Fig. 1.

Hydrothermal conveyor based on chaotic thermal convection. (A) Mineral formations near off-ridge alkaline hydrothermal vents lining the ocean floor contain embedded pore networks with microenvironments that impose thermal and geometric conditions robustly capable of sustaining internal convective flow fields. Image below depicts a cross-section of material retrieved from the Lost City vent illustrating its internal void morphology. (Scale bar, 2.5 cm.) Reproduced with permission from ref. 18. (B) These vent systems embed characteristic porosity and thermal gradients aligned with chaotic thermal convection. Length scales and thermal gradients associated with thermophoretic focusing are illustrated for comparison.