scholarly journals Initiation and evolution of knickpoints and their role in cut-and-fill processes in active submarine channels

Geology ◽  
2020 ◽  
Author(s):  
Léa Guiastrennec-Faugas ◽  
Hervé Gillet ◽  
Jeff Peakall ◽  
Bernard Dennielou ◽  
Arnaud Gaillot ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Submarine Canyon ◽  
Submarine Channels ◽  
Partial Channel ◽  
Key Drivers ◽  
Meander Bends ◽  
Annual Time ◽  
Cut And Fill ◽  
Headward Erosion ◽  
Over Time

Submarine channels are the main conduits and intermediate stores for sediment transport into the deep sea, including organics, pollutants, and microplastics. Key drivers of morphological change in channels are upstream-migrating knickpoints whose initiation has typically been linked to episodic processes such as avulsion, bend cutoff, and tectonics. The initiation of knickpoints in submarine channels has never been described, and questions remain about their evolution. Sedimentary and flow processes enabling the maintenance of such features in non-lithified substrates are also poorly documented. Repeated high-resolution multibeam bathymetry between 2012 and 2018 in the Capbreton submarine canyon (southeastern Bay of Biscay, offshore France) demonstrates that knickpoints can initiate autogenically at meander bends over annual to multi-annual time scales. Partial channel clogging at tight bends is shown to predate the development of new knickpoints. We describe this initiation process and show a detailed morphological evolution of knickpoints over time. The gradients of knickpoint headwalls are sustained and can grow over time as they migrate through headward erosion. This morphology, associated plunge pools, and/or development of enhanced downstream erosion are linked herein to the formation and maintenance of hydraulic jumps. These insights of autogenically driven, temporally high-frequency knickpoints reveal that cut-and-fill cycles with depths of multiple meters can be the norm in submarine systems.

Capabilities

2020 ◽  
pp. 39-57
Author(s):  
Scott Tannenbaum ◽  
Eduardo Salas
Keyword(s):  
Team Effectiveness ◽  
Dark Triad ◽  
Interpersonal Skill ◽  
Personal Traits ◽  
Collective Orientation ◽  
Key Drivers ◽  
The Right ◽  
Over Time

Capabilities, one of the seven key drivers of team effectiveness, refers to fairly stable competencies and predispositions that have been shown to consistently contribute to or detract from team effectiveness. While high capability levels don’t ensure success, and adding a “star” won’t always boost performance, a significant lack of capability will hurt team effectiveness. You can’t “team” away a large capability gap. This chapter highlights 11 transportable team capabilities that are beneficial in almost any team including communicating, giving and receiving feedback, dealing with conflict, interpersonal skill, and teamwork savvy. These competencies can be developed over time. Several personal traits are usually related to team effectiveness, including collective orientation, adaptability, conscientiousness, and agreeableness. Three toxic traits, referred to as the dark triad—Machiavellianism, narcissism, and psychopathy—adversely affect teamwork. Traits are quite difficult to change, so it is worth the effort to choose the right people to join your team.

scholarly journals Political influences on greenhouse gas emissions from US states

2015 ◽  
Vol 112 (27) ◽  
pp. 8254-8259 ◽  
Author(s):  
Thomas Dietz ◽  
Kenneth A. Frank ◽  
Cameron T. Whitley ◽  
Jennifer Kelly ◽  
Rachel Kelly
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Empirical Work ◽  
Demographic Factors ◽  
Anthropogenic Stress ◽  
Gas Emissions ◽  
Us States ◽  
Economic Forces ◽  
Key Drivers ◽  
Over Time

Starting at least in the 1970s, empirical work suggested that demographic (population) and economic (affluence) forces are the key drivers of anthropogenic stress on the environment. We evaluate the extent to which politics attenuates the effects of economic and demographic factors on environmental outcomes by examining variation in CO2 emissions across US states and within states over time. We find that demographic and economic forces can in part be offset by politics supportive of the environment—increases in emissions over time are lower in states that elect legislators with strong environmental records.

scholarly journals Introverted and knotted spaces within modern and contemporary urban fabrics: passages, gallerias and covered squares

2017 ◽  
Author(s):  
Marco Falsetti ◽  
Pina Ciotoli
Keyword(s):  
Public Space ◽  
Morphological Evolution ◽  
Existing Buildings ◽  
New Type ◽  
Theatrical Practice ◽  
Architectural Transformation ◽  
Set Up ◽  
Private Homes ◽  
San Carlos ◽  
Over Time

The scenic plaza mayor shares with the theater organisms some formative characters, since they both derive from a transformation, by knotting, of pre-existing buildings and fabrics. This architectural transformation is generated, at the beginning, by a change in the modalities of using public space. As for the corral de comedias, the process is due to the sedentarization of the theatrical practice, which abandons the itinerant dimension of the street to move inside the buildings (such as private homes and palaces). The original corral de comedias was in fact set up inside an open place that could be covered, and this feature became permanent  over time, creating a new building type. Similarly, since the sixteenth century,  squares became the fundamental location of Spanish civic life as well as they hosted all sorts of political, religious and festive representations, but also the venue of executions. For this purpose, namely to allow people to watch such events, the squares were transformed, by raising temporary walls and walkways. In some cases, like Tembleque and San Carlos del Valle, they began to realize permanent continuous balconies, with solutions that seem to have followed the same morphological evolution of corrales de comedias. In both cases it was necessary to unify different elements (buildings or rooms) and connect them to each other, through a process of “knotting”, in order to create a new organism. Over time the physiognomy of the spaces, originally open,  assumed the permanent characters of a new type, closed and similar to the courtyard of a “palazzo”.

