scholarly journals Commission 19: Rotation of the Earth

1985 ◽  
Vol 19 (1) ◽  
pp. 193-205 ◽  
Author(s):  
Ya. S. Yatskiv ◽  
W. J. Klepczynski ◽  
F. Barlier ◽  
H. Enslin ◽  
C. Kakuta ◽  
...  
Keyword(s):  
Time Frame ◽  
Laser Ranging ◽  
Earth’S Rotation ◽  
The Moon ◽  
Earth's Rotation ◽  
The Earth ◽  
Long Time ◽  
Terrestrial Reference System ◽  
Rotation Of The Earth

During the period, work on the problem of the Earth’s rotation has continued to expand and increase its scope. The total number of institutions engaged in the determination of the Earth’s rotation parameters (ERP) by different techniques has been increased significantly. The rotation of the Earth is currently measured by classical astrometry, Doppler and laser satellite tracking, laser ranging of the Moon, and radio interferometry. Several long time series of the ERP are available from most of these techniques, in particular, those made during the Main Campaign of the MERIT project. The various series have been intercompared and their stability, in the time frame of years to days, has been estimated for the purposes of establishing a new conventional terrestrial reference system (COTES). On the other hand, the difficulties of maintaining a regular operation for laser ranging to the Moon (LLR) have been recognized. It resulted in the proposal to organize an one-month campaign of observations in 1985 in order to complement the COTES collocation program and to allow additional intercomparisons with other techniques.

Addendum 2020 to ‘Measurement of the Earth’s rotation: 720 BC to AD 2015’

2021 ◽  
Vol 477 (2246) ◽  
pp. 20200776
Author(s):  
L. V. Morrison ◽  
F. R. Stephenson ◽  
C. Y. Hohenkerk ◽  
M. Zawilski
Keyword(s):  
Angular Momentum ◽  
Earth’S Rotation ◽  
The Sun ◽  
Earth's Rotation ◽  
Moon System ◽  
Link Type ◽  
The Earth ◽  
Solar Eclipses ◽  
Rotation Of The Earth

Historical reports of solar eclipses are added to our previous dataset (Stephenson et al. 2016 Proc. R. Soc. A 472 , 20160404 ( doi:10.1098/rspa.2016.0404 )) in order to refine our determination of centennial and longer-term changes since 720 BC in the rate of rotation of the Earth. The revised observed deceleration is −4.59 ± 0.08 × 10 −22  rad s −2 . By comparison the predicted tidal deceleration based on the conservation of angular momentum in the Sun–Earth–Moon system is −6.39 ± 0.03 × 10 −22  rad s −2 . These signify a mean accelerative component of +1.8 ± 0.1 × 10 −22  rad s −2 . There is also evidence of an oscillatory variation in the rate with a period of about 14 centuries.

scholarly journals Historic Variations in the Rotation of the Earth

1972 ◽  
Vol 48 ◽  
pp. 160-161
Author(s):  
R. R. Newton
Keyword(s):  
Earth’S Rotation ◽  
The Moon ◽  
Earth's Rotation ◽  
Tidal Friction ◽  
The Past ◽  
The Earth ◽  
Rotation Of The Earth

The purpose of this work is to investigate changes in the rotation of the Earth in the past few thousand years. Since most available observations involve the Moon, study of the Earth's rotation is inseparable from study of the Moon's motion. Since it is doubtful that present theories of tidal friction account for the present acceleration (Spencer Jones, 1939; Van Flandern, 1970; Pariisky et al., 1972) of the Moon, we cannot safely assume that consequence of the theories which says that tidal friction has been almost constant.

scholarly journals Specific Formation of the Bermuda and Dragon Triangles as a Result of a Change in the Axis of the Earth’s Rotation

2020 ◽  
pp. 19-25
Keyword(s):  
South America ◽  
Southeast Asia ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Axis Of Rotation ◽  
The Earth ◽  
Rotation Of The Earth ◽  
North And South America ◽  
North And South

The Bermuda Triangle is located in the area of the archipelago between North and South America and the Dragon Triangle is located in the area of the archipelago in Southeast Asia. There is a great resemblance between these two triangular areas; both were formed following special geological and tectonic conditions. It is herein proposed that their creation stems from the change in location of the axis of rotation of the earth and, accordingly, the change in the location of the equator.

scholarly journals Basic Problems in the Kinematics of the Rotation of the Earth

1979 ◽  
Vol 82 ◽  
pp. 7-18 ◽  
Author(s):  
Bernard Guinot
Keyword(s):  
Earth Rotation ◽  
Rotation Axis ◽  
Earth’S Rotation ◽  
International Astronomical Union ◽  
Earth's Rotation ◽  
The Earth ◽  
International Astronomical ◽  
Rotation Of The Earth

With the advent of more precise methods for measuring Earth rotation, a number of corrections to the apparent directions in space, to the terrestrial references, and to the rotation axis motion have to be carefully applied. It is the duty of the international Astronomical Union to give recommended or conventional expressions of these corrections in order to avoid inextricable difficulties in discussing the evaluated results. However, this task is not sufficient. The concepts used in the description of the Earth's rotation are somewhat obscured by traditions. They should be purified by removing notions which are not directly relevant.

