%; wave direction ±10°. Little change in the configuration of the coastline of Sylt is expected over the next 50 yr if the present strategy of western shore protection is maintained. No additional measures seem to be necessary. In contrast, if shore protection is not maintained, significant changes in coastline configuration (both west and east coasts) may occur, due in part to dramatic shore retreat by erosion, in the case of a 10% increase in wave height and a 10° change in all westerly wind directions toward the north. Only moderate changes in coastline configuration and weak shore retreat through erosion can be expected if wind direction is turned 10° to the south and wave height is maintained. KEY WORDS: Climate change · Coastline development · Modelling Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 18, No. 1-2. Online publication date: October 18, 2001 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2001 Inter-Research.

Introduction: marine geoscience research by the UNESCO-IOC Training-through-Research program in the Mediterranean and Black seas

Introduction: marine geoscience research by the UNESCO-IOC Training-through-Research program in the Mediterranean and Black seas

Suction Technology for Deep Installation of Structural Pipe

This article is a synopsis of paper SPE 39336, "Using Suction Technology for Deep Installation of Structural Pipe in Deep Water," by Gary L. Faul, SPE, Jean M.E. Audibert, and Thomas K. Hamilton, Fugro-McClelland Marine Geoscience Inc., originally presented at the 1998 IADC/SPE Drilling Conference, Dallas, 3-6 March.

Terrestrial record of Laurentide Ice Sheet reorganization during Heinrich events: Comments and Reply

Research Article| July 01, 1998 Terrestrial record of Laurentide Ice Sheet reorganization during Heinrich events: Comments and Reply Jaco H. Baas; Jaco H. Baas 1Geologisk Institutt, Universitetet i Bergen, Allégt. 41, N-5007 Bergen, Norway Search for other works by this author on: GSW Google Scholar Joachim Schönfeld; Joachim Schönfeld 2Geomar Research Center for Marine Geosciences, Wischhofstr. 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Gary N. Meyer; Gary N. Meyer 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Search for other works by this author on: GSW Google Scholar Carrie J. Patterson; Carrie J. Patterson 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Search for other works by this author on: GSW Google Scholar Howard C. Hobbs; Howard C. Hobbs 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Search for other works by this author on: GSW Google Scholar Mark D. Johnson; Mark D. Johnson 4Department of Geology, Gustavus Adolphus College, St. Peter, Minnesota 56082 Search for other works by this author on: GSW Google Scholar James F. P. Cotter; James F. P. Cotter 5Geology Discipline, University of Minnesota, Morris, Minnesota 56267 Search for other works by this author on: GSW Google Scholar Howard D. Mooers; Howard D. Mooers 6Department of Geology, University of Minnesota, Duluth, Minnesota 55812 Search for other works by this author on: GSW Google Scholar J. D. Lehr J. D. Lehr 7CAMAS Inc., 2915 Waters Road, Suite 105, Eagan, Minnesota 55121 Search for other works by this author on: GSW Google Scholar Author and Article Information Jaco H. Baas 1Geologisk Institutt, Universitetet i Bergen, Allégt. 41, N-5007 Bergen, Norway Joachim Schönfeld 2Geomar Research Center for Marine Geosciences, Wischhofstr. 1-3, D-24148 Kiel, Germany Gary N. Meyer 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Carrie J. Patterson 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Howard C. Hobbs 3Minnesota Geological Survey, 2642 University Ave., St. Paul, Minnesota 55114 Mark D. Johnson 4Department of Geology, Gustavus Adolphus College, St. Peter, Minnesota 56082 James F. P. Cotter 5Geology Discipline, University of Minnesota, Morris, Minnesota 56267 Howard D. Mooers 6Department of Geology, University of Minnesota, Duluth, Minnesota 55812 J. D. Lehr 7CAMAS Inc., 2915 Waters Road, Suite 105, Eagan, Minnesota 55121 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1998) 26 (7): 666–669. https://doi.org/10.1130/0091-7613(1998)026<0666:TROLIS>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jaco H. Baas, Joachim Schönfeld, Gary N. Meyer, Carrie J. Patterson, Howard C. Hobbs, Mark D. Johnson, James F. P. Cotter, Howard D. Mooers, J. D. Lehr; Terrestrial record of Laurentide Ice Sheet reorganization during Heinrich events: Comments and Reply. Geology 1998;; 26 (7): 666–669. doi: https://doi.org/10.1130/0091-7613(1998)026<0666:TROLIS>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract No Abstract Available. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

A new view into the Cascadia subduction zone and volcanic arc: Implications for earthquake hazards along the Washington margin

