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Vernal Pools at Redwyn’s Dunes

A cache by jillwx Send Message to Owner Message this owner
Hidden : 10/27/2011
In Michigan, United States
Difficulty:
2 out of 5
Terrain:
2.5 out of 5

Size: Size: not chosen (not chosen)

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Connection to the Earth Science Curriculum

Essential Lessons:

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

Common misconceptions 

·    Earth has always been the way it is now.

·         All rocks are more or less the same

·         The Great Lakes were always here

·         Rock layers are always flat

 Michigan State Science Content Expectations Addressed:

·         Grade 3- E.SE.E.2- Surface Changes- The surface of the Earth changes.  Some changes are due to slow processes, such as erosion and weathering; and some changes are due to rapid processes, such as landslides, volcanic eruptions and earthquakes

·         Grade 6- E.SE.M.4- Rock Formation- Rocks and rock formations bear evidence of the minerals, materials, temperature/pressure conditions, and forces that created them.

·         Grade 6- E.ST.M.4- Geologic Time- Earth Processes seen today (erosion, mountain building, and glacier movement) make possible the measurement of geologic time through methods such as observing rock sequences and using fossils to correlate the sequences at various locations.

·         High School- E3.1c- Advanced Rock Cycle- Explain how the size and shape of grains in a sedimentary rock indicate the environment of formation (including climate) and deposition.

Vocabulary

      moraine  An area of unsorted and angular rocks carried and deposited by glaciers at the location where the ice melts.

             outwash  A deposit of sand and gravel carried by running water from the melting ice of a glacier and laid down in layered deposits.

            albedo  The fraction of Sun’s radiation reflected from a surface.

             katabatic winds  A wind that carries high density air from a higher elevation down a slope under the force of gravity

             vernal ponds  Temporary pools of water created by snow melt and spring rains. The word ‘vernal’ refers to ‘occurring in the spring’.


Date Visited

 July 11, 2011

 Vernal Pools at Redwyn’s Dunes
EarthCache


 

Located on the coast of Lake Superior in the Keweenaw Peninsula, Redwyn’s Dunes display evidence of recent glaciations and forestation.  Visitors can observe vernal pools at this location created by the unique geologic conditions present.

1

Figure 1.  Keweenaw Peninsula Topography.  Color map of the Keweenaw Peninsula topography.  http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-1/Maps.html

Coordinates

N47°26.196’  W88°13.147’  (Trail Head)

N47°26.154’  W88°13.166’  (Waypoint)

2

Figure 2.  Redwyn Dunes Google Earth Waypoint.  Jill Weatherwax.  http://www.google.com/earth/index.html

Figure 3 Keweenaw Peninsule Eagle Point

Figure 3.  Keweenaw Peninsula Eagle Point.  Google Earth.  http://www.google.com/earth/index.html

 

 Matertials Needed:
Metric Ruler,  GPS, Hiking Shoes, Compass, Sketch Pad, Writing Utensil


  

Sand dunes can form anywhere there is sand and wind.  Redwyn’s Dunes are “perched dunes” which means they are located on a surface higher than the lake surface.  They were formed approximately 10,000 years ago during the last glacial recession of the Great Lakes.  Outwash sand deposits from the glaciers were left on the newly exposed barren lands.  This ground was able to quickly heat up due to its low specific heat, causing strong katabatic winds to form as the cold glacial air rushed toward the warmer terrain nearby.  These winds blew sands and outwash up the glacial moraine forming the perched Redwyn’s Dunes.  The dunes stabilized over time as the winds became weaker and different species of plants and animals moved into the area.  Today you can see this unique ecological system at Redwyn’s Dunes. 

Perhaps one of the most interesting habitats at Redwyn’s Dune are the vernal ponds or pools located at the lowest elevations of the dunes.  These wetlands are temporary small ponds of water that are dry for at least part of the year.  The vernal pools formed after glaciers scraped away the most of the surface soils leaving the bedrock close to the surface.  Clay layers and hard underlying bedrock impedes surface water infiltration, creating conditions for water to pool and drain slowly. The pooling can be at various depths throughout the seasons, higher in the rainy season and after snow melt and lower at other times of the year. Due to their concave shape and lack of direct support of a permanent water table, they are often described as “perched.”

The unique geologic conditions that make vernal pools, also create unique communities of organisms.  These temporary pools are home to many reptiles and amphibians.  Fish do not live in these ponds since they are not connected to other water and sometimes dry up completely.  Vegetation that is common here includes jack pine, red pine ferns, reindeer moss and other various deciduous plants that are well-adapted to the specific characteristics of vernal pools.  Many organisms associated with vernal pools spend dry seasons as eggs, seeds, or cysts and then grow and reproduce when the pool is again filled with water.

The land was cared for, in the past, by Native Americans who integrated their culture into protecting these dunes.  Today, people manage this land with rules that aim to preserve the site and also meet the needs and wants of various people and groups of people. 

   6

Figure 4.  Vernal Pond.  Jill Weatherwax. 

 

Logging Questions- 

Follow the trail system and answer the following questions along the way:

  • Describe the sediments found at Redwyn’s Dunes. Sketch the color and shape of the sediments you find.  
  • Describe and sketch at least two pieces of fauna you find near the vernal pond
  • Find the highest point of the dunes.  What do you see from this vantage point? 

Access Information
This site is owned and managed by The Michigan Nature Association and was given to the MNA via a private donation by Mr. and Mrs. William Skora.  Many of its features are named after

Skora relatives and characters from novels Mr. Skora wrote.
Michigan Nature Association
326 E. Grand River Ave.
Williamston, MI 48895
(517) 655-5655
michigannature@michigannature.org
www.michigannature.org

 

References

 Forgrave, Mike and Tricia (2011, August 6).  Retrieved from

             http://keweenawfreeguide.com/redwyns-dunes/

 Michigan Nature Association (2011, August 6).  Retrieved from

             http://www.michigannature.org/



 Rose, William (2011, August 6).  Retrieved from

            http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-1/Dunes.html

 Schaetzel, R., Darden, J., & Brandt, D.  (Eds.).  (2009).  Michigan geography and geology.  New York, NY: Custom Publishing.

 Unknown.  (2011, August 6).  Retrieved from

             http://www.enotes.com/earth-science/dunes

 Images

 MIGOL Digital Elevation Model 24k-30m. Retrieved August 6, 2011, from:  

            http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-1/Maps.html

 Redwyn Dunes Google Earth Waypoint. Retrieved August 6, 2011, from:

             http://www.google.com/earth/index.html

Tera Metrics.  (2009).  Great Sand Bay - OwlCr. [satellite image], Retrieved   August 6, 2011, from:

            http://www.geo.mtu.edu/~raman/MiTEP-ESS-1/GreatSandBay-OwlCr.JPG

 Weatherwax, J.  (Photographer).  (2011).  Vernal pond at redwyn’s dunes.

 



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Last Updated: on 9/16/2017 7:36:23 AM Pacific Daylight Time (2:36 PM GMT)
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