In this paper are presented the results from the investigations of the active landslide, located in front of the Thracian Cliffs golf club (Northern Bulgarian Black Sea Coast) for the period 2019–2021. Extensive research by means of in-situ and remote sensing has been carried out on the latest landslide activations. As part of the study, a control GNSS geodynamic network was established. This network was used as benchmark for the results obtained from satellite SAR data processing and UAV surveys targeted at monitoring the modern landslide developments.

Registering the ground deformations at the area of the archaeological site “Solnitsata”

The main idea of the present investigation is to study the relationship between post- seismic effects as a result of Petrinja, Croatia earthquake which occurred on December 29, 2020 in some ionospheric parameters. Two types of ionospheric data were used: the critical frequency of the F2 region (foF2), obtained from the vertical sounding of the ionosphere and Total Electron Content (TEC) data. The ionospheric response is studied by the relative deviation of both quantities foF2 and TEC. The results of the ionospheric parameter behaviour show the following: a) a positive anomaly is observed in both ionospheric characteristics; b) the most significant positive response is observed at ionospheric stations closer to the epicentre; c) the delay of the observed post-seismic ionospheric effect increases with distance from the epicentre in both data used. The observed anomalies in the behaviour of considered ionospheric parameters could be associated with the considered lithospheric phenomenon because the selected period is with completely quiet geomagnetic conditions. The results of this research gives additional insight into the Lithosphere-Atmosphere-Ionosphere Coupling during Earthquake processes.

Landslide processes are considered to be the major part of the natural hazards occurring on the northern part of the Bulgarian sea side. Their monitoring can be done with high precision using GNSS data. The objective of this study is to provide solid grounds for monitoring of the landslide processes using GNSS and SAR data. This goal will be achieved by implementation the following: 1) establishment a verified methodology for extracting high-quality information from SAR images aimed at continuous monitoring of landslide areas integrating InterFerometric Images (IFI) and GNSS data and 2) creation of working prototype of an information system for monitoring and prevention of the effects of earth crust movements (landslides, falls, etc.) based of freely accessible data provided by ESA and national sources. One of the scientific tasks to be solved includes the development of methodological approaches for comparison of the results from combined processing of interferometric images from SAR, measurements at permanent GNSS stations of the national NIGGG network in the area of study and geodetic measurements of a newly established test network covering a specific area on the Northern Black Sea coast of Bulgaria with active landslide processes.