Geophysical Prospecting of the Coptic Monastery of Apa Moses Using GPR and Magnetic Techniques: A Case Study, Abydos, Sohag, Egypt

Abstract

As a result of new discoveries, there is a greater opportunity for development and investment in the Al-Arraba EL-Madfuna region of Abydos, Sohag Governorate, Egypt, which benefits tourism and increases the national economy. The Coptic monastery, which was originally established by Apa Moses, the patriarch of the Coptic Church during the ancient Roman Empire, has vanished inside the current market on this site, along with numerous tombs. As a result, the primary goal of this work is to prospect on this site for these potential archaeological features. Ground magnetic and ground-penetration radar (GPR) surveys were employed for discovering these archaeological issues. This work was done in coordination with the Supreme Council of Antiquities. Ground magnetic and GPR surveys were implemented using the G-857 proton-precession magnetometer and GSSI SIR 4000 with a 200 MHz antenna. The data were processed and interpreted using Geosoft Oasis Montaj and REFLEXW v.5.8 software packages. The magnetic data were filtered to separate the shallower anomalies representing the archaeological remains from those of the deeper ones. Butterworth high pass filter, first vertical derivatives, analytical signal, and tilt derivative were employed to carry out the processing stages. The results were analyzed qualitatively and quantitatively to describe these anomalies and determine their locations, geometrical shapes, and depths. The source parameter imaging technique and 3D Euler deconvolution were used to calculate the depths. The analysis of magnetic maps shows that the study site is characterized by a number of anomalies that occur and have geometric squares and rectangle shapes with depths ranging from 0.7 m to ≈4 m. Some of these anomalies are related to potential archaeological objects. GPR findings reveal considerably scattered hyperbolas along several profiles, which may indicate the presence of potential buried objects. The integration of magnetic and GPR results showed that there is some consistency in the identification of the locations of the likely buried archaeological objects and their depths (0.7 to 3 m) for the majority of the discovered targets. The findings of this study suggest excavating at this location and relocating the market in order to protect the buried antiquities from being lost to be safeguarded as a tourist destination target.

1. Introduction

Over the centuries, Abydos developed as a cultural and, most importantly, religious center: the cult of Osiris played an important role. The archaeological site of Abydos is the most prominent burial ground for kings and top court officials in ancient Egypt, so this site is given strategic importance and tourist attraction. One of the most famous places to be buried in ancient Egypt for monarchs and top court officials was the Abdju site (the original name of the modern Abydos), where the early pharaohs were laid to rest. Additionally, it serves as the location of several ancient temples, including the royal necropolis. Due to its connections to Osiris’ religion and the preferred resting places for the earliest and oldest monarchs, including Seti I and Ramses II, the city of Abydos rose to become Egypt’s most revered region [1]. The difficulty with this study in this location is attributed to its strategic engineering value, as it is an ancient site with both explored and unknown elements where new facilities are likely to be built. The Abydos site is the focus of the majority of archaeologists since it is one of the oldest and most important archaeological sites with enormous social, historical, and cultural value. It is famous in the history of ancient Egypt due to its extensive archaeological contents, such as the royal necropolis, the tomb of Umm El-Qa’ab, the Temple of Seti I, and the Temple of Ramses II. Damarany and Abdallah from Egypt’s Supreme Council of Antiquities (SCA) conducted excavations in the marketplace south of Abydos between April 2009 and April 2013, and found some architectural construction remnants and ceramic material [2]. The phases of discovery and cultural growth are reflected by the finding of Egyptian archaeology at the Abydos site [2]. As a result, numerous Egyptian and foreign archaeological missions investigated some of these places to preserve and date artifacts; some of these investigations are still ongoing [2,3,4]. Excavations are required for ancient archaeological explorations, which require more time, effort, and money, and they have a negative impact on the loss of significant antiquities. As a result, the advancement of modern geophysical methods aids in the accurate and rapid exploration of buried antiquities while protecting them from damage.

