Autopsy of a reservoir: Facies architecture in a multidam system, Elwha River, Washington, USA

2019 ◽  
Vol 131 (11-12) ◽  
pp. 1794-1822 ◽  
Author(s):  
Laurel E. Stratton ◽  
Gordon E. Grant

AbstractThe 2011–2014 removal of two large dams on the Elwha River, Washington State, the largest dam removal yet completed globally, created extensive cutbank exposures of reservoir sediments, allowing the first characterization of the facies architecture of sediments through direct observation in reservoirs worldwide and providing an unparalleled opportunity to assess the relationship between environmental influences, such as changes in sediment supply, and their expression in the stratigraphic record. Using a combination of facies description from observation of 49 measured sections and >100 exposures and analysis of digital elevation models and historic aerial photographs, we delineated the characteristic depositional zones of each reservoir and mapped the evolution of the subaerial delta over the life span of the reservoir. Former Lake Mills, the younger, upstream reservoir, was characterized by a tripartite, subaerial Gilbert-style delta that prograded >1 km into the main reservoir from 1927 to 2011. Sediments were composed of coarse-grained topset beds, steeply dipping foreset beds, and a fine-grained, gently dipping prodelta. While individual event horizons were discernible in fine-grained sediments of former Lake Mills, their number and spacing did not correspond to known drawdown or flood events. Former Lake Aldwell, impounded from 1913 to 2011, was initially defined by the rapid progradation of a Gilbert-style, subaerial delta prior to the upstream completion of Glines Canyon Dam. However, the 1927 closure of Glines Canyon Dam upstream caused the delta to evolve to a fine-grained, mouth-bar–type delta indicative of low, finer-grained sediment. This evolution, combined with a previously unrecognized landslide deposit into the upper delta plain, suggests that understanding the exogenic influences on reservoir sedimentation is critical to interpretation and prediction of the sedimentation within individual systems.

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.


2017 ◽  
Vol 43 (2) ◽  
pp. 654
Author(s):  
A. Koutsios ◽  
N. Kontopoulos ◽  
D. Kalisperi ◽  
P. Soupios ◽  
P. Avramidis

Fine and coarse grained lithofacies and depositional environments were distinguished in Selinous River delta plain, from sediment cores using an Eijkelkamp percussion corer with barrel windows. The sedimentary sequence of deltaic plain deposits of Selinous River mostly consists of fine lithofacies interbedded occasionally with conglomerate facies. Fine grained lithofacies based on sediment types, structure, color, as well as contact depths and bed characteristics were interpreted as floodplain, crevasse splay, back swamp / fresh water swamp, permanent shallow fresh water lake and ephemeral fresh water lake facies. The coarse grained lithofacies consists of pebble - conglomerates and were interpreted as paleochannels. The Time-Domain Electromagnetic technique, (TEM) was applied in order to define the spatial distribution of lenses of conglomerates, palaeochannels and fine grained sedimentary material to be recognised, at a depth up to 35m. Both the sedimentological and geophysical approaches, in combination with the available geological and geomorphological data of the area, can provide information about the evolution, existence and the geometry of paleochannels of the Selinous River flood plain, and the paleoenvironment of the area of the ancient Helike.


1999 ◽  
Vol 28 ◽  
pp. 59-66 ◽  
Author(s):  
Jane K. Hart

AbstractDifferent types of fast ice flow (both spatial and temporal) in valley glaciers (surging glaciers, tidewater glaciers and deforming-bed glaciers) and ice sheets (ice streams and deforming-bed ice-sheet flow) are discussed briefly. Although there are unlikely to be any specific individual landforms associated with fast ice flow, there may be landform assemblages.At valley glacier scale, it is suggested that there are two landform assemblages: (1) an ice-thrust type, dominated by bulldozed push moraines and hummocky moraines (associated with glaciers with a high supraglacial sediment supply, a coarse-grained substrate and a coarse-grained proglacial sediment wedge); and (2) a bed-flow type dominated by “squeeze” push moraines, flutes and drumlins (associated with glaciers with a low supra- glacial sediment supply and fine-grained substrate). The ice-thrust type alone is only associated with discontinuous fast flow (on both rigid and deforming beds); whilst the bed-flow type is associated with both continuous and discontinuous fast flow.It is suggested that these two landform assemblages may also be indicative of fast ice flow at ice-sheet scale, in particular the bed-flow style. If that is the case, then discontinuous fast ice flow may be indicated by the ice-thrust landform assemblage and the bed-flow style where drumlins are present.It is also suggested that specific evidence for ice streams includes the distinctive land-form assemblages within valley or fan-like locations, and a predictable pattern of velocity reflected by drumlin elongation ratios.


