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
Novaya Zemlya effect two full weeks prior to its calculated return. They were met with disbelief by the rest of the crew (who accused De Veer of having used the old Julian calendar instead of the Gregorian calendar introduced several years earlier), but on January 27 the Sun was seen by all "in his full roundnesse". For centuries the account was the source of skepticism, until in the 20th century the phenomenon was finally proven to be genuine. Apart from the image of the Sun, the Novaya Zemlya effect can also elevate the image of other objects above the horizon, such as coastlines