Table of Contents
Underground Mapping: A Complete Guide
TL;DR
Underground mapping uses specialized technology to map subterranean structures for resource extraction, infrastructure planning, and safety improvement. Technologies like Ground Penetrating Radar (GPR), EM locators, seismic imaging, and bathymetric mapping provide accurate subsurface data.
These tools help avoid excavation delays, improve safety by locating utilities, and enhance collaboration between stakeholders. From detecting buried pipes to mapping the ocean floor, underground mapping enables efficient resource extraction and smarter urban development.
1. What Is Underground Mapping?
Underground Mapping is the use of specialized technology to map subterranean structures. Resource extraction is the primary goal of underground mapping. This includes oil and natural gas exploration and identifying the location of underground infrastructures.
Underground mapping also helps:
• Avoid time wasted on excavation and construction, due to encountering unplanned subsurface infrastructures.
• Improve safety by accurately locating utilities, allowing contractors to implement safety measures, like safe digging and the use of appropriate machines.
• Improve collaboration by having clear data on utilities. Project stakeholders and utility companies can reduce miscommunication and improve project execution. For example, urban planners can map utilities and identify dangerous areas.
This article describes the kinds of underground mapping technologies available today.
2. Ground Penetrating Radar
Ground penetrating radar (GPR) is one of the radar technologies designed to scan the subsurface of the Earth. To perform this function, the technology transmits a high frequency electromagnetic wave and measures the reflection time and the return waves. The depth of the reflections gives a good estimate of the structure and content of the subsurface. This technology is also used in LiDAR.
Ground Penetrating Radar (GPR) combines both geophysical and surveying techniques to collect information about the subsurface of the Earth. It is mainly used for detecting and locating subsurface structures and for non-destructive subsurface surveying. Data is gathered for a 2-dimensional map of a given area to visualize the layering of the subsurface materials and structures. This information can then be used in analysis to aid in decision making for the area being studied.
Uses of Ground Penetrating Radar
The uses of GPR encompass:
- • Detecting buried objects
- • Mapping subsurface infrastructure
- • Measuring peat thickness
- • Determining depth to the water table
- • Scanning the depth of water for mineral exploration
- • More readily mapping subsurface mineral bodies
3. EM Locator and Potholing
An EM Locator would be akin to a metal detector but for buried pipes. Rather than magnets, radio waves are used. They can pass a signal and create a loop with a metallic conductor (like pipes) and are able to trace the conductor and the signal is returned to the locator.
This works well if the pipes are connected to a fixture on the surface, but accuracy drops when attempting to trace the pipes in the ground. Potholing is the most accurate and direct method of utility location. It is a time consuming and labour-intensive method, it does save time and money in the long run.
4. Surveying Infrastructure
Infrastructure surveying from above can also give planners information relevant to large projects about utilities that are below ground. Though traditionally expensive, helicopter aerial inspection offers results that can take considerable time.
Over the past ten years, co-founders of ARGO Labs have pointed out that satellite imagery reduces the time to complete a locate from 72 hours to almost real time.
5. Seismic Imaging
Seismic imaging involves mapping the subsurface using sound waves and is also a means of subsurface surveying. This technique sends acoustic waves through the ground using a vibriosis or explosive detonation. As sound waves reflect off of ground objects, a computation of the time it takes for the wave to reflect is achieved.
The geophones at the survey site captures the resultant waves, and the exit waves are documented. Geophysicists can use the data to analyse the surface and rock layers for determining the geo resources.
Seismic imaging initially was designed for detecting the deposits of coal, gas, and oil, which is also used for water geo resources and geothermal resources and for geothermal exploration. It is beneficial for geothermal resource potential and geothermal energy resource surveying.
6. Bathymetric Mapping
Bathymetric mapping is a method of looking underneath the ocean surface. It is possible to create a map of the ocean floor by taking measurements from a ship that is equipped with Sonar technology. This method involves echo sounding and other map creation techniques for underwater mapping.
Bathymetric maps are useful for navigation, coastal zone planning, and for the environmental marine maps. Mapping the ocean floor opens a new way of understanding the ocean and its features. It provides information about the ocean floor and how it changes over time, its physical features, and the movement of the tectonic plates.
Conclusion
Underground mapping technologies enable efficient resource extraction and infrastructure planning by providing accurate, real-time data on subsurface structures and utilities. These innovations enhance safety, reduce project costs, and support smarter collaboration for urban development and mining operations.