Watermarks Essay

Introduction

Water is essential to Earth

and its inhabitants, and is located

all over the planet – in oceans,

glaciers, lakes, air, soil, and all

living tissue (Lutgens & Tarbuck,

2008). Water plays a huge factor in

the shaping of landscapes. The

earth has gone through many changes over

the last millions of years – temperatures have changed from warm to cool and back again,

resulting in changes in the water and land found on Earth. About 50 million years ago, the earth

began a cooling period of time. Then, approximately1.8 million years ago, the Earth was in the

middle of an ice age, which included ice caps and massive ice sheets that spread across the

continents. The last time the ice sheets began to melt and result in bodies of water that shaped the

landscapes, was said to be about 10,000 years ago (Carr, 1998). This continuous melting and

freezing of water on Earth has played a huge role in the shaping of the Earth.

Water Cycle

Water located on Earth’s surface is referred to as

the Hydrosphere (Lutgens & Tarbuck, 2008). The different

sources of water on Earth can change from one state of

matter to another depending on temperature and pressure.

As a result, water is constantly moving between the

Figure 1. Important dates and The Ice Age. Retrieved March 20, 2011, from http://store.applebazaar.com/blog/2009/12/04/are-we-entering-an-ice-age-soon/

Figure 2. Spheres of Earth. Retrieved March 22, 2011, from http://sourceoforigin.com/blog/hierarchy-of-life/biosphere/

hydrosphere – water portion of Earth; the atmosphere – the gaseous portion of Earth; the

geosphere – solid portion of Earth;

and the biosphere – the living organisms or life on Earth (Lutgens & Tarbuck, 2008). This

constant movement of water on Earth is referred to as the water cycle. The water cycle refers to

the constant exchange of water among the atmosphere, continents, and oceans (Lutgen &

Tarbuck, 2008). The sun is the overall energy

source for the water cycle, and there is no

definite beginning or end to the cycle – hence

the word “cycle” (USGS: The Water Cycle,

2011). Water is constantly changing states from

liquid, to vapor, to ice, and back again, which

happens at varied times and places

throughout the cycle and over millions and millions of years (USGS: The Water Cycle, 2011).

The different processes involved in the water cycle include, precipitation, evaporation,

infiltration, runoff, and transpiration (Lutgens & Tarbuck, 2008). Evaporation occurs when the

water evaporates into the atmosphere from oceans and the continents, this leads to cloud

formation and precipitation. Infiltration happens when the precipitation has fallen and soaks into

the ground – water then moves downward into lakes, streams, and oceans. When the ground can

no longer hold the excess water it flows over the surface into lakes and streams, which is referred

to as runoff. Some of the water that soaks into the ground is absorbed by different plant life,

which is then released back into the atmosphere through the process is of transpiration (Lutgens

& Tarbuck, 2008).

Figure 3. The Water Cycle. Retrieved March 20, 2011, from http://ga.water.usgs.gov/edu/watercycle.html

The Water Cycle has been working for billions of years, and Earths continued survival depends

on the cycle continuing to work (USGS: The Water Cycle, 2011).

Groundwater and the Great Lakes

A huge part of the water cycle on Earth is the Great Lakes. The five Great Lakes together

represent the largest unfrozen freshwater body on Earth (Larson & Schaetzl, 2001).

The Great Lakes have formed through

erosion, deposition, and weathering over

the course of thousands of years. Even

today, the Great Lakes continue to go

through these processes on a daily basis.

Groundwater in the Great Lakes Region

is an extremely important part of

maintaining the water in the region.

Groundwater is basically just water that comes

from the ground. It comes from any form of precipitation such as: rain, snow, sleet, or

hail (The Groundwater Foundation, 2011). The water soaks into the ground because of gravity.

Gravity pulls the water down, and then passes between particles of soil, sand, gravel, or rock

until it reaches a depth where the ground is soaked with water. The area that is packed with water

is called the saturated zone and the top of the saturated zone is called the water table (The

Groundwater Foundation, 2011). Groundwater is an extremely important part of the hydrology

of the Great Lakes, and to the overall wellbeing of the ecosystem in the watershed (USGS:

Groundwater, 2011). In general, groundwater is considered to be clean, but it can be polluted or

contaminated by outside influences.

