Lake Superior 蘇必略湖

作者： 蔡昇達

美國明尼蘇達州境內有許多湖，號稱「萬湖之州」，其中最大的為蘇必略湖(Lake Superior)，來到這邊一年多，終於有時間探訪這世界上面積最大的淡水湖。

日落時的蘇必略湖，紅藍混合的顏色很夢幻

五大湖的形成源於第四紀(Quaternary Period，距今約一萬年前)的巨大冰川(勞倫泰德冰蓋)往南移動時的冰蝕作用，因壓力造成地殼下沉，形成低漥的凹地，成為五大湖的基底，待氣候變暖時冰川融化，形成大型的淡水湖，其中最大的即為蘇必略湖。

1866 年，地質學家 Henry H. Eames 在明尼蘇達州北部發現豐富的高品質鐵礦，1891 年 Duluth, Missabe and Northern Railway (DM&N, DMN)鐵路公司成立，1892 年第一批鐵礦石通過此鐵路送到蘇必略湖畔的碼頭運出。(參考影片： Duluth, Missabe and Iron Range Railway, The Last Days - FULL VIDEO (2004))

紅色即表示在蘇必略湖附近發現的鐵礦(來自維基百科)，最主要的為 Mesabi (= Missabi) Range

最早運送鐵礦的 Duluth, Missabe and Iron Range Railway

Duluth 的秋景、鐵礦(在港口邊，放大才看得清楚)、及鐵路

1905 年 11 月底，繁忙的蘇必略湖風雪漸大，晚上時一艘貨船(Madeira 號)撞上岸邊礁石，許多人喪生，故幾年後在該地建造了燈塔，維護行船的安全，燈塔運行的數十年間，未再有貨船觸礁。

高聳峭壁上的燈塔 Split Rock Lighthouse，是全美排名很前面的熱門觀光燈塔

因北方的明尼蘇達州提供高品質的鐵礦、東部的阿帕拉契山脈（Appalachian Mountains）擁有豐富煤炭，加上五大湖的水運系統(如下照片)，使五大湖區成為理想的重工業帶，1920–1960年間，該區人口迅速增長，出現典型的工業城市，例如：底特律被稱為「汽車之都」，匹茲堡為「鋼鐵之城」，克里夫蘭為「機械之心」。

五大湖的通航路線圖，可以直接由最上游的蘇必略湖接到北大西洋

1970 年代後因海外低價鋼鐵與汽車競爭、高利率致美元升值……等因素，產業外移至美國南部或亞洲（如日本、韓國)、大量工廠關閉、失業率上升、城市人口外移，因而出現著名的「鐵鏽帶(Rust Belt)」，意思是曾經輝煌的重工業基地，如今設備生鏽、經濟停滯。

橘紅色為鐵鏽帶、灰色區為前面提到的煤炭產區(阿帕拉契山脈)
Source: Brendan H. Jennings--Saline County, Illinois, historian (2010).

不過 Lake Superior 附近的鐵礦至今仍持續開採中，且 Duluth 仍然為重要的港口、及觀光勝地，相當值得一訪。

Duluth 港出口處的 Aerial lift bridge，有船隻通過時即會升起

蘇必略湖北岸公路旁的 Gooseberry falls

Aerial lift bridge 夜景

而明尼蘇達州在 20 世紀後期經濟轉型，從農業與採礦業轉向服務業、金融與醫療保健，許多著名公司的總部皆在此，如 3M Health Care, Medtronic, UnitedHealth Group......等，當然還有最富盛名的 Mayo Clinic。明州在預期壽命、醫療水平與教育質量方面名列前茅，人均收入高於全美平均。

與合作的神外學長，陳醫師，在 Mayo 圖書館之梅約兄弟畫像前合照

English version:

Minnesota, known as the “Land of 10,000 Lakes,” is home to countless bodies of water, the largest of which is Lake Superior. Having lived here for more than a year, I finally found the time to visit this magnificent natural wonder — the largest freshwater lake by surface area in the world.

The formation of the Great Lakes dates back to the Quaternary Period (around ten thousand years ago), when the massive Laurentide Ice Sheet advanced southward. The glacier’s immense pressure eroded and depressed the Earth’s crust, carving out vast basins that later became the foundation of the Great Lakes. As the climate warmed and the glaciers melted, these basins filled with meltwater, forming a chain of immense freshwater lakes — among which Lake Superior is the largest.

In 1866, geologist Henry H. Eames discovered abundant high-grade iron ore in northern Minnesota. The Duluth, Missabe and Northern Railway (DM&N) was established in 1891, and by 1892, the first shipments of iron ore were transported by rail to the docks along Lake Superior for export.

(Reference video: “Duluth, Missabe and Iron Range Railway, The Last Days – FULL VIDEO (2004)”).

In late November 1905, a severe snowstorm struck busy Lake Superior. That night, the freighter Madeira crashed against the rocky shore, resulting in heavy loss of life. In response, a lighthouse was later built at the site to ensure maritime safety. During the many decades the lighthouse operated, no shipwrecks occurred in that area again.

Because northern Minnesota supplied high-quality iron ore, the Appalachian Mountains in the east provided abundant coal, and the Great Lakes offered an efficient inland waterway system (as shown in the photo below), the region became an ideal location for heavy industry. Between 1920 and 1960, the population of the Great Lakes area surged, and numerous industrial cities emerged: Detroit became known as the “Motor City,” Pittsburgh as the “Steel City,” and Cleveland as the “Heart of Machinery.”

However, after the 1970s, competition from low-cost foreign steel and automobiles, together with high interest rates and the rising value of the U.S. dollar, led to industrial decline. Many factories relocated to the southern United States or overseas (such as Japan and South Korea), resulting in widespread plant closures, soaring unemployment, and urban depopulation. This transformation gave rise to the so-called “Rust Belt,” referring to once-prosperous industrial centers now characterized by rusting facilities and economic stagnation.

Nevertheless, iron mining near Lake Superior continues today, and Duluth remains both an important port and a popular tourist destination — well worth a visit.

In the latter half of the 20th century, Minnesota underwent an economic transformation, shifting from agriculture and mining to service industries, finance, and healthcare. Many renowned companies are headquartered here, such as 3M Health Care, Medtronic, and UnitedHealth Group… and of course, the most prestigious of all, the Mayo Clinic. Minnesota ranks among the top in life expectancy, healthcare standards, and education quality, with a per capita income above the national average.