From the historical background of this site and the previous works of different authors, the investigation site was carefully chosen because of having numerous unidentified tombs as well as a Coptic monastery dating back to the 5th century CE and later. This monastery was established by Apa Moses, the patriarch of the Coptic Church. Numerous Roman-period artifacts were discovered during excavations at the site, particularly in its eastern portion [5,6]. Therefore, the main objective of this work is to discover this buried Coptic monastery and any other tombs within this site. To achieve this goal, an integration of two geophysical tools (ground magnetic and ground-penetrating radar techniques) was applied to survey the south Abydos marketplace to determine the locations, geometrical shapes, sizes, and depths of buried archaeological objects. The outcomes of this work can be used as guides during the excavation procedure.

The ground magnetic survey depends on the variations in the magnetic properties of an object of interest and its surroundings. Magnetization and magnetic susceptibility are the two essential magnetic parameters for archaeological study. The majority of artifacts contain magnetic elements, which have magnetic characteristics and enable them to produce magnetic anomalies that can be used in a variety of ways. The various compositions of the remains and the surrounding soil may allow the created total magnetic intensity map to follow changes in the strength of the Earth’s magnetic field. Depending on how magnetically sensitive the rock is, magnetic anomalies can either be positive or negative [7,8].

Ground-penetrating radar (GPR) is utilized for imaging the earth’s shallow subsurface, as well as the archaeological objects, roadways, and construction materials. It can give exact depth for a variety of subsurface features [9]. For archaeological studies, GPR is frequently employed. It is quick and enables the archaeologist to thoroughly cover a large area while obtaining high-resolution images of hidden archaeological features. The success of GPR surveys in archaeology depends significantly on the soil, clay content, sediment mineralogy, depth of burial, ground moisture, surface topography, and vegetation [9].

Several authors prospected archaeological features at various ancient locations for historical studies, using either magnetic or GPR methods or both. Land magnetic and GPR techniques in other sites in Abydos city were used to discover buried archaeological features [7,10,11,12,13,14,15,16,17,18,19]. Their results reveal eight distinct anomalies which may indicate the possibility of probable buried archaeological objects ranging from 2 to 4 m depth. The magnetic method was applied in Abydos city near this site [7,10,11,12,13,14,15,16,17,18,19] and recognized high magnetic anomalies which may be interpreted as archaeological features of mud brick, ranging in size and depth from 3 m to 12 m and 1 to 5 m, respectively. These techniques were used by researchers in other countries to find the depths of buried archaeological targets. The combined findings of these techniques reveal that most of the potential buried archaeological targets were mapped in accordance with the depths [7,10,11,12,13,14,15,16,17,18,19]. Additionally, these techniques were utilized in conjunction with other techniques such as electrical resistivity tomography (ERT) and MASW to detect the subsurface archaeological objects [20,21,22]. The external sectors of the Castle of Melfi in Italy were investigated by Leucci et al. using GPR and ERT Surveys. The findings showed the presence of anomalies in the initial subsoil layers, although they generally persist to deeper levels exceeding 1.50 m. The key features for mapping the geometry of the buried mud-brick walls and providing useful information for reconstructing the archaeological context of the site were the sharp and vertical contact of the buried walls and the contrast between the archaeological clay-rich layer and the basal sands [10] where these authors used GPR and ERT surveys as enhanced imaging of archaeological ruins in the Nile Delta, Egypt. To find near-surface caves in the Duqm region of Oman, Mohamed et al. used GPR, ERT, and MASW. The findings reveal two cavern systems with various thicknesses. Although the caves are divided at the top, occasionally—especially when moving north—they merge into a single cavern system. The cavern system is not entirely hollow; in some places, they are filled with materials having characteristics distinct from those of the host rock. The cavern system has varying depths between 0 and 5.2 m. The GPR method has continued to advance, enabling researchers in a variety of fields to obtain high-resolution images of subsurface objectives, including those in geology and civil engineering [23,24,25], management and conservation of the cultural heritage [26], and archaeology [27,28,29], in examining frescoes, decorations, and columns [23,30,31,32], and in describing ground conditions in urban areas [33].