scholarly journals Short-term evolution of submarine canyon head morphologies in the NW Mediterranean: Blanes and Cap de Creus canyons

2021 ◽  
Author(s):  
Cecilia Cabrera ◽  
Ruth Durán ◽  
Pere Puig ◽  
Jorge Guillén ◽  
Araceli Muñoz ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Morphological Evolution ◽  
Submarine Canyon ◽  
Small Scale ◽  
Time Interval ◽  
Shelf Water ◽  
Short Term ◽  
Seafloor Morphology ◽  
Term Evolution ◽  
Nw Mediterranean

<p>Submarine canyons are morphological features found along continental margins that play a key role channeling and connecting sediment from continental shelves to the abyssal plains. The current morphological characterization of the Blanes and Cap de Creus canyon heads, located on the Catalan continental margin (NW Mediterranean Sea), has been recently conducted during the CRIMA cruise in September 2020 using high-resolution (4 m grid size) multibeam bathymetry data. These data have been compared with a previous dataset collected in 2004 during the ESPACE project to evaluate the morphological changes during this 16-year interval. Since these canyon heads are located at shallow water depths and at short distances from the shoreline, their short-term evolution is related to the sediment dynamics on the continental shelf.</p><p>A large-scale change in the seafloor morphology was observed in the Blanes canyon head, indicating the prevalence of erosion in the western canyon rim and non-deposition in the eastern rim. In the Cap de Creus canyon head, the excavation of pre-existing erosive structures was also evidenced in the southwestern canyon rim. These changes mainly happen in the area where the shelf is narrower, which coincide with the main zone of dense water advection along the shelf and toward the canyon interior. The different small-scale morphological evolution between both canyon heads seems to be related to the local geological characteristic of the subsurface deposits of the continental shelf. The Blanes canyon head incises a succession of relict (Holocene) sediment bodies that can act as a source of erodible sediments to the canyon, mainly during strong storms. The continental shelf in the vicinity of the Cap de Creus canyon head, however, is characterized by a rocky substratum (Paleozoic) with a limited sediment coverage and numerous erosive features that evidence relative sand starvation. This creates a greater erosive resistance, although the erosive character of strong storms and major dense-shelf water cascading events occurring during the studied time interval is evident. Additionally, small changes in the shelf bedforms indicate that such high-energetic oceanographic processes also modify the fine-scale seafloor morphology.</p><p>These results reveal that both submarine canyon heads are dynamic and sensitive to oceanographic processes that enhance the erosion and transport of sediment from the shelf into the canyon, particularly during energetic storms and dense shelf water cascading events. Nevertheless, their small-scale evolution seems to be closely related to the type of geological substrate of the shelf on which they are developing.</p><p>This study has received funding from the ABRIC (RTI2018-096434-B-I00) and CRIMA (RTI2018-095770-B-I00) Spanish Research Projects, the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No. 867471 and the Generalitat de Catalunya (2017 SGR-663 and -1588). This work is contributing to the ICM’s ‘Center of Excellence’ Severo Ochoa (CEX2019-000928-S). The authors thank the Secretaría General de Pesca and Tragsa for the 2004 ESPACE Project dataset.</p>

Peopleware

2011 ◽  
pp. 1-17 ◽  
Author(s):  
R. Ryan Nelson ◽  
Peter A. Todd
Keyword(s):  
Job Satisfaction ◽  
Information Technology ◽  
Best Practices ◽  
Relative Importance ◽  
Key Drivers ◽  
Develop Strategy ◽  
It Personnel ◽  
Management Work ◽  
Over Time

The hiring and retention of IT personnel has remained a top priority for managers given the increasingly important role that information technology plays in the success of virtually all companies today. In this chapter, through a series of case studies, we report on a set of best practices that are designed to help organizations develop strategy, recruit, hire, develop, compensate, and ultimately retain valued IT personnel. In addition, a model is presented that describes the key drivers of job satisfaction, and ultimately determine turnover. It is suggested that the relative importance of these drivers, which include the quality of management, work attributes, compensation, and career development, will change for employees over time. Therefore, managing these drivers using the identified best practices can significantly assist organizations in attracting and retaining IT personnel.

