Michigan lies in the northern United States and is located between 41 degrees N and 49 degrees N in latitude and between 82 degrees W and 88 degrees W in longitude. Michigan’s area is 253,793 sq. km. (97,990 sq. mi.); its population is 10.1 million (2006 est.); in comparison, in 1950, the population was about 6.4 million. Its largest cities are Detroit and Grand Rapids. Lansing is Michigan’s capital.
The territory consists of two peninsulas. The southern peninsula is between Lakes Huron and Erie on the east, and Lake Michigan on the west. The northern peninsula is between Lakes Huron and Michigan on the south, and Lake Superior on the north. The Michigan topography is mostly hilly uplands, with many lowlands in the eastern portion of both peninsulas. The central part of southern Michigan is a plateau, surrounded by a chain of ancient shore terraces. On the western sections of the northern peninsula, the landmasses are up to 1,968 ft. (600 m.) in height. The highest point in Michigan is Mount Arvon 1,981 ft. (604 m.). The Ontonagon River, which flows into Lake Superior, is the largest river in Michigan. Ancient soft sandstone, limestone, and lake and glacial deposits compound the landmasses.
Michigan is located in the Great Lakes Region and has a shoreline with Lakes Superior, Michigan, Huron, and Erie. The Great Lakes Region is geographically located at the edges of the Northern Hemisphere polar vortex, and thus Michigan lies in the path of traveling cyclones and anticyclones. On a global scale, the Michigan climate is affected by three air masses: the Continental Polar air mass, with dry, cold winters and summers; the Marine Polar air mass, with cold, snowy winters and cool wet summers; and the Marine Tropical air mass with humid and hot summers. Which combination of air mass or masses dominates at a particular time of the year depends on the Earth’s general circulation and its global tele-connection patterns. The El Nino-Southern Oscillation (ENSO) phenomenon dominates, both phases of which—the ENSO warm phase (El Nino) and cold phase (La Nina)—have been linked to anomalous climatic patterns in the areas adjunct to the Great Lakes Region. The warm phase of ENSO brings heavy snow in winters to northern Michigan.
At the local scale, the Michigan climate is influenced by the lakes and local topography and, in general, has mild winters and cool summers. The climate in northern Michigan is cooler than the climate in the south. In southeastern Michigan, the average January temperature is 25 degrees F (minus 4 degrees C). In the northwestern part, it is as low as 14 degrees F (minus 10 degrees C); the July temperature ranges are from 64-74 degrees F (64-74 degrees C). Michigan annual precipitation ranges within 2-33 in. (50-850 mm.), with the highest amounts at the southern shore of Lake Superior and at the southwest shore of Lake Michigan, with the minimum amount at the western shore of Lake Huron. The summer lake surface temperatures range from the coldest temperatures of deep Lake Superior (the deepest point 1,330 ft., or 405.38 m.) to the warmest temperatures of shallow Lake Erie (the deepest point 210 ft., or 64 m.), with very small inter-annual variability for the latter. In contrast, the lake-level pressures have very similar mean values and amplitudes for all lakes, which indicates the homogeneity of the circulation pattern over the Great Lakes Region.
Most of the Michigan territory is occupied by agriculture and forestry. Michigan is a significant producer of livestock, cherries, blueberries, cranberries, black beans, soybeans, corn, dairy, wheat, and beets. In the 20th century, the number of farms decreased from the 19th century number, but had stabilized by the beginning 21st century. Climatologically, the annual growing period is 180 days on in the southwest portion of the state. The number of growing days decreases moving north (to 80 growing days per year), due to the lower temperatures. Spruce, hemlock, and fir forests occupy the northern part of Michigan. The main Michigan trees are sugar and red maples. Forestry was the main industry at the end of 19th century, but, due to the introduction of Michigan conservation policies, has fallen in importance. Other important Michigan industries are manufacturing (automotive), mining (iron ore, magnesium compounds, gypsum, cement, sand and gravel, salt and calcium chloride, crushed stone, natural gas, and petroleum) and fishing (chub, whitefish, yellow perch, lake herring, yellow pike, carp, catfish, smelts, suckers, white bass, lake trout, and pacific salmon). The Michigan ports on Lake Michigan have access to the Mississippi River and thus to the Gulf of Mexico.
The Michigan economy depends on fresh water supply from the lakes, groundwater, and rainfall. A combination of rainfall, evaporation, and groundwater recharge rates define the freshwater balance in Michigan. There is a seasonal cycle in precipitation, temperature, and runoff, which affects the lake water levels. The highest lake levels are in the spring (because of high runoff from melting snow), and the lowest levels are in the autumn (because of high evaporation rates). The consumption of fresh water increases with population growth and economics needs. Historically, the lowest lake level was recorded in 1930, which corresponds to the fast development of the city of Detroit.
CONSEQUENCES OF ECONOMIC ACTIVITIES
Michigan’s human economic activities increase pressure on Michigan’s environment and the global environment. Air and water pollution from industry, traffic, and greenhouse gases increase because of industrial and domestic fossil fuel combustion; soil erosion from fertilizers and farm runoff are the main consequences of human economic activities, which can be reduced by investigating and implementing alternative energy sources (such as atomic, wind, solar power, bio-fuels, and land-field fuel), developing new technologies (for example, solar and electric cars), and discovering new efficiencies in human economic activities. If the climate shifts even slightly from its averages, Michigan will face changes in crop yield, changes in pests population, a shift in forest composition and health, a loss of bird diversity, a change in local mammal populations (such as raccoons, skunks, white-tailed deer, and moose), a change in the distribution of fishes; spread of invasive species, release of nutrients and contaminants, change in groundwater recharge, and a change in lake levels.
