scholarly journals The unevenness of the north Iberian crustal root, a snapshot of an elusive stage in margin reactivation

Geology ◽  
2021 ◽  
Author(s):  
Gabriela Fernández-Viejo ◽  
Patricia Cadenas ◽  
Jorge Acevedo ◽  
Sergio Llana-Fúnez
Keyword(s):  
Crustal Thickening ◽  
Current View ◽  
Mountain Range ◽  
Data Sets ◽  
The North ◽  
Cantabrian Range ◽  
Cantabrian Region ◽  
Recent Developments ◽  
Mountain Systems ◽  
Rugged Topography

Crustal roots are identified in collision chains worldwide. Frequently mirroring the summits of mountain systems, they elegantly encapsulate the concept of isostasy. The rugged topography of northern Iberia results from convergence with the European plate during the Alpine orogeny that formed the Pyrenean-Cantabrian mountain range. From east to west, the range comprises three distinct parts: the Pyrenees, the Basque Cantabrian region, and the Cantabrian Mountains. The identification of the Pyrenean root in the 1980s and the observation of a similar geometry beneath the Cantabrian range in the 1990s gave place to the current view of crustal thickening as a continuous feature, resulting from the northward subduction of Iberian crust. Recent developments in rift architecture have delivered a complex rifting template for the area prior to convergence, and contrasting views based on two-dimensional restorations have led to a debate over its evolution. A crucial geophysical constraint is Moho topography. Using two different data sets and techniques, we present the most accurate Moho surface to date, evidencing abrupt changes throughout the orogen. The complexity of hyperextended margins underlies the current Moho topography, and this is ultimately transferred to the nonuniform orogenic pattern found in northern Iberia.

Assessment of the continuity of the orogenic root beneath the Cantabrian-Pyrenean orogen

2020 ◽  
Author(s):  
Gabriela Fernández-Viejo ◽  
Patricia Cadenas ◽  
Jorge Acevedo ◽  
Sergio Llana-Funez
Keyword(s):  
Ambient Noise ◽  
Accretionary Wedge ◽  
Bay Of Biscay ◽  
Cantabrian Mountains ◽  
The West ◽  
Cantabrian Range ◽  
Northern Iberian Peninsula ◽  
Cantabrian Region ◽  
Mountain Systems ◽  
Rugged Topography

<p>Crustal roots are a consequence of the contraction of continental masses during orogenesis identified in collisional chains worldwide. Frequently mirroring the summits of mountain systems, they portray the fundamental topic of isostasy. The northern Iberian Peninsula presents a rugged topography resulting of the collision with the European plate and the partial closure of the Bay of Biscay during the Cenozoic. Three differentiated systems formed along, from east to west:  a continental collisional chain, the Pyrenees, occupying the isthmus between Iberia and Europe; facing the Bay of Biscay, a deep Mesozoic basin inverted during contraction, the Basque-Cantabrian region, and in the west a crustal pop-up of Palaeozoic basement, the Cantabrian Mountains. The last two extend underwater in the form of a shortened platform, and an accretionary wedge fossilized by post orogenic sediments. The identification of a crustal root beneath the Pyrenees in the 80´s and the observation of a similar morphology beneath the Cantabrian range in the 90´s gave place to the interpretation of the thickening as a continuous feature of the Iberian crust. <br>However, a reappraisal of vintage refraction profiles and new data from autocorrelations of ambient noise recordings, challenge the alleged continuity. The Pyrenean-Cantabrian orogeny is a three-plate interaction. Beyond the three types of convergent boundaries we may need to introduce the hyperextended-continent destructive boundary, where this is a well-studied example but not the only one. </p>

scholarly journals Magmatism, migrating topography, and the transition from Sevier shortening to Basin and Range extension, western United States

2022 ◽  
Author(s):  
Jens-Erik Lund Snee ◽  
Elizabeth L. Miller
Keyword(s):  
Great Basin ◽  
Late Cretaceous ◽  
Basin And Range ◽  
Range Extension ◽  
Crustal Thickening ◽  
Data Sets ◽  
Geologic Mapping ◽  
North American Cordillera ◽  
The North ◽  
Volcanic Tableland