Long-term changes in the rotation of the Earth : 700 B.C. to A.D. 1980

1984 ◽  
Vol 313 (1524) ◽  
pp. 47-70 ◽  
Keyword(s):  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Temporal Behaviour ◽  
Tidal Friction ◽  
The Past ◽  
The Earth ◽  
Tidal Changes ◽  
Rotation Of The Earth ◽  
Tidal Variations

Occultations of stars by the Moon, and solar and lunar eclipses are analysed for variations in the Earth’s rotation over the past 2700 years. Although tidal braking provides the dominant, long-term torque, it is found that the rate of rotation does not decrease uniformly as would be expected if tidal friction were the only mechanism affecting the Earth’s rotation. There are also non-tidal changes present that vary on timescales ranging from decades to millennia. The magnitudinal and temporal behaviour of these non-tidal variations are evaluated in this paper.

scholarly journals Forced Nutation and Irregularity of the Rotation of the Earth

1980 ◽  
Vol 78 ◽  
pp. 235-237
Author(s):  
G. P. Pilnik
Keyword(s):  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Astronomical Observations ◽  
The Earth ◽  
Short Period ◽  
Rotation Of The Earth ◽  
The Waves

It is possible, in principle, to derive from astronomical observations both the tidal and nutational variations in the rotation of the Earth. However, in practice there are a number of difficulties. To detect the waves with periods of 18.6, 1.0 and 0.5 year one could use UT1-TAI. Unfortunately, this is impossible because of the lack of sufficiently long series of observations and because of significant non-periodic irregularities in the rate of the Earth's rotation. In addition, the annual wave consists of several harmonics of different natures which cannot be separated from one another. Investigation of short-period nutations is more promising, but it is also connected with specific difficulties.

II.—“The Origin of Mountains”: a Reply

1913 ◽  
Vol 10 (10) ◽  
pp. 434-435
Author(s):  
Rev. O. Fisher
Keyword(s):  
Rotation Velocity ◽  
Earth’S Rotation ◽  
The Moon ◽  
The Earth ◽  
Low Latitudes ◽  
Rotation Of The Earth ◽  
External Forces ◽  
Dense Liquid ◽  
Do So ◽  
Geological Magazine

I am content to leave to the readers of the Geological Magazine the question whether Colonel Burrard's theory of the elevation of mountains and Mr. Hayford's of the distribution of density to cause isostasy are more in accordance with geological phenomena than my theory of mountain roots supported in a dense liquid substratum. But in Colonel Burrard's reply to my paper in the Magazine for June there is a fundamental but specious error. I wrote: “Is it not possible that the earth's rotation may impart to it a ‘gyroscopic’ quasi rigidity, which may enable it to withstand the deforming influence of external forces [the attraction of the moon and sun], although at the same time forces internal to the earth will be unaffected by it.” To this Colonel Burrard replies: ”Mr. Fisher has argued that the rotation of the earth will give to the liquid interior an effective rigidity; but this rotation has conferred no rigidity upon our oceans, and even if it did render the liquid interior rigid, it would only do so in low latitudes where the rotation velocity is high. I understand, moreover, that the earth's interior was assumed by Mr. Fisher to be liquid, in order to explain the floatation of the crust. If the liquid is now proved to be rigid, the crust cannot be floating upon it.”

The Effect of the Earth’s Rotation on Channel Flow

1986 ◽  
Vol 53 (1) ◽  
pp. 198-202 ◽  
Author(s):  
C. G. Speziale
Keyword(s):  
Channel Flow ◽  
Stokes Equations ◽  
Rectangular Channel ◽  
Turbulent Channel Flow ◽  
Navier Stokes ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
The Earth ◽  
Laminar Channel Flow ◽  
Rotation Of The Earth

The influence that the rotation of the earth has on laminar channel flow is investigated theoretically. The full nonlinear Navier-Stokes equations relative to a reference frame rotating with the earth are solved numerically for laminar flow in a rectangular channel whose axis is aligned east-west: the orientation which yields the most drastic effect. It is demonstrated that for channels of moderate width (less than 1 ft for the flow of most liquids), the rotation of the earth can give rise to a roll instability which has a severe distortional effect on the classical parabolic velocity profile. Consequently, the usual assumption made of neglecting the effect of the earth’s rotation in the calculation of channel flow can lead to serious errors unless the channel is substantially smaller than this size. It is briefly shown that similar effects would be expected for turbulent channel flow when the channel width is approximately an order of magnitude larger.

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