2021 ◽  
Vol 9 (11) ◽  
pp. 289-301
Author(s):  
Koffi Chiaye Larissa ◽  
◽  
Djeya Kouame Leger ◽  
Douzo Jolie Wanesse Danielle ◽  
Monde Sylvain ◽  
...  

The KL block studies was carried out the eastern part of the San Pedro margin, it has an area of 2034 km2 with a water depth varying from 500 to 2750 m with two probings (K1 and K2).The objective of this work is to carry out a biostratigraphic and paleoenvironmental study based on the associations of planktonic and palynomorphicmicrofauna in the formations of the KL block boreholes. From a lithological point of view, the base of the boreholes generally comprises alternating limestone and argillite, very fine to fine grained quartz sandstone. Its upper part is overlain by claystoneinterbedded with limestone, silstone and siliceous cemented sandstone and alternating claystone, medium to coarse grained sand and siliceous cemented quartz sandstone. The Albian is determined by the presence of the species Ticinellamadecassiana. The Cenomanian is identified by the micropalaeontological assemblages composed of Globigerinelloides spp., Guembelitria spp., Hedbergella spp., Hedbergelladelrioensis, Globigerinelloides bentonensisandLoeblichella cf. hessi. The Turonian is based mainly on the species Hedbergellaplanispira, Heterohelixmoremani and Whiteinella archaeocretacea. The Early Senonian is characterized by associations of species (Hedbergellasp, Hedbergella cf. delrioensis, Buliminacrassa and Whiteinella baltica) and palynomorphs (Proteaciditestienabaensis, Odontochitinacostata, Odontochitinaporiferaand Tricolpites sp). The roof of the Campanian is known by the association of the palynomorph (Trichodinium castanae) and the microfossil (Gaudryina cretacea) The Maastrichtian is highlighted by the associations composed of species Rzehakina epigona fissistomata, Rzehakina minima, Plectina lenis, Reophax duplex, Reophax pilulifera, Reophax globosus, Gaudryina pyramidata and Afrobolivina afra) and palynomorphic species (Andalusiella gabonensis, Cerodinium granulostriatum and Palaeocystodinium australinium). All the micropalaeontological data coupled with those of the microfaunas make it possible to envisage a depositional environment of the internal platform type with continental influence on an external platform.


2014 ◽  
Vol 9 ◽  
Author(s):  
Shalom Lappin

Classical intensional semantic frameworks, like Montague’s Intensional Logic (IL), identify intensional identity with logical equivalence. This criterion of co-intensionality is excessively coarse-grained, and it gives rise to several well-known difficulties. Theories of fine-grained intensionality have been been proposed to avoid this problem. Several of these provide a formal solution to the problem, but they do not ground this solution in a substantive account of intensional difference. Applying the distinction between operational and denotational meaning, developed for the semantics of programming languages, to the interpretation of natural language expressions, offers the basis for such an account. It permits us to escape some of the complications generated by the traditional modal characterization of intensions.


Author(s):  
Wang Zheng-fang ◽  
Z.F. Wang

The main purpose of this study highlights on the evaluation of chloride SCC resistance of the material,duplex stainless steel,OOCr18Ni5Mo3Si2 (18-5Mo) and its welded coarse grained zone(CGZ).18-5Mo is a dual phases (A+F) stainless steel with yield strength:512N/mm2 .The proportion of secondary Phase(A phase) accounts for 30-35% of the total with fine grained and homogeneously distributed A and F phases(Fig.1).After being welded by a specific welding thermal cycle to the material,i.e. Tmax=1350°C and t8/5=20s,microstructure may change from fine grained morphology to coarse grained morphology and from homogeneously distributed of A phase to a concentration of A phase(Fig.2).Meanwhile,the proportion of A phase reduced from 35% to 5-10°o.For this reason it is known as welded coarse grained zone(CGZ).In association with difference of microstructure between base metal and welded CGZ,so chloride SCC resistance also differ from each other.Test procedures:Constant load tensile test(CLTT) were performed for recording Esce-t curve by which corrosion cracking growth can be described, tf,fractured time,can also be recorded by the test which is taken as a electrochemical behavior and mechanical property for SCC resistance evaluation. Test environment:143°C boiling 42%MgCl2 solution is used.Besides, micro analysis were conducted with light microscopy(LM),SEM,TEM,and Auger energy spectrum(AES) so as to reveal the correlation between the data generated by the CLTT results and micro analysis.


