Tsugaru Strait yana da gabas da yammacin wuyansa, duka kimanin 20 km (12 mi) a fadin. Binciken farko da aka gudanar a 1946 ya nuna cewa wuyan gabas yana da zurfin mita 200 (656 feet) tare da geology na volcanic. Yammacin wuyansa yana da zurfin mita 140 (459 feet) da kuma geology wanda ya ƙunshi yawancin dutsen da ke cikin Neogene. An zaɓi wuyan yammacin, tare da yanayin da ya dace da tunneling.
Abubuwan da suka faru na Igneous da kuskure