Related Experiment Video
Updated: May 25, 2026
11:34
Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography
Published on: May 15, 2017
Active thermal tracer tests for improved hydrostratigraphic characterization.
Andrew T Leaf1, David J Hart, Jean M Bahr
1Department of Geoscience, Universityof Wisconsin-Madison, Madison, WI 53706, USA. aleaf@geology.wisc.edu
Ground Water
|February 11, 2012
Summary
This study introduces distributed temperature sensing (DTS) for borehole dilution testing, improving hydrogeologic characterization. DTS accurately maps subsurface flow and inflows, enhancing understanding of complex hydrostratigraphic units.
Area of Science:
- Hydrogeology
- Environmental Science
- Geophysics
Background:
- Subsurface heterogeneity in hydraulic properties presents a significant challenge in hydrogeology.
- Accurate characterization of hydrostratigraphic units is crucial for understanding groundwater flow.
- Conventional borehole testing methods have limitations in speed, sensitivity, and disturbance.
Purpose of the Study:
- To develop and validate an improved method for borehole dilution testing using distributed temperature sensing (DTS).
- To enhance hydrostratigraphic characterization by monitoring advective heat movement.
- To gain a detailed understanding of borehole flow regimes and inflow locations.
Main Methods:
- Implemented distributed temperature sensing (DTS) for monitoring advective heat movement during borehole dilution tests.
- Conducted open-well thermal dilution tests in multiaquifer wells.
- Utilized DTS for synoptic temperature profiling without disturbing the fluid column.
Main Results:
- DTS provided rapid (seconds) and sensitive measurements of advective heat movement.
- Detailed information on borehole flow rates and inflow locations (fractures and porous media) was obtained.
- Identified previously unrecognized flow complexities within a supposedly homogenous hydrostratigraphic unit.
Conclusions:
- Distributed temperature sensing (DTS) offers significant advantages over conventional borehole flow logging technologies.
- The improved DTS method enhances the characterization of subsurface hydraulic properties and processes.
- This technique leads to a more nuanced understanding of groundwater flow in heterogeneous hydrogeologic settings.
Related Concept Videos
01:21Hyperthermophilic Bacteria
Domain Bacteria includes some unique hyperthermophilic species. They exhibit remarkable adaptations that enable survival in extreme environments.Thermotoga species are rod-shaped, gram-negative, non-sporulating hyperthermophiles that form a sheath-like envelope called a toga. They ferment sugars or starch, producing lactate, acetate, CO₂, and H₂, and can also grow via anaerobic respiration using H₂ and ferric iron. Found in hot springs and hydrothermal vents, over 20% of their genes show strong...
01:19Thermal Strain
Thermal strain is a concept that arises when we consider how temperature changes affect structures. Unlike the conventional assumption that structures remain constant under load, real-world scenarios often involve temperature fluctuations that can significantly impact these structures. Consider a homogeneous rod with a uniform cross-section resting freely on a flat horizontal surface. If the rod's temperature increases, the rod elongates. This elongation is proportional to the temperature...
01:22Thermal Expansion
The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, which is the change in size or volume of a given system as its temperature changes. The most visible example is the expansion of hot air. When air is heated, it expands and becomes less dense than the surrounding air, which then exerts an upward force on the hot air to, for example, make steam and smoke rise, and hot air balloons float. The same behavior happens in all liquids and gases,...