Dead Sea on the Israeli side allows production of magnesium metal (by a subsidiary, Dead Sea Magnesium Ltd.). Due to the popularity of the sea's therapeutic and healing properties, several companies have also shown interest in the manufacturing and supplying of Dead Sea salts as raw materials for body and skin care products. Since 1930, when its surface was and its level was below sea level, the Dead Sea has been monitored continuously. In recent decades, the Dead Sea has been rapidly shrinking because of diversion of incoming water from the Jordan River to the north. The southern end is fed by
Northern Dvina River the west-flowing Vychegda River ( long). The combined river flows northwest into the White Sea, which it joins near the city of Archangelsk. Looking more closely, the Sukhona flows east and meets the north-flowing Yug River at Veliky Ustyug. The combined stream, now called the Northern Dvina, flows north about 60 km and receives the west-flowing Vychegda at Kotlas and then turns northwest to flow into the White Sea. The Sukhona-Vychegda was an important east–west transportation route while the Northern Dvina-Yug was a north–south route. The upper Sukhona is now connected by the Northern Dvina Canal to the Volga–Baltic Waterway,