2. Location Map and Description of the Study Area

The study site is a part of the Abydos archaeological site, which is 13 km west of El-Balyana city in Sohag, Egypt, and positioned west of the Nile River. The study area is located between latitudes 26°10′49″ N and 26°10′54″ N and longitudes 31°55′15″ E and 31°55′24″ E (Figure 1). The archaeological site is inside the marketplace in the community of Al-Arraba; this is situated on an empty land south of Abydos (Figure 2). This land was leveled by the inhabitants, which is totally covered by sand and clay deposits to hold the market twice a week (on Saturdays and Tuesdays). The land is primarily flat, but the ground level is higher in its western end than in its center and eastern regions, with a little slope running down from west to east. The marketplace location is approximately 500 m south of the Seti I temple and 1500 m east of the Umm Al-Qa’ab ancient royal cemetery.

3. Archaeological Background

The city of Abydos has played an important role in the cultural development of ancient Egypt throughout its history. Royal and nonroyal individuals alike attempted to link their funerary cults with that of the god Osiris, ruler of the underworld, centered at North Abydos during the pharaonic era. Abydos was at the heart of cultural change once more during the latter Coptic period, however, as the new monotheistic religion fought with the nation’s pagan heritage. There is a good chance that the unknown monument founded by Apa Moses, the head of the Coptic church, is the location of the Coptic monastery whose pottery dates from the 5th century CE. However, this structure also had a fascinating window into a convoluted period of previous pharaonic history within its confines [4]. According to Apa Moses’ history, the renowned church figure known as Apa Shenoute predicted on his deathbed that a strong new monastic leader would emerge soon and finish the elimination of pagan institutions from Upper Egypt [34,35]. This monastic ruler was born in 470 CE and named Apa Moses. Documents praise Moses as a capable and inspirational monastic leader, but up to this point, modern archaeological research has been unable to locate the actual remnants of a Late Antique monastery at Abydos associated with Moses’ name where Late Antique Egypt ran from the reign of the Roman emperor Diocletian (284–305 CE) to the Arab conquest of Egypt (641 CE) [34,36]. The majority of researchers have come to the conclusion that the small object known as Apa Moses’ monastery might have originally been located in the contemporary Coptic church at south Abydos, which is dedicated to El-Sitta Damiana and the Forty Virgins [2,4,37].

4. Geological Setting

According to lithology, the many rock units found across the Sohag area are all made up of sedimentary sequences (Figure 3) that range in age from Lower Eocene to Recent [18,38].

Table 1. Major geological formations in Sohag governorate include the study site.

Formation	Age	Description	References
Wadi deposits	Neogene and Quaternary Recent (Holocene)	A disintegrated product of the neighboring Eocene carbonate, in addition to the sediments’ previously processed material	[43]
Alluvial deposits (Nile floodplain)	Pleistocene	Clays and silts with intercalations of sandstone	[43]
Dandara		Fluvial fine sand-silt intercalations and accumulations in low-energy environments	[44]
Ghawanim		Sandstone from the Nile showing the heavy mineral’s earliest occurrence	[38]
KomOmbo		Sediments made up of sand and gravel with a lot of large igneous and metamorphic fragments in them.	[45]
Qena		Sands and gravels that are quartzose and devoid of igneous and metamorphic pieces	[43]
Issawia	Late Pliocene/Early Pleistocene	Clastic facies along lake borders and carbonate facies in the middle zones	[43]
Muneiha	Early Pliocene	Fluviatile sediments have a predominance of sand, silt, and mud intercalations, as well as bedded grey and brown clays intercalated with thin beds and lenses of silt and fine sand	[44]
Drunka	Lower Eocene	A succession of medium- to thick-bedded limestone that contains siliceous concretions of various sizes and is heavily bioturbated in some horizons	[46]
Thebes		Massive to layered limestone that contains flint nodules, as well as marls that are abundant in nummulites and planktonic foraminifera	[46]

lists the major rock units in the studied site. Ahmed [39] asserts that a number of movements at various periods had an impact on the ground, resulting in the buildings that are present in the area southwest and west of Sohag. The Eocene plateau in the Nile valley is influenced by normal faults, strike-slip, and folds that exhibit tensional forces rather than compressional forces [40,41]. According to Youssef [42], faults typically follow the NE-SE (Gulf of Suez trend), NE-SW (Aqaba trend), and E-W trends (transverse trend).

