scholarly journals Novel Bathymetry of Lake Afdera Reveals Fault Structures and Volcano-Tectonic Features of an Incipient Transform Zone (Afar, Ethiopia)

2021 ◽  
Vol 9 ◽  
Author(s):  
Jean-Charles Schaegis ◽  
Valentin Rime ◽  
Tesfaye Kidane ◽  
Jon Mosar ◽  
Ermias Filfilu Gebru ◽  
...  
Keyword(s):  
Afar Depression ◽  
Nodal Basin ◽  
Bathymetric Data ◽  
The North ◽  
Transfer Zones ◽  
Fault Structures ◽  
Bathymetric Map ◽  
Endorheic Lake ◽  
Tectonic Features ◽  
Transfer Zone

Lake Afdera is a hypersaline endorheic lake situated at 112 m below sea-level in the Danakil Depression. The Danakil Depression is located in the northern part of the Ethiopian Afar and features an advanced stage of continental rifting. The remoteness and inhospitable environment explain the limited scientific research and knowledge about this lake. Bathymetric data were acquired during 2 weeks expeditions in January/February 2016 and 2017 using an easily deployable echosounder system mounted on an inflatable motorized boat. This study presents the first complete bathymetric map of the lake Afdera. Bathymetric results show that the lake has an average depth of 20.9 m and a total volume of 2.4 km3. The maximum measured depth is 80 m, making Lake Afdera the deepest known lake in Afar and the lowest elevation of the Danakil Depression. Comparison with historical reports shows that the lake level did not fluctuate significantly during the last 50 years. Two distinct tectonic basins to the north and the south are recognized. Faults of different orientations control the morphology of the northern basin. In contrast, the southern basin is affected by volcano-tectonic processes, unveiling a large submerged caldera. Comparison between the orientation of faults throughout the lake with the regional fault pattern indicates that the lake is part of two transfer zones: the major Alayta–Afdera Transfer Zone and the smaller Erta Ale–Tat’Ali Transfer Zone. The interaction between these Transfer Zones and the rift axis forms the equivalent of a developing nodal basin which explains the lake’s position as the deepest point of the depression. This study provides evidence for the development of an incipient transform fault on the floor of the Afar depression.

Synthetic Transfer Zone Characterization Using Seismic Attributes: An Example from the Parihaka Fault System in the Taranaki Basin, New Zealand.

2021 ◽  
pp. 1-73
Author(s):  
Pierre Karam ◽  
Shankar Mitra ◽  
Kurt Marfurt ◽  
Brett M. Carpenter
Keyword(s):  
New Zealand ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Seismic Attributes ◽  
Fault System ◽  
Structural Interpretation ◽  
Transfer Zones ◽  
Seismic Characterization ◽  
The Individual ◽  
Transfer Zone

Synthetic transfer zones develop between fault segments which dip in the same direction, with relay ramps connecting the fault blocks separated by the different fault segments. The characteristics of the transfer zones are controlled by the lithology, deformation conditions, and strain magnitude. The Parihaka fault is a NE-SW trending set of three major en-echelon faults connected by relay ramps in the Taranaki Basin, New Zealand. The structure in the basin is defined by extension during two episodes of deformation between the late Cretaceous and Paleocene and between the Late Miocene and recent. To better understand the evolution of a synthetic transfer zone, we study the geometry and secondary faulting between the individual fault segments in the Parihaka fault system using structural interpretation of 3D seismic data and seismic attributes. This interpretation allows for a unique application of seismic attributes to better study transfer zones. Seismic attributes, including coherence, dip, and curvature are effective tools to understand the detailed geometry and variation in displacement on the individual faults, the nature of secondary faulting along the transfer zones, and the relationship between the faults and drape folds. Seismic characterization of the fault system of Miocene to Pliocene age horizons highlights variations in the degree of faulting, deformation, and growth mechanism associated with different stages of transfer zone development. Coherence, dip, and curvature attributes show a direct correlation with structural parameters such as deformation, folding, and breaching of relay ramps.. All three attributes enhance the visualization of the major and associated secondary faults and better constrain their tectonic history. The observed correlation between seismic attributes and structural characteristics of transfer zones can significantly improve structural interpretation and exploration workflow.

