Gravity acceleration changes in Russian stations of comparing absolute gravimeters

2021 ◽  
Vol 977 (11) ◽  
pp. 8-15
Author(s):  
V.D. Yushkin ◽  
L.V. Zotov ◽  
A.V. Basmanov ◽  
R.A. Sermyagin
Keyword(s):  
Gravitational Field ◽  
Satellite Data ◽  
Gravity Changes ◽  
Grace Data ◽  
Urgent Task ◽  
The Absolute ◽  
Gravity Network ◽  
Gravity Acceleration

The article deals with the study of changes in the values of gravitational accelerations at the Russian comparison’s sites of the absolute gravimeters “Pulkovo”, “Svetloye” and “Zvenigorod” for the years of 2007–2013. A significant increase of the values instead of the expected decrease was obtained. The authors make an attempt to reveal the reasons for that basing on the calculation of the change in the gravitational field using the Bouguer and Faye corrections. The estimates do not fully explain the phenomenon, according neither to gravimeters nor to satellite data. At the sites of “Pulkovo” and “Svetloye”, the measured changes in the values differ from the calculated ones by +5,7 and 6,6 μGal, which significantly exceeds the errors of the absolute gravimeters. The change of the gravity varies from satellites GRACE data by 9,4 μGal at the “Zvenigorod” site. This may be due to local hydrological reasons. Determining the causes of gravity changes at the absolute stations of gravity network is an urgent task.

scholarly journals Measurement of absolute gravity acceleration in Firenze

2011 ◽  
Vol 3 (1) ◽  
pp. 43-64
Author(s):  
M. de Angelis ◽  
F. Greco ◽  
A. Pistorio ◽  
N. Poli ◽  
M. Prevedelli ◽  
...  
Keyword(s):  
Absolute Gravity ◽  
Noise Condition ◽  
Study Region ◽  
Gravity Measurements ◽  
European Laboratory ◽  
The Absolute ◽  
Gravity Network ◽  
Acceleration Of Gravity ◽  
Newtonian Constant ◽  
Gravity Acceleration

Abstract. This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) μGal and (980 492 048.3 ± 3.0) μGal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

Hydrogeology correction in the gravitational field from satellite data

2018 ◽  
Vol 931 (1) ◽  
pp. 2-7
Author(s):  
V.D. Jushkin ◽  
L.V. Zotov ◽  
O.A. Khrapenko
Keyword(s):  
Gravitational Field ◽  
Oil And Gas ◽  
Repeated Measurements ◽  
Geological Factors ◽  
Grace Satellite ◽  
Gas Pumping ◽  
Acceleration Of Gravity ◽  
Determination Of Parameters ◽  
Gravity Acceleration

The results of repeated measurements of the acceleration of gravity by the Russian absolute ballistic field gravimeter GABL-M on points of oil and gas deposits in the permafrost over a five year period are presented. The changes of gravity acceleration by the absolute gravimeter and GRACE satellite were compared. The results of comparisons of differences gravity acceleration by ballistic gravimeter GABL-M and relative Canadian gravimeters CG5 were [i]shown. The errors in determination of parameters of the gravitational field ballistic gravimeter GABL-M and CG5 gravimeters group were presented. The method of measurement with the gravimeter GABL-M and the method of determining the vertical gradients relative CG5 gravity meters was described. The necessity of introducing corrections of hydrogeology is caused by influence of hydro geological factors on the gravitational field in the permafrost. They are comparable with the values of the field change in the result of gas pumping.

scholarly journals Co-Seismic and Post-Seismic Temporal and Spatial Gravity Changes of the 2010 Mw 8.8 Maule Chile Earthquake Observed by GRACE and GRACE Follow-on

2020 ◽  
Vol 12 (17) ◽  
pp. 2768
Author(s):  
Wei Qu ◽  
Yaxi Han ◽  
Zhong Lu ◽  
Dongdong An ◽  
Qin Zhang ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Hanging Wall ◽  
Suppressive Effect ◽  
Gravity Gradient ◽  
Dislocation Model ◽  
Seismogenic Fault ◽  
First Order ◽  
Gravity Changes ◽  
Maule Earthquake ◽  
Temporal And Spatial

The Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-on (GRACE-FO) satellites are important for studying regional gravitational field changes caused by strong earthquakes. In this study, we chose Chile, one of Earth’s most active seismic zones to explore the co-seismic and post-seismic gravitational field changes of the 2010 Mw 8.8 Maule earthquake based on longer-term GRACE and the newest GRACE-FO data. We calculated the first-order co-seismic gravity gradient changes (GGCs) and probed the geodynamic characteristics of the earthquake. The earthquake caused significant positive gravity change on the footwall and negative gravity changes on the hanging wall of the seismogenic fault. The time series of gravity changes at typical points all clearly revealed an abrupt change caused by the earthquake. The first-order northern co-seismic GGCs had a strong suppressive effect on the north-south strip error. GRACE-FO results showed that the latest post-seismic gravity changes had obvious inherited development characteristics, and that the west coast of Chile maybe still affected by the post-seismic effect. The cumulative gravity changes simulated based on viscoelastic dislocation model is approximately consistent with the longer-term GRACE and the newest GRACE-FO observations. Our results provide important reference for understanding temporal and spatial gravity variations associated with the co-seismic and post-seismic processes of the 2010 Maule earthquake.

