Severnaya Zemlya any traces of land to the north of the wide strait between the Kara Sea and the Laptev Sea that they navigated. The archipelago was not put on the map until the 1913–1915 Arctic Ocean Hydrographic Expedition of icebreakers "Taimyr" and "Vaigach". The chief organiser and first captain of the Vaygach was officer Aleksandr Vasiliyevich Kolchak of the Imperial Russian Navy. The expedition was privately financed and was launched in 1910, being led by Boris Vilkitsky on behalf of the Russian Hydrographic Service. This venture accomplished its goal of exploring the uncharted areas of the continental side of the Northern
Severnaya Zemlya of the Severnaya Zemlya group and is separated from Komsomolets Island by the Yuny Strait. Pioneer island measures in area. This island houses the Pioneer Glacier. Thelodonti fossils from the Upper Silurian have been found in the island. Off Pioneer Island's southwestern end lies Krupskoy Island. This is a fairly large island, over in length and about in width. The sound that separates it from Pioneer is only in width. This island should not be confused with Pioneer Island in Canada (). Schmidt Island, measuring , is located at the far northwestern end of the archipelago. This island is quite