5. Materials and Methods

Ground magnetic and GPR methods are near-surface geophysical tools that were commonly applied in the investigation of the proposed archaeological site. Furthermore, the provided information from the Egyptian Antiquities Authority was collected from the reports of interior and exterior archaeological missions on the Abydos site. The geological and geophysical data about this site were gathered.

5.1. Magnetic Method

The shallow subsurface archaeological remains such as tombs, buried entrances, bricks, buried walls, and constructions can be mapped using the magnetic method, which is nondestructive, quick, and reliable. This technique concentrates mainly on the identification of magnetic minerals, particularly magnetite, present in archaeological components. It is common knowledge that most artifacts made of clay and mud contain a high concentration of magnetized materials, varying in percentage according to sedimentation circumstances and construction techniques. These materials are crucial for magnetic exploration in archaeology due to the clear distinction between these minerals and their environment [43,44,45,46].

In this survey, two Geometrics 857 proton precession magnetometers were used to conduct a ground magnetic survey, one as a base station instrument and the other as a field station instrument.

They have a precision of 0.5 nT and a high resolution of 0.1 nanotesla [47]. The data were corrected from diurnal variations of the earth’s magnetic field. Three blocks, A, B, and C, that constitute this site were surveyed (Figure 1). The block sizes of A, B, and C are 85 m × 70 m, 100 m × 100 m, and 100 m × 65 m, respectively. The surveyed lines in each block were measured in the NW-SE direction with line spacing and station intervals of 5 m producing 18, 21, and 14 lines for blocks A, B, and C, respectively. The total numbers of the measured stations are 987, and their locations were determined using Garmin 64 GPS. The Oasis Montaj Software package v. 8.4. was utilized for the processing and interpretation of the magnetic data [48]. The final output of the surveyed magnetic data after correction is the total magnetic intensity (TMI) anomaly map. Several processing and analysis techniques were applied to the TMI data. Different filters, including the Butterworth high pass filter, apparent magnetic susceptibility, first vertical derivatives, tilt derivative, and analytical signal, were used to carry out the processing processes for qualitative interpretation. Depth estimation techniques, such as source parameter imaging and 3D Euler deconvolution with structure indices 1 and 2, were applied to identify the depth of the buried archaeological objects.

5.2. Ground-Penetrating Radar (GPR) Method

GPR is a successful geophysical method that can make high-resolution subsurface imaging of buried objects. When using this method, radar waves are transmitted and received from a bistatic or monostatic antenna. These waves will reflect from the underground discontinuities, and the two-way travel times are determined. Using the appropriate velocity of the subsurface materials, the depth of these materials can be determined. Radargram sections can be converted into meaningful two-dimensional or three-dimensional images by utilizing advanced data processing [49,50].

The GPR instrument of GSSI-SIR-4000 was employed in the current survey. To choose the best antenna, according to the exposed archaeological objects in this site and the former background about the target’s depth, a monostatic 200 MHz antenna was employed in this study to provide good vertical resolution and accurate depth estimation of the buried objects. A GSSI surveyed wheel type 620 with a 16-inch diameter was attached to the antenna to measure the moved distance.

Each block of the previous three magnetic blocks was divided into small blocks according to the accessibility of the location to produce twelve small blocks (Figure 4). Block (A) provided two small blocks (A1 and A2 with dimensions of 40 × 85 m and 30 × 85 m). Block (B) provided four equal blocks (B1 to B4 with a dimension of 50 × 50 m). Block (C) provided six unequal small blocks (C1 with a dimension of 30 × 30 m, C2, C3, and C5 are 35 × 30 m, and C4 and C6 are 35 × 35 m). Comprehensive GPR surveys were implemented on all these blocks using a monostatic 200 MHz central frequency antenna in a zig-zag configuration in the NE-SW direction. A total of 86 profiles were surveyed on block A1 with 40 m profile length, and other 86 profiles were surveyed on block A2 with 30 m profile length; the profile spacing is 1 m, producing 172 profiles. A total of 35 profiles with a profile length of 50 m and a profile spacing of 1.5 m were surveyed on the blocks from B1 to B4 producing 140 profiles. The profile lengths of C1 and C2 blocks are 30 m, while those for C3–C6 blocks are 35 m, and profile spacing in these blocks is 1 m, producing 201 profiles. Thus, the total number of all surveyed profiles in all blocks is 513 profiles.

