Arctic Ocean Floor Research Articles

Sculpting micro-, meio-, and macrofauna


 
 
 Focus:
 To appreciate the biodiversity of the Arctic Ocean and ocean floor, with a particular focus on lesser-known species. What kind of micro- meio-, and macrofauna (species) live on the ocean floor and what do they look like?
 Learning objectives:
 In this activity, pupils will identify (one, two, or more) species living at or close to the Arctic Ocean floor and sculpt them using modelling clay. Through this activity, pupils will hopefully begin to understand difference between Arctic Ocean micro-, meio-, and macrofauna.
 Key words:
 Arctic ocean biodiversity, species, fauna.
 
 

Three-Dimensional Geomorphometric Modeling of the Arctic Ocean Submarine Topography: A Low-Resolution Desktop Application

Submarine topography is one of the key factors determining the course and direction of processes at the lithosphere–hydrosphere boundary. In this article, we present results of the first phase of a project to create a system for 3-D geomorphometric modeling of the Arctic Ocean floor. In this phase, a low-resolution desktop version of the system was developed. We utilized a small 5-km gridded digital elevation model extracted from the International Bathymetric Chart of the Arctic Ocean version 3.0. First, we smoothed the digital elevation model to suppress high-frequency noise. From the smoothed digital elevation model, we derived digital models of the following morphometric variables: horizontal, vertical, minimal, and maximal curvatures, catchment, and dispersive areas, as well as topographic and stream power indices. Then, to construct and visualize 3-D morphometric models of the territory, we applied an original approach for 3-D terrain modeling in the environment of Blender, free and open-source software. Finally, we present a series of the 3-D morphometric models (perspective views from the Atlantic, Eurasia, and North America). The experiment showed that the approach is efficient and can be applied for creating next desktop and web versions of the system for visualizing 3-D morphometric models of higher resolutions. The final versions of the system will be used to support marine geomorphological, geological, and biological studies of the Arctic Ocean.

Three-dimensional desktop morphometric models for the Arctic Ocean floor

Abstract. We present results of the first phase of an ongoing project to create a system for three-dimensional (3D) geomorphometric modeling of the Arctic Ocean submarine topography. In this phase, we developed a testing, lowresolution desktop version of the system. We utilized a small, 5-km gridded digital elevation model (DEM) extracted from the International Bathymetric Chart of the Arctic Ocean (IBCAO) version 3.0. From the smoothed DEM, we derived digital models of several morphometric variables: horizontal, vertical, minimal, and maximal curvatures, catchment and dispersive areas, as well as topographic and stream power indices. To construct and visualize 3D morphometric models, we applied an original approach for 3D terrain modeling in the environment of the Blender package, free and open-source software. Finally, we present a series of 3D morphometric models with perspective views from the Atlantic, Eurasia, the Pacific, and North America. The experiment showed that the approach is efficient and can be used for creating next, desktop and web versions of the system for visualizing 3D morphometric models of higher resolutions.

Three‐dimensional terrain modeling with multiple‐source illumination

AbstractThree‐dimensional (3D) terrain modeling based on digital elevation models (DEMs) with the use of orthographic and perspective projections is a standard procedure implemented in many commercial and open‐source geoinformation systems. However, standard tools may be insufficient for 3D scientific visualization. In particular, single‐source illumination of 3D models may be deficient for topographically complex terrains. We present an approach for 3D terrain modeling with multiple‐source illumination in the virtual environment of the Blender free and open‐source software. The approach includes the following key stages: (1) automatic creation of a polygonal object; (2) selecting an algorithm to model the 3D geometry; (3) selecting a vertical exaggeration scale; (4) selecting types, parameters, a number, and positions of light sources; (5) selecting methods for generating shadows; (6) selecting a shading method for the 3D model; (7) selecting a material for the 3D model surface; (8) overlaying a texture on the 3D model; (9) setting a virtual camera; and (10) rendering the 3D model. To illustrate the approach, we processed a test DEM extracted from the International Bathymetric Chart of the Arctic Ocean version 3.0 (IBCAO 3.0). The approach is currently being used to develop a system for geomorphometric modeling of the Arctic Ocean floor.

