Paleomagnetism of the Methow region, north-central Washington: structural application of paleomagnetic data in a complexly deformed, variably remagnetized terrane

1990 ◽  
Vol 27 (3) ◽  
pp. 330-343 ◽  
Author(s):  
David R. Bazard ◽  
Russell F. Burmester ◽  
Myrl E. Beck Jr. ◽  
Julian L. Granirer ◽  
Charles G. Schwarz

Jurassic through Paleocene rocks of the Methow–Pasayten belt were studied in order to use paleomagnetic directions to resolve the question of Cretaceous northward transport. In the end, circumstances prevented us from doing so. However, three independent studies of these rocks, summarized here, indicate that several units retain strong and stable magnetizations that are different from the present axial dipole field direction. When partly or completely corrected to paleohorizontal, these magnetizations become less dispersed, suggesting that they were acquired before at least the last stage of Late Cretaceous deformation. A pervasive northeast–southwest streak of magnetizations at various stages of structural correction indicates that at least some of the rocks were partly to completely remagnetized at different times during folding. This complex structural–remagnetization history and consequent loss of paleohorizontal prevent a simple analysis of paleolatitude during remagnetization. However, analysis of the youngest layered rocks of the Goat Peak syncline indicates that much of the remagnetization occurred when the structure was more open but still well developed. Subsequent tighter folding followed intrusion of the Fawn Peak stock. Our results are a useful case study of some of the problems that arise in studying the paleomagnetism of a complicated orogenic terrane.

1975 ◽  
Vol 12 (8) ◽  
pp. 1264-1271 ◽  
Author(s):  
J. M. Ade-Hall ◽  
Susann Gerstein ◽  
Robert E. Gerstein ◽  
Peter H. Reynolds ◽  
P. Dagley ◽  
...  

Paleomagnetic and K/Ar whole rock absolute age data are described for material from the Garian area of Libya, centered at 13°E, 32°N. Within-unit cleaned paleomagnetic directions from the essentially unaltered lavas are very well defined and can almost certainly be taken as reliable measurements of the geomagnetic field direction during the initial cooling of each flow. However, the distributions of mean direction, from which the effect of repeated sampling of the field at one time has been removed, does not suggest that a reversing axial dipole field has been recorded in a representative manner. Both N and R groups of directions are azimuthally elongated, and the average poles for the N and R groups differ by 21°, or four times the 95% level uncertainty for each average pole. A number of possible physical explanations for the paleomagnetic results are discussed. The conventional overall average pole at 88°N, 123°E, δp: 3°, δm: 7 °does not differ significantly from the geographic pole, a result which agrees closely with that of Schult and Soffel (1973). However, the value of these overall average poles in estimating absolute plate motion must await an understanding of the sources of the asymmetries in the paleomagnetic data.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 161-168 ◽  
Author(s):  
J. Einfeldt

A process, called Bio-Denipho, for combined biological phosphorus and nitrogen removal in a combination of an anaerobic tank and two oxidation ditches is described. In this process the anaerobic tank consisting of three sections working in series is followed by two oxidation ditches. These too are working in series, but with both inlet to and outlet from the tanks changing in a cycle. The Bio-Denipho process is described specifically for the process itself and as a case study for the implementation of the process on a 265,000 pe wastewater treatment plant for the city of Aalborg in Denmark. The plant was designed and erected in two stages and the last stage was inaugurated October 31,1989. Lay-out and functions for the plant is described and design loads, plan lay-out and tank volumes are given in this paper together with performance data for the first year in operation.


Author(s):  
K Gwirtz ◽  
M Morzfeld ◽  
A Fournier ◽  
G Hulot

Summary We study predictions of reversals of Earth’s axial magnetic dipole field that are based solely on the dipole’s intensity. The prediction strategy is, roughly, that once the dipole intensity drops below a threshold, then the field will continue to decrease and a reversal (or a major excursion) will occur. We first present a rigorous definition of an intensity threshold-based prediction strategy and then describe a mathematical and numerical framework to investigate its validity and robustness in view of the data being limited. We apply threshold-based predictions to a hierarchy of numerical models, ranging from simple scalar models to 3D geodynamos. We find that the skill of threshold-based predictions varies across the model hierarchy. The differences in skill can be explained by differences in how reversals occur: if the field decreases towards a reversal slowly (in a sense made precise in this paper), the skill is high, and if the field decreases quickly, the skill is low. Such a property could be used as an additional criterion to identify which models qualify as Earth-like. Applying threshold-based predictions to Virtual Axial Dipole Moment (VADM) paleomagnetic reconstructions (PADM2M and Sint-2000) covering the last two million years, reveals a moderate skill of threshold-based predictions for Earth’s dynamo. Besides all of their limitations, threshold-based predictions suggests that no reversal is to be expected within the next 10 kyr. Most importantly, however, we show that considering an intensity threshold for identifying upcoming reversals is intrinsically limited by the dynamic behavior of Earth’s magnetic field.


2021 ◽  
pp. 002190962199349
Author(s):  
Manh-Hung Nguyen ◽  
Dung P Le ◽  
Thang T Vo

This article investigates the impact of flood risk on vulnerability and welfare at the household level in Vietnam. The analytical sample is taken from a household survey conducted in a north central Vietnam community through a three-stage stratified random sampling method. The propensity score matching approach is employed to compare various welfare indicators between flooded and non-flooded households. This study finds that flooding results in significant income losses and imposes higher costs of living, especially housing costs. The two types of households are vulnerable, implying that other natural disasters or socio-economic disadvantages may have adverse effects on households’ livelihoods. The insignificant effect of floods on vulnerability indicates that the flooded households can cope with floods to some extent. However, contrary to family support, formal coping strategies are insufficient or ineffective at reducing household vulnerability to floods.