Tidal asymmetry in the Sylt-Romo Bight, south-eastern North Sea

2020 ◽  
Author(s):  
Vera Fofonova ◽  
Alexey Androsov ◽  
Lasse Sander ◽  
Ivan Kuznetsov ◽  
Felipe Amorim ◽  
...  
Keyword(s):  
Circulation Pattern ◽  
Tidal Energy ◽  
Tidal Asymmetry ◽  
Residual Circulation ◽  
Linear Processes ◽  
Bathymetric Data ◽  
Full Analysis ◽  
Bathymetric Map

<p> </p><p>The study is dedicated to the tidal dynamics in the Sylt-Rømø Bight with a focus on the non-linear processes. The FESOM-C model was used as the numerical tool, which works with triangular, rectangular or mixed grids and is equipped with a wetting/drying option. As the model’s success at resolving currents largely depends on the quality of the bathymetric data, we have created a new bathymetric map for an area based on recent studies of Lister Deep, Lister Ley, and the Højer and Rømø Deep areas. This new bathymetric product made it feasible to work with high resolution grids (up to 2 m in the wetting/drying zone). As a result, we were able to study the tidal energy transformation and the role of higher harmonics in the domain in detail. The tidal ellipses, maximum tidally-induced velocities, energy fluxes and residual circulation maps were constructed and analysed for the entire bight. Additionally, tidal asymmetry maps were introduced and constructed. The full analysis was performed on two grids with different structures and showed a convergence of the results as well as fulfillment of the energy balance. The tidal residual circulation and asymmetric tidal cycles largely define the circulation pattern, transport and accumulation of sediment and the distribution of bedforms in the bight, therefore the results are necessary and useful benchmarks for further studies in the area, including baroclinic and sediment dynamics investigations.</p>

scholarly journals What 2‐D multichannel seismic and multibeam bathymetric data tell us about the North Sumatra wedge structure and coseismic response

Tectonics ◽  
2015 ◽  
Vol 34 (9) ◽  
pp. 1910-1926 ◽  
Author(s):  
M. C. G. Frederik ◽  
S. P. S. Gulick ◽  
J. A. Austin ◽  
N. L. B. Bangs ◽  
Udrekh
Keyword(s):  
Bathymetric Data ◽  
The North ◽  
Wedge Structure ◽  
North Sumatra ◽  
Coseismic Response

scholarly journals TINJAUAN GEOLOGI KELAUTAN PERAIRAN SEMENANJUNG MURIA TERHADAP RENCANA TAPAK KONSTRUKSI PLTN

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ediar Usman ◽  
Wayan Lugra
Keyword(s):  
Nuclear Energy ◽  
Seismic Interpretation ◽  
North Coast ◽  
Quaternary Sediment ◽  
Fault Structure ◽  
Reflection Seismic ◽  
The North ◽  
Central Java ◽  
Fault Structures ◽  
Central Java Province

Semenanjung Muria terletak di pantai utara Kabupaten Jepara, Provinsi Jawa Tengah. Daerah ini akan dikembangkan menjadi daerah tapak Pembangkit Listrik Tenaga Nuklir (PLTN). Secara geologi, di daerah ini berkembang berbagai fenomena geologi seperti struktur sesar, gunungapi dan kegempaan. Berdasarkan hasil interpretasi rekaman seismik pantul di perairan Semenanjung Muria menunjukkan adanya struktur sesar pada penampang Lintasan L-1 dan L-3. Struktur sesar tersebut terbentuk pada Sekuen B dan di bawah Sekuen A. Adanya struktur sesar di laut tersebut perlu mendapat perhatian dalam perencanaan tapak kontruksi PLTN Muria, sehingga aspek yang dapat membahayakan konstruksi dapat diperhitungkan sebelumnya terhadap perencanaan kekuatan dan stabilitas konstruksi. Kata kunci : sesar, seismik pantul, perencanaan konstruksi, Semenanjung Muria. Muria Peninsula is located at the north coast of Jepara District, Central Java Province. This area will be developed for the foundation of Nuclear Energy Electrics Powers Station. Geologically, the study area has some geological phenomena such as fault structures, earthquakes and volcanisms. Based on seismic interpretation the Muria Peninsula waters shows the occurence of faults on L-1 and L-3. The fault structure formed at Sequence B and under Sequence A as a Quaternary sediment. These faults are seemly the continuation of faults present on land. Therefore, the construction of Muria station should be considered regarding the occurrence of these faults especially in the planning of stability and strength of foundation. Keyword : faults, reflection seismic, planning of construction, Muria Peninsula.

