Petropavlovsk became reshipping base for westbound cargo ships for Russia according to the U.S. Joint Intelligence Committee. Daily summary dated 3 March 1942

An item reported that Petropavlovsk (south east of the Kamchatka Peninsula) seemed to be used a reshipping base for cargoes westbound for Russia. Coastal vessels with a light draught transported the cargoes further via de Sahkalin and Tartary Straits to Vladivostok and Komsomolsk. In the manner could the Japanese-dominated straits like Tsushima be avoided. Main issue with this new shipping route was that the Tartary and Sakhalin Straits were still not ice-free for the next two months and the Okhotsk Sea still one month.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 83 dated 3 March 1942.