Related by context. Frequent words. (Click for all words.) 40 Doug Mellgren 39 USGS geophysicist 37 Seaside Ore. 36 Lonnie 35 Lorene 32 NASA MODIS Image 32 Seward Peninsula 32 USGS scientist 31 journal Geology 30 volcanically active 30 Iditarod musher 29 Wrangell St 29 Hugh Neff 29 Bella Vista Ark. 28 mountain glaciers 27 Sebastian Schnuelle 26 Sawtooth Mountains 26 snowline 25 Weddell Sea 25 caldera 25 conquered Everest 24 snowcapped peaks 24 Punta Arenas Chile 24 glacial retreat 24 huckleberries 23 Flagstaff Ariz. 23 Iditarods 23 shrinking glaciers 23 forest ecologist 23 glaciers melting 23 National Geographic Adventure 23 volcanoes 22 glaciologist 22 Burgess Shale 22 icecap 22 lichen 22 Puncak Jaya 22 glacier melt 22 Steamboat Springs Colo. 22 paleoclimate 22 aspens 21 Mount Kilimanjaro 21 marine ecologist 20 seamount 20 Yukon Territory 20 permafrost 20 Moab Utah 20 Mount Katahdin 19 polar regions 19 Revelstoke BC 19 glaciologists 19 icecaps 19 melting glacier 19 Kluane 19 lake sediments 19 aspen trees 19 Ed Viesturs 18 Cradle Mountain 18 Mt Kilimanjaro 18 Banff Alta 18 lichens 17 glaciers melt 17 Antarctic ice 17 geographer 17 Antarctic Ice 17 Antarctic peninsula 17 sediment cores 17 backcountry ski 17 Antarctic Peninsula 17 glaciers 17 retreating glaciers 16 polar ice 16 mountain ranges 15 Precambrian 15 melting 15 melting ice 15 Arctic explorer 15 dinosaur bones 14 glacial ice 14 Galapagos islands 14 Ilulissat 14 fabled Northwest Passage 14 summiting 13 Arctic Circle 13 Quaternary 13 glacier 13 Nome Alaska 12 Glaciers 12 Pleistocene era 12 Rocky Mountains 12 dinosaurs roamed 11 Ellesmere Island 11 continental drift 11 sequoias 10 giant sequoias 10 Antarctica 10 Arctic Ocean 8 expeditions 6 Antarctic 6 subarctic 5 expedition