7天冰川與阿拉斯加內海

The Seymour Narrows is a 3-mile/5 km stretch of the Discovery Channel north of Vancouver Island, British Columbia that is notorious for the strength of the tidal currents flowing through it. The average width of the narrows is just 750 meters. During extreme tides, the current through the narrows is subject to severe Venturi effect, resulting in an increased velocity that can reach 15 knots. For much of its modern history, there was an additional hazard in the narrows called Ripple Rock, a shallow obstruction that claimed no fewer than 119 ships and 114 lives. In 1958, after months of tunneling and preparation, Ripple Rock was blown up in the largest commercial, non-nuclear explosion ever recorded in North America. Still, the navigation of Seymour Narrows is dependent on tidal and other conditions, and requires skill and technical accomplishment.

The Queen Charlotte Sound lies between the Queen Charlotte Strait, which winds between Vancouver Island and the British Columbia mainland in the south, and Hecate Strait, which is northward, adjacent to the Haida Gwaii Islands off the Pacific coast of British Columbia. It is a broad reach in the long shipping route called the Inside Passage threading the myriad islands stretching from Washington’s Puget Sound to Alaska.

In the passage between Sumner Strait and Clarence Strait in Southeast Alaska’s Alexander Archipelago, midway between Price of Wales Island on the west and Zarembo Island on the east, is a small cluster of islands with a picturesque passageway between them called Snow Pass. It makes a scenic up-close route for your Seabourn ship during the transit.

Decision Passage is the western end of the Sumner Strait, which runs through the Alexander Archipelago into the Pacific Ocean in Southeastern Alaska, bounded on the north by Kuiu Island and Cape Decision, the location of a 1932 lighthouse. This is the route your ship takes when coming from or going to the colorful historic community of Sitka on the west coast of Baranof Island, which was originally the Russian fortress town of New Archangel.

Yakutat Bay is 18 miles wide at its entry, and cuts from the Gulf of Alaska into Disenchantment Bay, the entryway to the huge Hubbard Glacier, North America’s largest tidewater glacier. As the bay narrows and the shorelines draw closer, the 400-foot face of the glacier exerts a luminous, ghostly presence, often from as much as 30 miles away. More and more floating ice dimples the surface of the water, and seals bob up and disappear again. The chilled air from the glacier flows in a downdraft of cold that gives rise to mists and gray clouds, through which the vivid blue of the ice wall shimmers. It is an impressive sight of nature’s immense raw workplace, shaping the earth itself as part of an endless cycle of water from the sea evaporating to the sky, falling as snow on the heights and inching over centuries back again to the sea.

The Hubbard Glacier is the largest, and one of the most spectacular tidewater glaciers in North America. Its ice cliffs, some 400’ (121 m) tall, calve icebergs into the fjord, which may frequently be larger than a five-story building. The glacier’s surface is creased and contorted, resembling the wrinkled skin of a giant elephant. Records show it has been growing in thickness and advancing since 1895. This stands in stark contrast to other glaciers around the world, most of which have been receding during the past century. In 2002, the glacier blocked Russell Fjord for two and a half months, raising water levels 61’ (18 m) and threatening local communities with flooding. Nutrient-rich waters along the glacier face attract many species. Gulls and kittiwake colonies adorn smaller islands and harbor seals patrol the icy waters. In 1890, Israel Russell explored the area of Yakutat Bay and Hubbard Glacier, naming it after Gardiner G. Hubbard, a financier of his expedition and a founder and the first president of the National Geographic Society. VIEW CRUISES

Lynn Canal is a 90-mile long inlet into Alaska’s coast running from the Chilkat River in the north to the Chatham Strait and Stephens Passage in the south. Because it connects the towns of Skagway and Haines to Juneau and the rest of the Inside Passage, it is an important shipping lane for ferries, cargo and cruise ships, and was a crucial passageway to the Klondike gold fields during the Gold Rush. It was discovered by Joseph Whidbey in 1794 and named by George Vancouver after his birthplace, King’s Lynn in Norfolk, England. More than 2,000 feet in depth, it is one of the deepest and longest fjords in the world, and the deepest in North America outside Greenland.