pine island pine island pig large ice stream fastest melting antarctica responsible antarctica ice loss ice streams flow west northwest south antarctica mapped surveys united_states_navy air photos named association area drained comprises percent satellite measurements shown greater net contribution ice sea ice drainage basin world increased recent acceleration ice stream ice stream extremely remote nearest continually occupied research station nearly away area claimed nations treaty prohibits new claims force ice sheet drainage ice sheet largest mass ice earth containing volume water equivalent global sea level ice sheet forms snow falls continent weight ice moves weight edges continent transport sea ice streams faster moving channels ice surrounded slower moving ice walls outlet glaciers ice sheet consists large relatively stable smaller stable west ice sheet drained sea large ice streams flow ross ice shelf major ice streams flow large ice shelf area called sea total area km2 percent drains sea pine island area known drainage basin weak sheet glaciers antarctica largest ice streams scientists found flow ice streams accelerated recent years suggested melt global sea levels rise entire sheet sections proposed region weak based fact unlike majority large ice streams flowing protected ocean large floating ice shelves surface sea level base lies sea level slopes downward inland suggests geological barrier stop retreat ice started acceleration speed pine island increased percent end percent increase months period speed meant end pine island system negative mass balance year equivalent year global sea level rise words water sea pig replaced snowfall measurements centre ice stream gps demonstrated acceleration high nearly inland percent suggested recent acceleration triggered warm ocean waters end pig floating section ice shelf approximately long shown pig underwent rapid process continue centuries initiated ice stream getting rate central trunk current rate acceleration continue main trunk afloat years volcano january scientists reported years ago volcano erupted ice sheet biggest eruption years volcano situated close eruption spread layer volcanic ash surface ice sheet ash buried snow ice able map ash layer airborne radar system date eruption depth burial ash method uses dates calculated nearby ice presence volcano raises possibility volcanic activity contributed contribute future increases flow history ice pine island information available ice stream comes airborne satellite based measurements expedition visit ice stream united_states snow traverse spent week area pig january dug snow pits measure snow accumulation carried seismic surveys measure ice thickness scientists traverse claims didn know crossing time surprising pig wide point visited ground level visually distinguished surrounding ice expedition called field season team british survey aircraft equipped ice penetrating radar completed aerial survey pig adjacent ice sheet team americans led flew grid patterns pig mid january mapping sub glacial terrain area roughly equal size pig logistical difficulties fuel expedition future project resources ski equipped aircraft weeks weather delays men arrived began establish camp build camp established upper end ice stream remaining members team arrived approximately days later twin flown survey pilot unusually good weather area season survey completed flying early mid january began flying expedition experiencing unusually poor weather area year flying antarctica pine island research plane scientists participating nasa mission startling discovery october massive crack running kilometers floating tongue rift metres feet wide average meters deep marks moment creation new span square kilometers square miles breaks loose survey having completed end january survey crew flew leaving americans british camp week later remaining team members flew leaving fuel future expeditions team arrived ice stream december field seasons second field season spent months november february work included radar measurements seismic surveys january nasa landed floating ice shelf pig downstream end sea landing plane fitted landing ice shelf reason landing ice shelf reconnaissance mission investigate feasibility drilling ice lower instruments ocean cavity hoped provide important information link ocean decided small free area hard landings postponed gps units weather station positioned near possible pig decided establish helicopter camp scientists safely study ice ocean interaction summer field season antarctica planned haul equipment needed establish camp near ice shelf tractor train traverse needed deliver materials plan following field seasons scientists use helicopters fly sites ice shelf deploy specially designed ice shelf measure ocean properties field season weeks delays camp staff finally able establish new years following week team able arrive additional weather delays helicopters weren able arrive drop dead date field season essentially cancelled fortunately limited science accomplished team thanks series flights conditions changed drastically twin flights deployed small team summer field season carry series seismic radar surveys pig installed series gps stations field season separate team field parties location installed autonomous station followed radar traverse upstream survey linked previous radar lines sea ship reach pine island ice shelf ship operated mission known scientists board took sediment samples ocean floor summer field season months january february researchers aboard research vessel reached ice shelf second time successfully time collaboration british scientists robotic submarine explore carved channels continental shelf cavity ice shelf submarine known developed built completed successful missions travelling total ice shelf able map base ice shelf ocean floor measurements samples water way success particularly notable predecessor lost beneath ice shelf second mission
Pine Island Glacier