After data acquisition, processing GPR data is a crucial step. It cleans the raw data of any background noise and undesired reflections that may be created by the antenna, variations in the coupling of energy with the ground, and simultaneous reflections between the antenna and the ground surface [26]. To clarify the high reflections and identify potential artifacts in the study area, GPR data were analyzed using REFLEXW v.5.8 Software utilizing various filters and criteria [51]. The measured data were subjected to several processing phases, including subtract mean, static correction, background removing filter, gain, bandpass frequency, energy decay filter, running average, time cut, subtracting average, trace interpole 3D, X-flip, and time-depth analysis, where the velocity employed to transform the time to depth (V = 0.105 m/ns) gives a good resolution for the desired depth. In this work, both the reflected wave procedure and the hyperbolic shape way were used to determine the radar wave’s velocity.

6. Results and Discussion

6.1. Magnetic Data Interpretation

Identification of the subsurface sources of the potential archaeological targets and estimation of their shapes within the studied site are the fundamental aspects of the interpretation of magnetic maps. The TMI anomaly map and its derivatives were interpreted qualitatively and quantitatively.

6.1.1. Total Magnetic Field Intensity (TMI) Map

The TMI anomaly map showed different types of anomalies of deeper and shallower objects. To identify the potential location of these objects, the TMI map must be separated into a low-pass map of deeper origin sources and a high-pass map of shallower sources that may represent archaeological remains. The TMI map reveals a group of anomalies with low and high intensities that are dispersed in designated locations and have rectangular and square shapes with diameters ranging from 5 m to approximately 7 m. TMI values vary from 41,377 nT to a maximum value of 42,387 nT (Figure 5a). Comparing blocks (A) and (B), block (C) has considerably greater magnetic values. High concentrations of waste, including iron materials, granitic boulders, and burned materials, are present in Block (C) at this location. It is a location for marketing in El Araba Village. Some locations in this block have magnetic values of greater than 42,280 nT along the east and west boundaries of the mapped area. The eastern and western boundaries of the site are quite close to the wall of El Araba’s school and are above the animal wastes, respectively, explaining why the magnetic values are increasing more rapidly in this location.

6.1.2. Butterworth High Pass (HP) Residual Map

The TMI anomaly map was processed using a Butterworth high pass filter with a degree of filter function of 8 and a cut-off wavelength of 25 m to produce an HP residual map. Careful inspection of the HP map (Figure 5b) showed that the magnetic values vary from −295.5 nT to 134.1 nT. High and low anomalies of shallow sources are visible on this map. At various places, these anomalies are square or rectangular in shape and range in diameter from 5 to 7 m. These anomalies may be attributed to potential archaeological objects.

From the excavation of the adjacent archaeological remains within the investigated site, the buried objects that caused these anomalies are formed from multichambered mud-brick tombs of various sizes and forms of high magnetic susceptibility which were disturbed throughout time and were later replaced with low magnetic materials like sands; this conclusion is in consistent with the opinion of author [52] in another archaeological site. Thus, the magnetic values of the outer margins of the anomalies are higher than the magnetic values of the inner cores of these anomalies. These findings are extremely consistent with the results of the other archaeologists who worked near this site.

6.1.3. First Vertical Derivative (FVD) Map

Locations of the existing anomalies are illustrated in excellent detail in Figure 5c. The contacts between the magnetic anomalies are provided by the zero contour lines in this map, which outline the magnetic sources and highlight the connections between highly polarized and less polarized anomalies. The FVD map showed that the positive values reach up to 101.6 nT/m, while the negative ones are −200.3 nT/m.

