Connection to the Earth Science Curriculum
1. How do currents change the shape of Earth’s surface?
2. How can human activities impact and accelerate these changes on Earth’s surface?
Earth Science Literacy Principles-
Big Idea 4.8 – Weathered and unstable rock materials erode from some parts of Earth’s surface and are deposited in others.
Big Idea 5.6 – Water shapes landscapes.
Big Idea 9.5 – Human activities alter the natural land surfaces
1. Earth and its systems are too big to be affected by human actions.
2. Human activities cannot affect geological processes like river flows, flood cycles, etc.
3. The Earth has always been pretty much the way it is now.
Michigan State Science Content Expectations Addressed:
Grade 6 & 7
S.RS.07.17 Describe the effect humans and other organisms have on the balance of the natural world.
E.SE.06.12 Explain how waves, wind, water, and glacier movement shape the land surface of the Earth by eroding rock in some areas and depositing sediments in other areas.
E.ES.07.41 Explain how human activities (surface mining, deforestation, overpopulation, construction and urban development, farming, dams, landfills, and restoring natural areas) change the surface of the Earth and affect the survival of organisms.
Longshore Drift – the transport of sediment along a shoreline.
Stamp Sand – is the sediment produced from the breaking down of ore pulled from mines.
Big Traverse Bay is owned and maintained by the State of Michigan. It is a public beach.
July 14, 2011
Big Traverse Bay EarthCache
Along the eastern shore of the Keweenaw Peninsula lies Big Traverse Bay. Visiting here gives a great picture of how the past activities of humans can have an effect on the environment in the future. It will provide a vivid picture of how waves and currents are a powerful force that can change the Earth’s surface.
1. Before you leave make sure you know how to use your GPS to:
*Enter and label waypoint coordinates.
*Navigate to a waypoint.
2. Navigate to each of the stops on the tour.
3. At each stop read the introductory material and answer the questions associated with the stop.
Big Traverse Bay is found at 47°11.362’ N, 088°14.150’ W.
Figure 1: Aqueduct and smoke stack from the old stamp mill at Gay Sands. Photo by J. Ernstes
Background and History Information
Copper mining was a major part of life andindustry throughout the Keweenaw Peninsula from the 1840’sto the early 1900’s. One of these mines was Mohawk Mine in Gay, MI. The mine took large amounts of copper ore out of the mine and would send it to a stamp mill that was located next to the Lake Superior coastline (picture at right). The large smoke stack and cement aqua duct are mostly all that remain where the stamp mill once stood. The stamp mill consisted of large machines that would smash and break down the rocks into small sediment in order to separate the copper from the other rock. An example of a stamp that still stands is shown below. The copper was then taken to be purified and sold for money. The other sediment, known as stamp sands, then was useless to the mines and had to be thrown away. The mines looked for somewhere open and cheap to drop these stamp sands. Many of the mines, including this one, dumped thesesands into bodies of water. In this case they deposited these stamp sands into Lake Superior. Gay, MI is located north of Big Traverse Bay along the eastern coastline of the Keweenaw Peninsula.
Figure 2 - Stamp machine that was used to break up the poor rock. Photo by J. Ernstes
Figure 3 - Map of the eastern shore of the Keweenaw Peninsula. http://www.geo.mtu/~alguth/MiTEP-ESS 1
Tour of Big Traverse Bay
When you arrive at Big Traverse Bay you will notice that there is a boat launch along with a break water positioned between the two beaches. This will become a very important feature in understanding how humans have affected this area. After parking your car, walk out to the beginning of the break water and observe the beach to the North. Look at the sand that is found on the beach.
Logging Q1: Describe the sand that is found here. (Size, shape, colors, etc.)
Next turn and look at the beach that lies to the south of the break water at Big Traverse Bay. If you would like you can walk around the boat launch and go to the beach to get a better look at what is found there.
Logging Q2: Compare the sand found on the beach south of the water break to the sand that is found on the north side of the water break. (Size, shape, colors, etc.)
Last, walk out onto the break water and observe the beaches. This is also a great opportunity to get a picture that shows the differences between the two beaches. Now look back to the north and notice that the appearance of the beach continues towards the Gay Sands in Gay, MI. Notice that the waves tend to hit the shoreline at an angle. Water is a very strong erosional force on earth and can move large amounts of sediment, greatly changing the landscape of Earth’s surface. Since the waves hit the shores on this angle it tends to make an overall flow of water in the direction of the angle. This is called a longshore current because it creates a current that moves along the shore. The longshore current provides the energy to move the sediment in the direction of the current, in this case, to the south. This movement of sediment is called longshore drift. Longshore drift is the transport of sediment along a coast.
Figure 4 - Diagram of longshore drift. http://spinner.cofc.edu/CGOInquiry/longs 1
Logging Q3: Using what you have learned about longshore drift and the history of the Keweenaw Peninsula, explain what has produced the change in the beach to the north of the water break?
References and Citations
Keweenaw Free Guide. Retrieved from: http://keweenawfreeguide.com/gay-sands-upper/
[Lonshore Drift Diagram]. Retrieved July 25, 2010, from: http://spinner.cofc.edu/CGOInquiry/longshoredrift.htm?referrer=webcluster&
[Map of Keweenaw Peninsula]. Retrieved July 25, 2010, from: http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-1/Day_4_Keweenaw_Stamp_Sands.html
Rose, Bill. MiTEP Website. Retrieved from: http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-1/Welcome.html
Schaetzl, Randall J., Joe T. Darden, and Danita S. Brandt. Michigan Geography and Geology. New York: Custom, 2009. Print.