Skip to content

Pilgrim River Delta EarthCache

Hidden : 8/3/2012
Difficulty:
1.5 out of 5
Terrain:
1 out of 5

Size: Size:   not chosen (not chosen)

Join now to view geocache location details. It's free!

Watch

How Geocaching Works

Please note Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

Geocache Description:


Pilgrim RiverDelta

Cache Summary:  The Pilgrim River Delta is located off of US 41, Townsend Dr. There is a parking area and visitors will have to take a stroll over the Pilgrim River Bridge and down the boardwalk to get to the delta. By exploring this EarthCache visitors will be able to make observation on how the delta formed and make predictions on how the delta is changing.
 


Figure 1. Mouth of Pilgrim River at Portage Lake.: Photograph by B. Ergang
 
Cache Coordinates:  N 47° 6.345' W 88° 30.734'
Parking Coordinates:   N 47° 6.194' W 88° 30.979'
EarthCache Lesson: 
What processes are responsible for the formation of the Pilgrim River Delta?
Formation of river Deltas:
A delta is formed when a stream enters a relatively still water of an ocean or lake, its velocity drops abruptly, and the sediment being carried by the stream is then deposited.

Figure 2. Lena River Delta. Source: http://earthobservatory.nasa.gov/IOTD/view.php?id=2704
 
This eventually causes the channel to become choked with sediment from the slowing water.  The river then seeks a shorter, higher gradient route, resulting in the main channel dividing into several smaller ones called distributaries.  Distributaries carry water away from the main channel and the channel grows into a rough triangular shape. Because of this triangular shape it is called a delta like the Greek letter delta (Δ).Many river deltas however to not have this triangular shape. Differences in the configurations of shorelines and variations in the nature and strength of wave activity result in different shapes and sizes. Large rivers have deltas extending over thousands of square miles.  
 
Logging Your Visit:    
To obtain credit for visiting this EarthCache, please email me the responses to the following questions:
Logging Question 1:  Based on what you have learned on the deposition of sediments at a delta.Where are sediments being deposited and how do you know this?
Logging Question 2: After observing how sediments are being deposited what do you think this delta will look like in 200 years?
 
 
 
Earth Science Literacy Principles Big Ideas:
Big Idea 5: Earth is a water planet.
5.6 Water shapes landscapes. Flowing water in streams strongly shapes the surface through weathering, erosion, transport, and deposition. Water participates in both the dissolution and formation of Earth's materials.
Common Earth Science Misconceptions:
A common misconception in Earth Science is that-All Rivers in the northern hemisphere flow south.
Instead rivers flow from higher elevation to lower elevation.  Here, the Pilgrim River flows north into Portage Lake.
References:
Rose, Bill. (2011). Earth Science Institute. Available: http://www.geo.mtu.edu/~raman/SilverI/MiTEP_ESI-2. Last accessed 24th July 2012
Tarbuck, E. J., & Lutgens, F.K. (2003). Earth Science:Ten Edition. Upper Saddle River, New Jersey: Pearson Education, Inc.
 
Essential Features of Classroom Inquiry and Their Variations  
Essential Feature Variations  
Learner engages in scientifically oriented questions Learner poses a question Learner selects among questions, poses new questions Learner sharpens or clarifies a question provided by the teacher, materials, or other source Learner engages in a question provided by the teacher, materials, or other source
Learner gives priority to evidence in responding to questions Learner determines what constitutes evidence and collects it Learner is directed to collect certain data Learner is given data and asked to analyze Learner is given data and told how to analyze
Learner formulates explanations from evidence Learner formulates explanations after summarizing evidence Learner is guided in process of formulating explanations from evidence Learner is given possible ways to use evidence to formulate explanation Learner is provided with evidence
Learner connects explanations to scientific knowledge Learner independently examines other resources and forms the links to explanations Learner is directed toward areas and sources of scientific knowledge Learner is given possible connections  
Learner communicates and justifies explanations Learner forms reasonable and logical argument to communicate explanation Learner is coached in development of communication Learner is provided broad guidelines to use to sharpen communication Learner is given steps and procedures for communication
 
Source: National Research Council. 2002. Inquiry and the National Science Education Standards: A Guide for Teaching and Learning. Washington, D.C.: National Academy Press.  
             
 Image from: http://science.education.nih.gov/supplements/nih6/inquiry/guide/info_process-b.htm
 

Additional Hints (No hints available.)