Seismicity in the vicinity of the SNORCLE corridors of the northern Canadian Cordillera

2005 ◽  
Vol 42 (6) ◽  
pp. 1137-1148 ◽  
Author(s):  
John F Cassidy ◽  
Garry C Rogers ◽  
J Ristau
Keyword(s):  
Current Knowledge ◽  
Active Faults ◽  
Active Regions ◽  
Large Earthquake ◽  
Historical Earthquakes ◽  
Precise Determination ◽  
Canadian Cordillera ◽  
Waveform Modelling ◽  
The Moment

The Slave – Northern Cordillera Lithospheric Evolution (SNORCLE) corridors of the northern Cordillera sample some of the most, and least, seismically active regions of Canada. The earthquake history of this region is short. Precise determination of earthquake locations and depths is not possible even today. Nonetheless, significant gains in our knowledge of the seismicity of this region have been made in recent years from studies of historic earthquakes, microseismicity studies, and advances in waveform modelling techniques combined with broadband data that allow for determination of focal mechanisms and depths for moderate earthquakes. This article summarizes our current knowledge of the seismicity and seismic hazards across the region. These detailed analyses have shown that (i) the largest historical earthquakes have occurred in regions of ongoing microseismicity; (ii) the largest earthquakes have occurred in pairs or in swarms, suggesting that stress triggering is important in this region; (iii) the active faults are concentrated in the offshore region; (iv) there is a concentration of seismicity in the Fold and Thrust belt, several hundred kilometres from the active plate margin; and (v) there is no seismicity associated with the Quaternary volcanic zone in northern British Columbia. Potentially damaging (magnitude M ≥ 5) earthquakes can be expected every few years in the vicinity of the northern Cordillera. The Mw = 7.9 Denali, Alaska, earthquake (where Mw is the moment magnitude) was a good reminder that the effects of a large earthquake can be substantial, even hundreds of kilometres from the epicentre. Detailed studies of seismicity, earth structure, and tectonics, with the latter made possible in large part by the SNORCLE transect, will allow for informed decision-making for resource development and the design of safe structures and infrastructure in the northern Canadian Cordillera.

Determining seismic hazard in slowly deforming region: Can we gather enough information from karst caves?

2021 ◽  
Author(s):  
Ana Mladenović ◽  
Jelena Ćalić
Keyword(s):  
Seismic Hazard ◽  
Active Faults ◽  
Active Regions ◽  
Research Area ◽  
Geological Structure ◽  
Probabilistic Methods ◽  
Radiometric Dating ◽  
Southeastern Part ◽  
Karst Caves

<p>Methods to determine seismic hazard in any region vary depending on the regional seismicity, but can be roughly grouped into two main groups: one based on probabilistic methods that use data about known seismicity in the region, and another, which is based on data related to the faulting processes and determination of seismically active faults. Both groups of methods are relatively good for seismically active regions. However, in regions of low seismic activity and slow deformations, there is neither enough data for proper probabilistic determination of seismic hazard, nor enough data about deformation that can indicate possibly active faults. Because of that, all sets of data have to be combined in order to gather necessary information needed to determine seismic hazard for a given area.</p><p>One of such regions of low seismicity and very slow deformation is the region of Carpatho-Balkan orogen, situated in Eastern Serbia. This orogen represents the western part of the Carpatho-Balkan orogenic chain, extending in the north to the Romanian Southern Carpathians and in its southeastern part to the Balkan massif in Bulgaria. In its central part, in Eastern Serbia, Carpatho-Balkanides are made up of a system of east-vergent nappes, that have been formed in Early Cretaceous and were multiply activated during their geological history. This activity led to the formation of faults that are favorably oriented in respect to the main thrust system. It is suspected that some of these fault systems are also active in recent times.</p><p>Relatively complex geological structure and existence of a large number of rock discontinuities, as well as relatively long time during which these geological units have been exposed on the surface, led to intensive karst process and formation of both surface and underground karst forms. Therefore, investigations of faults and deformations on the field surface are very difficult, but investigations of neotectonically active faults inside the karst caves can give a lot more information.</p><p>In this abstract, we present evidence about the youngest and recently active faults in the region of interest, based on data from karst caves. Age of activity of faults mapped inside the caves was determined based on indicators of faults cutting speleothems, forming fault breccias that incorporate cave sediments (broken speleothems), and based on speleogenetic considerations. Samples for radiometric dating have been collected, that will help to quantify fault activity rate.</p><p>Preliminary results show that the research area is characterized by strike-slip tectonics, most likely resulting from far-field stress generated by the collision of the Adriatic microplate, the Moesian indenter and the tectonic units in-between. Such stress field is shown to be highly heterogeneous even in this relatively small research area, so local areas of transtension and transpression have also been very important in controlling the recent fault kinematics in this part of the Carpatho-Balkanides. These preliminary conclusions are also of high importance for seismic hazard characterization.</p>

scholarly journals Precision of Calibrated Radiocarbon Ages of Historic Earthquakes in the Dead Sea Basin

