Glenn Spinelli and Demian Saffer Trench-parallel fluid flow in the Nicoya margin subduction zone resulting from temperature differences Glenn Spinelli and Demian Saffer

Subduction zone hydrogeology Saffer and Bekins, 1998 fluid pressure affects fault strength transport of chemical species nutrients to vent communities heat transport

Subduction zone fluid flow in 3-D Screaton and Ge, 1998 Bangs et al., 1996

Thermal controls on hydraulic conductivity Kato et al., 2004 Morrow et al., 2001 Khot > Kcold Kcold > Khot

Nicoya margin heat flow and temperature Spinelli et al., 2006 Fisher et al., 2003

Along-strike differences in hydraulic conductivity

Nicoya margin trench-parallel fluid flow

Nicoya and other circum-Pacific examples

Conclusions Along-strike differences in temperature influence subduction zone hydrogeology trench-parallel differences in fluid pressure & flow shallow, cold decollement  flow from cold to hot side deep, hot decollement  flow from hot to cold side

Along-strike differences in hydraulic conductivity

Effect of dewatering distribution