Seabed mapping of tropical tidal channels, NE Brazil

2020 ◽  
Author(s):  
Andressa Lima Ferreira ◽  
Helenice Vital ◽  
Moab Gomes ◽  
Andre Aquino da Silva ◽  
Yoe Perez
Keyword(s):  
Sea Level ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Water Dynamics ◽  
Central Portion ◽  
Tidal Channel ◽  
Tidal Channels ◽  
The South ◽  
Average Width ◽  
Radar Images

<p>The Galinhos-tidal-channel system is located in the Brazilian equatorial margin, northeastern coast of Rio Grande do Norte State. The economic importance of the region began around 1600s and continues until today with salt exports, later shrimp farms, handmade fishing, oil and gas industry, ecotourism and wind energy. A spit, behind which an intricate system of tidal channels has developed, with practically absent riverine influence, characterizes the area. The integration of interferometric sonographic data (total of 4.7 km<sup>2</sup>), calibrated with sediment samples, and radar images were used to map geomorphological features on the area.  The ALOS PALSAR image, allowed to integrate the altitude information of the emerged and submerged portions, resulting in efficient method for coastal flooding areas and substrate mapping. The sonographic study allowed recognizing bedforms, which are important morphological elements that influence water and sediment discharge. Four main types of submerged geomorphic units were identified: a) 2D sandy dunes, b) 3D sandy dunes c) muddy flatbeds and d) irregular beds. Dunes were classified according to their size into small, medium and large. Bathymetric data revealed that depths from 2 to 8 m along the area. The main tidal channel Galinhos has a width of 900m, 12km long, irregular bottom, and asymmetrical margins. The Pisa Sal tidal channel has an average width of 150m and 3km long, U shaped cross-section, slight asymmetric margins and slightly irregular bottom. Deepest parts occurs close to its mouth (between 6,5m and 8m), gradually decreasing until they reach 5m on its inner portion. The Tomaz tidal channel, until to central portion has an asymmetrical bed with the highest depths on its right side reaching 7m. Its left side range from 5.5m to 6m. In the south portion, this channel becomes shallower (5m) and its asymmetry is reversed. After splitting the channel width is reduced from 260m to 140m and the bottom becomes less irregular and flat sometimes. In this portion, the highest depths reach 7m. The data made it possible to identify the regions of higher and lower altitudes using as reference the mean sea level. Altitudes throughout the region range from 0 (sea level) to 20m and come from local topographic elevation. The south portion concentrates altitudes above 10m and the lower regions are located in the central portion of the area. The central portion is the flattest and this behaviour extends over 5km to the dunes located in the Galinhos spit, when the altitudes exceed values above 10m. The Galinhos spit integrates an area with average altitude ranging from two to seven m. Flooded or wet regions were well delimited due to non-penetration or absorption of electromagnetic energy (low frequency) when it interacts with the water dynamics; however, results are better where the depth is higher than 3m.</p>

scholarly journals Entrepreneurial orientation and corporate governance structures at the firm level in the South African oil and gas industry

2013 ◽  
Vol 11 (1) ◽  
Author(s):  
Vincent B. Molokwu ◽  
Jose Barreria ◽  
Boris Urban
Keyword(s):  
Corporate Governance ◽  
South African ◽  
Entrepreneurial Orientation ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Board Members ◽  
Governance Structures ◽  
The South ◽  
Firm Level ◽  
Gas Industry