ABSTRACT The paleogeographic evolution of the western U.S. Great Basin from the Late Cretaceous to the Cenozoic is critical to understanding how the North American Cordillera at this latitude transitioned from Mesozoic shortening to Cenozoic extension. According to a widely applied model, Cenozoic extension was driven by collapse of elevated crust supported by crustal thicknesses that were potentially double the present ~30–35 km. This model is difficult to reconcile with more recent estimates of moderate regional extension (≤50%) and the discovery that most high-angle, Basin and Range faults slipped rapidly ca. 17 Ma, tens of millions of years after crustal thickening occurred. Here, we integrated new and existing geochronology and geologic mapping in the Elko area of northeast Nevada, one of the few places in the Great Basin with substantial exposures of Paleogene strata. We improved the age control for strata that have been targeted for studies of regional paleoelevation and paleoclimate across this critical time span. In addition, a regional compilation of the ages of material within a network of middle Cenozoic paleodrainages that developed across the Great Basin shows that the age of basal paleovalley fill decreases southward roughly synchronous with voluminous ignimbrite flareup volcanism that swept south across the region ca. 45–20 Ma. Integrating these data sets with the regional record of faulting, sedimentation, erosion, and magmatism, we suggest that volcanism was accompanied by an elevation increase that disrupted drainage systems and shifted the continental divide east into central Nevada from its Late Cretaceous location along the Sierra Nevada arc. The north-south Eocene–Oligocene drainage divide defined by mapping of paleovalleys may thus have evolved as a dynamic feature that propagated southward with magmatism. Despite some local faulting, the northern Great Basin became a vast, elevated volcanic tableland that persisted until dissection by Basin and Range faulting that began ca. 21–17 Ma. Based on this more detailed geologic framework, it is unlikely that Basin and Range extension was driven by Cretaceous crustal overthickening; rather, preexisting crustal structure was just one of several factors that that led to Basin and Range faulting after ca. 17 Ma—in addition to thermal weakening of the crust associated with Cenozoic magmatism, thermally supported elevation, and changing boundary conditions. Because these causal factors evolved long after crustal thickening ended, during final removal and fragmentation of the shallowly subducting Farallon slab, they are compatible with normal-thickness (~45–50 km) crust beneath the Great Basin prior to extension and do not require development of a strongly elevated, Altiplano-like region during Mesozoic shortening.

scholarly journals TraceAll: A Real-Time Processing for Contact Tracing Using Indoor Trajectories

Information ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 202
Author(s):  
Louai Alarabi ◽  
Saleh Basalamah ◽  
Abdeltawab Hendawi ◽  
Mohammed Abdalla
Keyword(s):  
Infectious Diseases ◽  
Infected Patient ◽  
Public Health Problem ◽  
Real Data ◽  
Exposure Period ◽  
Contact Tracing ◽  
Data Sets ◽  
Major Public Health Problem ◽  
Real Time Processing ◽  
Recent Developments

The rapid spread of infectious diseases is a major public health problem. Recent developments in fighting these diseases have heightened the need for a contact tracing process. Contact tracing can be considered an ideal method for controlling the transmission of infectious diseases. The result of the contact tracing process is performing diagnostic tests, treating for suspected cases or self-isolation, and then treating for infected persons; this eventually results in limiting the spread of diseases. This paper proposes a technique named TraceAll that traces all contacts exposed to the infected patient and produces a list of these contacts to be considered potentially infected patients. Initially, it considers the infected patient as the querying user and starts to fetch the contacts exposed to him. Secondly, it obtains all the trajectories that belong to the objects moved nearby the querying user. Next, it investigates these trajectories by considering the social distance and exposure period to identify if these objects have become infected or not. The experimental evaluation of the proposed technique with real data sets illustrates the effectiveness of this solution. Comparative analysis experiments confirm that TraceAll outperforms baseline methods by 40% regarding the efficiency of answering contact tracing queries.

scholarly journals Three-dimensional deformation time series of glacier motion from multiple-aperture DInSAR observation

2019 ◽  
Vol 93 (12) ◽  
pp. 2651-2660 ◽  
Author(s):  
Sergey Samsonov
Keyword(s):  
Time Series ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Three Dimensional ◽  
Data Sets ◽  
Ice Flow ◽  
The North ◽  
Glacier Ice ◽  
Deformation Component ◽  
3D Deformation

