scholarly journals Space weather effects on drilling accuracy in the North Sea

2005 ◽  
Vol 23 (9) ◽  
pp. 3081-3088 ◽  
Author(s):  
S. J. Reay ◽  
W. Allen ◽  
O. Baillie ◽  
J. Bowe ◽  
E. Clarke ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Field ◽  
North Sea ◽  
Survey Method ◽  
Magnetic Observatory ◽  
Magnetic Survey ◽  
Earth’S Magnetic Field ◽  
The North ◽  
Earth's Magnetic Field ◽  
The North Sea

Abstract. The oil industry uses geomagnetic field information to aid directional drilling operations when drilling for oil and gas offshore. These operations involve continuous monitoring of the azimuth and inclination of the well path to ensure the target is reached and, for safety reasons, to avoid collisions with existing wells. Although the most accurate method of achieving this is through a gyroscopic survey, this can be time consuming and expensive. An alternative method is a magnetic survey, where measurements while drilling (MWD) are made along the well by magnetometers housed in a tool within the drill string. These MWD magnetic surveys require estimates of the Earth's magnetic field at the drilling location to correct the downhole magnetometer readings. The most accurate corrections are obtained if all sources of the Earth's magnetic field are considered. Estimates of the main field generated in the core and the local crustal field can be obtained using mathematical models derived from suitable data sets. In order to quantify the external field, an analysis of UK observatory data from 1983 to 2004 has been carried out. By accounting for the external field, the directional error associated with estimated field values at a mid-latitude oil well (55° N) in the North Sea is shown to be reduced by the order of 20%. This improvement varies with latitude, local time, season and phase of the geomagnetic activity cycle. By accounting for all sources of the field, using a technique called Interpolation In-Field Referencing (IIFR), directional drillers have access to data from a "virtual" magnetic observatory at the drill site. This leads to an error reduction in positional accuracy that is close to matching that of the gyroscopic survey method and provides a valuable independent technique for quality control purposes.

The Earth's magnetic field variations at the Algerian magnetic observatory of Tamanrasset from 1932 to 2020.

2021 ◽  
Author(s):  
Lemgharbi Abdenaceur ◽  
Hamoudi Mohamed ◽  
Abtout Abdeslam ◽  
Abdelhamid Bendekken ◽  
Ener Aganou ◽  
...  
Keyword(s):  
Magnetic Field ◽  
International Association ◽  
Sampling Rate ◽  
Magnetic Data ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
Data Set ◽  
Secular Variations ◽  
The World ◽  
Earth's Magnetic Field

<p>In order to understand the spatial and temporal behavior of the Earth's magnetic field, scientists, following C.F. Gauss initiative in 1838 have established observatories around the world. More than 200 observatories aiming to continuously record, the time variations of the magnetic field vector and to maintain the best standard of the accuracy and resolution of the measurements.</p><p>This study focused on the acquisition and analysis of the magnetic data provided by the Algerian magnetic observatory of Tamanrasset (labelled TAM by the International Association of Geomagnetism and Aeronomy). This observatory is located in southern Algeria at 5.53°E longitude, 22.79°N Latitude. Its altitude is 1373 meters above msl. TAM is continuously running since 1932, using old brand variometers, like Mascart and La Cour with photographic recording at the very beginning. Nowadays modern electronic equipment are used in the framework of INTERMAGNET project. Very large geomagnetic database collected over a century is available. We will describe the history and the various improvement of the methods and instrumentation.</p><p>Preliminary analysis of time series of the observatory data allowed to distinguish two kinds of data: the first type, with low resolution, collected between 1932 and 1992. This data set comes from the annual, monthly, daily and hourly means. The second one with high resolution is represented by minutes and seconds sampling rate since 1993 when TAM was integrated to the world observatory network, INTERMAGNET. Part of the second dataset contains many gaps. We try to fill these gaps thanks to mathematical methods. Absolute measurements and repeat station data allow better accuracy in the secular variations and an improved regional model.</p><p>Keywords: TAM observatory, temporal variation, terrestrial magnetic field, secular variations, INTERMAGNET.</p>

Aerial Magnetic Survey

1950 ◽  
Vol 3 (2) ◽  
pp. 121-132 ◽  
Author(s):  
G. E. Roberts
Keyword(s):  
Magnetic Field ◽  
United States ◽  
World Wide ◽  
Presidential Address ◽  
The United States ◽  
Aerial Survey ◽  
Magnetic Survey ◽  
Earth’S Magnetic Field ◽  
General Survey ◽  
Earth's Magnetic Field

In his Presidential Address to the Institute this year the Astronomer Royal, Sir Harold Spencer Jones, stresses the importance of an early resumption of the general survey of the Earth's magnetic field and developments in airborne magnetometers in the United States have suggested the possibility of using aircraft for this purpose. The techniques which are available for aerial survey will be discussed in this paper and an attempt will be made to evaluate the relative merits of conducting world wide magnetic surveys by sea and by air.

