Geophysical Survey

About: Geophysical Survey is a facility organization based out in Obninsk, Russia. It is known for research contribution in the topics: Geology & Seismology. The organization has 308 authors who have published 256 publications receiving 3067 citations. The organization is also known as: Federal State Institution of Science Geophysical Survey of the Siberian Branch of the Russian Academy of Sciences.

Extraction and monitoring of Karst rock desertification information

Abstract: Karst Rock desertification is one of the ecological geology problems in southwest of China. The investigation of this problem can provide scientific evidence for its evolution analysis and post arrangement, so monitoring the dynamic change of desertification using quick, precise and economic method is the most important task. In this paper, the fundamental remote sensing dynamic monitoring theory and method is applied, and it mainly discussed these aspects including remote sensing data choice, data preprocessing, extraction of rock desertification change information, classification of rock desertification information, etc. It summed up the technologic route and method of the Karst rock desertification monitoring using remote sensing technology. Based on the research of testing area and random sample investigation, it is indicated that the result using this method is precise and satisfying.

SEISMIC MODEL OF THE UPPER EARTH`s CRUST ON NORTH-EAST PART OF TRAVERSE 3-DV BASED ON RESULTS OF HEAD WAVES DIGITAL PROCESSING

Abstract: Digital processing of refracted waves data, which are registered on North-East part of profile3-DV, is done. Time sections and velocity model are formed. It is proved, that refraction horizons on depth interval of 0-1.5 km are geologic boundaries in sedimentary cover on Ayan-Yuryakh tectonic block. Refraction boundary on depth of ~1.0 km is not lithologic border on Inyaly-Debin block. Layers, which are potentially productive for ore mineral resources, are substracted by low values of V/V (1.66-1.70) on depth below 1.0 km, on Inyaly-Debin block and Orotukan-Balygychan elevation.

First results of studies in the gorlovskaya values by ground methods of electric exploration with controlled sources

Abstract: The article presents the first results of the study of the Gorlovskaya depression in the area of coal deposits of the Novosibirsk region by methods of ground electrical prospecting using transient electromagnetic sounding and electrical tomography. Near-surface models were obtained to depths of 100 m, as well as deep geoelectric characteristics of the sedimentary filling of the depression and the eastern fault boundary.

Mysterious geomagnetic response to minor solar wind disturbance: Observations

Abstract: On 15 April 2022, the Kiruna magnetometer detected an isolated geomagnetic spike of 400 nT with rising time of 2 minutes. This is on the same level of large sudden commencements (historically largest one is about 1000 nT in Kiruna), but this event was not followed by any magnetic storm or substorm.  In this sense, the observed 400 nT spike is unique in the history of Kiruna magnetometer (more than 30 years of digital data). At the same time, the Kiruna riometer detected a strong absorption with short rise time, indicating a sudden increase of the electron density.  The world-wide geomagnetic observations available at IMAGE, SuperMAG and INTERMAGNET geomagnetic networks, show isolated localised geomagnetic spikes in the dawn sector in both hemispheres, but not in the dusk sector, gradually moving toward midnight with decreasing intensity.  Detailed analyses of geomagnetic deviation in the northern hemisphere indicates strong shear in the ionospheric Hall current with the sense of downward field.  Considering its location and electron density increase, this field-aligned current is most likely caused by the ring current particles, as is indicated by DMSP data. The solar wind velocity is constant with no specific variation that can cause such a unique event.  However, multi-spacecraft observations by SOHO, DSCOVR, ACE, Cluster and MMS suggest the possibility of a very localized IMF structure.  We thank magnetic stations of IMAGE, SuperMAG and INTERMAGNET network, and SOHO, DSCOVR, ACE, Cluster, DMSP and MMS team for providing data.

Simultaneous observations of whistler mode waves by the DEMETER spacecraft and the Kannuslehto station

Abstract: We use conjugate observations of magnetospheric whistler mode electromagnetic waves at frequencies up to 16 kHz to determine their typical spatial scales and propagation to the ground. For this purpose, we use data obtained by the DEMETER spacecraft at an altitude of about 700 km and by the ground-based Kannuslehto station in Finland. The overlap between the two data sets corresponds to more than 500 DEMETER half-orbits between November 2006 and March 2008. Two different approaches are used. First, specific wave events observed simultaneously by both the spacecraft and the ground station are analyzed in detail. Second, the correlations of the power spectral densities of measured signals are calculated as a function of the frequency and geomagnetic longitude/L-shell separation. These are used to determine typical longitudinal/L-shell correlation lengths and to discuss wave propagation to the ground.