scholarly journals Refinement of parameters gravitational anomaly relative to the focal zone of the 2011 earthquake (Japan) based on satellite data

2021 ◽  
Vol 333 ◽  
pp. 02011
Author(s):  
Tatyana Rubleva ◽  
Konstantin Simonov ◽  
Valentin Kashkin ◽  
Anna Malkanova ◽  
Roman Odintsov
Keyword(s):  
Gravitational Field ◽  
Satellite Data ◽  
Gravitational Anomaly ◽  
Space System ◽  
Aftershock Activity ◽  
Focal Area ◽  
Focal Zone ◽  
Gravitational Anomalies

The aim of this work is to study gravitational anomalies that have arisen in the region of the sources of strong underwater earthquakes with a magnitude of Mw > 8. For this purpose, data obtained by the GRACE space system were used. Variations of the EWH program with a period of 30 days were investigated relative to the focal area of the 2011 Japanese earthquake for the period 2010-2012. It was found that during the preparation of an earthquake, the EWH values significantly increase in this area for three months, with aftershock activity, the EWH values decrease within a month. Maps of variations of the EWH parameter in the conditions of a disturbed geomedia and in background seismic conditions are constructed. The indices of the anomaly δEWH were calculated, which made it possible to analyze in more detail the local gravitational field for the investigated focal zone.

scholarly journals Joint Uses of VLBI with Astronomical Optical Instruments for Studying Vertical Changes

1988 ◽  
Vol 129 ◽  
pp. 421-421
Author(s):  
Li Zhi-sen ◽  
Zhang Guo-dong ◽  
Han Yan-ben
Keyword(s):  
Gravitational Field ◽  
Vertical Direction ◽  
Gravitational Acceleration ◽  
Absolute Value ◽  
Optical Instruments ◽  
The Earth ◽  
Effective Instrument ◽  
Vertical Changes ◽  
The Absolute

The description of the gravitational field at the surface of the Earth requires two quantities: the absolute value of the gravitational acceleration and the gravitational direction (deviation from vertical direction). At present, the various gravimeters measure the former quantity, and there is no effective instrument for monitoring the latter. This shortcoming seriously affects the comprehension and further knowledge of the gravitational field.

Reduction of geometric leveling results to a system of normal heights using the global gravity models of the Earth

2018 ◽  
Vol 935 (5) ◽  
pp. 2-9
Author(s):  
K.I. Markovich
Keyword(s):  
Gravitational Field ◽  
Gravity Models ◽  
Mean Error ◽  
The Earth ◽  
Global Gravity ◽  
Normal Heights ◽  
The Republic ◽  
Acceleration Of Gravity ◽  
Gravity Acceleration ◽  
Global Gravity Models

The possible range of application of models of the Earth’s gravitational field is considered in the article by reducing the results of geometric leveling to a system of normal heights. The accuracy of the global gravity models EGM2008, EIGEN-6C4, GECO on the gravity acceleration differences calculated for the territory of the Republic of Belarus by the results of instrumental gravimetric measurements and obtained from gravity models was estimated. Areas of Belarus are determined for which the gravitational correction for the transition to the system of normal heights will be caused by the deviation of the level surfaces of the normal gravitational field from the actual, and not by the errors of the gravitational models in the form of acceleration of gravity. It is shown that the error of the gravitational correction obtained from the data of gravity models for the territory of Belarus is many times less than the permissible random mean error of geometric leveling of the first class.

The Performances of GRACE Mascon Solutions in Studying Seismic Deformations

2020 ◽  
Author(s):  
Lan Zhang ◽  
He Tang ◽  
Le Chang ◽  
Wenke Sun
Keyword(s):  
Tohoku Earthquake ◽  
Gravity Change ◽  
Mathematical Treatment ◽  
Seismic Signals ◽  
Gaussian Filter ◽  
Seismic Deformations ◽  
Gravity Changes ◽  
Grace Data ◽  
Basin Scale ◽  
Large Earthquakes

<p>The GRACE mascon solutions, called the advanced products of GRACE data, are widely used in cryosphere science or hydrology research. It has been demonstrated that the mascon solutions have the same or better performances compared with the spherical harmonic (SH) solutions at the basin scale. However, although the mascon solutions are expected to have the ability to recover the transient gravity signals due to large earthquakes, few studies have investigated the performances of the mascon solutions in studying seismic deformations systematically. In this study, we attempt to examine the performances of the mascon solutions for transient gravity signals induced by three M9 class earthquakes: the 2011 Tohoku-Oki, 2004 Sumatra and 2010 Chile earthquakes, and compare them with the SH solutions and theoretical gravity changes modelled by dislocation theory. We analyse the co-seismic gravity changes and conclude that the mascon solutions contain almost identical information as the SH solutions and can retrieve the co-seismic gravity change signals in the resolutions equivalent to the Gaussian filter radii of 210~270 km. However, the mascon solutions have other strengthening gravity change signals, with magnitudes that are the same order as that of the SH solutions and contain pre-seismic gravity change signals in the Tohoku earthquake. These strengthening and pre-seismic signals are both considered artificially introduced noise due to the mathematical treatment before releasing rather than real geophysical signals.</p>

scholarly journals Seasonal gravity changes estimated from GRACE data

2010 ◽  
Vol 1 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Zhengbo Zou ◽  
Hui Li ◽  
Zhicai Luo ◽  
Lelin Xing
Keyword(s):  
Gravity Changes ◽  
Grace Data
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