A review of the ecology of the deep-water pelagic fauna of the Rockall Trough

1986 ◽  
Vol 88 ◽  
pp. 145-157
Author(s):  
J. Mauchline
Keyword(s):  
Deep Water ◽  
Quantitative Description ◽  
Demersal Fish ◽  
Historical Account ◽  
Production Rates ◽  
Qualitative And Quantitative ◽  
The North ◽  
Rockall Trough

SynopsisA brief historical account of the early faunal investigations is given. Modern studies concentrate on qualitative and quantitative description and interpretation of the processes taking place within the Rockall Trough. Demographic analyses are feasible on a variety of species allowing estimation of growth and production rates. The pelagic fauna impinges on the benthopelagic environments of the slope regions of the Trough. There it is predated by populations of demersal fish. Advection of fauna takes place to the north and northeast, probably primarily in the slope current.

Reproductive patterns in two deep-water solitary corals from the north-east Atlantic—Flabellum alabastrumandF. angulare(Cnidaria: Anthozoa: Scleractinia)

2010 ◽  
Vol 91 (3) ◽  
pp. 669-675 ◽  
Author(s):  
Rhian G. Waller ◽  
Paul A. Tyler
Keyword(s):  
Sex Ratio ◽  
Deep Water ◽  
Oocyte Size ◽  
East Atlantic ◽  
Broadcast Spawning ◽  
Reproductive Patterns ◽  
Size Dependent ◽  
North East ◽  
The North ◽  
Rockall Trough

Gametogenesis and reproductive periodicity of the solitary scleractiniansFlabellum alabastrum(from the Rockall Trough) andF. angulare(from the Porcupine Seabight) were investigated. Samples were collected between depths from 1370 to 2190 m forF. alabastrumand 2412 to 2467 m forF. angulare. Both species showed gonochorism with a 1:1 sex-ratio and broadcast spawning of gametes is inferred from the lack of brooded planulae. Oocyte sizes were large in both species (925 μm inF. alabastrumand 1015 μm inF. angulare), suggesting lecithotrophic larval development. Fecundity and periodicity of oocyte development differed between the two species.Flabellum alabastrumproduced a maximum of 2800 oocytes per polyp quasi-continuously, whereas the deeper speciesF. angulareproduced a maximum of 550 oocytes per polyp either seasonally or periodically. Both species showed size-dependent fecundity. The data show a decrease in oocyte size and fecundity with depth, in concordance with other deep-water scleractinian species.

The geology, crustal structure and evolution of the Rockall Trough and the Faeroe-Shetland Channel

1986 ◽  
Vol 88 ◽  
pp. 7-26 ◽  
Author(s):  
Roger A. Scrutton
Keyword(s):  
Oceanic Crust ◽  
Crustal Structure ◽  
Deep Water ◽  
Upper Cretaceous ◽  
Sedimentary Rocks ◽  
Acoustic Basement ◽  
The North ◽  
Early Tertiary ◽  
Late Palaeozoic ◽  
Rockall Trough

SynopsisFrom direct sampling, the deeper Rockall Trough and Faeroe-Shetland Channel are known to have a Tertiary-Quaternary sedimentary sequence up to 3000 m thick, which is in places, particularly in the north, underlain by early Tertiary basaltic volcanic rocks. The seamounts in the Rockall Trough are of basic volcanics of probable Upper Cretaceous age. The eastern shelf areas have a rifted basement of Precambrian-Devonian (-?Carboniferous) age, overlain by Permian + Mesozoic sedimentary rocks that reach 5000 m in thickness in rift basins. Tertiary sediments thicken rapidly from the shelf into deep water. The western shelf areas have extensive early Tertiary basalts from the Faeroe Islands to the southern part of Rockall Bank. A thin Tertiary—Quaternary cover exists and Precambrian basement lies beneath.The pre-Tertiary geology of the deep water areas and the overall crustal structure have been inferred from geophysical investigations. In the Rockall Trough the crust is of oceanic thickness, about 6 km, but it is probably slightly thicker beneath the Faeroe-Shetland Channel. This fact, coupled with the size of the channel compared with other small ocean basins and the knowledge that fully developed oceanic crust exists just outside the mouth of the Rockall Trough, strongly suggests that at least parts of the deep water areas are floored by oceanic crust. However, seismic reflection and magnetic anomaly profiles do not yield observations characteristic of normal oceanic crust.The age of any oceanic crust in the Rockall Trough and Faeroe-Shetland Channel is equivocal. Between 54° and 59° N a succession of largely sedimentary rocks up to 3000 m in thickness occurs between the Tertiary and the acoustic basement. To the north this succession is masked on seismic profiles by early Tertiary basalts but it is probably present; to the south it is interrupted by a series of acoustically opaque basement ridges. With slow sedimentation rates, this succession could extend back to the late Palaeozoic, but with rapid rates, only to the mid-Upper Cretaceous. An age of mid-Lower to mid-Upper Cretaceous for oceanic crust, equal to that of the ocean crust outside the mouth of the Rockall Trough, is accepted here. Although rapid subsidence and infill in Upper Cretaceous time is not characteristic of major shelf basins around Britain, it may be acceptable for the Rockall Trough and Faeroe-Shetland Channel if they are underlain by oceanic crust rather than continental crust.A likely model for the formation of the Rockall Trough and Faeroe-Shetland Channel is of continental rifting and subsidence from late Palaeozoic or earliest Mesozoic to mid-Cretaceous time, then sea-floor spreading in Albian (c.105My)–Santonian (c.85 My) time, accompanied and immediately followed by rapid subsidence and deposition. The Tertiary was heralded by widespread basaltic igneous activity which briefly arrested subsidence, but was largely a period of subsidence without sedimentation keeping pace.

