The capabilities of analyzing the seismo-electromagnetic satellite CSES-01 data for monitoring of seismic activity of the Northern Tien Shan

The relationship between space weather and earthquakes occurring in seismically active areas with the seismo-electromagnetic satellite CSES-01 data are observed. The study assumes the presence of possible ionospheric precursors of strong earthquakes. The sets of measuring instruments of the satellite and data are considered. Subsequently, to prove the non-random nature of the space weather effects, the results of ground-based geomagnetic or electromagnetic observations should be used, for example, magnetotelluric soundings (MTS). Stationary and regime points of the MTS network of the Research Station RAS in Bishkek (RS RAS) are suitable for these purposes in the Northern Tien Shan. The MTS data are presented in the form of hourly frequency-time series with system rotation from 0° to 180°. To obtain information on earthquakes, it is proposed to use data from the NEIC or ISC seismic catalog, since they aggregate data from regional catalogs, including the KNET seismological network maintained by the RS RAS. It is concluded that it is necessary to select the CSES-01 trajectories and times of flight over the territory of Kyrgyzstan and download the electric field detector (EFD) data. The results of comparing satellite and ground-based observations can be used in future technologies for short-term earthquake prediction.

ANALYSIS OF GEOPHYSICAL PARAMETERS VARIATIONS AND SEISMIC EVENTS AT THE POINT OF DEEP MAGNETOTELLURIC SOUNDING

The paper considers the results of processing and analysis of data from deep magnetotelluric soundings (DMT) performed in 2018. Comparison of variations in apparent resistivity, the endogenous component of the magnetotelluric field, lunar-solar tidal deformations and seismic events that were recorded during the research. The objective of the study is to detect the relationship between the appearance of variations in electromagnetic parameters of the data of magnetotelluric monitoring from the occurred earthquakes, their distance, energy class and position, relative to the DMT point.

STUDY OF THE DEPTH STRUCTURE OF SEISMICALLY ACTIVE ZONES BY THE METHOD OF MAGNETOTELLURIC SOUNDING

The paper presents the results of the analysis of data from magnetotelluric soundings performed in 2003-2020. A comparison of geoelectric models for the Chui and Kochkor basins of the Northern Tien Shan is shown. The main objective of the study is to identify patterns in the distribution of geoelectric inhomogeneities in the deep structure of the Bishkek geodynamic test site. Particular attention in geoelectric models was paid to the study of key objects of transition zones from mountain ranges to intermontane basins. The nature of crustal electrical conductivity anomalies is considered.

STUDY OF THE DEPTH STRUCTURE OF SEISMICALLY ACTIVE ZONES BY THE METHOD OF MAGNETOTELLURIC SOUNDING

The paper presents the results of the analysis of data from magnetotelluric soundings performed in 2003-2020. A comparison of geoelectric models for the Chui and Kochkor basins of the Northern Tien Shan is shown. The main objective of the study is to identify patterns in the distribution of geoelectric inhomogeneities in the deep structure of the Bishkek geodynamic test site. Particular attention in geoelectric models was paid to the study of key objects of transition zones from mountain ranges to intermontane basins. The nature of crustal electrical conductivity anomalies is considered.

ANALYSIS OF GEOPHYSICAL PARAMETERS VARIATIONS AND SEISMIC EVENTS AT THE POINT OF DEEP MAGNETOTELLURIC SOUNDING

The paper considers the results of processing and analysis of data from deep magnetotelluric soundings (DMT) performed in 2018. Comparison of variations in apparent resistivity, the endogenous component of the magnetotelluric field, lunar-solar tidal deformations and seismic events that were recorded during the research. The objective of the study is to detect the relationship between the appearance of variations in electromagnetic parameters of the data of magnetotelluric monitoring from the occurred earthquakes, its’ distance, energy class and position, relative to the DMT point.

3-D Geoelectrical Characterisation of the Central Volcanoes of São Miguel Island (Azores Archipelago, Portugal) using Broad-Band Magnetotelluric Data

<p>The Azores islands are located at the triple junction between the North American, Eurasian and African plates. The Mid-Atlantic Ridge separates the North America from Eurasia and African plates, while Azores-Gibraltar Fracture Zone is the boundary between Eurasia and African plates. São Miguel Island, situated at the southeastern part of the western segment of the Azores-Gibraltar Fracture Zone, has three active strato-volcanoes, Sete Cidades, Fogo (Água de Pau), and Furnas. At Furnas and Fogo volcanoes, intense circulation of volcanic fluids at depth leads to high CO<sub>2</sub> outgassing and flank destabilisation, whereas its neighbour Congro Fissural volcanic system, located between Fogo and Furnas volcanoes, experiences significant seismic swarm activity and poses considerable threat to the local population. Enhanced electrical conductivity values are typically associated with volcanic-hydrothermal systems and the modelled conductivity structures can provide constraints on these volcanic and hydrothermal processes.</p><p>Our previous work on Furnas volcano, which yielded a revised conceptual model developed from 39 high-frequency magnetotelluric soundings that imaged the hydrothermal system of the volcano to a depth of 1 km directly beneath the caldera, has now been expanded to include 35 additional broad-band magnetotelluric soundings from a recent field campaign conducted in late 2018, to image deeper and broader to gain new insights into the regional context of the Furnas volcanic system. The resistivity model of Furnas shallow hydrothermal system constructed from high-frequency dataset delineated two enhanced conductive zones, one at 100 m and another at 500 m depth, separated by a resistive layer. The shallow conductor has conductivity less than 1 S/m, which can be explained by clay mineral surface conduction with a mass fraction of at least 20% smectite. The deeper conductor extends across the majority of the survey area and is located at depths where smectite is generally not formed. We interpret this as the result of saline aqueous fluids near the boiling point, inferring temperatures of at least 240 <sup>o</sup>C. The less conductive layer found between these conductors is interpreted to be steam-dominated and coincides within the mixed-clay zone found in many volcanic hydrothermal systems. 3-D inversions using the deep-probing data indicate continuation of a strong conductive zone towards the south, beneath the 1630 Dome, which represents the most recent phase of eruptive activity in the multi-caldera complex. During the 2018 field campaign, we have enlarged our study to include 50 broad-band soundings on the adjacent Fogo (Água de Pau) volcano and Congro Fissural volcanic system. The Fogo-Congro region is subjected to seismic swarm activity and its relationship with the geoelectrical structure is being investigated.</p>