Related by context. Frequent words. (Click for all words.) 62 permafrost 55 woolly mammoths 54 woolly mammoth 53 glaciation 53 wooly mammoth 52 coprolites 52 mammoths 52 Younger Dryas 52 interglacial period 52 Antarctic ice 52 Lyuba 52 marine sediments 51 Permafrost 51 melting glacier 51 microfossils 51 icecaps 51 methane hydrates 51 lunar soil 51 atmospheric methane 50 glacial ice 50 equatorial regions 50 dinosaur fossils 50 Oetzi 50 volcanism 49 Weddell Sea 49 thawing permafrost 48 megafauna 48 Greenland glaciers 48 Greenland ice 48 Greenland Ice 48 retreating glaciers 48 fossils 48 methane hydrate 48 supercontinent 48 Antarctica 48 radiocarbon 48 icecap 48 hadrosaur 48 glacial 47 fossilized 47 polar ice 47 geologically active 47 glaciers melting 47 glacial melting 47 melting permafrost 47 polar caps 47 fossil 47 solar nebula 47 sediment cores 47 journal Geology 47 Saturn moon Enceladus 47 salt crystals 47 frozen 46 Neandertal 46 interglacial 46 polar 46 Martian soil 46 archaea 46 Meridiani 46 Ice Age 46 gas hydrates 46 lake sediments 46 melting 46 glacier 46 dinosaur fossil 45 Wilkins Ice Shelf 45 glaciers 45 Opportunity rover 45 peat bogs 45 mitochondrial genome 45 Microorganisms 45 atmospheric carbon dioxide 45 NSIDC 45 Ross Ice Shelf 45 moon Europa 45 Arctic tundra 45 fossilized remains 45 glaciers melt 45 Antarctic Peninsula 45 thawed 45 radiocarbon dating 45 sedimentary rock 45 diatoms 44 thawing 44 kerogen 44 plesiosaur 44 oxygen isotopes 44 lithosphere 44 Pleistocene 44 lavas 44 plate tectonics 44 zircons 44 Ellesmere Island 44 microlensing 44 Gliese #g 44 western Siberia 44 greenhouse warming 44 trilobites 44 polar regions 44 hydrological cycle 44 mid latitudes