Mapping Submerged Landscapes Using Multibeam Bathymetric Data: a case study from the north coast of Ireland

2011 ◽  
Vol 40 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Kieran Westley ◽  
Rory Quinn ◽  
Wes Forsythe ◽  
Ruth Plets ◽  
Trevor Bell ◽  
...  
Keyword(s):  
North Coast ◽  
Bathymetric Data ◽  
The North

scholarly journals Using the geodetic and hydroacoustic measurements to investigate the bathymetric and morphometric parameters of Lake Hancza (Poland)

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Dariusz Popielarczyk ◽  
Tomasz Templin ◽  
Michał Łopata
Keyword(s):  
Digital Elevation Model ◽  
Measurement Techniques ◽  
Morphometric Parameters ◽  
Great Opportunity ◽  
Single Beam ◽  
Bathymetric Data ◽  
Digital Elevation ◽  
Hydroacoustic Measurements ◽  
Elevation Model ◽  
Bathymetric Map

Abstract Most of the inland lakes do not have up-to-date bathymetry. However, a significant progress in surveying technologies creates a possibility to quickly and accurately describe the underwater environment. Modern geodetic and global positioning techniques integrated with hydroacoustic systems provide a great opportunity to study the bottom shape with high resolution. Our study presents a reliable methodology for investigation of bathymetry and morphometric parameters with the use of GNSS positioning techniques and single beam echosounder. The research was implemented on the deepest, glacial reservoir in the central part of European Depression - Lake Hancza. Direct hydroacoustic and geodetic measurements completed by sediment study were conducted by the authors in 2010-2013. After performing a field survey the Digital Elevation Model was constructed and the new bathymetric map and morphometric card were elaborated. The maximum depth was confirmed to be 105.55 m. The final conclusions show that the available bathymetric data and morphometric parameters of lakes are highly dependent on the research methodology used, the precision and accuracy of measurement techniques, proper water level determination, digital elevation model and bathymetric map elaboration processes.

scholarly journals Igneous Activity and Structural Development of the Mianhua Terrace, Offshore North Taiwan

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 303
Author(s):  
Jih-Hsin Chang ◽  
Eason Yi-Cheng Yang ◽  
Ho-Han Hsu ◽  
Tzu-Ting Chen ◽  
Char-Shine Liu ◽  
...  
Keyword(s):  
High Amplitude ◽  
Shelf Break ◽  
Normal Faults ◽  
Structural Development ◽  
Bathymetric Data ◽  
Orogenic Wedge ◽  
Igneous Activity ◽  
Fault Structures ◽  
Volcanic Influence ◽  
Northern Taiwan