2021 ◽  
Author(s):  
Aditya Varma ◽  
Binod Sreenivasan

<p>It is known that the columnar structures in rapidly rotating convection are affected by the magnetic field in ways that enhance their helicity. This may explain the dominance of the axial dipole in rotating dynamos. Dynamo simulations starting from a small seed magnetic field have shown that the growth of the field is accompanied by the excitation of convection in the energy-containing length scales. Here, this process is studied by examining axial wave motions in the growth phase of the dynamo for a wide range of thermal forcing. In the early stages of evolution where the field is weak, fast inertial waves weakly modified by the magnetic field are abundantly present. As the field strength(measured by the ratio of the Alfven wave to the inertial wave frequency) exceeds a threshold value, slow magnetostrophic waves are spontaneously generated. The excitation of the slow waves coincides with the generation of helicity through columnar motion, and is followed by the formation of the axial dipole from a chaotic, multipolar state. In strongly driven convection, the slow wave frequency is attenuated, causing weakening of the axial dipole intensity. Kinematic dynamo simulations at the same parameters, where only fast inertial waves are present, fail to produce the axial dipole field. The dipole field in planetary dynamos may thus be supported by the helicity from slow magnetostrophic waves.</p>


2020 ◽  
Vol 2 (3) ◽  
pp. 281-300
Author(s):  
Hadi Nurdin ◽  
Dang Eif Saiful Amin ◽  
Dyah Rahmi Astuti

ABSTRAK Tulisan ini bertujuan untuk mengetahui implementasi  CSR PT. Pos Indonesia pada program bantuan sarana peribadatan mulai dari tahap perencanaan, pengorganisasian, pelaksanaan dan pengawasan. Metode penelitian ini menggunakan metode studi kasus untuk mengetahui karakteristik  dengan cara berinteraksi secara langsung dan mendalam mengenai sebuah kasus dan ringkasan yang digambarkan pada konteks di atas mendasari untuk menggali dan mendeskripsikan kegiatan-kegiatan divisi PKBL PT. Pos Indonesia. Analisis penelitian ini menggunakan deskriptif kualittaif. Hasil penelitian menunjukan bahwa Implementasi Kegiatan Responsibility CSR pada program bantuan sarana peribadatan, mulai dari tahap pertama yaitu perencanaan agenda proposal, peninjauan proposal, dan perencanaan anggaran. Tahap kedua yaitu tahap pengorganisasian dengan mengorganisasikan persiapan, mengorganisasikan koordinasi dan mengorganisasikan pengelolaan anggaran. Tahap ketiga yaitu tahap pelaksanaan melaksanan briefing, melaksanakan program dilapangan dan melaksankan penyaluran dan. Tahap terakhir yaitu pengawasan  mengawasi program, mengawasi dana yang telah disalurkan. Kata Kunci : CSR; Implementasi; Bantuan Sarana Peribadatan ABSTRACT This research aims to determine the implementation of CSR PT. Pos Indonesia in the assistance program for worship facilities starting from the planning, organizing, implementing and monitoring stages. This research method uses a case study method to find out the characteristics by interacting directly and deeply about a case and a summary illustrated in the above context is underlying to explore and describe the activities of the PKBL division of PT. Indonesian post. The analysis of this study uses descriptive qualitative. The results of the study show that the implementation of CSR Responsibility Activities in the worship facilities assistance program, starting from the first stage, namely planning the proposal agenda, reviewing proposals, and budget planning. The second stage is the organizing stage by organizing preparations, organizing coordination and organizing budget management. The third stage is the stage of carrying out the briefing, implementing the program in the field and implementing the distribution and. The last stage is supervision overseeing the program, overseeing the funds that have been channeled. Keywords : CSR; Implementation; Religious Facilities Assistance


2021 ◽  
Vol 9 (206) ◽  
pp. 1-23
Author(s):  
Ailton Queiroz Junior ◽  
Antonio Ribeiro Santos Junior

With the expressive increase in the demand for increasingly tall and robust constructions, plus more and more complex structural details that end up becoming a key element for the projects of the structures of the undertakings, it is important to consider the efforts made by the reinforced concrete structures are subjected. In this sense, the present work has as objective the approach of the parameters of global stability a and Yz followed by the verification of the efforts on the pavements and the displacements of the building caused by the loads acting on the structure. In this work, the use of the global stability parameter a and Yz, which is of fundamental relevance and also prescribed in NBR 6118 (ABNT, 2014), was evaluated. The use of the parameter a considered for the evaluation of the overall stability of the structure, but which is not capable of estimating second order efforts, allows us to classify a structure as being of fixed or mobile nodes. The Yz parameter, on the other hand, can be used to obtain second order efforts. To carry out this work, a case study was launched in the structural analysis software Ftool. The present analysis carried out showed that it is possible to conceive a bracing system for a building with up to 30 floors, using the pillar-wall solution having as a substitute resource for the aforementioned solution the solution of frames formed by beams and columns addressed continuously by tall building literature. Therefore, it is worth mentioning that the solution with wall pillars tends to be more expensive than the solution with frames, a system adopted in the development of this work due to the economic viability of the construction, in view of a higher consumption of materials in the superstructure and also higher costs in the construction. execution of foundations, due to the efforts that will be generated in the building (horizontal forces and bending moments).


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