Stable oxygen and carbon isotopes in planktonic foraminifera Neogloboquadrina pachyderma in the Arctic Ocean: An overview of published and new surface-sediment data

A summary study on oxygen and carbon stable isotopes in planktonic foraminifera from Arctic Ocean floor appeared in Marine Geology 20 years ago (Spielhagen and Erlenkeuser, 1994). We revisit this topic with a wealth of new data focused on the western (Amerasian) Arctic, a spotlight in the current climatic and oceanic change. Neogloboquadrina pachyderma , the most abundant polar planktonic foraminiferal species, is an important tool for reconstructing surface/subsurface water changes in the Arctic. Our new data on N. pachyderma (150–250 μm) from the surface sediments show δ 18 O and δ 13 C values of < 1.5‰ and 0.8–1.5‰, respectively, in the ice covered Canada Basin, and 2–3.5‰ and 0.6–0.9‰, respectively, at the shelf break. Combined data from the western and eastern Arctic indicate that planktonic δ 18 O and δ 13 C are both influenced by complex water sources, water column structure, and foraminiferal depth habitat. The observed distribution of N. pachyderma stable isotopes confirms a shallow habitat of this species in the sea-ice covered central Arctic, especially in the Canada Basin, probably in relation to the shallow chlorophyll maximum. The associated light N. pachyderma δ 18 O reflects the long-term storage of fresh water. At the shelf break, a deeper dwelling of N. pachyderma with heavier δ 18 O is supported by a more extensive photic zone and nutrient availability. Air–sea exchange plays an important role in δ 13 C distribution and is consistent with heavy N. pachyderma δ 13 C in the perennially ice-covered central Arctic Ocean. Light δ 13 C composition at the shelf break is additionally influenced by shelf bottom waters enriched in isotopically light, remineralized terrestrial carbon. Distribution of foraminiferal δ 13 C on the Chukchi Shelf reflects primary production patterns in the area. • Shallow dwelling of N. pachyderma in the ice covered central Arctic Ocean. • Deeper N. pachyderma dwelling near shelf break follows deeper nutrient maximum. • N. pachyderma δ 18 O distribution in the Arctic mostly related to freshwater storage. • Accompanying δ 13 C values consistent with air–sea exchange patterns and DIC sources.

Study of the possibility of the use of the magnetotelluric sounding method in the Arctic ocean with quantitative modeling

The task of the magnetotelluric (MT) sounding of the heterogeneous deep section of the Arctic ocean floor on the idealized model of gorst and graben lying on the typical oceanic, or continental Earth’s, crust is solved with the use of 3D quantitative modeling. In both cases, the sequence is covered by a layer of seawater with a thickness of 4 km. In this work, the difference in the MT sounding with the use of ocean-floor and surface equipment is considered. As a result, the conclusion was made that the floor equipment has a higher resolution than the surface equipment, in spite of the fact that the observations from the ice cover’s surface can be done more easily.

History of sea ice in the Arctic

Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This information can be provided by proxy records from the Arctic Ocean floor and from the surrounding coasts. Although existing records are far from complete, they indicate that sea ice became a feature of the Arctic by 47 Ma, following a pronounced decline in atmospheric pCO 2 after the Paleocene–Eocene Thermal Optimum, and consistently covered at least part of the Arctic Ocean for no less than the last 13–14 million years. Ice was apparently most widespread during the last 2–3 million years, in accordance with Earth's overall cooler climate. Nevertheless, episodes of considerably reduced sea ice or even seasonally ice-free conditions occurred during warmer periods linked to orbital variations. The last low-ice event related to orbital forcing (high insolation) was in the early Holocene, after which the northern high latitudes cooled overall, with some superimposed shorter-term (multidecadal to millennial-scale) and lower-magnitude variability. The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.