Using bathymetric and multichannel seismic (MCS) data, we explored the volcanic influence on the bathymetric and stratigraphic features of the Mianhua Terrace. The Mianhua Terrace occupies the marine counterpart of the Northern Taiwan Volcanic Zone (NTVZ) along the collapsed Taiwan orogenic wedge and is dominated by post-collisional magmatism and extensional structures. The bathymetric data showed several semicircular-shaped features near the shelf break. The MCS profiles showed that the Pleistocene unconformity buried beneath the Mianhua Terrace is partly difficult to observe due to seafloor multiples, suggesting that the seafloor is dominated by physically hard lithology, probably volcanic lavas. We interpreted the high-amplitude reflectors and their projected seafloor relief as intrusive sills and associated extrusive edifice. Similarly, we interpreted high-amplitude reflectors in the vicinity of normal faults as intrusive sills emplaced and facilitated by fault structures. A volcanic or hydrothermal mound was also recognized. We propose that the Mianhua Terrace is a breached ramp in a transfer zone between the tips of two successive normal faults along the shelf break. Once the fault tips reactivate and extend toward each other, the Mianhua Terrace may continue to collapse, leading to catastrophic volcanic or associated hydrothermal events.

scholarly journals Submarine Evidence of the Late Weichselian Maximum Extent and the Little Ice Age (LIA) Glacier Limits in the St. Jonsfjorden Region (Svalbard)

2010 ◽  
Vol 3 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Michał Król ◽  
Marek Grześ ◽  
Ireneusz Sobota ◽  
Marcin Ćmielewski ◽  
Tomasz Jaworski
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Main Stream ◽  
Tidewater Glaciers ◽  
Cooling Period ◽  
Bathymetric Data ◽  
The North ◽  
Late Weichselian ◽  
Marginal Zones ◽  
Shaded Relief

Abstract The paper presents the results of bathymetric mapping of selected tidewater glaciers in the St. Jonsfjorden (Svalbard) between 2004 and 2007. We also used the bathymetric data collected by the Norwegian Hydrographic Service (NHS) as well as the shaded relief images based on them. The most clearly visible traces in submarine marginal zones of the glaciers come from the Little Ice Age (LIA), i.e. the cooling period which in the area of St. Jonsfjorden might have ended no later than about 1900. At the beginning of the 20th century, i.e. during a warm period, the glaciers of St. Jonsfjorden reached their maximums. The youngest traces in the seafloor of the fjord and the bays date from this period, similar to the case of the land marginal zones. In front of the cliff of the Dahl Glacier there is a clearly visible zone of submarine moraines. It finishes exactly along the line of the LIA maximum. The sea-floor relief of the fjord and bays shows traces which we interpret as having been formed during the Late Weichselian (13-10 ka B.P.). At that time, the Dahl Glacier advanced onto the northern part of Hermansenøya; its main stream passed to the north of the island. Simultaneously, the Konow-Osborne Glacier terminated 2 to 4 km from the fjord mouth, leaving about 15 km2 of the fjord ice-free.

scholarly journals Numerical analysis of the transport of brine in the Odra River downstream of a mine's discharge

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Szymon Zieliński ◽  
Stanisław Kostecki ◽  
Paweł Stefanek
Keyword(s):  
Copper Ore ◽  
Mine Waters ◽  
Bathymetric Data ◽  
The North ◽  
Safe Level ◽  
North Eastern ◽  
Odra River ◽  
Point Data ◽  
The Impact ◽  
Inflowing Water

Abstract The mining of underground deposits causes the inflow of water to workings and the necessity of pumping them to the surface. The mining plant of KGHM Polska Miedź S.A. extracts copper ore in plant branches with different hydrogeological conditions. The inflowing water into the workings is characterised by variable mineralisation, which depends on the location of the branch. In the south-western part of the deposit, a low-mineralised stream with a relatively high flow rate can be observed, while the outflow of highly saline waters occurs in the north-eastern branch. Despite the activities undertaken that aim at using the pumped-off mine waters industrially, it is necessary to deposit them into the Odra River. Reducing the environmental impact on the Odra River is one of KGHM's goals, which is being implemented by stabilising its salt concentration at a safe level. The paper presents the results of a 3D simulation of brine plume propagation based on a numerical model of advection–diffusion and turbulent flow. Bathymetric data from a section of the river approximately 500 m long and point data from an Odra water quality test were used to develop and validate the model. The paper discusses the types of factors that minimise the impact of brine discharge. The developed model will be used in the future to propose solutions that accelerate the mixing of mine waters with the waters of the Odra River.

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