Orientation: Corporate governance systems (CGS) have been observed as one of the most important structures and mechanisms that regulate the relationships between executives and shareholders. By having well-defined and established CGS, company board members and executives are able to shape company vision and increase managerial commitment towards formulating strategies that espouse an entrepreneurial orientation (EO). Firms with high levels of EO tend to be innovative and encourage creative initiatives in new products and technology developments. Research purpose: In an emerging economy such as South Africa, one of the primary goals of an organisation is growth and good governance, which can be achieved through wellgoverned structures and continuous innovation in the face of challenges. This study identified potential links between the multidimensional constructs of CGS and EO at the firm level in the South African oil and gas industry.Motivation for the study: One of the greatest challenges faced by organisations when implementing CGS is to ensure compliance.Research design, approach and method: Board members and senior decision-makers were surveyed in the South African oil and gas industry, using a structured questionnaire. A series of correlational analyses were used to determine the strength of relationships between the dimensions of EO and CGS.Main findings: By drawing extensively on existing theory on EO, this study found that the different dimensions of CGS have a significant and positive relationship with each of the EO dimensions – innovation, risk-taking and proactiveness.Practical/managerial implications: Corporate boards supportive of entrepreneurship must provide appropriate reward systems, top management support, explicit goals and appropriate organisational values which signal to employees that entrepreneurial behaviour action is desirable. Practitioners should scrutinise their governance structures in their organisations to ensure an alignment with EO practices.Contribution/value-add: Generally, research on EO and governance in Africa as a whole may be considered as valuable, as very few empirical studies have been previously conducted which focus on the nexus of CGS and EO. The study is one of the first to conduct empirical research on EO and CGS in an emerging market and unique industry context – the South African oil and gas industry.

scholarly journals Interconnected Accommodation Space Controls Between Sand-Charged Shallow Tidal Channels and Wind-Wave Truncated Tidal Flats During Latest-Holocene Sea Level Rise (~3.0 m) in a Large Mesotidal Wave-Dominated Estuary, Grays Harbor, Washington, USA

2018 ◽  
Vol 10 (3) ◽  
pp. 26 ◽  
Author(s):  
Curt D Peterson ◽  
Sandy Vanderburgh
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Flat ◽  
Wind Wave ◽  
Tidal Flats ◽  
Tidal Channel ◽  
Tidal Channels ◽  
Accommodation Space ◽  
Global Sea Level

The late-Holocene (5–0 ka) record of accommodation space controls of tidal channel and tidal flat deposition in the shallow mesotidal wave-dominated Grays Harbor estuary (236 km2 surface area) was investigated in previously reported drill cores (n=15) and new vibracores (n=20), reaching 3–10 m depth subsurface. Continuous vibracore facies sequences (3–4 m depth subsurface) discriminate between tidal channel and tidal flat deposition and demonstrate responses of both depositional settings to interseismic uplift and coseismic subsidence (1±0.5 m vertical) from cyclic neotectonic forcing (200–800 yr recurrence intervals) in the Cascadia subduction zone. Vibracore channel samples, at 0.5 m or 1.0 m depth intervals, were analyzed for sediment grain size (sample n=124) and sand source mineralogy (sample n=67). The mean and standard deviation of sand size in the sand fraction is 175±x34 1σ µm. Sediment 14C dates (n=29) range from 376 to 6,579 median calyrBP and establish long-term sedimentation rates in subtidal channel accretionary banks (average 4.2 m ka-1), intertidal channel accretionary banks (average 3.7 m ka-1), and tidal flats (average 1.1 m ka-1). Tidal channel accretionary bank deposition largely reflects reworking of pre-existing estuary deposits. Long-term total basin sediment accumulation rates (232x106 m3 ka-1) are tied to rates of net sea level rise (1.0 m ka-1) or increasing basin accommodation space. In latest Holocene time (3–0 ka) littoral sand import (117x106 m3 ka-1) was about twice as large as the retention of river sand and mud in the estuary. The selective export of winnowed mud from the estuary provided the necessary accommodation space for the import of littoral sand in latest-Holocene time. Shallow intertidal settings in Grays Harbor (60% by surface area) are maintained by self-regulating conditions of channelized sediment import, wind-wave erosion of tidal flats, and tidal prism forcing of tidal channel discharge. Hind-casted wind-wave bottom orbital velocities (>20 cm sec-1) are sufficient to truncate tidal flat elevations to lower-intertidal levels, which maintain substantial tidal prism volumes (modern MLLW-MHHW ~6.1 x 108 m3) and associated tidal channel discharge in the shallow estuary. Net sediment deposition in the estuary is controlled by the interaction of limiting accommodation space controls in the tidal flats and tidal channels. The balance between sediment supply, energy of sediment transport/resuspension, and sediment export has survived small changes in relative sea level (1±0.5 m) from cyclic neotectonic forcing. However, the prehistoric (natural) balance could be altered by future anthropogenic impacts from sustained global sea level rise (> 1.5 m during the next century) or diminished wind-wave fetch distances, which could result from tidal flat diking/filling or uncontrolled spread of non-native invasive stabilizing sea grass (Spartina). In this regard, the susceptibilities of prehistorically-balanced sediment dynamics in Grays Harbor serve as warning for other similar mesotidal wave-dominated estuaries that could be impacted by future global sea level rise, changing sediment inputs, and/or tidal flat diking/filling, which could reduce intertidal habitat and associated ecosystem functions. 