6.1.4. Analytical Signal (AS) Map

Examination of the analytical signal map (Figure 5d) reveals significant gradient peaks that coincide with those predicted by the Butterworth high pass filter. The analytical signal values are between 1.3 to 286.3 nT/m. With an average radius between 5 and 10 m, most high analytical signal anomalies have rectangular and square geometrical shapes. The shallow sources in this site are reflected in sharp gradient peaks. Several very high anomalies with an average diameter of 5 m are dispersed across the block (A). Most of the anomalies in block (B) exhibit low analytical signal values. There is a significant anomaly in block (C) with a 15 m-diameter and high values near the southeast corner of the mapped area, which is close to El Araba’s school wall.

6.1.5. Tilt Angle Derivative Map (TDR)

After computing the TMI map, the tilt derivative map was created. The fact that the zero-contour line of the TDR is on or near the fault/contact area is its greatest advantage. From −1.417 to 1.433 nT, TDR data are available (Figure 5e).

6.1.6. Source Parameter Imaging (SPI) Technique

SPI is a method for automatically identifying source depth using TMI data. The source parameter imaging depth map (Figure 5f) indicates that the depth ranges of the causative bodies are from 0.7 to 4.8 m.

6.1.7. The 3D Euler Deconvolution Technique

The Euler method was used to create a total magnetic intensity map with the Geosoft Oasis Montaj software v. 8.4. The shape of the assumed geometric bodies that make up the Euler solutions is indicated by the structural index. Sill, dyke, or edge look best when exhibited at an index of 1.0, whereas a distant spherical or compact body could look best when displayed at an index of 3.0 [53]. The analysis of the source depth maps produced by the Euler deconvolution approach reveals that the depths of the source bodies are found between 0.7 and 5 m. These findings are in good agreement with the SPI procedure. Using structural index (SI) equal 1, the depth ranges of most magnetic sources are from 0.7 m to 4.0 m (Figure 5g), while they are from 0.7 m to 4.8 m when SI = 2 (Figure 5h).

6.2. GPR Data Interpretation

Examination of 513 radargram sections within all 12 blocks reveals that some of these profiles contain considerable hyperbolas of different amplitudes and widths reflecting different types of source bodies. On the other hand, some profiles do not have noticeable hyperbolas. Therefore, to keep the length of this article, only the profiles with distinct hyperbolas are illustrated. A summary of all hyperbolas that are predicted from all blocks with the current site that reflect potential targets is presented in

Table 2. Summarize the parameters of the detected anomalies features at the study area.

Grid	Profile No.	Recognized Archaeological Anomaly	Surface Distance (m)	Maximum Horizontal Dimension (m)	Two-Way Time (ns)	Depth to Its Top and Bottom (m)	Amplitude (m)
(A1)	P36	1	1 to 5	4	10	0.7 to 1.7	1
		2	7 to 11	4	12	0.8 to 2	1.2
	P37	1	0.4 to 4.4	4	11	0.6 to 1.6	1
		2	8.3 to 12.3	3	14	0.8 to 1.8	1
	P59	1	18.2 to 24.2	6	14	0.8 to 3	2.2
		2	29.8 to 34.8	5	12	0.6 to 2.8	2.2
	P60	1	17.8 to 22.9	5.1	15	0.8 to 3.1	2.3
		2	29 to 34.9	5.9	12	0.6 to 2.8	2.2
	P61	1	18.2 to 24.3	6.1	15	0.8 to 2.7	1.9
		2	28.1 to 34	5.9	14	0.7 to 2.7	2
	P64	1	11 to 16.3	5.3	18	0.9 to 2.8	1.9
		2	26.8 to 31.9	5.1	17	0.8 to 2.9	2.1
(C3)	P2	1	23 to 27	4	18	0.9 to 2.7	1.8
	P3	1	23 to 27	4	14	0.8 to 2.7	1.9
	P4	1	22 to 28	6	13	0.7 to 2.6	1.9
	P9	1	21 to 25.8	4.8	10	0.6 to 2.6	2
		2	27.3 to 31.3	4.3	12	0.8 to 2.5	1.7
	P10	1	20.5 to 25.1	4.6	13	0.7 to 2.7	2
		2	27 to 31.5	4.5	15	0.8 to 2.4	1.6
	P13	1	22 to 27	5	10	0.6 to 2.3	1.7
	P14	1	23 to 28	5	12	0.8 to 2.7	1.9
	P15	1	21.8 to 26.6	4.8	17	0.9 to 2.5	1.6

. For each hyperbola that was marked by a black circle, the surface distance, maximum horizontal dimension, amplitude, two-way time (TWT), and depth to its top and bottom were estimated (Figure 6 and Figure 7).

