Breakup at Chicken

[chickenminer]

Ice jam on the Mosquito Fork at Chicken.

MF ice jam small.jpg

[chickenminer]

Looking downstream from on the bridge.

Mosquito downstream small.jpg

[Jim_Alaska]

Yup. it looks like the breakup I remember. Thanks for posting those pics Dick. Hope you have a great summer, wish I was there to see your operation, but never made it even when I lived there, so no chance now.

[Geowizard]

Ice Jams;

Next to volcanic eruptions and earthquakes, ice jams are the next most dangerous event that happens in Alaska. Mosquito Fork has oxbows and meanders that serve as stark reminders of the forces involved when millions and millions of tons of water and ice "jump the bank" ripping out trees and brush cutting a NEW river channel!

In one second a jam occurs and the next second the water level rises several more feet - maybe ten feet and all hell breaks loose.

Enormous noise levels of crashing boulders of ice crushing and grinding as they move too!

People have old homesteads along there that can be wiped off the map in an instant. It actually is a very scary situation because it's completely unpredictable from one second to the next.

Nice photos!

- Geowizard

[waveaction]

Thank you for the pictures Dick. It is so close to taking out the Bridge. When I waited for the South Fork to open up at the end of April/early May, I loved listing to all the Ice Breaking up. Really impressive. More impressive was running the Jet Boat down river to get camp ready, with many chunks still in the water. lol

[chickenminer]

Jam is still holding. Shifted some and water level is up.
( Click on photo for expanded view)

may 11 jam small.jpg

[chickenminer]

May 11 jam 2 small.jpg

[Jim_Alaska]

A great opportunity for pictures Dick, thanks for posting them.

[Geowizard]

Something to think about...

A dam can be considered to be a storage device having capacity like a battery. Water is stored and the more water stored at increasing elevation has potential energy and the capacity to do WORK.

What are the dynamics of potential energy?

One cubic meter of water is by definition one metric tonne.

Looking at Dicks photos, it's easy to estimate the dimension of the potential energy. If we estimate 300 meters across and 1000 meters long by 3 meters deep combined ice and water, the capacity is roughly one million metric tonnes.

Meanders in rivers like Mosquito Fork are the product of work. The more or less random forces that existed over periods of time measured in centuries include many ice dams and assemblages of ice than channel water into narrow passages. Erosion of river banks result from ice dam events that are historic and legendary when viewed over thousands of years in nature!

We know miners have used water to perform work! Diversion ditches line most of the rivers and many creeks in Alaska where miners diverted water to do work where work was needed.

In the prehistoric past, ice dams undoubtedly occurred that make modern ice dams look trivial. Sweeping horse shoe shaped meanders that were the products of ice blockages and ice buildup along the inside bends of rivers eventually are washed out (blown out) by sudden releases of million ton "out flows" from a sudden release from an up-river ice dam. The result is an oxbow.

Of interest is the locations of ice dams are in relatively flat valleys. The flow is slow, the build up of ice is slow. The broken ice has time to find a hole and is actually driven into holes by the force of water toward the hole. Flow is increasing as the ice seals holes in an otherwise inconspicuous dam.

The force increases as water pressure increases! As in every case, there is a limit. Millions of tons of water and solid ice make an ideal cutting machine and they suddenly go to work!

https://water.weather.gov/ahps2/hydrogr ... 2&wfo=pafg

- Geowizard

[Geowizard]

In the news;

Ice jams, snowmelt result in catastrophic flooding in Alaska

https://www.yahoo.com/news/ice-jams-sno ... 12366.html

- Geowizard