In situ thermal measurements were successfully conducted within Hole 1115B using the Adara on Cores 180-1115B-3H, 5H, 7H, and 9H at 26.2, 45.2, 64.2, and 83.2 mbsf, respectively (Fig. F76). An additional temperature measurement was obtained before Core 180-1115B-25X using the DVTP at a probe-tip depth of 226.9 mbsf (Fig. F77).
Equilibrium formation temperatures were estimated using the TFIT program for Adara runs, and the CONEFIT program for the DVTP run (see "In Situ Temperature Measurements" in the "Explanatory Notes" chapter). The estimates of equilibrium temperature used the thermal conductivity determined by core measurements (see "Thermal Conductivity") rounded to the nearest 0.1 W·m-1·ºC-1.
The mudline temperature in Hole 1115B is equivocal. The lowest temperatures (~4.6°C) were observed briefly in the water column rather than during the interval where the tool was held at mudline (~5.2°C to 5.5°C; Fig. F76). This occurred during all the Adara runs. A possibility is that mudline temperature is anomalously warm, either because of flow out of the borehole or very recent bottom-water temperature fluctuations. The alternate possibility is that the tool was being consistently held slightly below mudline. The lowest temperature observed during the runs (4.6°C) is shown on the depth profile, but it is likely that this is an overestimate, because the tool would not have had time to fully equilibrate.
If the mudline temperature is excluded on the assumption that it is either inaccurate or nonrepresentative, a linear regression results in an estimated thermal gradient of 0.028°C·m-1 (28°C·km-1; Fig. F78). Core measurements suggest an average thermal conductivity of 1.0 W·m-1·ºC-1 above 170 mbsf (see "Thermal Conductivity"), yielding a heat flow of 28 mW·m-2 (± 5%, for rounding of the thermal conductivity estimates).