Identification of probable new faults based on remote sensing in northwestern Iran

The area is located in Northwestern Iran and includes the provinces of East Azerbaijan, West Azerbaijan, Ardabil and Zanjan. One of the most important structures in this area is the North Tabriz fault, Aras, Ardabil-Miyaneh and Astara faults, which have controlled the geology of the region. North Tabriz fault is one of the most important structures in the northwestern region of Iran, which has controlled the geology of the region. These faults have played an important role in the seismicity of this region and have caused major earthquakes in the history of this land. It is also very important to identify the origin of named faults and lineaments and their importance in future construction and reinforcement of structures. Therefore, detection of the pattern of distribution and spatial epicenter of earthquakes, and Lineation in GIS, help to relocated the faults and revealed the new faults.

Considering that many fault lineation in the North-West of Iran have not been identified and studied so far, or parts of them are hidden, therefore, in this research, an attempt has been made to first prepare a map of the known faults drawn from the different sources. Then by examining them and remote sensing studies, the unknown important and effective fault lineation in the Northwestern Iran should be identified and introduced.

The northwestern region of Iran is located on the Alpine-Himalayan orogenic belt, in an area between the South Caspian, the South Caucasus Orogen, the Eastern Anatolia Plateau and the Northern Zagros, and is affected by the movements caused by the convergence of the Arabian and Eurasian Plates.

The data used for this research include Geological, Tectonic and seismic maps of the of Iran.

After preparing information layers from the mentioned maps and referencing them to the ground, first the faults related to different maps were identified and unified, then the location of all the faults due to the non-observance of the grid and the global coordinate system in most of the maps that have been Now they have been published, from the point of view of the location of the faults, the images with a spatial resolution of 15 meters were corrected. In this connection, in this research, the identification of structures has been carried out with the use of Remote Sensing. Remote sensing can be used as a method to reveal geological Lineaments by using different digital processing methods on satellite images, important information can be revealed. The techniques used in this project are: combining color images (RGB), performance filters and using DEM images. By examining the faults in the reference layer using the images and filters used (Gussian, Laplacian, Sobel).

It was found that each of the faults extracted from different maps are located in different positions and sometimes it is observed that the faults cross the boundaries. In the other cases in some of the geological maps one could see that faults are on the virtues of the mountains. The integration of information and data related to the improvement of remote sensing images and geological maps, tectonic earthquakes significantly helped in the analysis and processing of the lineaments. In this research a lot of these errors have corrected and renew the design of the fault maps in the North-West of Iran.

In order to extract new fault lines, various evidences have been used, among them are shifting of layers, lithology change, stretching of strata, and remote sensing signs. The results obtained from this analysis, the spatial correction of the faults extracted from the maps that reduced from various sources which were located in different positions were drawn at the exact location using satellite images, hidden faults and new lineaments with the help of Landsat 8 images. Also fault detection signs were identified in the studied area and thy help about 38 lineaments have been identified in the entire study area. Mainly these faults have East-West and North-East and South-West trend that was for the first time have identified and introduced.

The new lineaments identified in the study area have been extracted based on evidence and external signs of fault detection and using satellite images and existing filters, so calling a lineament as a fault, they require identifying the field signs for fault detection, including fault surfaces, fault mirrors, crash on it, etc., therefore, in this research, the name of the lineation is used for them.