In light of suggestions that the Cascadia subduction margin may pose a significant seismic hazard for the highly populated Pacific Northwest region of the United States, the U.S. Geological Survey (USGS), the Research Center for Marine Geosciences (GEOMAR), and university collaborators collected and interpreted a 530-km-long wide-angle onshore-offshore seismic transect across the subduction zone and volcanic arc to study the major structures that contribute to seismogenic deformation. We observed (1) an increase in the dip of the Juan de Fuca slab from 2°–7° to 12° where it encounters a 20-km-thick block of the Siletz terrane or other accreted oceanic crust, (2) a distinct transition from Siletz crust into Cascade arc crust that coincides with the Mount St. Helens seismic zone, supporting the idea that the mafic Siletz block focuses seismic deformation at its edges, and (3) a crustal root (35–45 km deep) beneath the Cascade Range, with thinner crust (30–35 km) east of the volcanic arc beneath the Columbia Plateau flood basalt province. From the measured crustal structure and subduction geometry, we identify two zones that may concentrate future seismic activity: (1) a broad (because of the shallow dip), possibly locked part of the interplate contact that extends from ∼25 km depth beneath the coastline to perhaps as far west as the deformation front ∼120 km offshore and (2) a crustal zone at the eastern boundary between the Siletz terrane and the Cascade Range.

The future of marine geosciences discussed

Our nation's research community is in the midst of an unusually stressful period. In this flat (or declining) budgetary environment, innovative science, novel collaborations, and the development of the next generation of technology are sometimes difficult to justify and support. In recognition of the increased importance of long‐range planning during such times, the Marine Geology and Geophysics (MG&amp;G) and Ocean Drilling programs within the Ocean Sciences Division of the National Science Foundation (NSF) held a workshop titled “The Future of Marine Geosciences” (FUMAGES). The product of this workshop is to serve as a contribution to NSF's Geosciences Directorate for evaluating opportunities and needs for research, infrastructure, and education.

Navigating Shrinking Financial Seas

Ashland, Oregon—Deep-sea oceanography was once supported by several different agencies, but the National Science Foundation (NSF) now finds itself funding the lion's share of research in everything from the geochemistry of deep-sea vents to the development of new undersea robotic craft. Last month, NSF's Marine Geology and Geosciences program invited about 40 marine researchers to a gloves-off workshop to discuss future directions. They got an emotional response. Researchers offered ideas ranging from more interdisciplinary research to better public relations, but if there was one single theme it was this: hard choices lie ahead.

Siliclastic margins record terrestrial and oceanographic conditions

Sediments of the continental margin contain a geologic record of climate and sea level as well as variations in tectonics, sediment source/transport, and postdepositional environment. Increased attention is focusing on coastal environments as societal needs demand that scientists address such wide‐ranging problems as land and coastal erosion, and the flux and fate of anthropogenic inputs to coastal seas. Despite these efforts, however, our ability to understand and predict sedimentary processes in marginal seas and adjacent land masses remains inadequate. Given the future prospects of flat or declining funding for marine geoscience, we must define our knowledge and ignorance of coastal and nearshore environments if we are to address their scientific and societal challenges.

About this title

Hydrothermal venting at mid-ocean ridges has become one of the fastest-growing areas of interest in the marine geosciences since their discovery at the beginning of the 1980s. Marine geologists, geochemists and biologists are beginning to unravel the processes that generate and focus these high-temperature, chemically charged fluid exhalations, and those that control the colonization and ecology of the bizarre gamut of fauna and flora resident at these sites. Researchers, on the edge of understanding how volcanic and tectonic processes interact to control fluid flow, can show how they can predict the likely occurrence of hydrothermal systems throughout the world ridge system, and how the biomass has flourished in such inhospitable settings. Indeed, the very isolation of the communities has led workers to suggest that their restricted evolutionary path has direct significance for studies of the early origins of life itself. Hydrothermal processes are four-dimensional in their character, on a range of time-scales, which are of the order of thousands of years in terms of the of the lifetime of the hydrothermal sites, down to days in terms of the dispersal of plume products in the water column. The papers in this volume represent the latest reviews and reports of the state-of-the-art understanding of an area of marine science that we are only just beginning to recognize the scope and impact of.

Exploring the eastern Arctic Ocean margins

A joint German‐Russian oceanographic expedition was made in August and September 1993 to the Eurasian continental margin of the Barents and Laptev seas, a region of high scientific interest that until recently was inaccessible to western oceanographers. The expedition addressed a range of scientific problems spanning geology, oceanography, biology, and sea‐ice research, and it marks a major breakthrough in Arctic Ocean research cooperation among Russian and western scientists.The program grew out of discussions between ocean researchers from the Alfred Wegener Institute for Polar and Marine Research (AWI) in Bremerhaven, Germany, the GEOMAR Research Center for Marine Geosciences and the Institute for Polar Ecology (IPO) in Kiel, Germany, the Arctic and Antarctic Institute (AARI) in St. Petersburg, Russia, and several institutes involved in ecological research within the Russian Academy of Sciences (RAS). It was coordinated by the AWI and AARI.