Records of deep water chondrichthyan fish caught on long-line in the Rockall Trough

2000 ◽  
Vol 80 (2) ◽  
pp. 377-378 ◽  
Author(s):  
M.W. Clarke
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Zoological Museum ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
Long Line ◽  
Rockall Trough ◽  
Line Survey ◽  
Depth Ranges

A number of chondrichthyan fish species were caught on long-line in the Rockall Trough (north-east Atlantic) in 1997, which are first records for this area; Raja hyperborea, Raja kukujevi and Raja fullonica. The occurrence of R. hyperborea, usually found in colder boreal waters appears to be temperature related. The presence of the deep water squaliform shark Centrophorus uyato in the area was also confirmed and several species were caught at previously undocumented depths.The Rockall Trough is an extension of the North Atlantic deep environment (Mauchline, 1990). A long-line survey was undertaken in August 1997 on the eastern and southern slopes of the Rockall Trough (Figure 1), fishing gear and procedures are described by Connolly (1997). Identifications were undertaken by means of several texts (Compagno, 1984; Whitehead, et al., 1984; Stehmann, 1997). The specimens described below were lodged in the National Museum of Ireland (NMI) and the Hamburg University Zoological Museum, Germany (ZMH). Depth ranges, positions and catalogue numbers of the specimens described are given in Table 1.

A Note on The Distribution and Diet of Deep-Water Rays (Rajidae) in An Area of The Rockall Trough

1989 ◽  
Vol 69 (3) ◽  
pp. 655-658 ◽  
Author(s):  
J.D.M. Gordon ◽  
J.A.R. Duncan
Keyword(s):  
Deep Water ◽  
Trophic Ecology ◽  
Demersal Fish ◽  
Fish Populations ◽  
Rockall Trough ◽  
Different Types

The demersal fish populations of the slopes of the Rockall Trough (250 to 3000m) have been sampled by a number of different types of trawl (Gordon & Duncan, 1985; Gordon, 1986). The diets of most species have been described (Mauchline & Gordon, 1980, 1983a,b, 1984a,b,c) and aspects of the trophic ecology discussed (Mauchline & Gordon, 1985, 1986). Rays were relatively uncommon in the early sampling but the more recent use of a Marinovitch semi-balloon trawl with mud rollers and chain on the footrope has increased catches. This paper describes the distribution and diet of 12 species of ray from the slopes of the Rockall Trough.

Palaeogene and Neogene

1992 ◽  
Vol 13 (1) ◽  
pp. 141-147 ◽  
Author(s):  
J. W. Murray
Keyword(s):  
North Sea ◽  
Deep Water ◽  
Regional Scale ◽  
Thermal Relaxation ◽  
British Isles ◽  
Seismic Profiles ◽  
The North ◽  
Rockall Trough ◽  
History Of ◽  
The North Sea

AbstractMost of the British Isles has been a land area throughout the Tertiary and the basic shape of the coastline had been determined by the late Palaeocene. Only in southeast England are there marine Palaeogene and Neogene successions and these were deposited in embayments marginal to the North Sea and English Channel.Much of the key information for the interpretation of the Tertiary history of the British Isles lies offshore. Thousands of kilometres of seismic profiles have been run and hundreds of boreholes drilled, mainly in the search for oil. The only part of the Tertiary which has been of economic interest is the Palaeocene of the northern North Sea. Summaries of the offshore data are given in Woodland (1975) and Illing & Hobson (1981).Thick Tertiary successions are known from the central Graben of the North Sea, the Rockall Trough and the Faeroe Basin (Map Pg 1). The North Sea was the site of great subsidence caused by thermal relaxation following stretching of the continental crust (Sclater & Christie 1980). None of the Tertiary sediments was deposited in very deep water. By contrast, the Rockall Trough and the Faeroe Basin are underlain by oceanic crust and deep water has existed there throughout the Tertiary. The successions are known only from seismic studies (Roberts 1975) but are thought to be mainly fine-grained and with some contourites.On a regional scale, the Tertiary history of northwest Europe must be considered in relation to the plate tectonic events proceeding in the adjacent ocean.

