Tanaga Island was established as a Navy emergency landing field in July 1943 as an adjunct to the Adak Naval Operation Base.Seabees of Naval Construction Battalion 45 built a runway, small-craft pier, mooring area, office and storage buildings, radio building, galley and mess facilities, dispensary, and 4 miles (6 kilometres) of gravel road in 1943, near Lash Bay in the southwest of the island.Takawangha's 4,754-foot-high (1,449-metre) summit is mostly ice-covered, except for four young craters that have erupted ash and lava flows in the last few thousand years.Parts of Takawangha's edifice are hydrothermally altered and may be unstable, and could produce localized debris avalanches.[1] A swarm of earthquakes was reported in January 2017 about 6 kilometers from Takawangha, causing the Alaska Volcano Observatory to raise the alert level to YELLOW/ADVISORY[4]