Systematic heat flow measurements across the Wagner Basin, northern Gulf of California #

Abstract #

This dataset comprises heat flow measurements collected along a 40 km transect across the Wagner Basin in the northern Gulf of California, a region of active continental rifting. Measurements were taken using a 6.5 m violin-bow probe at ~1 km spacing, co-located with a seismic reflection profile. Bottom water temperatures were corrected using long-term CTD (conductivity-temperature-depth) records. After correction, mean heat flow values were 220 ± 60 mW m⁻² (western basin), 99 ± 14 mW m⁻² (central basin), and 889 ± 419 mW m⁻² (eastern basin). Additional corrections for sedimentation are estimated to increase central basin heat flow by 40–60%. The results suggest conductive heat transfer in the basin center, with advective contributions from fluid flow on the flanks. These data provide new constraints on the thermal regime and degree of lithospheric rupture in an incipient oceanic rift setting.

Methods #

Heat flow data were acquired across the Wagner Basin using a 6.5 m violin-bow heat flow probe deployed along a ~40 km transect. Measurements were taken at ~1 km intervals and aligned with a co-located seismic reflection profile to facilitate correlation with subsurface structure.

Given the shallow water setting and known temporal variability in bottom water temperatures, raw heat flow values were corrected using a multi-year archive of CTD data. These corrections account for seasonal and interannual temperature fluctuations at the sediment-water interface.

Conductive heat flow was calculated from measured temperature gradients and assumed or measured sediment thermal conductivity. Although sedimentation rates were not directly measured, existing geological data were used to estimate the magnitude of heat flow suppression due to recent sediment accumulation, particularly in the central basin, where adjustments of 40–60% are inferred.

The final dataset includes corrected heat flow values along the profile, associated uncertainties, and metadata on location, probe penetration depth, and local bathymetry.

Other #

The Wagner Basin lies near the southern end of the Cerro Prieto fault zone and represents a key site for investigating the thermal and tectonic processes associated with early-stage continental rifting in the northern Gulf of California. The thermal regime provides critical insight into lithospheric structure, fluid circulation, and magmatic activity in this transitional tectonic setting.

Overall, this dataset helps constrain the extent of lithospheric extension, the role of fluid circulation in heat transport, and the thermal evolution of nascent rift basins. It contributes to broader understanding of rift-to-drift transition processes along the Gulf of California rift system.