Glaciations H2 exploration H2 venting Research & information: general Sao Francisco Basin atmospheric pressure tides basin modeling basin modelling capillary seals chalk chemical alteration compaction computer simulations conductivity effects on maturation critical state physics crustal flow channeling crustal fluid flow crustal fracture imaging crustal fracture seismics crustal power law scaling crustal sills crustal well-core poroperm diagenesis direct inversion method of fault slip analysis diurnal hydrogen gas venting draining faults earth tides faults finite element method flexural stress