Figure 4. Ground Water Flow. Retrieved March 20, 2011, from http://water.usgs.gov/ogw/pubs/WRI004008/groundwater.htm#f5

Common things that lead to contamination include: leaky underground tanks that store gasoline,

leaky landfills, or too much fertilizer or pesticides on farmland (The Groundwater Foundation,

2011). Other environmental problems that involve groundwater include: overuse by intense

irrigation and land subsidence caused by groundwater withdrawal (Lutgens & Tarbuck, 2008).

Ground water helps the ecosystems in the Great Lakes Region, because it provides a consistent

minimum level of water flow to streams, lakes, and wetlands (USGS: Groundwater, 2011). This

then helps to maintain a habitat for marine

animals and also helps to maintain marine

plants when there is little to no precipitation

for long periods of time. (USGS: Groundwater,

2011).

Glaciers

Go back in time in Michigan history to

around 14,000 years ago, and you will find that the

Great Lakes were covered with a huge sheet of ice – called a glacier (Michigan Department,

2011). This huge sheet measured to be about one kilometer thick. Over a slow rate of time –

estimated about a couple centimeters per day – the huge glacier made its way across the Great

Lakes basin. As the glacier traveled, it formed valleys and transported big amounts of soil. The

glacier continued to move towards Canada, as it moved it left behind gigantic holes that filled

with melt-water from the glacier. These gigantic holes formed the basic shapes of the Great

Lakes, but the lakes did not take their final forms until an estimated 6,000 years ago (Michigan

Department, 2011). Glaciers erode or “wear down” in two different ways – plucking and

abrasion (Lutgens & Tarbuck, 2008). Plucking takes place when the glacier flows over different

Figure 5. Glacier Layers. Retrieved March 20, 2011, from http://www.glaciers.pdx.edu/Projects/LearnAboutGlaciers/Skagit/Basics00.html

bedrocks, picking up the loose sediments and then integrates the sediments in to the ice. As a

result of plucking, sediments of all sizes become part of the glacier. Abrasion happens as the

glacier and its load flow over bedrocks, the glacier and the sediments located in the glacier, hit

the ground below resulting in a smoothing and polishing appearance to the surface (Lutgens &

Tarbuck, 2008). There are four different erosional agents at work which affect the rate of glacial

erosion, these include: rate of glacial movement, thickness of the ice, shape abundance, and

hardness of the rock fragments contained in the glacier, and the “erodibility” of the surface

beneath the glacier (Lutgens & Tarbuck, 2008). There are many different landforms created by

glacial erosion – glaciated valleys, cirques, arêtes, horns, and fiords. Glaciated valleys form

when a glacier moves down a

valley; once this happens the

valley becomes wider and

deeper, and is either termed

a glacial trough or a hanging

valley (Lutgens & Tarbuck, 2008). Cirques are amphitheater-shaped basins at the head of a

glaciated valley. Aretes are narrow sharp ridges that separate two bordering glaciated valleys.

Horns are pyramid shaped peaks. Fiords are steep inlets of the sea formed when a glacier was

once located underwater (Lutgens & Tarbuck, 2008). Glaciers pick up and transport huge piles of

debris as they travel across land. All of the materials that are picked up are ultimately deposited

once the ice melts. Glacial sediments play a large role in the forming of landscapes when they

are deposited along the way (Lutgens & Tarbuck, 2008). Drift is used to refer to any sediment of

glacial beginning (Weathering and Erosion, 2011). The two different types of drift include: till,

which is material deposited directly by the glacier, and stratified drift, which is the material laid

Figure 6. Difference between Till and Stratified Drift. Retrieved March 22, 2011, from http://elearning.stkc.go.th/lms/html/earth_science/LOcanada3/307/1_en.htm

down by the glacial melt-water (Weathering and Erosion, 2011). Different types of glacial drift

and different types of depositional features include: moraines, plains, kettles, drumlins, eskers,

and kames (Lutgen & Tarbuck, 2008). Glaciers have and continue to shape landscapes and

bodies of water on Earth. Along with glaciers, there have been many other factors which have

influenced the formation of the Great Lake Region and other landscapes and water sources on

Earth.

