o ▁G uten berg , ▁And ri ja ▁Moh or ovi č ić , ▁Harold ▁Jeff re ys , ▁In ge ▁Le h mann , ▁Edward ▁Bull ard , ▁Charles ▁Francis ▁Rich ter , ▁Francis ▁Bir ch , ▁Frank ▁Press , ▁H iro o ▁Kan am ori ▁and ▁Walter ▁Els asser . ▁ ▁One ▁highly ▁deb ated ▁topic ▁about ▁Earth ' s ▁interior ▁is ▁mant le ▁pl umes . ▁These ▁are ▁the or ized ▁to ▁be ▁rising ▁mag ma , ▁which ▁is ▁responsible ▁for ▁the ▁hot sp ots ▁in ▁the ▁world , ▁like ▁Hawai i . ▁Origin ally ▁the ▁theory ▁was ▁that ▁mant le ▁pl umes ▁rose ▁up ▁in ▁a ▁direct ▁path , ▁but ▁now ▁there ▁is ▁evidence ▁that ▁the ▁pl umes ▁may ▁def lect ▁by ▁small ▁degrees ▁as ▁they ▁rise . ▁It ▁was ▁also ▁found ▁that ▁the ▁proposed ▁hot spot ▁under ne ath ▁Y ellow stone ▁may ▁not ▁be ▁related ▁to ▁a ▁rising ▁mant le ▁pl ume . ▁This ▁theory ▁has ▁not ▁been ▁fully ▁research ed . ▁ ▁Pl ate ▁t ect on ics ▁ ▁In ▁the ▁second ▁half ▁of ▁the ▁ 2 0 th ▁century , ▁plate ▁t ect on ics ▁theory ▁was ▁developed ▁by ▁several ▁contrib utors ▁including ▁Alfred ▁Weg ener , ▁Maurice ▁E wing , ▁Robert ▁S . ▁Diet z , ▁Harry ▁Hamm ond ▁H ess , ▁Hugo ▁Ben io ff , ▁Walter ▁C . ▁Pit man , ▁III , ▁Frederick ▁V ine , ▁Dr um mond ▁Matt he ws , ▁Keith ▁R unc orn , ▁Bry an ▁L