ARCTIC OCEAN GEOPHYSICAL STUDIES: THE SOUTHERN HALF OF THE SIBERIA BASIN

Geophysics ◽  
1966 ◽  
Vol 31 (4) ◽  
pp. 683-710 ◽  
Author(s):  
Henry Kutschale
Keyword(s):  
Seismic Reflection ◽  
Magnetic Measurements ◽  
Abyssal Plain ◽  
Turbidity Currents ◽  
The North ◽  
Northern Half ◽  
Gravity Measurements ◽  
Southern Half ◽  
Basement Ridge ◽  
Seismic Reflection Profiles

In 1962, ice island Arlis II drifted over a portion of the southern half of the Siberia Basin. Depth recordings made between 81°N, 170°E and 82°30′N, 160°E show that the ocean floor in this area is an abyssal plain at about 2,825 m depth dissected by several interplain channels. This abyssal plain, here called the Wrangel Abyssal Plain, is bounded on the north by Arlis Gap, which joins it with the Siberia Abyssal Plain at about 3,946 m depth. The Siberia Abyssal Plain occupies the northern half of the Siberia Basin. Seismic reflection profiles show that a prominent subbottom basement ridge exists in the vicinity of Arlis Gap. This ridge strikes in an approximately northwest direction and appears to connect with Alpha Ridge, which bounds the Siberia Basin on the east and north, and with Lomonosov Ridge, which bounds the Siberia Basin on the west. The seismic reflection profiles also show that at least 3.5 km of subhorizontal, stratified sediments underlie Wrangel Abyssal Plain south of the ridge. Each layer within these sediments appears to correspond to a fossil surface of Wrangel Abyssal Plain. This thick sequence of stratified sediments shows the influence of the Asian continent, which bounds the Siberia Basin on the south, on sedimentation within the Siberia Basin. Presumably the buried basement ridge forms a dam which has permitted the accumulation of a thick sequence of sediments under the higher‐level Wrangel Abyssal Plain. Turbidity currents moving through Arlis Gap presumably carried the overflow of sediments from Wrangel Abyssal Plain into the lower‐level Siberia Abyssal Plain. The structure of the sediments suggests that the Siberia Basin has been free from deformation during the deposition of the sediments, except for possible broad crustal down warping. A crustal model based on the water depth measurements, seismic reflection profiles, gravity measurements, and magnetic measurements yields a crustal thickness of 15 km south of the buried ridge and 22 km under the ridge measured from sea level.

scholarly journals Observations upon the marine barometer, made during the examina­tion of the coasts of New Holland and New Wales, in the Years 1801, 1802, and 1803. By Matthew Flinders, Esq. Com­mander of His Majesty’s Ship Investigator . In a letter to the Right Hon. Sir Joseph Banks, K. B. P. R. S. &c. &c. &c

1832 ◽  
Vol 1 ◽  
pp. 230-232
Keyword(s):  
The State ◽  
The Other ◽  
South Coast ◽  
The South ◽  
South Side ◽  
The North ◽  
North Side ◽  
Northern Half ◽  
Southern Half ◽  
The Right

The chief circumstance that induced Capt. Flinders to think his observations Upon the marine barometer were worthy of attention, was the coincidence that took place between the rising and falling of the mercury, and the setting in of winds that blew from the sea and from off the land, to which there seemed to be at least as much reference as to the strength of the wind or the state of the atmosphere. Our author’s examination of the coasts of New Holland and the other parts of the Terra Australis, began at Cape Leuwen, and con­tinued eastward along the south coast. His observations, which, on account of their length, we must pass over, show, that a change of wind from the northern half of the compass to any point in the southern half, caused the mercury to rise; and that a contrary change caused it to fall. Also, that the mercury stood considerably higher When the wind came from the south side of east and west, than when, in similar weather, it came from the north side.

scholarly journals The marine record of the Russell Fiord outburst flood, Alaska, U.S.A.