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.

On the possibility of an intra-Earth source of Sq-variations of the Earth's magnetic field

2021 ◽  
Author(s):  
Beibit Zhumabayev ◽  
Ivan Vassilyev
Keyword(s):  
Magnetic Field ◽  
Coordinate System ◽  
Local Coordinate System ◽  
Spherical Body ◽  
Time Of Day ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
The Earth ◽  
Earth's Magnetic Field ◽  
Variation Vector

<p>Analysis of the direction of motion of the vector of Sq-variations of the Earth's magnetic field, depending on the time of day and season of the year, shows that the observed Sq-variation is similar to the magnetic field created by a negatively charged spherical body moving in space. Transformations of the Sq-variation vector from the local coordinate system of the magnetic observatory to the ecliptic coordinate system are performed. A possible connection between the origin of the Sq-variation and the electric dipole moment of quartz molecules oriented towards the center of the Earth during the crystallization of the mineral and causing the electric and dipole magnetic fields of the Earth is considered. A scheme for conducting an experiment that allows us to separate the effects of extraterrestrial and extraterrestrial sources of Sq-variations is proposed.</p>

Paleomagnetism of the Abitibi dyke swarm, southern Superior Province, and implications for the Logan Loop

1993 ◽  
Vol 30 (9) ◽  
pp. 1886-1897 ◽  
Author(s):  
Richard E. Ernst ◽  
Kenneth L. Buchan
Keyword(s):  
Magnetic Field ◽  
Secular Variation ◽  
Dyke Swarm ◽  
Earth’S Magnetic Field ◽  
The North ◽  
Apparent Polar Wander Path ◽  
Earth's Magnetic Field ◽  
Reversed Polarity ◽  
Magma Pulses ◽  
Middle Proterozoic

The trace of the Middle Proterozoic Logan Loop of the North American apparent polar wander path is controversial. The older 1270–1110 Ma limb of the loop is poorly constrained, while the depth of the loop, based on the 1110–1080 Ma Keweenawan data of the younger limb, is thought by some to be largely an artifact of reversal asymmetry in the Earth's magnetic field. Paleomagnetism of the 1141 Ma Abitibi mafic dyke swarm is one of the keys to constraining the geometry of the Logan Loop.Unfortunately, previous paleomagnetic studies failed to distinguish dykes of the northeast-trending Middle Proterozoic olivine-bearing Abitibi swarm from subparallel Early Proterozoic olivine-free Biscotasing (formerly Preissac) dykes, and hence paleomagnetic poles determined in these studies should no longer be used. In the present study, sampling of eight Abitibi dykes has identified 23 normally magnetized sites in four dykes and, for the first time, five reversely magnetized sites in three dykes. One of the normally magnetized sites corresponds to the locality for which a high-precision U–Pb age was previously reported. A baked contact test establishes that the characteristic remanence of one normally magnetized dyke is primary. In addition, sites along individual dykes exhibit much smaller secular variation than is observed between dykes, indicating that the remanences of the other dykes are also primary. One of the normally magnetized dykes, the 700 km long Great Abitibi dyke, exhibits two primary directions that correspond to two geochemically distinct magma pulses. The five normally magnetized units, which consist of four separate dykes plus the second pulse of the Great Abitibi dyke, yield a well-defined mean paleomagnetic pole at 42.8°N, 151.5°W, dm = 16.3°, dp = 12.5°. It falls close to the reversely magnetized poles from the Keweenawan Track and establishes a minimum depth for the Logan Loop of about 40°. The reversed-polarity data from three other dykes are more scattered and may not average out secular variation. Hence, the present study is inconclusive regarding asymmetry of the Earth's magnetic field at 1141 Ma, even though a mean pole based on combined normal-and reversed-polarity dykes is indistinguishable from that based on normal-polarity dykes alone.

scholarly journals Roald Amundsen's contributions to our knowledge of the magnetic fields of the Earth and the Sun

2011 ◽  
Vol 2 (2) ◽  
pp. 99-112
Author(s):  
A. Egeland ◽  
C. S. Deehr
Keyword(s):  
Magnetic Field ◽  
Analytical Techniques ◽  
Short Review ◽  
Polar Regions ◽  
Earth’S Magnetic Field ◽  
Late 20Th Century ◽  
The North ◽  
Earth's Magnetic Field ◽  
Regular Manner