Deployment of Digital NDT Solutions in the Oil and Gas Industry

2020 ◽  
Vol 78 (7) ◽  
pp. 861-868
Author(s):  
Casper Wassink ◽  
Marc Grenier ◽  
Oliver Roy ◽  
Neil Pearson
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry

What Does Rent Give to Federal Budget (on the Russia's Budget Dependence upon "Oil Dollars")

2004 ◽  
pp. 51-69 ◽  
Author(s):  
E. Sharipova ◽  
I. Tcherkashin
Keyword(s):  
Oil And Gas ◽  
Strong Dependence ◽  
Oil Prices ◽  
Federal Budget ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Resource Rent ◽  
Tax Legislation ◽  
Russian Economy ◽  
The Government

Federal tax revenues from the main sectors of the Russian economy after the 1998 crisis are examined in the article. Authors present the structure of revenues from these sectors by main taxes for 1999-2003 and prospects for 2004. Emphasis is given to an increasing dependence of budget on revenues from oil and gas industries. The share of proceeds from these sectors has reached 1/3 of total federal revenues. To explain this fact world oil prices dynamics and changes in tax legislation in Russia are considered. Empirical results show strong dependence of budget revenues on oil prices. The analysis of changes in tax legislation in oil and gas industry shows that the government has managed to redistribute resource rent in favor of the state.

The Political Economy of Power: Approaches to the Analysis of Relationships between the State and Business in Russia

2011 ◽  
pp. 19-33
Author(s):  
A. Oleinik
Keyword(s):  
Oil And Gas ◽  
Road Construction ◽  
Oil And Gas Industry ◽  
Retail Trade ◽  
Business Community ◽  
The Political ◽  
Economic Power ◽  
Gas Industry ◽  
The Road ◽  
Ruling Elites

The article deals with the issues of political and economic power as well as their constellation on the market. The theory of public choice and the theory of public contract are confronted with an approach centered on the power triad. If structured in the power triad, interactions among states representatives, businesses with structural advantages and businesses without structural advantages allow capturing administrative rents. The political power of the ruling elites coexists with economic power of certain members of the business community. The situation in the oil and gas industry, the retail trade and the road construction and operation industry in Russia illustrates key moments in the proposed analysis.

Consideration of Geopolitical Challenges within the Analysis of Geoenvironmental Risks for Oil and Gas Development of the Russian Arctic

2019 ◽  
Vol 16 (6) ◽  
pp. 50-59
Author(s):  
O. P. Trubitsina ◽  
V. N. Bashkin
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Optimal Operation ◽  
The Arctic ◽  
Stage Model ◽  
Oil And Gas Development ◽  
Gas Industry ◽  
The Impact ◽  
Further Development ◽  
Geopolitical Risks

The article is devoted to the consideration of geopolitical challenges for the analysis of geoenvironmental risks (GERs) in the hydrocarbon development of the Arctic territory. Geopolitical risks (GPRs), like GERs, can be transformed into opposite external environment factors of oil and gas industry facilities in the form of additional opportunities or threats, which the authors identify in detail for each type of risk. This is necessary for further development of methodological base of expert methods for GER management in the context of the implementational proposed two-stage model of the GER analysis taking to account GPR for the improvement of effectiveness making decisions to ensure optimal operation of the facility oil and gas industry and minimize the impact on the environment in the geopolitical conditions of the Arctic.The authors declare no conflict of interest

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