Greenhouse gas leaking from Arctic Ocean floor

Methane is drifting up from ocean depths as a result of climate warming, researchers believe.

Russia's Polar Hero

Artur Chilingarov has led researchers exploring the polar regions, the Arctic ocean floor, and the world's deepest lake. But is he promoting science or his homeland?

The relief plasticity of the Arctic Ocean floor: A pilot cartographical study

The map of convex forms of the Arctic Ocean floor called flows was compiled using a new cartographical method of relief plasticity (geometrical transformation of contour lines). The flows are physical bodies submitting to terrestrial laws of gravity. From high altitudes of continents (repellers), their end parts tend to the lowest areas of the ocean (attractors). Over a long geological time influenced by the terrestrial gravity field, they form treelike systems. The ocean floor at the North Pole as the major attractor drawing the flows became a criterion for their delimitation. Here, the drift finishes its long journey from the continent to the ocean, finally consolidating and composing underwater mountain ranges, ridges, and elevations. Cartographic work with maps of a larger scale is necessary for precise delineation of the oceanic floor. The five arctic states, Russia, the United States, Canada, Denmark, and Norway have decided to specify their claims on the floor of the Arctic Ocean on the basis of its relief. An area of influence may be defined on the basis of the main structures of underwater relief continued from the land area of one state or another. Thus, the underwater ocean floor will belong to Russia if it is proved that the underwater relief commences in the subsurface of plains of Siberia and Eastern Europe. The United States has to prove that its sea floor area is genetically related to the northern terminations of the Cordillera (the Yukon River basin). Canada may pretend to the oceanic part historically related to the Canadian Arctic Archipelago (Ellesmere Island). Denmark may lay claim to the sea floor area structurally continuing the northern extremity of Greenland, and Norway, to Spitsbergen. Today, the arguments of their scientists are based on old empirical notions. Extension of one ridge or another is often based on

Tracking mantle depletion

Extraction of the continental crust has left the Earth's mantle depleted in certain elements. Some rocks from the Arctic Ocean floor suggest that the extent of depletion and heterogeneity in the Earth's mantle may be greater than we thought.

Drilling in the Arctic: Unearthing the planet's secrets

The icy Arctic has long lured explorers, testing many and rewarding few. Now secrets of our planet's past, long buried in the Arctic's sediments and rocks, beckon to scientists. Among these hidden stories, one is making headlines: global climate change.The Nansen Arctic Drilling Program (NAD), an international scientific effort, will unite scientists worldwide to tackle the challenges of the Arctic and answer questions about past global climate change: How has Earth's climate evolved apart from human influence? Has the Arctic driven or responded to changes in Earth's climate? If so, how? These aspects of Earth's history will be revealed from long cores of the Arctic Ocean floor.

