Related by context. Frequent words. (Click for all words.) 77 gas hydrates 59 methane 58 hydrates 57 geological formations 56 hydrocarbons 55 melting permafrost 54 subsurface 53 sedimentary rock 53 polar caps 53 diatoms 52 volcanism 52 permafrost 52 shales 52 Arctic Ocean 52 hydrothermal vents 52 silicates 51 regolith 51 moon Europa 51 earth crust 51 hydrocarbon 50 shale 50 marine organisms 50 magma 50 geologic formations 50 water vapor 50 subduction zones 50 magmatic 49 gases 49 meltwater 49 shale formations 49 rocky planets 49 crustal 49 Greenland ice 49 supercooled 49 shale deposits 48 peridotite 48 greenhouse warming 48 carbonates 48 oceans 48 coal seams 48 organic compounds 48 nucleation 48 polar ice 48 olivine 48 polar regions 48 sedimentary basins 48 Earth crust 48 ionic liquids 48 sediments 48 buckyballs 48 organic molecules 48 Enceladus 47 carbon dioxide 47 microbes 47 geologic 47 seafloor 47 Arctic 47 spacetime 47 methane gas 47 ice crystals 47 hydrothermal 47 coalbed methane 47 IceCube 47 microscopic organisms 47 liquid hydrocarbons 47 Microbes 47 carbon sequestration 47 Antarctic Ice 46 coronal mass ejections 46 hydrogen 46 volcanoes 46 cosmological constant 46 oceanographers 46 Nature Geoscience 46 glacial melt 46 oceanic 46 seabed 46 glaciers 46 shale gas 46 subduction zone 46 anoxic 46 Antarctic ice 46 sedimentary rocks 45 economically recoverable 45 plate tectonics 45 underground caverns 45 Melting ice 45 Antarctica 45 cyanobacteria 45 molten rock 45 earths 45 CO2 45 helium 45 superfluid 45 fullerenes 45 sulfides 45 ozone depletion 45 condensates 45 anthropogenic climate 45 hydrogen sulphide 45 ocean currents