1996 ◽  
Vol 22 ◽  
pp. 194-199 ◽  
Author(s):  
Ellen A. Cowan ◽  
Paul R. Carlson ◽  
Ross D. Powell
Keyword(s):  
High Resolution ◽  
Debris Flow ◽  
Seismic Reflection ◽  
Seismic Facies ◽  
Turbidity Currents ◽  
Outburst Flood ◽  
Gravity Core ◽  
Channel System ◽  
Seismic Reflection Profiles ◽  
Long Channel

The advance of Hubbard Glacier, near Yakutat, Alaska, U.S.A., in spring 1986 blocked the entrance to Russell Fiord with an ice-and-sediment dam, behind which a lake formed. The water level in Russell Lake rose to 25.5 m a.s.l. The dam catastrophically failed in October 1986, releasing 5.4 km3of water into Disenchantment Bay. High-resolution seismic-reflection profiles show a 7.5 km long channel system cut into and buried by glacimarine sediment, represented by continuous, parallel reflections. The chaotic seismic facies filling the channel is interpreted to be debris flow deposits. A gravity core from channel-overbank deposits contained sandy diamicton with mud clasts. Above the channel a 1–2 m thick sediment drape extends across the bay. Laminated mud, fining-upward sand beds and diamicton were recovered from this unit. The sediment-drape deposits were produced by suspension settling from turbid plumes and non-channelized turbidity currents generated by the outburst flood.

scholarly journals Grenville Foreland Deformation and Sedimentation in Southwest Ohio Indicated by Reprocessed Seismic Reflection Profiles near Middletown, Ohio, USA

2020 ◽  
Vol 120 (2) ◽  
pp. 39
Author(s):  
David J. Peterman ◽  
Ernest C. Hauser ◽  
Doyle R. Watts
Keyword(s):  
Cross Section ◽  
Seismic Reflection ◽  
Vertical Displacement ◽  
Reverse Fault ◽  
Seismic Line ◽  
The North ◽  
North American Craton ◽  
Tectonic Style ◽  
Seismic Reflection Profiles ◽  
Depositional Setting

The late Mesoproterozoic to early Neoproterozoic Middle Run Formation contains vital information about the crustal evolution of the North American Craton. Four reprocessed seismic reflection lines in the vicinity of the AK Steel facility in Middletown, Ohio, provide new insights into the structural and depositional setting of the Middle Run Formation in this region. A residual statics solution improved the resolution and coherency of reflections in these profiles that underlie the Cambrian Mount Simon Sandstone. Reprocessing revealed gently inclined, west-southwest-dipping reflectors and the occurrence of an angular unconformity between the Middle Run Formation and the overlying Paleozoic strata. The weak and discontinuous seismic reflection character of the Middle Run Formation in these seismic lines overlies a sequence of stronger parallel reflections that are like those observed on the eastward ODNR-1-88 seismic line located near core hole DGS 2627, the stratotype of the Middle Run Formation. This inferred thickness indicates that the basin in which the Middle Run Formation was deposited ranges from at least 670 to 1,128 m (2,200 to 3,700 ft) deep at the AK Steel area and dips gently west-southwest, which is in contrast with the moderate easterly dip observed on the ODNR-1-88 seismic line to the northeast. Correlation of these features across the 10 km (approximately 6 mi) cross-strike gap between the AK Steel lines and the ODNR-1-88 seismic line suggests the presence of a reverse fault with approximately 792 m (2,600 ft) of estimated vertical displacement. A regional cross section—including the WSU 1990 seismic line eastward of the ODNR-1-88 line—exhibits a faulted west-verging asymmetric syncline in near proximity to the Grenville Front. This cross section also shows that deformation of the Middle Run Formation and the underlying layered sequence exhibits a consistent tectonic style of reverse faulting and folding that developed in response to Grenville Front tectonism.