Significance of Atmospheric Dust and Ice Rafting for Arctic Ocean Sediment

Research Article| January 01, 1972 Significance of Atmospheric Dust and Ice Rafting for Arctic Ocean Sediment RUTH E MULLEN; RUTH E MULLEN Department of Geology and Geophysics, University of Wisconsin, Madison 53706 Search for other works by this author on: GSW Google Scholar DENNIS A DARBY; DENNIS A DARBY Department of Geology and Geophysics, University of Wisconsin, Madison 53706 Search for other works by this author on: GSW Google Scholar DAVID L CLARK DAVID L CLARK Department of Geology and Geophysics, University of Wisconsin, Madison 53706 Search for other works by this author on: GSW Google Scholar Author and Article Information RUTH E MULLEN Department of Geology and Geophysics, University of Wisconsin, Madison 53706 DENNIS A DARBY Department of Geology and Geophysics, University of Wisconsin, Madison 53706 DAVID L CLARK Department of Geology and Geophysics, University of Wisconsin, Madison 53706 Publisher: Geological Society of America Received: 07 Jun 1971 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1972, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1972) 83 (1): 205–212. https://doi.org/10.1130/0016-7606(1972)83[205:SOADAI]2.0.CO;2 Article history Received: 07 Jun 1971 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation RUTH E MULLEN, DENNIS A DARBY, DAVID L CLARK; Significance of Atmospheric Dust and Ice Rafting for Arctic Ocean Sediment. GSA Bulletin 1972;; 83 (1): 205–212. doi: https://doi.org/10.1130/0016-7606(1972)83[205:SOADAI]2.0.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 SocietyGSA Bulletin Search Advanced Search Abstract Atmospheric dust fallout and ice-rafted glacial detritus are significant factors for the Arctic Ocean sediment budget. Atmospheric dust amounting to .09 mm/1,000 yrs is being delivered to the Canada Basin, Chukchi Plain and Alpha Cordillera areas today. This is 10 percent of the sedimentation rate for some parts of the Arctic Ocean during the past 2 to 3 m.y. Clay mineralogy of the modern atmospheric dust and of the Arctic Ocean sediment is approximately 40 percent illite with almost equal amounts of chlorite and kaolinite.Ice-rafted detritus is widespread on the Arctic Ocean floor today. In addition, erratics greater than 8 mm and less than 40 mm have been found in 44 of almost 100 cores studied to date. These erratics are carbonates and sandstones in large part; metamorphics and cherts are less abundant. No pattern of lithologic and vertical distribution correlation of erratics among the cores is present. The oldest erratic occurs in sediment approximately 3.5 m.y. old. In excess of 30 percent by weight of some Arctic sediment consists of greater than 62 μ material. This is largely ice-rafted material. Together with the atmospheric dust fallout, this is a significant part of the average 2 to 3 mm/1,000 yrs sedimentation rate determined from magnetic stratigraphy. 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.

Heat flow through the Arctic Ocean floor: The Canada Basin-Alpha Rise Boundary

Twenty heat-flow measurements were made from drifting ice in a 100-km equidimensional region on the boundary between the Alpha rise and the Canada basin in the central Arctic Ocean. The heat flow in the basin is uniform (1.41±4% μcal/cm2 sec) over a distance of at least 75 km from the boundary. On the flank of the rise, six consecutive measurements confirm a decrease in heat flow to a minimum of 0.77 in a distance of less than 25 km. The anomaly cannot be explained in terms of superficial effects relating to water circulation, sedimentary processes, or topography. Uniformity of heat flow in the basin and the rapid change on the rise preclude credible explanations in terms of source distributions, mantle convection, phase change, or recent tectonic movements. The anomaly can be explained in terms of relatively low-conductivity rock extending to a depth of 10 or 20 km, either locally under the low heat-flow zone or generally under the entire rise. In the latter case, a projection would extend 50 or more kilometers under the adjacent basin at depth. In either case, low heat flow would occur only at the periphery of the rise. It is unlikely that conductivity contrasts in the crust and upper mantle would ever cause an appreciable surface heat-flow anomaly whose width exceeds 100 km. This is less than the spacing of most heat-flow stations, which therefore yield little information on the subject. Empirical formulas based on water content underestimate sediment conductivity by 10 to 20% on the rise and 5 to 10% in the basin.

IGY Bulletins: No. 46, No. 47, No. 48

The following material is based on a report by Kenneth Hunkins, Lamont Geological Observatory, Columbia University. The original, more‐detailed report, prepared by Lamont for the Geophysics Research Directorate of the Air Force Cambridge Research Laboratories, was published as AFCRC‐TN‐60‐257, Seismic Studies of the Arctic Ocean Floor, October 1960.

Geotectonics of the Arctic Ocean and the great Arctic magnetic anomaly

A tentative description of the structure of the Arctic Ocean floor is presented, in terms of recent data from Soviet sources and of certain representative Soviet theories of Arctic tectonics. Two theories of the Great Arctic Magnetic Anomaly are compared: the anomaly may be related either to an interplatform geosynclinal corridor extending across the Arctic Ocean floor, or to ancient centers of crustal consolidation in the Canadian and Central Siberian Platforms.