Mikhail Lavrov Mikhail Lavrov Mikhail Andrianovich Lavrov () (1799–1882) was a Russian rear-admiral and Arctic explorer. Mikhail Lavrov was born on 13 September 1799 in the city of Arkhangelsk. He graduated from Cadets Corps in Saint Petersburg and served at the Baltic Fleet. He participated in the voyage of the cargo ship "Mezen" from Kronstadt to Arkhangelsk and back in 1819–1820. In 1821–1824, in the rank of senior officer, he participated in the expedition of Fyodor Litke on board of the brig "Novaya Zemlya", making description of coast line of Murmansk and Novaya Zemlya archipelago. In 1825–1827, he made a round-the-world voyage
Novaya Zemlya effect gradient. The sunlight must bend to the Earth's curvature at least 400 km to allow an elevation rise of 5° for sight of the solar disk. The first person to record the phenomenon was Gerrit de Veer, a member of Willem Barentsz's ill-fated third expedition into the north polar region in 1596–1597. Trapped by the ice, the party was forced to stay for the winter in a makeshift lodge on the archipelago of Novaya Zemlya and endure the polar night. On January 24, 1597, De Veer and another crew member claimed to have seen the Sun appear above the horizon,