scholarly journals The archaeomagnetic field recorded in ancient kiln walls in Si Satchanalai, Sukhothai

2021 ◽  
Vol 2145 (1) ◽  
pp. 012049
Author(s):  
R Supakulopas
Keyword(s):  
Magnetic Field ◽  
Confidence Limit ◽  
Field Model ◽  
Luminescence Dating ◽  
Human History ◽  
Earth’S Magnetic Field ◽  
Argon Dating ◽  
Dating Methods ◽  
Earth's Magnetic Field ◽  
The Mean

Abstract Archaeological dating is crucial in archaeology as it is a key to understand human history. However, traditional dating methods used by archaeologists such as potassium-argon dating and luminescence dating can provide ambiguous age results, e.g., argon loss during the dating returns young apparent ages. Therefore, I plan to establish an archaeomagnetic secular variation (ASV) curve to resolve this problem and use the ASV curve as an alternative tool to date archaeological artefacts. However, archaeomagnetic data in Thailand are absent from literature. Therefore, the ASV curve cannot be constructed from the archaeomagnetic data for this locality. To provide archaeomagnetic data to construct the ASV curve, the directions of the Earth’s magnetic field recorded in kiln walls from Ban Ko Noi (KN123, age 1,370 ± 100 A.D.), Si Satchanalai were measured. The mean declination and inclination of 49.6° and 32.6° with 95% confidence limit of 5.4° were determined from 10 samples from kiln KN123. Mean directions from this study were also compared with the directions of the Earth’s magnetic field in Thailand during 1,370 A.D. from the global archaeomagnetic field model ARCH3k.1. Declination and inclination from this study show significant departure from the field predicted by the ARCH3k.1 model.

HORIZONTAL MOTIONS IN RADAR ECHOES FROM AURORA

1958 ◽  
Vol 36 (12) ◽  
pp. 1661-1671 ◽  
Author(s):  
G. F. Lyon ◽  
A. Kavadas
Keyword(s):  
Magnetic Field ◽  
Magnetic Disturbance ◽  
Statistical Relation ◽  
Earth’S Magnetic Field ◽  
The West ◽  
Mean Velocity ◽  
The North ◽  
Radar Echoes ◽  
Earth's Magnetic Field ◽  
The Mean

A systematic motion of 48.2 Mc/sec echoes associated with aurora is found at Saskatoon. The motion is towards the west before midnight and towards the east after midnight, the mean velocity in either direction showing a statistical relation to variations in the earth's magnetic field. No correlation is found between individual echo velocity and magnetic disturbance, and no period of zero velocity is observed. There is also evidence of an ordered relation between motion in the north–south direction and disturbances in the earth's magnetic field.

scholarly journals RECENSIÓN. Preusser, F. Hajdas, I. & Ivy-Ochs. S. (eds.) 2008. Recent progress in Quaternary dating methods. E & G Quaternary Science Journal, 252 pp.

2021 ◽  
Vol 24 (1) ◽  
pp. 105
Author(s):  
Juan Usera
Keyword(s):  
Magnetic Field ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Recent Progress ◽  
Science Journal ◽  
Earth’S Magnetic Field ◽  
Spin Resonance ◽  
Dating Methods ◽  
Earth's Magnetic Field ◽  
Sobre Todo

La datación de los materiales cuaternarios ha sido, desde siempre, uno de los principales problemas con los que se han encontrado los investigadores que trabajan en esta Época o Sistema. Esto es verificable por los numerosos trabajos dedicados a precisar la edad de los afloramientos mediante estudios isotópicos, Luminiscencia, Racemización de aminoácidos, reacciones inducidas por la radiación cósmica, Paleomagnetismo, ESR (Electron Spin Resonance), etc. Los trabajos editados por Preusser et al. (2008) recogen una parte importante de los métodos más recientes utilizados en la datación de los materiales cuaternarios. Algunos son bien conocidos como las dataciones por isótopos del Carbono, como el C14, o del U234/Th230. Otros métodos de datación de materiales cuaternarios no son tan conocidos, como la utilización de la EMF (Earth’s Magnetic Field. Así mismo, se tratan las dataciones por Luminiscencia. El trabajo continúa con un análisis de los resultados de las dataciones basadas en las señales de ESR, en cuarzos sometidos a diferentes situaciones ambientales. Otro de los procedimientos expuestos en este número especial de E & G Quaternary Science Revue, son las dataciones a partir de nuclidos cosmogénicos. Por último, hay que tener en cuenta, que la mayor parte de las propuestas de estos procedimientos de datación se hacen aplicables sobre todo a materiales continentales: depósitos fluviales, glaciares, eólicos y también yacimientos arqueológicos, aunque hay referencias a lo largo de los trabajos a su aplicación con éxito a materiales de origen marino.

