Geomagnetic observations in Borok geophysical observatory

2011 ◽  
Vol 3 (5) ◽  
pp. 1-8 ◽  
Author(s):  
S. V. Anisimov ◽  
E. M. Dmitriev ◽  
K. V. Aphinogenov ◽  
A. V. Guriev
Keyword(s):  
Geophysical Observatory ◽  
Geomagnetic Observations

Fast (non-)diffusive Quasi-Geostrophic Magneto-Coriolis Modes in the Earth's core

2021 ◽  
Author(s):  
Felix Gerick ◽  
Dominique Jault ◽  
Jerome Noir
Keyword(s):  
Magnetic Field ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Outer Core ◽  
Equatorial Region ◽  
Earth’S Core ◽  
Earth's Core ◽  
Strong Focusing ◽  
Geomagnetic Observations ◽  
And Diffusion

<p> Fast changes of Earth's magnetic field could be explained by inviscid and diffusion-less quasi-geostrophic (QG) Magneto-Coriolis modes. We present a hybrid QG model with columnar flows and three-dimensional magnetic fields and find modes with periods of a few years at parameters relevant to Earth's core. These fast Magneto-Coriolis modes show strong focusing of their kinetic and magnetic energy in the equatorial region, while maintaining a relatively large spatial structure along the azimuthal direction. Their properties agree with some of the observations and inferred core flows. We find additionally, in contrast to what has been assumed previously, that these modes are not affected significantly by magnetic diffusion. The model opens a new way of inverting geomagnetic observations to the flow and magnetic field deep within the Earth's outer core.</p>

Investigation of volcanic emissions in Antikythera PANGEA station using near-real-time alerts

2021 ◽  
Author(s):  
Anna Kampouri ◽  
Vassilis Amiridis ◽  
Stavros Solomos ◽  
Anna Gialitaki ◽  
Eleni Marinou ◽  
...  
Keyword(s):  
Real Time ◽  
Dispersion Model ◽  
Atmospheric Composition ◽  
Dust Particles ◽  
Volcanic Plume ◽  
Observation Data ◽  
National Observatory ◽  
Development Fund ◽  
Model Simulations ◽  
Geophysical Observatory

<p>In the last years, several Etna eruption events are documented, forming lava flows and explosive activity. The Pilot EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash of the e-shape project provides the PANhellenic GEophysical observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), in Greece with near-real-time alerts from Etna volcano eruptions. These alerts are used in the PANGEA station to monitor and reveal the presence of volcanic particles above the area the days following an eruption, also the station is supported by a volcanic particle monitoring and forecasting warning system. In this work, we investigate the volcano eruption between 30 May and 6 June 2019 which affected the southern parts of Greece and reaching the Antikythera station. Due to the prevailing meteorological conditions, volcanic particles and gases followed an easterly direction and were dispersed towards Greece. FLEXPART dispersion model simulations confirm the volcanic plume transport from Etna towards PANGEA, mixing also with co-existing desert dust particles. Model simulations are evaluated with Polly<sup>XT</sup> lidar measurements performed at PANGEA and satellite-based SO<sub>2</sub> observations from the TROPOspheric Monitoring Instrument onboard the Sentinel-5 Precursor (TROPOMI/S5P). This is the first time that Etna volcanic products are monitored at the Antikythera station, in Greece with implications for the investigation of their role in the Mediterranean weather and climate.</p><p><strong>Acknowledgments</strong>: We acknowledge the support by EU H2020 E-shape project (Grant Agreement n. 820852). Also, this research was supported by data and services obtained from the PANhellenic Geophysical Observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), Greece, and by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). NOA team acknowledges the support of the Stavros Niarchos Foundation (SNF).</p>

The lidar ratio derived from sun-photometer measurements at Belsk Geophysical Observatory

2009 ◽  
Vol 57 (2) ◽  
pp. 476-493 ◽  
Author(s):  
Aleksander Pietruczuk ◽  
Jerzy Podgórski
Keyword(s):  
Geophysical Observatory ◽  
Lidar Ratio ◽  
Sun Photometer

scholarly journals Geomagnetic field disturbances from the fall of the Lipetsk (june 21, 2018) and Chelyabinsk (february 15, 2013) meteorites