Rivers

Rivers and streams play a

key role in the formation of a

landscape. According to Idaho

Museum (2011), rivers are

geographic features, which collect

and

then transport water from one distinct region to another. Glaciers and lakes store large amounts

of water – rivers flow from these sources through valleys until the water reaches the oceans or

other destinations (Idaho Museum, 2011). Rivers help to form the land by cutting through

Earth’s layers and forming canyons and valleys along the way (Idaho Museum, 2011). Lutgens

& Tarbuck (2008) state rivers have three distinct roles in the formation of landscape. First, the

rivers erode the channels in which they flow, secondly, they transport sediments, and thirdly,

they produce a variety of erosional and depositional landforms (p. 71). Erosion, which creates

new erosional landforms, takes place when the river begins to erode already weathered rock

material.

Figure 7. River erosion and deposition. . Retrieved March 20, 2011, from http://www.bbc.co.uk/scotland/learning/bitesize/higher/geography/physical/hydrosphere_rev3.shtml

Transportation happens when the load of new materials is brought to new geographic locations.

Deposition – which creates new depositional landforms –then takes place when the loads are

deposited at their new locations (Physical Geography, 2002). Erosional landforms include:

gulleys, canyons, and river valleys, whereas examples of depositional landforms include: flood

plains, alluvial fans, and point bars (Physical Geography, 2002). One landform in Michigan that

was formed by erosion and deposition is Isle Royale, located near Hancock, MI.

People and Water

Michigan and its waterways have been shaped by people and other inhabitants for many

years. People have altered the quality of water, and have built ways to travel around the water.

Two distinct ways that people have altered the travel across waterways include the Mackinaw

Bridge and the Soo Locks. The Mackinaw Bridge was built to connect the Upper Peninsula and

the Lower Peninsula, allowing travel between the two. The Soo Locks was built to make it

possible for ships to travel between Lake Superior and the lower Great Lakes. Each has

contributed to the growth of Michigan, by allowing travel and opportunities that would not be

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possible without them. Pollution has also been a huge issue in contaminating the water on Earth

and in Michigan. Great Lakes Information Network GLIN (2011) defines water pollution as,

“A change in the chemical, physical and biological health of a waterway due to human activity.”

GLIN (2011) goes on to state,

“Ways that humans have affected the quality of the Great Lakes water over the centuries

include sewage disposal, toxic contamination through heavy metals and pesticides,

overdevelopment of the water's edge, runoff from agriculture and urbanization, and air

pollution.”

Overall the pollution of the water has to be controlled or the inhabitants of Earth will be the

one’s suffering the consequences.

Conclusion

Glacier and rivers have played key roles in the formation of land and water systems on

Earth. One of these water systems, the Great Lakes, have formed over thousands of years and

plays a major part in the freshwater supply to the United States and to the world, so it is

important to take care of this region, along with other water sources on Earth. Water goes

through a distinct cycle and it is important that this cycle is maintained and not altered. People on

Earth need to protect their water and respect how it came to be.

References

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Carr, K. (1998). Land of frozen time. Research in review, spring/summer issue. Retrieved from

http://www.rinr.fsu.edu/springsummer98/features/frozentime.html

Glacier Change in Upper Skagit River Basin. (2011). What is a Glacier? Retrieved March 20,

2011, from

http://www.glaciers.pdx.edu/Projects/LearnAboutGlaciers/Skagit/Basics00.html

Great Lakes Information Network (GLIN). (2011). Water Pollution in the Great Lakes.

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http://www.great-lakes.net/teach/pollution/water/water4.html

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http://imnh.isu.edu/Exhibits/Online/waterdiscoverybox/SubMenu1/content_geography_temp.htm

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Michigan Department of Environmental Quality. (2011). The Great Lakes Ecosystem. Retrieved

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Michigan Tech. (2011). Isle Royale Erosional Landforms. Retrieved March 21, 2011, from

http://www.ed.mtu.edu/esmis/id304.htm

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Source of Origin. (2011). Biosphere. Retrieved March 22, 2011, from

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The Groundwater Foundation. (2011). What is Groundwater? Retrieved March 21, 2011, from

http://www.groundwater.org/kc/whatis.html

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