TEM‐fast small‐loop soundings to map underground tunnels and galleries connecting the rock‐hewn churches of Lalibela, Ethiopia

Abstract

As one of the first attempts to utilize the technique for intrasite archaeological prospection, a series of coincident square-loop TEM-fast geophysical surveys were carried out over the compounds of the largest of the rock-hewn churches of Lalibela-Bete Maryam and Bete Amannuelin North Ethiopia. Archaeologists have long believed that the different churches within each group were connected by underground tunnels. The aim of this survey was to identify, delineate, and map these underground channels and galleries. A total of 33 sounding surveys were conducted, the majority of which used a 3-m-side square loop. The survey traverses explored around the sides of the churches where underground connections to the other churches are possible. The results of the surveys, which are presented in terms of resistivity and depth pseudosections, clearly depict the presence of anomalies that could be associated with cavities, whose orientation suggests the presence of connecting galleries between the different churches. Whether these cavities were actually connecting galleries with religious implications or designed to be used as drainage paths remains a subject requiring further study involving additional geophysical investigations and physical excavation.

Fast Forward Modeling of Electromagnetic Induction Using Correspondence Principle

“…They are enlisted in the World Cultural Heritage by UNESCO and have been referred as the "New Jerusalem," and the "New Golgotha". A series of coincident 3-m square-loop transient electromagnetic (TEM) surveys was conducted around Church Bete Maryam (Figure 1) aiming to image un-documented intra-site subsurface tunnels (Ranieri et al 2005). The possible tunnels seem to have a depth to the ceiling of the tunnel around 10 m (Figure 2).…”

What kind of volcanite the rock-hewn churches of the Lalibela UNESCO's world heritage site are made of?

“…Nowadays, the site is still the main center of the Ethiopian Christian Coptic Church. The churches, having trenches and courtyards, are interconnected by a maze of tunnels and passages with openings to hermit caves and catacombs [4]. The walls of the trenches and courtyards contain cavities and chambers sometimes filled with the mummies of pious monks and pilgrims.…”

“…1). As concerning the mode of carving, three group of churches were identified [4,5]: (i) built-up cave churches, which are ordinary structures inside a natural cave (e.g. Biet Medhane-Alem); (ii) rock-hewn cave churches, which are cut inwards from a more or less vertical cliff face, locally using and widening an existing natural cave (e.g.…”

The Ancient Roman Aqueduct of Karales (Cagliari, Sardinia, Italy): Applicability of Geophysics Methods to Finding the Underground Remains

“…Nowadays, electrical and electromagnetic geophysical methods are widely used in very shallow archaeological prospection (Ranieri, 2000;Gaffney and Gater, 2003;Ranieri et al, 2005bRanieri et al, , 2007Ullrich et al, 2007;Godio and Ranieri, 2008;Cozzolino et al, 2012;Osella et al, 2013), up to 2-3 m in depth, while their application to detection of deeper remains, down to 10 m or more, is less common (Ranieri et al, 1996(Ranieri et al, , 2005aPfaffhuber et al, 2012).…”