My First Attempt(s) at Gigapans

Over the summer I acquired at Gigapan EPIC 100 with the goal of using gigapans within my Earth Science classroom.  The idea of placing students at an outcrop or location, even though it may be hundreds of miles away, is intriguing.  Ideally, many of the gigapans used in the classroom would have a Minnesota focus, that way students would be able to visit locations in the state virtually.  Many times, individual rock samples cannot tell the complete story that the entire outcrop can, and that is one reason why gigapans are coming to my classroom.

I've put together a list of some gigapans that focus on different parts of Minnesota's geology and have shown these informally in the classroom at various times in the past.  So many of my students have been introduced to gigapans and some browse the gigapan website on their own time.  

Each fall, we take the entire 8th grade class (198 students this year) on a field investigation to three different locations in or near the Minnesota River Valley (you can read about last years trip here), with the goal of being able to make observations about how the valley formed.  This was an obvious place to start my gigpan experience, some of these went very well, but there were certainly lessons learned.

The first gigapan was shot just beneath the highway bridge over the Minnesota River near Blakeley.  We stop here to get an idea of how big the valley is and how little of the valley the river occupies.  To view the gigapan online, click here. 

The second gigapan was at the Rush River County Park, shot from a rocky point bar.  This was basically shot to allow the sun to rise a little higher in the sky to set up the next gigapan.  The gigapan can be found online here.

The third gigapan was the one that I wanted the most for the classroom, but it's also the one where the most mistakes were made.  First the batteries on the camera died, then the memory card of the camera got full, missing a picture or two before I realized it (of course I was using the 1 GB card, not the 16 GB card that I have).  The mistakes are correctable and I'm currently making time in my schedule to get back to the site to make a better gigapan.  

Obviously, you can see the missing picture, which threw the rest off slightly.  The site here is continually eroded by the Rush River and exposes at least three distinct glacial tills, the source of the rocky point bars.  The gigapan can be found here.

So the learned are:

1.  Use the bigger memory card.
2.  Don't forget about the batteries.
3.  Keep practicing.

If anyone has any ideas about how they are using gigapans in the classroom, I would love to listen! 

Roche-A-Cri State Park, Wisconsin

In the book 101 American Geo-Sites You've Gotta See, one of the sites listed for Wisconsin was Roche-A-Cri State Park.  Roche-A-Cri is a 300-foot, bedrock mound that rises above the Central Plain, formerly the floor of Glacial Lake Wisconsin during late-Wisconsin glaciation.  The bedrock mound is comprised of Cambrian sandstones deposited by braided river channels.  Roche-A-Cri translates as "crying or shrieking rock", perhaps a name referring to the hawks that next within the crevices of the mound.

There are numerous vantage points alongside country roads to view Roche-A-Cri.

Reaching the top of Roche-A-Cri requires climbing 303 steps, in two places, resting platforms are provided.

The picture below shows the view visitors can expect while climbing the 303 steps to the top.

The viewing platform at the top of Roche-A-Cri provides great views across Glacial Lake Wisconsin's former floor.

Glacial Lake Wisconsin existed between 18,000 to 14,000 years ago.  This glacial lake formed as the Green Bay lobe approached from the northeast and blocked the early Wisconsin River near the Baraboo Hills.  As the climate warmed, the lake water again found an outlet path through the Baraboo Hills and Glacial Lake Wisconsin catastrophically discharged in a period of a few days to weeks, forming the Dells of the Wisconsin River.

Found throughout the former glacial lakebeds are numerous bedrock mounds, including Roche-A-Cri.  These mounds would have been islands sticking out of Glacial Lake Wisconsin.  All of the mounds have steep slopes that formed by wave erosion.

Interestingly, on the south side of Roche-A-Cri are numerous prehistoric Indian and more recent petroglyphs and pictographs.  An example is found in the picture below, the inscription says:  A.V. Dean. N.Y. 1861.

Minnesota Geology Monday - Mississippi River Headwaters

The Mississippi River is the fourth longest river (2,552 miles) in the world and drains parts of 31 states and 2 Canadian provinces.  The river also has the 4th largest drainage basin in the world (over 1,245,000 square miles), representing almost 40% of the continental United States landmass.  Historically important for early Native Americans and used during the fur trade, today the river is important for tranport of materials via commercial barges.

Expeditions in the early 1800s sought to discover the headwaters of the Mississippi River.  In 1832, led by Native American guides, Henry Schoolcraft identified Lake Itasca as the source of the river.  Schoolcraft named the lake Itasca as a combination of two Latin words, veritas (meaning truth) and caput (meaning head).  The lake is now the namesake of Lake Itasca State Park, which was created in 1891 to preserve the area's remaining virgin pine forests and is Minnesota's oldest state park.

Lake Itasca is at an elevation of 1,475 feet above sea level and is a typical kettle lake found in the area, a result of late-Wisconsin glaciation.  The lake is 1.8 square miles and has an average depth of 20-35 feet deep.  Retention time, the amount of time needed for water to flow from Lake Itasca to the Gulf of Mexico, is approximately 90 days.

The headwaters area was originally swampland.  To give tourists better access, the Civilian Conservation Corps in the 1930s drained the surrounding swamp, dug a new channel and installed a rock rapids.  Many visitors to the area walk across these rock rapids and some subsequently fall into the brand new, Mississippi River.