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How do wire-line logging tools measure properties inside holes drilled into the seafloor?

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Wire-line logging tools are specialized instruments used to analyze geologic formations within holes drilled into the seafloor. These tools are typically lowered into a borehole using a steel cable after the core has been removed.12

As the tools are moved through the hole, they measure various physical properties of the surrounding rock and sediment, including:

Electrical properties: Measuring electrical resistance and conductivity to identify different materials.12
Acoustic properties: Utilizing sound waves to determine formation characteristics.12
Magnetic and gravitational effects: Detecting variations in the local fields.1

These instruments relay response signals to the surface for immediate observation and recording, which allows scientists to make informed decisions regarding the formation. In some cases, these packages may also include remote television cameras to provide visual data from within the borehole. This process is distinct from logging-while-drilling (LWD) technologies, which perform measurements simultaneously as the hole is being drilled.12