2019 ◽  
Vol 485 (3) ◽  
pp. 361-365
Author(s):  
A. A. Spivak ◽  
S. A. Riabova
Keyword(s):  
Delay Time ◽  
Geomagnetic Field ◽  
Maximum Effect ◽  
Impact Point ◽  
Cosmic Body ◽  
Meteorite Impact ◽  
Geomagnetic Disturbances ◽  
Geophysical Observatory ◽  
Earth’S Atmosphere ◽  
The Impact

Based on the Chelyabinsk (February 13, 2013) and Lipetsk (June 21, 2018) events, disturbances in the Earth's geomagnetic field, which were induced by the fall of these meteorites, were studied. Based on the data provided by geomagnetic observatories of the INTERMAGNET network and the mid-latitude Mikhnevo geophysical observatory (IDG RAS), it was established that the fall of meteorites through the Earth's atmosphere, in general, induces geomagnetic disturbances of up to 5 nT at distances up to 2700 km from the impact point of a cosmic body; the maximum effect is reached with a delay time ranging from ~5 to ~10 min, and the duration of the period of the induced geomagnetic field disturbances varies from ~5 to ~20 min. The estimation dependencies of the amplitude and duration of induced geomagnetic disturbances from a distance from the meteorite impact points are proposed.

scholarly journals Infrasound signals from earthquakes of December 5, 2014 in the water area of lake Hovsgol, Northern Mongolia

2019 ◽  
Vol 484 (5) ◽  
pp. 610-614
Author(s):  
A. G. Sorokin ◽  
A. V. Klyuchevskii
Keyword(s):  
Water Area ◽  
Comprehensive Analysis ◽  
Signal Generation ◽  
Flexural Waves ◽  
Geophysical Observatory ◽  
Russian Academy Of Sciences ◽  
Lake Hovsgol ◽  
Northern Mongolia ◽  
Academy Of Sciences ◽  
Infrasonic Signal

A comprehensive analysis of waveforms of seismic and infrasonic vibrations from the earthquake that occurred on December 5, 2014, in the water area of Lake Hovsgol was performed. The analysis showed that the infrasonic signal recorded at the Tory station (Geophysical Observatory of the Institute of Solar-Terrestrial Physics, Russian Academy of Sciences) was formed by the sources of three generation types: local, secondary, and epicentral. The obtained results allow us to propose the model of epicentral infrasonic signal generation by flexural waves from an elastic ice membrane on the surface of Lake Hovsgol.

scholarly journals Comparison of simultaneous variations of the ionospheric total electron content and geomagnetic field associated with strong earthquakes

2001 ◽  
Vol 1 (1/2) ◽  
pp. 53-59 ◽  
Author(s):  
Sh. Naaman ◽  
L. S. Alperovich ◽  
Sh. Wdowinski ◽  
M. Hayakawa ◽  
E. Calais
Keyword(s):  
Total Electron Content ◽  
Vertical Displacement ◽  
Temporal Variations ◽  
Electron Content ◽  
Geomagnetic Disturbances ◽  
Total Electron ◽  
Strong Earthquakes ◽  
Ionospheric Total Electron Content ◽  
Geomagnetic Observations ◽  
Gps Observations

Abstract. In this paper, perturbations of the ionospheric Total Electron Content (TEC) are compared with geomagnetic oscillations. Comparison is made for a few selected periods, some during earthquakes in California and Japan and others at quiet periods in Israel and California. Anomalies in TEC were extracted using Global Positioning System (GPS) observations collected by GIL (GPS in Israel) and the California permanent GPS networks. Geomagnetic data were collected in some regions where geomagnetic observatories and the GPS network overlaps. Sensitivity of the GPS method and basic wave characteristics of the ionospheric TEC perturbations are discussed. We study temporal variations of ionospheric TEC structures with highest reasonable spatial resolution around 50 km. Our results show no detectable TEC disturbances caused by right-lateral strike-slip earthquakes with minor vertical displacement. However, geomagnetic observations obtained at two observatories located in the epicenter zone of a strong dip-slip earthquake (Kyuchu, M = 6.2, 26 March 1997) revealed geomagnetic disturbances occurred 6–7 h before the earthquake.

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