The Bantu Expansion and the SOAS Network

1988 ◽  
Vol 15 ◽  
pp. 261-301 ◽  
Author(s):  
Colin Flight
Keyword(s):  
Boundary Line ◽  
The South ◽  
Irregular Boundary ◽  
African Languages ◽  
North East ◽  
The North ◽  
Northern Half ◽  
Southern Half ◽  
Independent Families ◽  
The Many

One difference between linguists and other Africanists seemed to be that others were prepared to jettison one part of their training to help other disciplines, but linguists apparently would not. Was this so, and if so, why?The Bantu expansion has been a problem for historians ever since the recognition by linguists of a single startling fact. During the nineteenth century, the descriptions of African languages available to scholars in Europe grew steadily in number; they also tended to gain in detail, and in accuracy. It thus became increasingly clear that a sinuous line could be traced across the map distinguishing a zone of extremely high diversity in the north from a zone of low diversity in the south. By the 1880s a popularizing writer could claim that this contrast was generally recognized “by students of African languages.” The situation as he described it was that in the northern half of the continent there are bewildering multitudes of diverse tongues belonging to many independent families, and apparently irreducible to a common origin. Yet cross the irregular boundary-line which runs over the continent from 6° N. on the west coast to the Equator on the east coast … and what do we find? Why that the whole of the southern half of Africa, with the exception of the Masai and Galla intrusion in the north-east and the Hottentot enclave in the south-west, is the domain of a single homogeneous family of languages, … differing perhaps less among themselves than do the many offshoots of the Aryan stock.

The Alston Block

1928 ◽  
Vol 65 (10) ◽  
pp. 433-448 ◽  
Author(s):  
F. M. Trotter ◽  
S. E. Hollingworth
Keyword(s):  
Rigid Block ◽  
The South ◽  
The West ◽  
Lower Carboniferous ◽  
The North ◽  
Fault Block ◽  
Eastern Boundary ◽  
Northern Half ◽  
Southern Half ◽  
Coal Measures

The area covered by this paper embraces the northern end of the Pennines—the uplands of Lower Carboniferous rocks centred about Alston, together with the low ground of the Tyne-Irthing gap to the north. It is bounded on the west by the Vale of Eden. The Pennine portion is separated structurally from the regions to the north and west by the Stublick and Pennine Faults respectively. The former trends E.N.E., it has a downthrow to the north and has resulted in the preservation of the string of Coal Measures outliers which form a connecting link between the Cumberland and Northumberland coalfields. The Pennine Fault, trending S.S.E., with a throw of several thousand feet to the west, brings the New Red rocks of the Vale of Eden against the Lower Carboniferous beds of the Pennine Escarpment. These two faults meet at right angles near Castle Carrock. To the south the Pennine Fault dies out near Stainmore, and another dislocation, the Dent Fault, trending S.S.W., develops, and eventually links up with the Craven Faults which have an E.S.E. trend. These four faults, as pointed out by Professor Kendall, have the form of a reversed 3, and the region within this figure has become known generally as the Northumbrian Fault Block. Professor Marr has aptly termed the southern half of this area the “Rigid Block”. The northern half of the Northumbrian Fault Block, which will be shown to possess many characters in common with the southern half, is here called the “Aiston Block”. Its limits are defined on three sides—by the Stublick Fault on the north, the Pennine Fault on the west, and by the Stainmore depression on the south. The last thus divides the Northumbrian Fault Block into two, physiographically and structurally. The eastern boundary of the Alston Block is concealed beneath the Mesozoic rocks.

Seismic investigations of sedimentary structure in the northern Rockall Trough—a synopsis

1986 ◽  
Vol 88 ◽  
pp. 53-54
Author(s):  
R. J. Whittington ◽  
M. R. Dobson
Keyword(s):  
Seismic Reflection ◽  
Single Channel ◽  
Sedimentary Structure ◽  
The North ◽  
Air Gun ◽  
Late Tertiary ◽  
Rockall Trough ◽  
Seismic Reflection Profiles ◽  
Small Capacity ◽  
North Rockall Trough