2017 ◽  
Author(s):  
Kathryn Grace De Rego ◽  
◽  
Brett Eaton ◽  
J. Wesley Lauer ◽  
Marwan Hassan

Author(s):  
Zhuliang Yao ◽  
Shijie Cao ◽  
Wencong Xiao ◽  
Chen Zhang ◽  
Lanshun Nie

In trained deep neural networks, unstructured pruning can reduce redundant weights to lower storage cost. However, it requires the customization of hardwares to speed up practical inference. Another trend accelerates sparse model inference on general-purpose hardwares by adopting coarse-grained sparsity to prune or regularize consecutive weights for efficient computation. But this method often sacrifices model accuracy. In this paper, we propose a novel fine-grained sparsity approach, Balanced Sparsity, to achieve high model accuracy with commercial hardwares efficiently. Our approach adapts to high parallelism property of GPU, showing incredible potential for sparsity in the widely deployment of deep learning services. Experiment results show that Balanced Sparsity achieves up to 3.1x practical speedup for model inference on GPU, while retains the same high model accuracy as finegrained sparsity.


2021 ◽  
Vol 83 (4) ◽  
Author(s):  
S. Adam Soule ◽  
Michael Zoeller ◽  
Carolyn Parcheta

AbstractHawaiian and other ocean island lava flows that reach the coastline can deposit significant volumes of lava in submarine deltas. The catastrophic collapse of these deltas represents one of the most significant, but least predictable, volcanic hazards at ocean islands. The volume of lava deposited below sea level in delta-forming eruptions and the mechanisms of delta construction and destruction are rarely documented. Here, we report on bathymetric surveys and ROV observations following the Kīlauea 2018 eruption that, along with a comparison to the deltas formed at Pu‘u ‘Ō‘ō over the past decade, provide new insight into delta formation. Bathymetric differencing reveals that the 2018 deltas contain more than half of the total volume of lava erupted. In addition, we find that the 2018 deltas are comprised largely of coarse-grained volcanic breccias and intact lava flows, which contrast with those at Pu‘u ‘Ō‘ō that contain a large fraction of fine-grained hyaloclastite. We attribute this difference to less efficient fragmentation of the 2018 ‘a‘ā flows leading to fragmentation by collapse rather than hydrovolcanic explosion. We suggest a mechanistic model where the characteristic grain size influences the form and stability of the delta with fine grain size deltas (Pu‘u ‘Ō‘ō) experiencing larger landslides with greater run-out supported by increased pore pressure and with coarse grain size deltas (Kīlauea 2018) experiencing smaller landslides that quickly stop as the pore pressure rapidly dissipates. This difference, if validated for other lava deltas, would provide a means to assess potential delta stability in future eruptions.


Author(s):  
Shanshan Yu ◽  
Jicheng Zhang ◽  
Ju Liu ◽  
Xiaoqing Zhang ◽  
Yafeng Li ◽  
...  

AbstractIn order to solve the problem of distributed denial of service (DDoS) attack detection in software-defined network, we proposed a cooperative DDoS attack detection scheme based on entropy and ensemble learning. This method sets up a coarse-grained preliminary detection module based on entropy in the edge switch to monitor the network status in real time and report to the controller if any abnormality is found. Simultaneously, a fine-grained precise attack detection module is designed in the controller, and a ensemble learning-based algorithm is utilized to further identify abnormal traffic accurately. In this framework, the idle computing capability of edge switches is fully utilized with the design idea of edge computing to offload part of the detection task from the control plane to the data plane innovatively. Simulation results of two common DDoS attack methods, ICMP and SYN, show that the system can effectively detect DDoS attacks and greatly reduce the southbound communication overhead and the burden of the controller as well as the detection delay of the attacks.


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