MN Physical Geography

Minnesota from Space

Minnesota’s Natural Boundaries

Northwest Angle

Minnesota’s Topography

Minnesota Relief (Elevation)

Eagle Mountain Highest Point in MN (2,301’)

Minnesota’s Glaciers 4 continental glaciers advanced and retreated across MN The Pleistocene ice age was the most recent and covered most of MN Along the way glaciers picked up rocks and soil and transported it to the south

Minnesota’s Glaciers The rocks and soil left behind known as “glacial drift” The melting also left behind many shallow lakes Soils left behind are an “unsorted” mixture of soil, rocks and pebbles

Glacier’s Southern Edge

Canadian Shield Physical region of mostly bare bedrock and little topsoil Covers much of central Canada, northeastern MN and northern Wisconsin

Glacial Abrasion Extreme weight of nearly a mile of moving ice wears away the surface known as an “ice-scoured” region

“Ice-Scoured” Surface Much of the Arrowhead is “ice-scoured”. Like sandpaper, glaciers have worn down the surface and smoothed it. Most of the Arrowhead region is “ice-scoured”

Boundary Waters Canoe Area Much bare bedrock Soil pushed to the south by glaciers Little soil left behind is thin and rocky BWCA is a good example of “ice-scoured” topography

Minnesota Relief (Elevation)

Glacial Moraines Moraines are belts of hills that form at the edges of melting glaciers when boulders, stones and soil accumulates Moraine Glacial Lakes

MN Moraine Belts Glaciers moved across “Moraine and Lakes” region of central MN several times leaving many moraines Region is hilly with many shallow lakes Moraine and Lakes

Moraine and Lakes Region This region is covered by “Glacial drift” (soil, rocks, sand and pebbles) deposited on the land when glaciers melted Region is hilly with many shallow lakes Flattest areas are “outwash plains”

MN Moraines Monticello’s “Little Mountain” Powder Ridge

Minnesota Relief (Elevation) Buffalo Ridge

Buffalo Ridge Buffalo Ridge

Minnesota Relief (Elevation) Driftless Area

Glacier’s Southern Edge

Driftless Area SE MN is described as “Driftless” because it was never touched by glaciers

Driftless Area Driftless area has no glacial drift Few lakes and many rivers and streams Millions of years of erosion visible

Minnesota Relief (Elevation) Red River Valley Minnesota Relief (Elevation)

Minnesota’s 3 Continental Divides A continental divide is a high point of land separating the direction rivers flow Laurentian Divide Most of southern MN’s water drains into Mississippi and Gulf of Mexico Much of Arrowhead drains into Lake Superior eventually reaching Atlantic NW MN drains north to Lake Winnipeg and Hudson Bay

Laurentian Divide From Lookout Mountain

MN’s Glacial Lakes Lake Agassiz Lake Duluth Brown’s Valley Lake Minnesota

Glacial Lake Agassiz When last glacier melted the drainage path of the melt water was blocked Lake Agassiz formed until glacier melted Overflow created Minnesota River Sediments settled to the bottom filling in low spots and creating an extremely flat surface

Red River Valley Red River Valley is an extremely flat area that was once covered by Lake Agassiz Sediments fell to bottom creating thick and sticky soils known as “gumbo”

Red River of the North Why is the path of the Red River Valley so crooked? The land is so level the river struggles to find a consistent downhill slope

Downtown Moorhead/Fargo Red River of the North Downtown Moorhead/Fargo

Moorhead Floods Spring 2009

MN’s Physical Regions Arrowhead Red River Valley Moraine and Lakes Buffalo Ridge Driftless

MN Topography

Minnesota’s Climate

Wide ranges in temperatures Minneapolis Climate Humid Continental Wide ranges in temperatures

Hot Summers and Cold Winters MN Temperatures Hot Summers and Cold Winters

MN Precipitation Most of the moisture that falls in MN comes from Gulf of Mexico Precipitation greatest in the SE and least in the NW Jet Stream

4 Distinct Seasons March 29, 1881

Only southern MN has a long enough growing season for corn MN Growing Season Consecutive Days Averaging 43oF or More Only southern MN has a long enough growing season for corn

Minnesota’s Natural Vegetation

MN Natural Vegetation

Coniferous Forests

Deciduous Forests

Prairie

MN Natural Vegetation Natural vegetation is an indicator of a region’s precipitation, temperatures and soil NE MN mostly coniferous forest Central MN mostly deciduous S & W MN mostly prairie

Percent of MN in Commercial Forests 70% of MN’s commercial forest industry located in NE MN

Natural Soil Fertility Have students speculate on which regions will be highest in soil fertility

MN Soil Fertility Best soils are found in the southern and western MN Least fertile soils are found in northeast MN (thin, rocky and acidic podzol soils)

Minnesota’s Natural Regions

Arrowhead Red River Valley MN Natural Vegetation Dairy Belt Corn Belt

MN’s Natural Regions Red River Valley Arrowhead Dairy Belt Corn Belt

MN Topography

Natural Soil Fertility

Percent of Land in Farms Arrowhead

Arrowhead Ice-scoured by glaciers Thin and rocky soils Cool temps and short growing season Coniferous forest Podzol (acidic) soils Little agriculture Much land remains in forests Paper, mining and tourism impotant economic activities

MN’s Natural Regions Red River Valley Arrowhead Dairy Belt Corn Belt

Dairy Belt Hilly topography Glacial moraines Many lakes and marshes Soil better than Arrowhead but not as good as the Corn Belt Most farmers raise livestock, particularly dairy cattle

MN’s Agricultural Regions Red River Valley Arrowhead Dairy Belt Corn Belt

Percent of Land in Farms Red River Valley

Red River Valley Once the bottom of glacial Lake Agassiz Extremely flat Spring floods common Thick and sticky “gumbo” soils Soils are soil to dry in the spring Short growing season

MN’s Natural Regions Red River Valley Arrowhead Dairy Belt Corn Belt

Percent of Land in Farms Corn Belt

Corn Belt Buffalo Ridge Rock County

Corn Belt Relatively flat topography except “Buffalo Ridge” in southwest corner Thick, black soils Long growing season Adequate precipitation One of the best agricultural regions in the nation

MN’s Agricultural Regions Red River Valley Arrowhead MN’s Agricultural Regions Dairy Belt Corn Belt