Radiocarbon ◽  
2001 ◽  
Vol 43 (3) ◽  
pp. 1371-1382 ◽  
Author(s):  
Revital Ken-Tor ◽  
Mordechai Stein ◽  
Yehouda Enzel ◽  
Amotz Agnon ◽  
Shmuel Marco ◽  
...  
Keyword(s):  
Historical Earthquakes ◽  
Arid Environment ◽  
Dead Sea ◽  
Precise Determination ◽  
Dead Sea Basin ◽  
Lag Period ◽  
The Dead ◽  
Historic Earthquakes ◽  
Error Envelope

The precise determination of the age of historical and geological events by radiocarbon dating is often hampered by the long intersection ranges of the measured data with the calibration curve. In this study we examine the possibility of narrowing the calibrated range of the 14C ages of earthquake-disturbed sediments (seismites) from the Late Holocene lacustrine section in the Dead Sea Basin. The calibrated ranges of samples collected from seismites were refined by applying stratigraphic constraints and tuning the calibrated ranges to known historical earthquakes. Most of the earthquakes fall well within the 1σ error envelope of the 14C age. This refinement demonstrates that the lag period due to transport and deposition of vegetation debris is very short in this arid environment, probably not more than a few decades. This assessment of seismite 14C ages attests to the validity of 14C ages in Holocene sediments of the arid area of the Dead Sea. Furthermore, it demonstrates our ability to achieve highly precise (correct to within several decades) 14C ages.

scholarly journals Detection of Aircraft Touchdown Using Longitudinal Acceleration and Continuous Wavelet Transformation

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7231
Author(s):  
Jerzy Bakunowicz ◽  
Paweł Rzucidło
Keyword(s):  
Wavelet Transformation ◽  
Precise Determination ◽  
Landing Gear ◽  
Continuous Wavelet ◽  
Passenger Compartment ◽  
Aircraft Structure ◽  
Longitudinal Acceleration ◽  
Structural Parts ◽  
The Moment

The paper presents a methodology enabling the detection of aircraft touchdowns based on data obtained from accelerometers attached to the structural parts of the airframe in the cockpit or passenger compartment. Precise determination of the moment and place of touchdown of the main landing gear is challenging when analysing parameters such as height, flight speed and rate of descent. During the tests of the I-31T aircraft, it turned out that vibrations of the aircraft structure caused by the contact of the front and main landing gear with the ground have a repetitive character. In particular, this applies to longitudinal acceleration. The use of continuous wavelet analysis (CWT) allowed finding unique periodic features of the landing phenomenon that distinguish it from other forms of vibration occurring in individual flight phases. Ground and flight observations of experimental aeroplane MP-02 Czajka verified the proposed method of virtual touchdown detection. The results presented in this paper justify that this method may find broader application, especially for the light aircraft class.

On-the-Fly Determination of Active Region Centers in Adaptive-Partitioning QM/MM

2020 ◽  
Author(s):  
Zenghui Yang
Keyword(s):  
Quantum Mechanics ◽  
Active Region ◽  
Molecular Mechanics ◽  
Active Regions ◽  
Available Energy ◽  
Adaptive Partitioning ◽  
Different Levels

Quantum mechanics/molecular mechanics (QM/MM) methods partition the system into active and environmental regions and treat them with different levels of theory, achieving accuracy and efficiency at the same time. Adaptive-partitioning (AP) QM/MM methods allow on-the-fly changes to the QM/MM partitioning of the system. Many of the available energy-based AP-QM/MM methods partition the system according to distances to pre-chosen centers of active regions. For such AP-QM/MM methods, I develop an adaptive-center (AC) method that allows on-the-fly determination of the centers of active regions according to general geometrical or potential-related criteria, extending the range of application of energy-based AP-QM/MM methods to systems where active regions may occur or vanish during the simulation.

PREDICTION OF THE EFFICIENCY OF RECONSTRUCTIVE INTERVENTIONS ON THE MAJOR NERVES OF THE FOREARM, DEPENDING ON THE DEFECT DURATION AND THE FOLLOWING REHABILITATION

2020 ◽  
pp. 77-88
Author(s):  
Дмитрий Валериевич Судаков ◽  
Олег Валериевич Судаков ◽  
Людмила Валентиновна Кретинина ◽  
Наталья Владимировна Якушева ◽  
Артём Николаевич Шевцов
Keyword(s):  
Nervous Tissue ◽  
Clinical Situation ◽  
Economic Importance ◽  
Important Data ◽  
Subsequent Period ◽  
Complete Restoration ◽  
Reconstructive Microsurgery ◽  
The Moment