AbstractThe previously presented Multidimensional Small Baseline Subset (MSBAS-2D) technique computes two-dimensional (2D), east and vertical, ground deformation time series from two or more ascending and descending Differential Interferometric Synthetic Aperture Radar (DInSAR) data sets by assuming that the contribution of the north deformation component is negligible. DInSAR data sets can be acquired with different temporal and spatial resolutions, viewing geometries and wavelengths. The MSBAS-2D technique has previously been used for mapping deformation due to mining, urban development, carbon sequestration, permafrost aggradation and pingo growth, and volcanic activities. In the case of glacier ice flow, the north deformation component is often too large to be negligible. Historically, the surface-parallel flow (SPF) constraint was used to compute the static three-dimensional (3D) velocity field at various glaciers. A novel MSBAS-3D technique has been developed for computing 3D deformation time series where the SPF constraint is utilized. This technique is used for mapping 3D deformation at the Barnes Ice Cap, Baffin Island, Nunavut, Canada, during January–March 2015, and the MSBAS-2D and MSBAS-3D solutions are compared. The MSBAS-3D technique can be used for studying glacier ice flow at other glaciers and other surface deformation processes with large north deformation component, such as landslides. The software implementation of MSBAS-3D technique can be downloaded from http://insar.ca/.

Parasites as biological tags in marine fisheries research: European Atlantic waters

Parasitology ◽  
2014 ◽  
Vol 142 (1) ◽  
pp. 54-67 ◽  
Author(s):  
K. MACKENZIE ◽  
W. HEMMINGSEN
Keyword(s):  
Marine Mammals ◽  
Gadus Morhua ◽  
Clupea Harengus ◽  
Melanogrammus Aeglefinus ◽  
Ecological Group ◽  
The North ◽  
Recent Developments ◽  
Host Parasite ◽  
Mediterranean And Black Seas ◽  
Biological Tags

SUMMARYStudies of the use of parasites as biological tags for stock identification and to follow migrations of marine fish, mammals and invertebrates in European Atlantic waters are critically reviewed and evaluated. The region covered includes the North, Baltic, Barents and White Seas plus Icelandic waters, but excludes the Mediterranean and Black Seas. Each fish species or ecological group of species is treated separately. More parasite tag studies have been carried out on Atlantic herring Clupea harengus than on any other species, while cod Gadus morhua have also been the subject of many studies. Other species that have been the subjects of more than one study are: blue whiting Micromesistius poutassou, whiting Merlangius merlangus, haddock Melanogrammus aeglefinus, Norway pout Trisopterus esmarkii, horse mackerel Trachurus trachurus and mackerel Scomber scombrus. Other species are dealt with under the general headings redfishes, flatfish, tunas, anadromous fish, elasmobranchs, marine mammals and invertebrates. A final section highlights how parasites can be, and have been, misused as biological tags, and how this can be avoided. It also reviews recent developments in methodology and parasite genetics, considers the potential effects of climate change on the distributions of both hosts and parasites, and suggests host-parasite systems that should reward further research.

Surface wave attenuation of seismic records with the co-core trace transform filter

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. V115-V128 ◽  
Author(s):  
Ning Wu ◽  
Yue Li ◽  
Baojun Yang
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Field Data ◽  
Wave Attenuation ◽  
Seismic Events ◽  
Data Sets ◽  
Transform Domain ◽  
Recent Developments ◽  
Seismic Records ◽  
Trace Transform

To remove surface waves from seismic records while preserving other seismic events of interest, we introduced a transform and a filter based on recent developments in image processing. The transform can be seen as a weighted Radon transform, in particular along linear trajectories. The weights in the transform are data dependent and designed to introduce large amplitude differences between surface waves and other events such that surface waves could be separated by a simple amplitude threshold. This is a key property of the filter and distinguishes this approach from others, such as conventional ones that use information on moveout ranges to apply a mask in the transform domain. Initial experiments with synthetic records and field data have demonstrated that, with the appropriate parameters, the proposed trace transform filter performs better both in terms of surface wave attenuation and reflected signal preservation than the conventional methods. Further experiments on larger data sets are needed to fully assess the method.

A 2011-2018 Fukushima Perspective on North Pacific Mode Water Pathways

2021 ◽  
Author(s):  
Alison Macdonald ◽  
Sachiko Yoshida ◽  
Irina Rypina
Keyword(s):  
North Pacific ◽  
Half Life ◽  
Nuclear Power ◽  
North Pacific Ocean ◽  
Data Sets ◽  
Mode Water ◽  
Eastern Basin ◽  
Mode Waters ◽  
The North ◽  
The Pacific