Abstract. Roald Amundsen (1872–1928) was known as one of the premier polar explorers in the golden age of polar exploration. His accomplishments clearly document that he has contributed to knowledge in fields as diverse as ethnography, meteorology and geophysics. In this paper we will concentrate on his studies of the Earth's magnetic field. With his unique observations at the polar station Gjøahavn (geographic coordinates 68°37'10'' N; 95°53'25'' W), Amundsen was first to demonstrate, without doubt, that the north magnetic dip-pole does not have a permanent location, but steadily moves its position in a regular manner. In addition, his carefully calibrated measurements at high latitudes were the first and only observations of the Earth's magnetic field in the polar regions for decades until modern polar observatories were established. After a short review of earlier measurements of the geomagnetic field, we tabulate the facts regarding his measurements at the observatories and the eight field stations associated with the Gjøa expedition. The quality of his magnetic observations may be seen to be equal to that of the late 20th century observations by subjecting them to analytical techniques showing the newly discovered relationship between the diurnal variation of high latitude magnetic observations and the direction of the horizontal component of the interplanetary magnetic field (IMF By). Indeed, the observations at Gjøahavn offer a glimpse of the character of the solar wind 50 yr before it was known to exist. Our motivation for this paper is to illuminate the contributions of Amundsen as a scientist and to celebrate his attainment of the South Pole as an explorer 100 yr ago.

scholarly journals Solar storms may trigger sperm whale strandings: explanation approaches for multiple strandings in the North Sea in 2016

2017 ◽  
Vol 17 (4) ◽  
pp. 336-344 ◽  
Author(s):  
Klaus Heinrich Vanselow ◽  
Sven Jacobsen ◽  
Chris Hall ◽  
Stefan Garthe
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
North Sea ◽  
Sperm Whales ◽  
The North ◽  
Particle Flows ◽  
Terrestrial Life ◽  
The North Sea ◽  
Solar Storms ◽  
Geomagnetic Anomalies

AbstractThe Earth's atmosphere and the Earth's magnetic field protects local life by shielding us against Solar particle flows, just like the sun's magnetic field deflects cosmic particle radiation. Generally, magnetic fields can affect terrestrial life such as migrating animals. Thus, terrestrial life is connected to astronomical interrelations between different magnetic fields, particle flows and radiation. Mass strandings of whales have often been documented, but their causes and underlying mechanisms remain unclear. We investigated the possible reasons for this phenomenon based on a series of strandings of 29 male, mostly bachelor, sperm whales (Physeter macrocephalus) in the southern North Sea in early 2016. Whales’ magnetic sense may play an important role in orientation and migration, and strandings may thus be triggered by geomagnetic storms. This approach is supported by the following: (1) disruptions of the Earth's magnetic field by Solar storms can last about 1 day and lead to short-term magnetic latitude changes corresponding to shifts of up to 460 km; (2) many of these disruptions are of a similar magnitude to more permanent geomagnetic anomalies; (3) geomagnetic anomalies in the area north of the North Sea are 50–150 km in diameter; and (4) sperm whales swim about 100 km day−1, and may thus be unable to distinguish between these phenomena. Sperm whales spend their early, non-breeding years in lower latitudes, where magnetic disruptions by the sun are weak and thus lack experience of this phenomenon. ‘Naïve’ whales may therefore become disoriented in the southern Norwegian Sea as a result of failing to adopt alternative navigation systems in time and becoming stranded in the shallow North Sea.

scholarly journals RESPONSE OF BIOLOGICAL SYSTEMS TO GEOMAGNETIC STORMS

2018 ◽  
Vol 3 (5) ◽  
pp. 126-131
Author(s):  
A. A. Bazhenov ◽  
M. V. Prikop ◽  
A. S. Averina ◽  
V. V. Sukhovskaya ◽  
A. V. Ukhova
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Activity ◽  
Geomagnetic Storms ◽  
Biological Systems ◽  
Magnetic Storms ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
Motion Activity ◽  
Earth's Magnetic Field ◽  
The City

At present, influence of weak magnetic fields associated with solar and geomagnetic activity on biological systems is gaining more interest. Taking into account the accumulated data on the influence of geomagnetic storms on different biological levels, it is obvious that the mechanism of influence is universal. One of the approaches in this search may be the study of patterns and differences in the response to geomagnetic storms of various biological objects. As a research material served: data on the number of ambulance calls in the city of Irkutsk for acute myocardial infarction, cerebral infarction; results of retrospective analysis of the number of spontaneous parturition of the city of Irkutsk; data on the motion activity of fruit fly Drosophyla melanogaster, obtained by automated monitoring. The investigated indicators were compared with the parameters of geomagnetic activity at different time scales. As indicators of geomagnetic storms, three-hour (ap) and daily (Ap) equal to the average amplitude of variation of the geomagnetic field of the Earth. In the case of comparing the motion activity of fruit flies with magnetic storms, the local companions of the Earth’s magnetic field were additionally considered according to the data of the Irkutsk magnetic observatory. As a result of the conducted studies it was established that the detected response of biological systems depends on the characteristics of the state of the Earth’s magnetic field, which falls on the period of passage of magnetic storms. The obtained data also indicate possible gender differences in the response to the effects of the geomagnetic factor by organisms of different levels.

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