Important potential successive profiles P36, P37, P59–P61, and P64 at block (A1) with lengths of 40 m are shown in Figure 6. All these mentioned profiles exhibit two prominent hyperbolas that are remarkable anomalies. Important potential consecutive profiles P2–P4, P9, P10, and P13–P15 in block (C3) with lengths of 35 m are shown in Figure 7. One distinct hyperbola is seen in all the profiles, with the exception of P9 and P10 which contain two hyperbolas. These hyperbolas may represent fundamental objects of archaeological nature, such as walls, tombs, or any buried artifacts. Figure 6 and Figure 7 illustrate a comparison of the magnetic anomaly and the hyperbola of the radargram for the same profile using the 2D sections of the magnetic data and the GPR.

A three-dimensional visualization of the radar data in the current site was made by collecting all measured 2D radargram profiles in the small blocks (A and C) into Reflex Software v.5.8 (Figure 8 and Figure 9). To emphasize the most significant features, this model can be sliced vertically at any place. The black circles indicate the potential targets.

7. Integration of the Geophysical Data

Integration of two geophysical techniques yields reliable and confirmed results during data interpretation. The magnetic and GPR findings used in the current study confirmed each other where the positions and depths of potential anomalies in both tools were the same. Only the anomalies confirmed by the two methods were proposed to be archaeological objects with depths ranging from 0.7 m to 3 m.

Figure 10 shows the precise positions of buried targets with different dimensions, shapes, and depths based on magnetic and GPR results. To confirm these findings, excavation must be implemented, which could not be done by the current authors due to security reasons. Therefore, one of the most important recommendations to the Egyptian Antiquities Authority is to excavate in the places of the inferred targets. A close examination of Figure 10 reveals that most of the anomalies are small (approximately 5 m × 4 m), indicating the presence of tombs, while anomaly No. 6 is the largest, measuring 17 m × 11 m and indicating the location of the buried Coptic Monastery of Apa Moses. Many authors have investigated different sites in Egypt using the GPR technique, and their results are compatible with our findings [54,55].

8. Summary and Conclusions

The Abydos site is one of the most well-known ancient Egyptian sites for popular tourist destinations due to the abundance of many discovered and undiscovered monuments. Therefore, the main objective of this work is to explore the Coptic Monastery of Apa Moses in Abydos marketplace which is found in the ancient heritage books in Abydos site, Sohag, Egypt, and any other artifacts such as ancient walls and tombs. Magnetic and GPR surveys were implemented to achieve this goal. Advanced software packages were used for analyzing and interpreting the data. Analyzing the magnetic maps showed that the site is distinguished by number of anomalies scattered in various locations with different depths, sizes, and shapes, including squares and rectangles. According to the source parameter imaging technique, the detected magnetic anomalies have an average depth of between 0.7 and 4.8 m. However, using 3D Euler deconvolution with structure indices of 1 and 2, the depths ranges are 0.7 to 4.0 m and 0.7 to 4.8 m, respectively. Some of the anomalies correspond to potential archaeological objects and others to non-archaeological aspects. The magnetic results are well confirmed by the excavations data that were conducted in some sites of the Abydos region. GPR findings showed several hyperbolas in different locations of the Abydos site that may be interpreted as archaeological features by comparing them to those inferred from magnetic results. These sites were identified as buried shallow tombs due to their depth, which ranges from 0.6 to 3 m.

Integration of magnetic and GPR techniques reveals that there are six shallow prospective targets in the current site which were attributed to archaeological features; their depths are between 0.7 and 3 m. Anomaly No. 6 is the most likely the location of the buried Coptic Monastery of Apa Moses due to its large size rather than the other targets of small sizes. This study recommends excavating areas that have previously contained archaeological features that may be extended and are very likely to be strategic targets that will increase the number of artifacts found at this site, thus increasing tourism opportunities, and thereby increasing Egypt’s national income.