Single channel, analogue, seismic reflection profiles using Sparker and small capacity Air gun sources were used to investigate late Tertiary and Quaternary sedimentation both around the margins and on the floor of the north Rockall Trough. The data complement, by being intermediate in penetration and resolution, previous seismic studies; particularly, they allow the upper 500 m of the sediment sequence to be examined in greater detail than hitherto.

scholarly journals II.—On the Cudgegong Diamond Field, New South Wales

1879 ◽  
Vol 6 (10) ◽  
pp. 444-458
Author(s):  
Norman Taylor ◽  
R. Etheridge
Keyword(s):  
New South ◽  
The West ◽  
North West ◽  
The North ◽  
North Side ◽  
South Wales ◽  
Northern Half ◽  
Southern Half ◽  
Extreme North ◽  
The Hill

The next appearance of the older lead is at the “Rocky-ridge,” where the river, after running northerly for three-quarters of a mile, along the strike of the metamorphic beds, turns abruptly to the west. This ridge is a basalt-capped hill on the north side of the river, running in a north-west direction; it is about a mile long, with a bold rocky escarpment on its west side, facing the Sandy or Cudgebeyong Creek. Some tunnels have been driven in, and shafts sunk on this hill, and tolerably rich deposits of gold were found, but never followed out.Only in the southern half of the hill have diamonds been found(all more or less spotted).The drift is remark-able for the number and size of the agates it contains.The northern half of “the ridge” is underlaid by another outlier of the before-mentioned doubtful purple conglomerate, into which some tunnels have been driven in the western escarpment.The basalt is merely a fringe here, resting against the flank of the conglomerate, in which a small quantity of nuggetty gold was obtained;and form one to two inches thickness of lignite, or carbonaceous clay, is seen between it and the bottom of the basalt. Tte basali is intersected by numerous veins of a mineral allied to kaolin. The purple con-glomerate is similar in character to that near “the flat”and contains, on some of the joint faces, smll spherical crystalline aggreations of chalybite(carbonate of iron).At the extreme north ead of “the ridge”are great quantities of ironstone and conglomerate, but, from their Carbpniferous series, which is largely developed further north.The first diamonds which found their way to Melbourne were obtained.

scholarly journals Impacts of Climate Modes on Air–Sea Heat Exchange in the Red Sea

2015 ◽  
Vol 28 (7) ◽  
pp. 2665-2681 ◽  
Author(s):  
Yasser Abualnaja ◽  
Vassilis P. Papadopoulos ◽  
Simon A. Josey ◽  
Ibrahim Hoteit ◽  
Harilaos Kontoyiannis ◽  
...  
Keyword(s):  
Heat Exchange ◽  
Red Sea ◽  
Boreal Winter ◽  
Climate Modes ◽  
The North ◽  
Monsoon Index ◽  
Northern Half ◽  
Multivariate Enso Index ◽  
Southern Half ◽  
The North Atlantic Oscillation

Abstract The impacts of various climate modes on the Red Sea surface heat exchange are investigated using the MERRA reanalysis and the OAFlux satellite reanalysis datasets. Seasonality in the atmospheric forcing is also explored. Mode impacts peak during boreal winter [December–February (DJF)] with average anomalies of 12–18 W m−2 to be found in the northern Red Sea. The North Atlantic Oscillation (NAO), the east Atlantic–west Russia (EAWR) pattern, and the Indian monsoon index (IMI) exhibit the strongest influence on the air–sea heat exchange during the winter. In this season, the largest negative anomalies of about −30 W m−2 are associated with the EAWR pattern over the central part of the Red Sea. In other seasons, mode-related anomalies are considerably lower, especially during spring when the mode impacts are negligible. The mode impacts are strongest over the northern half of the Red Sea during winter and autumn. In summer, the southern half of the basin is strongly influenced by the multivariate ENSO index (MEI). The winter mode–related anomalies are determined mostly by the latent heat flux component, while in summer the shortwave flux is also important. The influence of the modes on the Red Sea is found to be generally weaker than on the neighboring Mediterranean basin.

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