Large-scale traction-produced structures in deep-water fan-channel conglomerates in southern Chile

Geology ◽  
1977 ◽  
Vol 5 (1) ◽  
pp. 41 ◽  
Author(s):  
R. D. Winn ◽  
R. H. Dott
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Southern Chile

scholarly journals A mass-flux perspective of the tidewater glacier cycle

2016 ◽  
Vol 62 (231) ◽  
pp. 82-93 ◽  
Author(s):  
JASON M. AMUNDSON
Keyword(s):  
Deep Water ◽  
Mass Flux ◽  
Large Scale ◽  
Stable Configuration ◽  
Simple Explanation ◽  
Surface Mass ◽  
Tidewater Glaciers ◽  
Tidewater Glacier ◽  
Variable Sensitivity ◽  
Negative Feedbacks

AbstractI explore the tidewater glacier cycle with a 1-D, depth- and width-integrated flow model that includes a mass-flux calving parameterization. The parameterization is developed from mass continuity arguments and relates the calving rate to the terminus velocity and the terminus balance velocity. The model demonstrates variable sensitivity to climate. From an advanced, stable configuration, a small warming of the climate triggers a rapid retreat that causes large-scale drawdown and is enhanced by positive glacier-dynamic feedbacks. Eventually, the terminus retreats out of deep water and the terminus velocity decreases, resulting in reduced drawdown and the potential for restabilization. Terminus readvance can be initiated by cooling the climate. Terminus advance into deep water is difficult to sustain, however, due to negative feedbacks between glacier dynamics and surface mass balance. Despite uncertainty in the precise form of the parameterization, the model provides a simple explanation of the tidewater glacier cycle and can be used to evaluate the response of tidewater glaciers to climate variability. It also highlights the importance of improving parameterizations of calving rates and of incorporating sediment dynamics into tidewater glacier models.

scholarly journals 14C in the Deep Water of the East Atlantic

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 391-396 ◽  
Author(s):  
Reiner Schlitzer
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Bottom Water ◽  
Source Parameters ◽  
Potential Temperature ◽  
Source Terms ◽  
East Atlantic ◽  
The West ◽  
Model Calculations ◽  
Inflowing Water

The renewal of east Atlantic deep water and its large-scale circulation and mixing have been studied in observed distributions of temperature, silicate, ΣCO2, and 14C. 14C variations in northeast Atlantic deep water below 3500m depth are small. Δ14C values range from − 100‰ to −125‰. 14C bottom water concentrations decrease from Δ14C =−117‰ in the Sierra Leone Basin to Δ14C = − 123‰ in the Iberian Basin and are consistent with a mean northward bottom water flow. The characteristic of the water that flows from the west Atlantic through the Romanche Trench into the east Atlantic was determined by inspection of θ/Δ14C and θ/SiO2 diagrams. A mean potential temperature of θ = 1.50 ± .05°C was found for the inflowing water. A multi-box model including circulation, mixing, and chemical source terms in the deep water has been formulated. Linear programing and least-squares techniques have been used to obtain the transport and source parameters of the model from the observed tracer fields. Model calculations reveal an inflow through the Romanche Trench from the west Atlantic, which predominates over any other inflow, of (5 ± 2) Sv (potential temperature 1.50°C), a convective turnover of (150 ± 50) years and a vertical apparent diffusivity of (4 ± 1) cm2/s. Chemical source terms are in the expected ranges.

scholarly journals A Molecular Survey on Neglected Gurltia paralysans and Aelurostrongylus abstrusus Infections in Domestic Cats (Felis catus) from Southern Chile

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1195
Author(s):  
Natasha Barrios ◽  
Marcelo Gómez ◽  
Macarena Zanelli ◽  
Lisbeth Rojas-Barón ◽  
Paulina Sepúlveda-García ◽  
...  
Keyword(s):  
Risk Factors ◽  
Large Scale ◽  
Nematode Species ◽  
Epidemiological Studies ◽  
Felis Catus ◽  
Domestic Cat ◽  
Southern Chile ◽  
Domestic Cats ◽  
Aelurostrongylus Abstrusus ◽  
Factors Associated

