Evidence of rapid changes in the Permian geomagnetic field during the Zechstein marine transgression

Nature ◽  
1977 ◽  
Vol 270 (5638) ◽  
pp. 593-594 ◽  
Author(s):  
P. TURNER ◽  
D. J. VAUGHAN
Keyword(s):  
Geomagnetic Field ◽  
Marine Transgression ◽  
Rapid Changes

Rapid changes and near-stationarity of the geomagnetic field during a polarity reversal

Nature ◽  
1987 ◽  
Vol 330 (6144) ◽  
pp. 145-148 ◽  
Author(s):  
Carlo Laj ◽  
Sylvie Guitton ◽  
Catherine Kissel
Keyword(s):  
Geomagnetic Field ◽  
Polarity Reversal ◽  
Rapid Changes

scholarly journals Geomagnetic jerks characterization via spectral analysis

Solid Earth ◽  
2012 ◽  
Vol 3 (1) ◽  
pp. 131-148 ◽  
Author(s):  
B. Duka ◽  
A. De Santis ◽  
M. Mandea ◽  
A. Isac ◽  
E. Qamili
Keyword(s):  
Time Series ◽  
Geomagnetic Field ◽  
Synthetic Data ◽  
Spatial Evolution ◽  
Spectral Techniques ◽  
The Third ◽  
Rapid Changes ◽  
Geomagnetic Jerks ◽  
Third Derivative ◽  
Harmonic Power

Abstract. In this study we have applied spectral techniques to analyze geomagnetic field time-series provided by observatories, and compared the results with those obtained from analogous analyses of synthetic data estimated from models. Then, an algorithm is here proposed to detect the geomagnetic jerks in time-series, mainly occurring in the eastern component of the geomagnetic field. Applying such analysis to time-series generated from global models has allowed us to depict the most important space-time features of the geomagnetic jerks all over the globe, since the beginning of XXth century. Finally, the spherical harmonic power spectrum of the third derivative of the main geomagnetic field has been computed from 1960 to 2002.5, bringing new insights to understand the spatial evolution of these rapid changes of the geomagnetic field.

scholarly journals Using spectral analysis to detect singular events such as jerks in the geomagnetic field time series

2011 ◽  
Vol 3 (2) ◽  
pp. 615-654
Author(s):  
B. Duka ◽  
A. De Santis ◽  
M. Mandea ◽  
A. Isac ◽  
E. Qamili
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Geomagnetic Field ◽  
Synthetic Data ◽  
Global Scale ◽  
Spherical Harmonic Analysis ◽  
Global Models ◽  
Spectral Techniques ◽  
Rapid Changes ◽  
Geomagnetic Jerks

Abstract. In this study we have applied two spectral techniques in terms of Fourier and wavelet analysis to geomagnetic field time series and compared the results with those obtained from analogous analyses to synthetic data. Then, an algorithm has been proposed to detect the geomagnetic jerks in time series, mainly being considered by the Eastern component secular variation. Applying such analysis to time series generated from global models has allowed us to depict the most important space-time features of the geomagnetic jerks on global scale, since the beginning of XXth century. Finally, a spherical harmonic analysis of the secular acceleration power spectrum has been computed since 1960 to 2000, bringing new insights in understanding these rapid changes of the geomagnetic field and their origin.

scholarly journals Toward a possible next geomagnetic transition?

2013 ◽  
Vol 13 (12) ◽  
pp. 3395-3403 ◽  
Author(s):  
A. De Santis ◽  
E. Qamili ◽  
L. Wu
Keyword(s):  
Critical Point ◽  
Geomagnetic Field ◽  
Outer Core ◽  
Reverse Time ◽  
Geomagnetic Reversal ◽  
Rapid Changes ◽  
Global Mean Sea Level ◽  
Logarithmic Functions ◽  
Near Future ◽  
Global Mean

Abstract. The geomagnetic field is subject to possible reversals or excursions of polarity during its temporal evolution. Considering that: (a) in the last 83 million yr the typical average time between one reversal and the next (the so-called chron) is around 400 000 yr, (b) the last reversal occurred around 780 000 yr ago, (c) more excursions (rapid changes in polarity) can occur within the same chron and (d) the geomagnetic field dipole is currently decreasing, a possible imminent geomagnetic reversal or excursion would not be completely unexpected. In that case, such a phenomenon would represent one of the very few natural hazards that are really global. The South Atlantic Anomaly (SAA) is a great depression of the geomagnetic field strength at the Earth's surface, caused by a reverse magnetic flux in the terrestrial outer core. In analogy with critical point phenomena characterized by some cumulative quantity, we fit the surface extent of this anomaly over the last 400 yr with power law or logarithmic functions in reverse time, also decorated by log-periodic oscillations, whose final singularity (a critical point tc) reveals a great change in the near future (2034 ± 3 yr), when the SAA area reaches almost a hemisphere. An interesting aspect that has recently been found is the possible direct connection between the SAA and the global mean sea level (GSL). That the GSL is somehow connected with SAA is also confirmed by the similar result when an analogous critical-like fit is performed over GSL: the corresponding critical point (2033 ± 11 yr) agrees, within the estimated errors, with the value found for the SAA. From this result, we point out the intriguing conjecture that tc would be the time of no return, after which the geomagnetic field could fall into an irreversible process of a global geomagnetic transition that could be a reversal or excursion of polarity.

scholarly journals Toward a possible next geomagnetic transition?