Inorganic Geochemistry of Organic-Rich Sediments: Paleoceanographic Evidence from the Eastern Mediterranean and Sea of Japan

In the Neogene sedimentological record, organicrich sediments, termed sapropels when they have greater than 2% by weight organic carbon (Kidd et aL, 1978), have been recovered from a number of marginal seas and basins including the Mediterranean and Japan Seas, and have been compared with the black shale facies from the geological record. Detailed research has failed to fully comprehend the significance of these Marine Geosciences, Department of Earth Sciences, Cardiff University, Cardiff, UK

North Grand Banks Basin, offshore Newfoundland: a sedimentary epeiric basin west of the Murre-Mercury detachment fault

The eastern Newfoundland offshore area is geologically the best known region of the northwestern Atlantic margin. Extensive geophysical coverage and about 140 exploratory and delineation wells have allowed structural and stratigraphic mapping of a Mesozoic rift basin network that includes the South Whale, Whale, Horseshoe, South Jeanne d'Arc, Carson-Bonnition, Jeanne d'Arc, Orphan and Flemish Pass Basins. A less explored basin, not yet targeted by the oil industry and accordingly less explored, has recently been discussed in the marine geoscience literature. Located on the Bonavista platform, west of the Jeanne d'Arc Basin bounding fault and defined here as the North Grand Banks Basin, this area has been described from refraction work correlated with deep seismic profiling (LITHOPROBE East) data as a possible Mesozoic rift basin with hydrocarbon potential, or as a Palaeozoic basin. Detected first by gravity measurements, but unconfirmed as a rift basin by reflection data, this basin is only 2 km deep and contains Palaeozoic and probably undeformed Mesozoic sedimentary infill. Its hydrocarbon potential is low. The Mesozoic sedimentary rocks, if present, are probably platform carbonates and clastics, formed during thermal subsidence episodes following the first two rifting stages that affected the Grand Banks of Newfoundland. The placement of the pre-rift unconformity within the sedimentary successions of the North Grand Banks Basin, and the precise nature of the rocks situated above the Avalon basement remain unresolved. A geodynamic model involving simple shear extension in the upper crust is used to explain the evolution of Newfoundland offshore sedimentary basins including the North Grand Banks. According to this model the basin is located on the upthrown side of the Murre-Mercury fault system that represents the upper crustal expression of a crustal penetrative detachment.

A decade of growth in the South Pacific marine geoscience data base

The marine geoscience data base for the South Pacific has grown by an order of magnitude over the past decade. The catalyst for this growth has been the South Pacific Applied Geoscience Commission (SOPAC), a regional organisation that serves as a marine and coastal geological and geophysical survey for the island nations. Work programmes developed at its international workshops and annual technical sessions have been implemented, in part through the Tripartite Programme that has resulted in several monographs and many research papers, including some in this special issue. These results have encouraged work by other agencies. The outcome has been a much-enhanced understanding of the tectonic framework and hydrocarbon and mineral resource potential of the region and the development of new play concepts and process models for mineralisation of interest to explorationists.

A window on Soviet marine geoscience

The Soviet marine geoscience community has for many years held biennial scientific meetings at Gelendzhik on the Black Sea coast south of Novorossisk, a few kilometers from the campus of the Southern Division of the Institute of Oceanology, Soviet Academy of Sciences. The ninth AU‐Union School of Marine Geology, held October 15–20, 1990, was the first to specifically invite foreign scientists, and the eighteen who participated from nine countries look forward to more meetings of this kind. Total attendance was 203, including scientists from 20 centers in the USSR. Two‐thirds of those present held Ph.D or D.Sc. degrees. The opportunity to meet and communicate with young Soviet scientists was mutually beneficial and much appreciated.

Scientific applications of downhole measurements in the ocean basins

Abstract The well logging activity of the Ocean Drilling Programme, which deploys the most technically advanced suite of downhole measurements available for routine use, is providing new opportunities for advancement in marine geoscience. Particular examples are cited of the application of wireline data to problems associated with global environmental changes, crust/ mantle interactions, crustal fluid circulation in the context of a global geochemical budget, lithospheric stress and deformation, and evolutionary processes in oceanic communities. Further technological developments will expand the scientific role of downhole measurements still further, especially in terms of the integration of geophysical data at different scales of measurement, and the interpretation of these data in accordance with; global scientific themes.

Germany's New Research Center for Marine Geosciences (GEOMAR)

Germany's New Research Center for Marine Geosciences (GEOMAR)