Summary of the history and research of the U.S. Geological Survey gas hydrate properties laboratory in Menlo Park, California, active from 1993 to 2022

First posted September 8, 2023 For additional information, contact: Earthquake Science CenterU.S. Geological Survey350 N. Akron RoadMoffett Field, CA 94035 The U.S. Survey (USGS) Clathrate Hydrate Properties Project, active from 1993 to 2022 in Menlo Park, California, stemmed an earlier project on the properties of planetary ices supported by National Aeronautics and Space Administration’s (NASA’s) Planetary Geology Geophysics Program. We took a material science approach both projects, emphasizing chemical purity samples, having controlled grain size texture, verified crystal structures phase relations. A foundational contribution our USGS Gas Laboratory (GHPL) was demonstrating ability reproducibly create such pure clathrate hydrate samples for study. sample synthesis achieved heating sieved weighed granular water ice presence cold clathrate-forming gas or liquid. During heating, melts at scale reacts with form clathrate. resulting has desired uniformity purity, known intergranular porosity; subsequent measurements showed that these clathrates exhibited established This novel method successful creating methane, ethane, propane, carbon dioxide, multi-component gases. By mixing sand silt ice, we were also able make clathrate-sediment aggregates textures. simple method, adopted many others community, permitted us measure physical well-characterized well-crystallized clathrate/sediment aggregates. At about same time, adapted conventional scanning electron microscopy cryogenic conditions analysis grain-scale characteristics made GHPL as well those collected nature drill core. reproducibility allowed investigate how respond environmental changes chemistry, temperature, pressure: measured exchange rates dissolved species—such noble gases chlorofluorocarbons—as dissolution decomposition. These advances include first accurate mapping promote remarkable process “anomalous preservation” room pressure, metastability offers potential application low-cost safe transportation natural fields far pipelines.Another advancement stemming compaction as-synthesized porous nearly full density applying external pressure using three different techniques. Compaction allows high-accuracy fundamental materials, elastic wavespeeds moduli, complete thermal properties, decomposition rates, expansion, equations state. others, turn, have helped scientists interpret geophysical logs surveys, model production deposits nature.Studying this class icy minerals occur abundance Earth outer solar system been fascinating laboratory journey. Here, summarize history major findings including in-house research synergistic collaborations other agencies institutes key success laboratory. Park more formally incorporated within Hydrates collaboration among multiple Centers, early 2000s under leadership Deborah Hutchinson, now Carolyn Ruppel Timothy Collett.