<p>This investigation uses the tracer information provided by the 2011 direct ocean release of radio-isotopes, (<sup>137</sup>Cs, ~30-year half-life and <sup>134</sup>Cs, ~2-year half-life) from the Fukushima Dai-ichi nuclear power plant (FDNPP) together with hydrographic profiles to better understand the origins and pathways of mode waters in the North Pacific Ocean. While using information provided by radionuclide observations taken from across the basin, the main focus is on the eastern basin and results from analyses of two data sets 2015 (GO-SHIP) and 2018 (GEOTRACES) along the 152°W meridian. The study looks at how mode waters formed in the spring of 2011 have spread and mixed, and how they have not. Our radiocesium isotope samples tell a story of a surprisingly confined pathway for these waters and suggest that circulation to the north into the subpolar gyre occurs more quickly than circulation to the south into the subtropical gyre. They indicate that in spite of crossing 6000 km in their journey across the Pacific, the densest 2011 mode waters stayed together spreading by only a few hundred kilometers in the north/south direction, remained subsurface (below ~200 m) for most of the trip, and only saw the atmosphere again as they followed shoaling density surfaces into the boundary of the Alaska Gyre. The more recent data are sparse and do not allow direct measurement of the FDNPP specific <sup>134</sup>Cs, however they do provide some information on mode water evolution in the eastern North Pacific seven years after the accident. </p>

Trends and Variability of North American Cool-Season Extratropical Cyclones: 1979–2019

2021 ◽  
Author(s):  
Robert Fritzen ◽  
Victoria Lang ◽  
Vittorio A. Gensini
Keyword(s):  
North American ◽  
Research Question ◽  
Weather Conditions ◽  
Extratropical Cyclones ◽  
Mountain Range ◽  
Cool Season ◽  
The North ◽  
Primary Driver ◽  
Regional Reanalysis ◽  
Log Linear

AbstractExtratropical cyclones are the primary driver of sensible weather conditions across the mid-latitudes of North America, often generating various types of precipitation, gusty non-convective winds, and severe convective storms throughout portions of the annual cycle. Given ongoing modifications of the zonal atmospheric thermal gradient due to anthropogenic forcing, analyzing the historical characteristics of these systems presents an important research question. Using the North American Regional Reanalysis, boreal cool-season (October–April) extratropical cyclones for the period 1979–2019 were identified, tracked, and classified based on their genesis location. Additionally, bomb cyclones—extratropical cyclones that recorded a latitude normalized pressure fall of 24 hPa in 24-hr—were identified and stratified for additional analysis. Cyclone lifespan across the domain exhibits a log-linear relationship, with 99% of all cyclones tracked lasting less than 8 days. On average, ≈ 270 cyclones were tracked across the analysis domain per year, with an average of ≈ 18 year−1 being classified as bomb cyclones. The average number of cyclones in the analysis domain has decreased in the last 20 years from 290 year−1 during the period 1979–1999 to 250 year−1 during the period 2000–2019. Spatially, decreasing trends in the frequency of cyclone track counts were noted across a majority of the analysis domain, with the most significant decreases found in Canada’s Northwest Territories, Colorado, and east of the Graah mountain range. No significant interannual or spatial trends were noted with bomb cyclone frequency.

scholarly journals Great differences in performance and outcome of high-throughput sequencing data analysis platforms for fungal metabarcoding

MycoKeys ◽  
2018 ◽  
Vol 39 ◽  
pp. 29-40 ◽  
Author(s):  
Sten Anslan ◽  
R. Henrik Nilsson ◽  
Christian Wurzbacher ◽  
Petr Baldrian ◽  
Leho Tedersoo ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Computation Time ◽  
Potential Effect ◽  
Data Sets ◽  
Sequencing Data ◽  
Operational Taxonomic Units ◽  
High Throughput Sequencing Data ◽  
Recent Developments

Along with recent developments in high-throughput sequencing (HTS) technologies and thus fast accumulation of HTS data, there has been a growing need and interest for developing tools for HTS data processing and communication. In particular, a number of bioinformatics tools have been designed for analysing metabarcoding data, each with specific features, assumptions and outputs. To evaluate the potential effect of the application of different bioinformatics workflow on the results, we compared the performance of different analysis platforms on two contrasting high-throughput sequencing data sets. Our analysis revealed that the computation time, quality of error filtering and hence output of specific bioinformatics process largely depends on the platform used. Our results show that none of the bioinformatics workflows appears to perfectly filter out the accumulated errors and generate Operational Taxonomic Units, although PipeCraft, LotuS and PIPITS perform better than QIIME2 and Galaxy for the tested fungal amplicon dataset. We conclude that the output of each platform requires manual validation of the OTUs by examining the taxonomy assignment values.

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