GLOBAL GEODYNAMICS FROM 14 YEARS OF LAGEOS SATELLITE RANGING DATA

Author(s):  
Nikolay Dimitrov
2021 ◽  
Author(s):  
Roberta Ivaldi ◽  
Maurizio Demarte ◽  
Massimiliano Nannini ◽  
Giuseppe Aquino ◽  
Cosimo Brancati ◽  
...  

<p>New hydro-oceanographic data were collected in the Arctic Ocean during HIGN NORTH20 marine geophysical campaign performed in July 2020, in a COVID-19 pandemic period. HIGH NORTH20 was developed as part of the IT-Navy HIGH NORTH program, a Pluriannual Joint Research Program in the Arctic devoted to contribute to oceans knowledge in order to ensure ocean science improving conditions for sustainable development of the Ocean in the aim of United Nations Decade of Ocean Science for Sustainable development and the GEBCO - SEABED 2030 project. In order to contribute in exploration and high-resolution seabed mapping new data was collected using a multibeam echosounder (EM 302 - 30 kHz). The particular sea ice environmental condition with open-sea allowed to survey and mapping the Molloy Hole, the deepest sector of the Arctic Ocean, a key area in the global geodynamics and oceanographic context. A 3D model of the Molloy Hole (804 km<sup>2</sup>) and the detection of the deepest seafloor (5567m - 79° 08.9’ N 002° 47.0’ E) was obtained with a 10x10m grid in compliance to the IHO standards.</p>


2021 ◽  
Author(s):  
Dimitar Ouzounov ◽  
Menas Kafatos ◽  
Patrick Taylor

<p>The forefront of science now is in bridging fields and making connections across different disciplines, challenging our current understanding of the Earth's changes and overall state. Some of the most challenging science questions now have to do with warnings for significant geohazards and Earth-Space systems' response to climate variability affecting adaptation processes, such as geosphere changes due to climate change and resultant strategies. In recent years, the study of pre-earthquake processes has led for example to developing the lithosphere-atmosphere-ionosphere-coupling concept. This in turn provides new information about the Earth's energy balance (Pulinets and Ouzounov, 2011). From space-born NASA and NOAA Earth observation of atmospheric conditions, we have shown the consistent occurrence of radiative emission anomalies in the atmosphere near or over regions of earthquakes, volcanoes, and geothermal fluxes. Our assessment shows that the latent heat released before major earthquakes is larger than the seismic energy released during the quake (Ouzounov et al., 2018). We find that the associated pre-earthquake phenomena for large events may create an additional thermodynamic contribution in the atmosphere and impact on climate, caused by sources of Earth de-gassing in the lithosphere and followed by ionization processes. Because of these findings, we start exploring major global geodynamics activities and their impact on atmospheric processes and climate through the geosphere coupling channels as a potential forward process of interaction between geohazards and climate adaptation. The reverse mechanism of climate adaptation's impact on geohazards is based on the initial idea that climate adaptation could force additional geohazards activities (McGuire, 2010). The removal of ice sheets may somehow or likely have permitted the release of stresses that had accumulated on previously confined faults, triggering earthquakes in the US, Canada, and Europe. How realistically is it to expect a change in the existing earthquake patterns in Europe, the USA, and Canada during climate change processes? It is plausible, but we do not yet know the answer. Our goal is to explore the coupling between geohazards processes and climate change processes through the lithosphere-atmosphere framework, focusing on dynamic environments, exhibiting a change in physical and thermodynamics processes over relatively small-time scales.</p>


1991 ◽  
Vol 96 (B1) ◽  
pp. 729 ◽  
Author(s):  
R. Scharroo ◽  
K. F. Wakker ◽  
B. A. C. Ambrosius ◽  
R. Noomen
Keyword(s):  

2004 ◽  
Vol 38 (3-5) ◽  
pp. 355-374 ◽  
Author(s):  
M. Llubes ◽  
N. Florsch ◽  
J. Hinderer ◽  
L. Longuevergne ◽  
M. Amalvict

The measurement of intersite distances with laser ranging to satellites has been demon­strated during the last few years for distances of several hundred to several thousand kilometres with precisions of a few tens of centimetres. These techniques are now being tested across the San Andreas fault in California where it is hoped plate motion will be observable after several years of measurements. The first measurements, between sites in southern and northern California, were made in 1972 and repeated again in 1974 with agreement between the baselines for each of the two years at the 10 cm level. The next measurements are planned for the summer of 1976. The results of these and related experiments will be described together with simulations of the projected capability using the high altitude Lageos satellite. General plans for future experiments will be described.


1998 ◽  
Vol 41 (2) ◽  
Author(s):  
G. Casula

From August 1995 up to now, at the Enea Research Center of Brasimone, in the Italian Apennines between Bologna and Florence (Italy: 44º07'N, 11º.07'E, 890 m height), the superconducting gravimeter GWR model TT70 number T015 has been continuously recording the variation of the local gravity field, in the frame of the Global Geodynamics Project. The gravimetric laboratory, being a room of the disused nuclear power plant of Brasimone, is a very stable site, free from noise due to human activities. Data blocks of several months of continuous gravity records have been collected over a time span of three years, together with the meteorological data. The gravimeter has been calibrated at relative accuracy better than 0.3% with the aid of a mobile mass system, by imposed perturbations of the local gravity field and recording the gravimeter response. The results of this calibration technique were checked by two comparison experiments with absolute gravimeters performed during this period: the first, in May 1994 with the aid of the symmetrical rise and fall gravimeter of the Institute of Metrology Colonnetti of Turin, and the second in October 1997 involving an FG5 absolute gravimeter of the Institute de Physique du Globe of Strasbourg. The gravimeter signal was analysed to compute a high precision tidal model for Brasimone site. Starting from a set of gravimetric and atmospheric pressure data of high quality, relative to 46 months of observation, we performed the tidal analysis using Eterna 3.2 software to compute amplitudes, gravimetric factors and phases of the main waves of the Tamura catalogue. Finally a comparison experiment between two of the STS-1/VBB broadband seismometers of the MedNet project network and the gravity records relative to the Balleny Islands earthquake (March 25, 1998) were analysed to look for evidence of normal modes due to the free oscillations of the Earth.


2012 ◽  
Vol 03 (04) ◽  
pp. 767-771 ◽  
Author(s):  
Valera P. Rudakov ◽  
Pavel P. Firstov ◽  
Vladislav V. Tsyplakov

1998 ◽  
pp. 569-598
Author(s):  
G. Beutler ◽  
R. Weber ◽  
E. Brockmann ◽  
M. Rothacher ◽  
S. Schaer ◽  
...  
Keyword(s):  

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