Late Quaternary palaeo-oceanography of the Denmark Strait overflow pathway, South-East Greenland margin

1998 ◽  
Vol 180 ◽  
pp. 163-167
Author(s):  
Antoon Kuijpers ◽  
Jørn Bo Jensen ◽  
Simon R . Troelstra ◽  
And shipboard scientific party of RV Professor Logachev and RV Dana
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Deep Convection ◽  
Conveyor Belt ◽  
Water Masses ◽  
Labrador Sea ◽  
Greenland Sea ◽  
The North ◽  
Denmark Strait ◽  
The North Atlantic

Direct interaction between the atmosphere and the deep ocean basins takes place today only in the Southern Ocean near the Antarctic continent and in the northern extremity of the North Atlantic Ocean, notably in the Norwegian–Greenland Sea and Labrador Sea. Cooling and evaporation cause surface waters in the latter region to become dense and sink. At depth, further mixing occurs with Arctic water masses from adjacent polar shelves. Export of these water masses from the Norwegian–Greenland Sea (Norwegian Sea Overflow Water) to the North Atlantic basin occurs via two major gateways, the Denmark Strait system and the Faeroe– Shetland Channel and Faeroe Bank Channel system (e.g. Dickson et al. 1990; Fig.1). Deep convection in the Labrador Sea produces intermediate waters (Labrador Sea Water), which spreads across the North Atlantic. Deep waters thus formed in the North Atlantic (North Atlantic Deep Water) constitute an essential component of a global ‘conveyor’ belt extending from the North Atlantic via the Southern and Indian Oceans to the Pacific. Water masses return as a (warm) surface water flow. In the North Atlantic this is the Gulf Stream and the relatively warm and saline North Atlantic Current. Numerous palaeo-oceanographic studies have indicated that climatic changes in the North Atlantic region are closely related to changes in surface circulation and in the production of North Atlantic Deep Water. Abrupt shut-down of the ocean-overturning and subsequently of the conveyor belt is believed to represent a potential explanation for rapid climate deterioration at high latitudes, such as those that caused the Quaternary ice ages. Here it should be noted, that significant changes in deep convection in Greenland waters have also recently occurred. While in the Greenland Sea deep water formation over the last decade has drastically decreased, a strong increase of deep convection has simultaneously been observed in the Labrador Sea (Sy et al. 1997).

NILAI KERJA DITINJAU DARI ETNIS BATAK TOBA PADA ANGGOTA SATUAN BRIGADE MOBILE KEPOLISIAN DAERAH SUMATERA UTARA

2019 ◽  
Vol 4 (1) ◽  
pp. 8-14
Author(s):  
Debi Angelina Br. Barus
Keyword(s):  
Work Values ◽  
Quantitative Description ◽  
The North ◽  
Work Value ◽  
Toba Batak ◽  
Relationship Of ◽  
The Relationship ◽  
North Sumatra

This study aims to determine the relationship of work values with the Batak Toba ethnic. This research was conducted at the Mobile Brigade Unit of the North Sumatra Regional Police. The subjects in this study were 45 people. This study uses a quantitative description approach. The results of the study are to find that hamoraon, hagabeon and hasangapon (3H) are in line with the principle of the work value of Brimob members. 3H is the peak achievement of individual Toba Batak ethnic work value in the mobile brigade unit of the North Sumatra regional police. Keyword: Work value, Batak Toba Etnic   Penelitian ini bertujuan untuk mengetahui hubungan nilai kerja dengan etnis Batak Toba. Penelitian ini dilakukan di Satuan Brigade Mobile Kepolisian Daerah Sumatera Utara. Subjek dalam penelitian ini adalah 45 orang. Penelitian ini menggunakan pendekatan kuantitatif deskripsi. Hasil penelitian adalah menemukan bahwa hamoraon, hagabeon dan hasangapon (3H) sejalan dengan prinsip nilai kerja pada satuan anggota Brimob. 3H merupakan puncak pencapaian dari nilai kerja individu yang beretnis Batak Toba di satuan brigade mobile kepolisian daerah Sumatera Utara. Kata Kunci: Nilai kerja, Etnis Batak Toba

Uncommon Grounds

2017 ◽  
Author(s):  
Jeffrey Lawrence
Keyword(s):  
American Literature ◽  
Latin American ◽  
Historical Novel ◽  
Latin American Literature ◽  
Historical Account ◽  
American Novel ◽  
Song Of Solomon ◽  
The Past ◽  
The North ◽  
The Us

This chapter turns from a historical account of the development of the US literature of experience and the Latin American literature of reading to a textual analysis of the US and Latin American historical novel. Hemispheric/inter-American scholars often cite William Faulkner’s Absalom, Absalom! (1936), Gabriel García Márquez’s One Hundred Years of Solitude (1967), and Toni Morrison’s Song of Solomon (1977) as exemplifying instances of literary borrowing across the North–South divide. As I demonstrate, however, each of the later texts also realigns its predecessor’s historical imaginary according to the dominant logics of the US and Latin American literary fields. Whereas the American works foreground experiential models of reconstructing the past and conveying knowledge across generations, García Márquez’s Latin American novel presents reading as the fundamental mode of comprehending and transmitting history.

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