2013 ◽  
Vol 1 (5) ◽  
pp. 5117-5139
Author(s):  
A. De Santis ◽  
E. Qamili ◽  
L. Wu
Keyword(s):  
Critical Point ◽  
Geomagnetic Field ◽  
Outer Core ◽  
Reverse Time ◽  
Geomagnetic Reversal ◽  
Rapid Changes ◽  
Global Mean Sea Level ◽  
Logarithmic Functions ◽  
Near Future ◽  
Global Mean

Abstract. The geomagnetic field is subject to possible reversals or excursions of polarity during its temporal evolution. Considering that: (a) the typical average time between one reversal and the next (the so-called chron) is around 300 000 yr, (b) the last reversal occurred around 780 000 yr ago, (c) more excursions (rapid changes of polarity) can occur within the same chron and (d) the geomagnetic field dipole is currently decreasing, a possible imminent geomagnetic reversal or excursion would not be completely unexpected. In that case, such a phenomenon would represent one of the very few natural hazards which are really global. The South Atlantic Anomaly (SAA) is a great depression of the geomagnetic field at the Earth's surface, caused by a reverse magnetic flux in the terrestrial outer core. In analogy with critical point phenomena characterised by some cumulative quantity, we fit the surface extent of this anomaly over the last 400 yr with power or logarithmic functions in reverse time, also decorated by log-periodic oscillations, whose final singularity (a critical point tc) reveals a great change in the near future (2034 ± 3 yr), when the SAA area reaches almost a hemisphere. An interesting aspect that has been recently found is the possible direct connection between the SAA and the global mean sea level (GSL). That the GSL is somehow connected with SAA is also confirmed from the similar result when an analogous critical-like fit is performed over GSL: the corresponding critical point (2033 ± 11 yr) agrees, within the estimated errors, with the value found for SAA. From this result, we point out the intriguing conjecture that tc would be the time of no return, after which the geomagnetic field could fall into an irreversible process of a global geomagnetic transition that could be a reversal or excursion of polarity.

scholarly journals Geomagnetic jerks characterization via spectral analysis

2012 ◽  
Vol 4 (1) ◽  
pp. 131-172
Author(s):  
B. Duka ◽  
A. De Santis ◽  
M. Mandea ◽  
A. Isac ◽  
E. Qamili
Keyword(s):  
Time Series ◽  
Geomagnetic Field ◽  
Synthetic Data ◽  
Power Spectra ◽  
Spatial Evolution ◽  
Spectral Techniques ◽  
Rapid Changes ◽  
Geomagnetic Jerks ◽  
Third Derivative ◽  
Harmonic Power

Abstract. In this study we have applied spectral techniques to analyze geomagnetic field time-series provided by observatories, and compared the results with those obtained from analogous analyses of synthetic data estimated from models. Then, an algorithm is here proposed to detect the geomagnetic jerks in time-series, mainly occurring in the Eastern component of the geomagnetic field. Applying such analysis to time-series generated from global models has allowed us to depict the most important space-time features of the geomagnetic jerks all over the globe, since the beginning of XXth century. Finally, the spherical harmonic power spectra of the third derivative of the main geomagnetic field has been computed from 1960 to 2002.5, bringing new insights to understanding the spatial evolution of these rapid changes of the geomagnetic field.

Economic Way of Thought and Legislationon Nonprofit Organizations

2012 ◽  
pp. 48-63
Author(s):  
L. Yakobson
Keyword(s):  
Nonprofit Organizations ◽  
Empirical Data ◽  
Nonprofit Sector ◽  
Social Medium ◽  
The State ◽  
Rapid Changes ◽  
Comparative Advantages ◽  
Essential Prerequisite

The article considers proper legislation as an essential prerequisite for actualization of NPOs comparative advantages. Restrictions imposed on NPOs are reasonable if they are compensated by benefits from greater trust. The rigidity of constrains and requirements should be optimized while accounting for peculiarities of a social medium, the state of the nonprofit sector, and the governments readiness to encourage the development of the latter. As empirical data suggests, Russian NPOs being on different stages of maturity need separate legal treatment. In the meanwhile, interests that prevail in the NPOs community are not always conducive to rapid changes.

Section 6.a Introduction

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Rebecca PRICE ◽  
Christine DE LILLE ◽  
Cara WRIGLEY ◽  
Kees DORST
Keyword(s):  
Case Studies ◽  
Organizational Leadership ◽  
Research Community ◽  
Design Management ◽  
Management Research ◽  
Research Methodologies ◽  
Organizational Research ◽  
Research Perspectives ◽  
Rapid Changes

There is an increasing need for organizations to adapt to rapid changes in society. This need requires organizations’ and the leader within them, to explore, recognize, build and exploit new capabilities. Researching such capabilities has drawn attention from the design management research community in recent years. Dominantly, research contributions have focused on perspectives of innovation and the strategic application of design with the researcher distanced from context. Descriptive and evaluative case studies of past organizational leadership have been vital, by building momentum for the design movement. However, there is a need now to progress toward prescriptive and explorative research perspectives that embrace context through practice and the simultaneous research of design.  Therefore, the aim of this track is to lead and progress discussion on research methodologies that support the research community in developing explorative and prescriptive research methodologies for context-orientated organizational research. This track brings together a group of diverse international researchers and practitioners to fuel discussion on design approaches and subsequent outcomes of prescriptive and explorative research methodologies.

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