Gurltia paralysans and Aelurostrongylus abstrusus are neglected metastrongyloid nematode species which infect domestic and wild cats in South American countries and in Chile, but no epidemiological studies on concomitant infections have been conducted in Chile so far. The aim of this study was not only to evaluate the occurrence of concomitant infections, but also to identify epidemiological risk factors associated with of G. paralysans and A. abstrusus infections in urban domestic cats (Felis catus) from Southern Chile. Blood samples from clinically healthy domestic cats from three cities of Southern Chile—Temuco, Valdivia, and Puerto Montt—were analyzed by an experimental semi-nested PCR protocol. A total of 171 apparently healthy domestic cats in Temuco (n = 68), Valdivia (n = 50), and Puerto Montt (n = 53) were sampled and analyzed. A total of 93 domestic cats (54.4%) were positive for G. paralysans, and 34 (19.9%) were positive for A. abstrusus infections. From those animals, 34 (19.9%) were co-infected. Cats positive with G. paralysans were found in all three cities; 47.2% in Puerto Montt, 48% in Valdivia, and 64.7% in Temuco. Levels of infection for A. abstrusus in the population under study were 4% (Valdivia), 10% (Puerto Montt), and 32.4% (Temuco). The present large-scale epidemiological study confirmed the presence of these neglected nematodes in domestic cat populations in Southern Chile, and described the possible risk factors associated with feline gurltiosis and aelurostrongylosis.

scholarly journals Distinguishing between Deep-Water Sediment Facies: Turbidites, Contourites and Hemipelagites

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 68 ◽  
Author(s):  
Dorrik Stow ◽  
Zeinab Smillie
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Tectonic Setting ◽  
Regional Scale ◽  
Small Scale ◽  
Physical Parameters ◽  
Sedimentary Characteristics ◽  
Natural Systems ◽  
Facies Types ◽  
Water Facies

The distinction between turbidites, contourites and hemipelagites in modern and ancient deep-water systems has long been a matter of controversy. This is partly because the processes themselves show a degree of overlap as part of a continuum, so that the deposit characteristics also overlap. In addition, the three facies types commonly occur within interbedded sequences of continental margin deposits. The nature of these end-member processes and their physical parameters are becoming much better known and are summarised here briefly. Good progress has also been made over the past decade in recognising differences between end-member facies in terms of their sedimentary structures, facies sequences, ichnofacies, sediment textures, composition and microfabric. These characteristics are summarised here in terms of standard facies models and the variations from these models that are typically encountered in natural systems. Nevertheless, it must be acknowledged that clear distinction is not always possible on the basis of sedimentary characteristics alone, and that uncertainties should be highlighted in any interpretation. A three-scale approach to distinction for all deep-water facies types should be attempted wherever possible, including large-scale (oceanographic and tectonic setting), regional-scale (architecture and association) and small-scale (sediment facies) observations.

Deep-Water, Large-Scale Sediment Waves Bounded by the Valencia Channel

2016 ◽  
pp. 299-305
Author(s):  
Araceli Muñoz ◽  
Elena Elvira ◽  
Patricia Jiménez ◽  
Juan Acosta ◽  
Laura Pascual
Keyword(s):  
Deep Water ◽  
Large Scale ◽  
Sediment Waves

scholarly journals The stratigraphic expression of decreasing confinement along a deep-water sediment routing system: Outcrop example from southern Chile

Geosphere ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 114-134 ◽  
Author(s):  
Erin A.L. Pemberton ◽  
Stephen M. Hubbard ◽  
Andrea Fildani ◽  
Brian Romans ◽  
Lisa Stright
Keyword(s):  
Deep Water ◽  
Southern Chile ◽  
Sediment Routing

scholarly journals Temperate fish community variation over seasons in relation to large-scale geographic seascape variables

2018 ◽  
Vol 75 (10) ◽  
pp. 1723-1732 ◽  
Author(s):  
Diana Perry ◽  
Thomas A.B. Staveley ◽  
Linus Hammar ◽  
Alyssa Meyers ◽  
Regina Lindborg ◽  
...  
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Seasonal Changes ◽  
Fish Community ◽  
Large Scale ◽  
Spatial Scales ◽  
Wave Exposure ◽  
Fish Assemblage Structure ◽  
Swedish West Coast ◽  
Latitudinal Position

In shallow-water marine environments, ecosystem functioning is a complex interworking of fine-scale characteristics and region-wide factors, and the importance of these variables can vary on multiple temporal and spatial scales. This underwater video study targeted seasonal changes in the fish community of seagrass habitats along the Swedish west coast and the influence of offshore seascape variables (latitudinal position, wave exposure, open ocean, and deep water). Results showed that fish assemblage structure exhibited seasonal changes between summer and autumn and strong spatiotemporal variations in the importance of offshore factors affecting shallow-water fish communities. In summer, abundance from the Gobiidae family responded to wave exposure, whereas the Gadidae family and juvenile migrant habitat preference guild responded to latitudinal position and proximity to deep water. In autumn, deep water was related to abundance of Gadidae and juvenile migrants, whereas latitudinal position influenced Gasterosteidae. These findings underscore the importance of understanding the influence of offshore factors on facets of coastal fish assemblages to address large-scale geographic connectivity along nearshore–offshore gradients.

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