# Scanning Inside Volcanoes with Synthetic Aperture Radar Echography Tomographic Doppler Imaging
## 3 Experimental Results
The debris layers are detailed within circle 1 (visible in Figure 9b). The maximum depth of the layers is measured to be about 2 km deep, relative to the top surface of the volcano. Figure 10 is an overview of Vesuvius for which the seismic tomogram has been calculated through a purely azimuth-oriented line, which is visible in Figure 10a, and tracked through yellow line 1. The tomographic result is shown in Figure 10b, for which the main section is shown within the red circle visible in Figure 10a. The result shows probable magmatic fluid conduits, detected in terms of vibrational energy discontinuities. Figure 11 represents the tomographic result obtained considering an oblique section, visible in Figure 11a. For this case, the tomographic line is traced through yellow line 1. The proposed tomographic map shows the entire volcano internal section (Figure 11b). The tomogram was calculated at a higher resolution and taking into account a longer orbital variation. Figure 6: Range-line echographic tomography detailed result (magnitude). (**a**) SLC SAR image (in magnitude). (**b**) Tomographic result (in magnitude). Figure 8: Range-line echographic tomography result (magnitude). (**a**) SLC SAR image (in magnitude). (**b**) Tomographic result (in magnitude). The yellow tomographic line is indicated by the number \(1\). Figure 10: Range-line echographic tomography result (magnitude). (**a**) SLC SAR image (in magnitude). (**b**) Tomographic result (in magnitude). The yellow tomographic line is indicated by the number \(1\). Figure 7: Range-line echographic tomography result (magnitude). (**a**) SLC SAR image (in magnitude). (**b**) Tomographic result (in magnitude). Figure 9: Range-line echographic tomography result (magnitude). (**a**) Tomographic result (in magnitude). (**b**) SLC SAR image (in magnitude). (**c**) Tomographic result (in magnitude). The following information is obtained from the calculated tomograms:  
* The inner western volcano crater tomographic slopes consist of layered material, visible within yellow circle 1 of Figure 9b;
* The main volcano crater can be plugged by a cap of material consistent with vibration energy singularity, depicted within the yellow circle 2 of Figure 11b;
* The main conduits from the magma chamber rise from the east and west tomographic sections, indicated by arrows 3 and 4 of Figure 11b;
* The same results are obtained by calculating the sonic tomogram at a lower vibrational frequency, for which the result is visible in Figure 12.  
A detailed list of feeder conduits is proposed in Figure 13. These natural passages are made of material that does not resonate. We consider this characteristic as possible  
Figure 11: Range-azimuth line echographic tomography result (magnitude). (**a**) SLC SAR image (in magnitude). (**b**) Tomographic result (in magnitude). The yellow tomographic line is indicated by the number 1. Figure 5:0 Range-azimuth line echographic tomography result (magnitude). magmatic fluid paths that a hypothetical new eruption might prefer. From the western side of the great crater, it is possible to edit 11 fractures. The ones belonging from 1 through 5 are located within the main crater, while fractures 9-11 may extend outside the crater. The complete list of possible magmatic fluid paths can be seen in Figure 13a. A detailed tomographic section of the fractures finishing inside the crater can be seen in Figure 13b, while a detailed tomogram of the upper magmatic fluid ducts is visible in Figure 13c-e, and finally some external magmatic fluid paths are depicted in Figure 13f.