Статья посвящена построению прогноза эффективности реконструктивных вмешательств на магистральных нервах предплечья в зависимости от протяженности дефекта нервной ткани и особенностей последующего периода реабилитации пациентов. Данная тематика является весьма актуальной, так как с каждым годом во всем мире наблюдается определенный рост случаев травм различного генеза магистральных нервных стволов, которые затем нередко приводят к временной нетрудоспособности и даже инвалидности пациентов. Реконструктивная микрохирургия многие десятилетия пытается решить целый ряд проблем аутотрансплантации нервных стволов и повысить ее общую эффективность. Но из-за определенных проблем связанных с финансированием, некоторые вопросы трансплантологии и реабилитации остаются нерешенными и в настоящий момент. Все это придает представленной работе важное значение не только медицинского, но и социально - экономического плана. Целью работы стала попытка построения прогноза восстановительных операций на нервной ткани, с учетом объема пораженных структур и периода реабилитации. Объектами исследования стало 180 больных, которым по той или иной причине, осуществлялась реконструктивная операция на одном из магистральных нервов предплечья. Все пациенты были разделены на 3 группы по 60 человек, в зависимости от протяженности дефекта магистрального нерва: до 4 см, от 4 до 8 см и от 8 до 12 см. Последующее разделение внутри каждой группы на подгруппы производилось в зависимости от определенного поврежденного нерва (лучевой, локтевой, срединный). В работе изучалось течение раннего послеоперационного воспалительного процесса, с определением бактериальной микрофлоры в ране. Изучались и отдаленные последствия оперативного вмешательства. Своеобразной новизной для данной тематики в целом, стало выявление последующего установления инвалидности пациентов. Кроме того, важные данные были получены и по срокам реабилитации и частичного или полного восстановления утраченных функций по срокам в зависимости от размеров восстанавливаемого дефекта и от наличия или отсутствия необходимой реабилитации. Полученные в работе данные могут представлять интерес не только для врачей хирургов и травматологов, но и для организаторов здравоохранения, позволяя производить прогнозы по выздоровлению пациентов в каждой определенной клинической ситуации The article is devoted to the construction of a forecast of the effectiveness of reconstructive interventions on the main nerves of the forearm, depending on the length of the defect in the nervous tissue and the characteristics of the subsequent period of rehabilitation of patients. This topic is very relevant, since every year all over the world there is a certain increase in cases of injuries of various origins of the main nerve trunks, which then often lead to temporary disability and even disability of patients. For many decades, reconstructive microsurgery has been trying to solve a number of problems of autotransplantation of nerve trunks and improve its overall efficiency. But due to certain problems associated with funding, some issues of transplantation and rehabilitation remain unresolved at the moment. All this gives the presented work important not only medical, but also socio - economic importance. The aim of this work was to attempt to predict restorative operations on the nervous tissue, taking into account the volume of the affected structures and the period of rehabilitation. The objects of the study were 180 patients who, for one reason or another, underwent a reconstructive operation on one of the main nerves of the forearm. All patients were divided into 3 groups of 60 people, depending on the length of the main nerve defect: up to 4 cm, from 4 to 8 cm, and from 8 to 12 cm. Subsequent division within each group into subgroups was performed depending on the specific damaged nerve ( radial, ulnar, median). The work studied the course of the early postoperative inflammatory process, with the determination of bacterial microflora in the wound. The long-term consequences of surgery were also studied. A peculiar novelty for this topic as a whole was the identification of the subsequent establishment of disability in patients. In addition, important data were obtained on the timing of rehabilitation and partial or complete restoration of lost functions in terms of timing, depending on the size of the restored defect and on the presence or absence of the necessary rehabilitation. The data obtained in this work may be of interest not only for surgeons and traumatologists, but also for healthcare organizers, allowing them to make predictions about the recovery of patients in each specific clinical situation

PRECISE DETERMINATION OF THE IRRATIONAL PRE-FERRED INTERFACE ORIENTATION BY TEM

2010 ◽  
Vol 46 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Yang MENG ◽  
Lin GU ◽  
Wenzheng ZHANG
Keyword(s):  
Precise Determination ◽  
Interface Orientation

Nauwkeurige methode voor de aanwasbepaling van het grondvlak met behulp van de Pressler-boor

1968 ◽  
Vol 12 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Basal Area ◽  
Precise Determination ◽  
Maximum Diameter ◽  
Precise Method ◽  
Maximum Radius ◽  
The Core ◽  
Two Parameters

A precise method for the determination of the increment of the  basal area using the PressIer bore. Refering to  previous research showing that the basal area of the corsica pine could be  characterized by an ellips, we present in this paper a precise method for the  determination of the increment of the basal area. In this method we determine  the direction of the maximum diameter, we measure this diameter and we take a  core in one of the points of tangency of the caliper with the measured tree.  The determination of the diameter perpendicular to the maximum diameter  finishes the work wich is to be done in the forest. From the classical  measurements effectuated on the core and from the measured diameters we can  then determine the form (V) and the excentricity (e). Substituting these two  parameters in the formula 2 or 2', we can also calculate the error of a  radius measured on the core with respect to the representative radius, This  error with them allow us to correct the measured value of the minimum or the  maximum radius and we will be able to do a precise determination of the  increment.

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