Terra Exploration Group specializes in providing simple solutions to extraordinary geophysical survey needs such as locating caves and tunnels, underground water, mineral deposits, and even buried caches in difficult terrains or hard to reach locations anywhere in the World.


Terra Explorations' extensive field experience has helped them to understand and effectively use complicated technologies such as Ground Penetrating Radar, Magnetic Gradiometry, Electrical Resistivity Tomography, Pulse Induction Metal Detection, Thermal Imaging, Drone Surveying , and even Satellite based NMR Remote Survey Technologies.

With over 40 years of experience with multiple technologies, they provide a unique service to those that are searching for lost histories or hidden mysteries. They have appeared on the History Channel’s hit TV show “The Curse of Oak Island” and will be appearing on 3 more hit shows later this year utilizing our equipment and expertise.

Here is a photo of owners and operators Bob and Robert Leonard(a.k.a. The Bob’s) during the filming of “The Curse of Oak Island” TV show on History Channel.


Terra Exploration offers the following services worldwide:

Remote Sensing with satellite or aerial data and imaging can be used to do a ‘macro’ search on a large area to get an idea of possible anomalies. Technologies such as Nuclear Magnetic Resonance (NMR), Multispectral Imaging, and LIDAR can penetrate the earth’s surface and potentially identify minerals, metals, water, caves and tunnels, structures, and other sub-surface anomalies, without having to be on site.


Ground Penetrating Radar (GPR) sends radio waves into the ground and a sophisticated computer program reads the signals as they bounce back off of different substances underground. GPR is very effective at finding anomalies such as caves, tunnels, mine shafts, grave sites, and buried caches at depths up to 30 meters.


Electrical Resistivity Tomography (ERT) is a technology that uses an electrical current to detect anomalies underground. Depending on the resistance that the current encounters, it can detect voids (high resistance) and metals, minerals, and water (low resistance) to depths of 100 meters or more.



Magnetic Gradiometry is a technology that uses sensors that read changes in the earth’s magnetic field in nano teslas. Buried objects such as old walls or foundations can change the magnetic field. An imaging magnetometer can detect these small changes and produce an image of what lies below the surface. Magnetometers are also very effective at finding ferrous metals.



Thermal Imaging basically uses infrared sensors to see heat. Different temperatures are seen in different colors. Because everything hold heat differently, a  thermal camera can be used to find cave openings, old trails, walls, foundations, and even burials.



Pulse Induction Metal Detection is the most powerful metal detection technology available. Pulse Induction detectors send an electro-magnetic pulse into the ground that creates eddy currents when it encounters metal. These currents are then read by the main unit that determines whether the object is ferrous or non-ferrous. Very large coils can be made to reach depths of 10 meters or more.



Aerial Drones (UAV) can be used to survey an area from a ‘birds eye’ point of view. This is very useful as a scouting tool, saving valuable time in the field. Drones can also carry infrared and LIDAR sensors.



To contact Terra Exploration Group about your project, please call 512-280-9600, or email at info@texgru.com

(Mention KellyCo to get special pricing!)