The FIELAX heatflow measuring system records temperature as a function of time. The temperatures are recorded with 22 thermistors that are placed within a sensor string. The sensor string also contains a heating wire with which a distinct amount of energy is released into the sediments.

- A: lowering to seabed
- B: penetrating into seabed
- C: measuring thermal decay of frictional heat
- D: heat pulse
- E: measuring thermal decay of heat pulse
- F: pullout and retrieve to surface