scholarly journals Observing Earth’s magnetic environment with the GRACE-FO mission

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
C. Stolle ◽  
I. Michaelis ◽  
C. Xiong ◽  
M. Rother ◽  
Th. Usbeck ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Local Time ◽  
Noise Level ◽  
High Amplitude ◽  
Magnetic Data ◽  
Storm Event ◽  
Earth’S Magnetic Field ◽  
Magnetic Field Model ◽  
Earth's Magnetic Field ◽  
The Mean

AbstractThe Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission carries magnetometers that are dedicated to enhance the satellite’s navigation. After appropriate calibration and characterisation of artificial magnetic disturbances, these observations are valuable assets to characterise the natural variability of Earth’s magnetic field. We describe the data pre-processing, the calibration, and characterisation strategy against a high-precision magnetic field model applied to the GRACE-FO magnetic data. During times of geomagnetic quiet conditions, the mean residual to the magnetic model is around 1 nT with standard deviations below 10 nT. The mean difference to data of ESA’s Swarm mission, which is dedicated to monitor the Earth’s magnetic field, is mainly within ± 10 nT during conjunctions. The performance of GRACE-FO magnetic data is further discussed on selected scientific examples. During a magnetic storm event in August 2018, GRACE-FO reveals the local time dependence of the magnetospheric ring current signature, which is in good agreement with results from a network of ground magnetic observations. Also, derived field-aligned currents (FACs) are applied to monitor auroral FACs that compare well in amplitude and statistical behaviour for local time, hemisphere, and solar wind conditions to approved earlier findings from other missions including Swarm. On a case event, it is demonstrated that the dual-satellite constellation of GRACE-FO is most suitable to derive the persistence of auroral FACs with scale lengths of 180 km or longer. Due to a relatively larger noise level compared to dedicated magnetic missions, GRACE-FO is especially suitable for high-amplitude event studies. However, GRACE-FO is also sensitive to ionospheric signatures even below the noise level within statistical approaches. The combination with data of dedicated magnetic field missions and other missions carrying non-dedicated magnetometers greatly enhances related scientific perspectives.

scholarly journals Earth’s Magnetic Field Holds Clues to Human History

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Alice McBride
Keyword(s):  
Magnetic Field ◽  
Human History ◽  
Earth’S Magnetic Field ◽  
Geomagnetic Data ◽  
Earth's Magnetic Field

Items burned in the sacking of ancient cities are time capsules of geomagnetic data.

The Atlas of the Earth's Magnetic Field

2012 ◽  
Author(s):  
A. Soloviev ◽  
A. Khokhlov ◽  
E. Jalkovsky ◽  
A. Berezko ◽  
A. Lebedev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

Atlas of Earth's magnetic field

2011 ◽  
Vol 12 (2) ◽  
pp. 1-9
Author(s):  
A. E. Berezko ◽  
A. V. Khokhlov ◽  
A. A. Soloviev ◽  
A. D. Gvishiani ◽  
E. A. Zhalkovsky ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

scholarly journals Night-time Sferic Propagation at Frequencies Below 10 KHz

1967 ◽  
Vol 20 (1) ◽  
pp. 101 ◽  
Author(s):  
KJW Lynn ◽  
J Crouchley
Keyword(s):  
Magnetic Field ◽  
Geographic Distribution ◽  
Angle Of Incidence ◽  
European Studies ◽  
Earth’S Magnetic Field ◽  
Night Time ◽  
The West ◽  
Earth's Magnetic Field ◽  
Effective Angle

Results of a study at Brisbane of individual night-time sferics of known origin are described. A propagation attenuation minimum was observed in the 3-6 kHz range. The geographic distribution of sferic types was also examined. Apparent propagation asynunetries were observed, since sferics were detected at greater ranges to the west than to the east at 10 kHz, whilst the number of tweek-sferics arising from the east was about four times that arising from the west. Comparison with European studies suggest that these asymmetries are general. These results are then " interpreted in terms of an ionospheric reflection cgefficient which is a function of the effective angle of incidence of the wave on the ionosphere and of orientation with respect to the Earth's magnetic field within the ionosphere.

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