Professor Criss specializes in hydrogeology, the geology of water and systems of water. Much of his work has an environmental slant.
Professor Criss' research spans many disciplines and has appeared in 50 different scientific journals, several government series, and several books. He has conducted extensive field and geochemical work in many geologic environments in North America, including Cordilleran batholiths, volcanic plateaus, metamorphic zones, gold-silver districts, karst and cave regions, alluvial aquifers, and rivers. In his long career as a professor he has taught several classes including Geochemistry, Hydrology, Stable Isotope Geochemistry, Chemical Thermodynamics, Geochronology, Speleology, Field Geology, and Environmental Potamology.
Criss’ research embodies the development of new mathematical formulae that explain huge datasets on natural systems. In the 1980’s and 1990’s he published detailed maps of the world’s largest fossil hydrothermal systems, and developed theoretical equations for kinetic and equilibrium fractionation effects in isotopic systems. Another series of papers with M.L. Davisson used stable isotope and radiocarbon data to prove that intense pumping and fertigation practices have rendered ancient groundwater supplies in the Central Valley of California unsuitable for human consumption.
More recent papers describe his diffusive theory of flash floods, explain geochemical variations in deep formation waters and the Missouri River, predict the levels of alluvial groundwaters, provide new statistical equations for flood risk, document man’s aggravation of recent floods, and explain the dynamics and geomorphology of landslides and karst landscapes in China. Recent papers coauthored with Prof. Anne Hofmeister provide a new interpretation of the Virial theorem, quantify the moments of inertia of polytropic stars, provide new equations for Earth’s heat flow, and quantitatively explain galactic rotation without resort to hypothetical dark matter.
Criss frequently applies his knowledge of Missouri hydrogeology to local environmental problems. He has testified at many public hearings on flooding, floodplain development, landfill problems, and groundwater contamination. His op-eds on these and other issues have appeared in several newspapers.