Morphological evolution of Cap Lopez Canyon (Gabon): Illustration of lateral migration processes of a submarine canyon

2013 ◽  
Vol 340 ◽  
pp. 49-56 ◽  
Author(s):  
Laurie Biscara ◽  
Thierry Mulder ◽  
Vincent Hanquiez ◽  
Vincent Marieu ◽  
Jean-Pierre Crespin ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Submarine Canyon ◽  
Lateral Migration

Millennial to annual volume changes in the Humber Estuary

2007 ◽  
Vol 463 (2079) ◽  
pp. 837-854 ◽  
Author(s):  
I.H Townend ◽  
Z.B Wang ◽  
J.G Rees
Keyword(s):  
Climate Change ◽  
Sustainable Management ◽  
Analytical Approach ◽  
Volume Changes ◽  
Accommodation Space ◽  
Morphological Model ◽  
Annual Volume ◽  
Humber Estuary ◽  
Annual Time ◽  
Over Time

Analysis of stratigraphic records and historic charts has allowed comparison of Holocene and historical rates of accommodation space change in the Humber Basin. Apparent rate differences are explained using a morphological model and an analytical approach to separate out the effect of differing forcing signals. This understanding is then used to construct a simple behavioural model of how estuary volumes change over time that is consistent over millennial to annual time-scales. Given the desire to promote the sustainable management of estuaries, the approach provides a means to identify the natural variability that should be anticipated. Distinguishing such signals from influences such as sea - level rise is also important for the proper attribution of impacts due to climate change.

scholarly journals Morfologia Urbana: Um exercício em torno do Castelo de Ourém

2020 ◽  
pp. 1665-1675
Author(s):  
André Donas-Botto ◽  
Jaqueline Pereira
Keyword(s):  
Aerial Photography ◽  
Morphological Evolution ◽  
Urban Morphology ◽  
Archaeological Sites ◽  
Urban Network ◽  
Over Time

The study of aerial photography through photointerpretation and photointerpretation of urban morphology is not new in Archaeology, although it is increasingly used to draw conclusions within this field. In addition to identifying possible archaeological sites, aerial photography is also a resource for reading urban morphologies. In fact, it is very useful for the perception of the evolution of the layout of an urban network. When observing a landscape - urban or not - we must always pay attention to its dynamism. Thus, through the detection of Isotopic, Isoaxial and Isocline transmissions, we propose to develop a proposal for the morphological evolution of the Medieval Nucleus of Ourém over time and cross this analysis with what is already known within archaeological reality.

Influence of morpho-evolution on the earthquake-induced mobility of the Albuñuelas landslide (Granada, Spain) 

2021 ◽  
Author(s):  
Mara Mita ◽  
Céline Bourdeau ◽  
Jose Delgado ◽  
Luca Lenti ◽  
Salvatore Martino
Keyword(s):  
Seismic Hazard ◽  
Seismic Waves ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
Signal Frequency ◽  
Landslide Mass ◽  
Landslide Slope ◽  
Geomorphological Evolution ◽  
First Time ◽  
Over Time

<p>The morphological evolution of landslide slopes is generally controlled by the combination of weathering, tectonics, gravity and river erosion. Among them, seismic shaking plays a fundamental role in landslide activity and mobility in high seismicity regions. It can result in important modifications of landslide geometry and consequently, of its response to external loadings. In particular, morphological changes in landslide slope can imply changes in the interactions between seismic waves and landslide mass, which could theoretically modify the hazard related to the earthquake-induced effects. This study aims at pointing out the effects of slope morpho-evolution on the long-term modification of earthquake-induced landslide dynamics, which is here quantified in terms of expected seismically induced displacements, considering unaltered seismic hazard conditions. The Albuñuelas landslide was selected, located in Andalusia (South Spain) which is one of the most seismic regions of Spain. This landslide is a large roto-translational process whose last earthquake-induced reactivation occurred during the 1884 Andalusia Earthquake (M<sub>w</sub> 6.5), causing relevant damages to the Albuñuelas village. Data available from field surveys and geophysical investigations, allowed to derive the current engineering-geological model of the landslide slope. According to the available geological and geomorphological data, the slope shape was back-deformed to reproduce the landslide geomorphological evolution sequence over time, until its first-time failure. The reconstructed sequence is consistent with a geomorphological evolution mainly driven by the combination of earthquake-induced re-activations and low rates of deformation caused by the intense incision of the Albuñuelas River, responsible for the valley deepening. 2D-dynamic stress-strain numerical simulations were performed on several stages of such sequence applying 17 equivalent signals derived following the LEMA_DES (Levelled-Energy Mutifrequential Analysis for Deriving Equivalent Signals) approach with an Arias Intensity of 0.1 m/s, according to the Andalusia regional seismic hazard. The outputs were expressed in terms of seismically induced displacements vs. characteristic periods diagrams, in order to highlight the role of signal frequency content as well as the effect of the landslide 2D-geometry (T<sub>l</sub>) and thickness (T<sub>s</sub>) on the resulting displacements. Since the morpho-evolution resulted in a progressive increasing of the landslide mass length and its dislodgment into several blocks since the first-time failure, the landslide mobility was analysed over time at each single-block scale. The comparison revealed a not neglectable modification of the Albuñuelas landslide susceptibility to the local seismic hazard over time, highlighting the necessity to understand the mechanisms driving the natural system evolution to provide more reliable earthquake-induced hazard scenarios.</p>

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