Best month to view calving at glaciers?

[HALNEWBY]

Just curious to know the best months that the glacier's (Hubbard,Glacier Bay...) are active in their calving?

[Toyz711]

it depends on the glacier's movement. we were in glacier bay during mid/late sept. john hopkins are a series of (maybe) 5 mini calvings. DH did heard the crack and the big "boom" they some hit the water. i missed it.

[Chenega]

Just curious to know the best months that the glacier's (Hubbard,Glacier Bay...) are active in their calving?

 

Really no way to tell since it depends on internal pressure within the glacier vs. the time of year.

[ute_fan]

Chenega -- a little off the thread topic, but I've been thinking of asking what factors influence the glaciers to calve also. For instance, I've been glancing periodically at the webcam from Mendenhall, and it looks like the lake in front is still frozen. I wouldn't think that the glacier can calve if the lake is frozen, but I've learned over the years that my thought processes can be very misleading :D .

 

You mentioned internal pressure. How about things like temperature and length of daylight? Does anything like that influence calving? Can you provide any more information or point me in a direction that would have that information available??

 

Thanks!

[HALNEWBY]

How about things like temperature and length of daylight? Does anything like that influence calving? Can you provide any more information or point me in a direction that would have that information available??

 

Thanks!

 

My point exactly...It should make more sense that in the warmer months there should be more calving, but I am not sure...

[Chenega]

How about things like temperature and length of daylight? Does anything like that influence calving? Can you provide any more information or point me in a direction that would have that information available??

 

Thanks!

 

I've talked to scientists who think that weather, sunlight, etc. may play a factor while others dismiss it. Years ago the ferry captains in Alaska used to sound the ship's horn to make calving occur; now that is dismissed as having no effect.

 

I'd recommend a search on the internet for glaciers and Alaskan Glaciers. There are more sites than I can possibly list.

 

However, one I can recommend and have used for my geography classes is http://nsidc.org/glaciers

The site is filled with information on glaciers including multiple links.

 

Another good site specifically on the Hubbard Glacier (one of the most active in Alaska) is http://www.ak.water.usgs.gov/glaciology/hubbard

 

Have fun!

 

My point exactly...It should make more sense that in the warmer months there should be more calving, but I am not sure...

[ute_fan]

My point exactly...It should make more sense that in the warmer months there should be more calving, but I am not sure...

 

I'm glad I'm not the only one who dreams up questions like this. My kids (in their early 20's) have me convinced that I've gone over the edge with my curiosity about Alaska :D .

[Chenega]

If anyone wants more information on Alaska from a scientific viewpoint, go to the excellent website sponsored by the University of Alaska Geophysical Institute http://www.gi.alaska.edu/

 

It's loaded with information.

[HALNEWBY]

I'm glad I'm not the only one who dreams up questions like this. My kids (in their early 20's) have me convinced that I've gone over the edge with my curiosity about Alaska :D .

 

Don't worry you are not the only one...my wife thinks that I am a bit crazy about alaska too...

 

thanks to all for your responses!!

[wolfie11]

Tidewater glaciers calve all year round (Mendenhall is on a lake which freezes during the winter). However, to the best of my knowledge, no one has ever set up a "calve cam" to see if they calve more in the winter than the summer. Since the calving rate of a glacier is dependent on it's movement rate, I would suspect they calve more in the summer. Movement rates are based on the length of the glacier, steepness of the slope, amount of snow in the accumulation area, etc. However, in the summer, rain and meltwater find their way through the crevasse system to the base of the glacier, thus "lubricating" the bed of the glacier and allowing movement to speed up, kind of like a slip-n-slide. It follows that if the glacier is moving faster, it should be calving more.

 

Some glaciers also go thru calving "cycles" where they seem to calve like crazy for a day or two and then be relatively quiet for a day or two. You can usually tell when you pull up to a glacier what mode it's in. Potentially active glaciers have lots of seracs (ice towers) leaning over and lots of jagged edges on the face of the glacier. Calved-out glaciers have large smooth areas where calving has already occured.

 

Glaciers also tend to calve more in the middle and less on the edges, since this is the part of the glacier that is moving the fastest.

[irisheileen]

Chenega -- a little off the thread topic, but I've been thinking of asking what factors influence the glaciers to calve also. For instance, I've been glancing periodically at the webcam from Mendenhall, and it looks like the lake in front is still frozen. I wouldn't think that the glacier can calve if the lake is frozen, but I've learned over the years that my thought processes can be very misleading :D .

 

You mentioned internal pressure. How about things like temperature and length of daylight? Does anything like that influence calving? Can you provide any more information or point me in a direction that would have that information available??

 

Thanks!

 

What site has the webcam?

Eileen

[ute_fan]

Mendenhall webcam link: http://www.fs.fed.us/r10/tongass/districts/mendenhall/webcam.html

 

It's been fun over the past month or so to watch the snow melting from the trails and ground. I keep watching to see if the ice is off the lake yet, but so far it still looks pretty frozen!

[irisheileen]

Mendenhall webcam link: http://www.fs.fed.us/r10/tongass/districts/mendenhall/webcam.html

 

It's been fun over the past month or so to watch the snow melting from the trails and ground. I keep watching to see if the ice is off the lake yet, but so far it still looks pretty frozen!

 

Thanks! I'm off to that site.......

Eileen

[Chenega]

A correction to the excellent website on Hubbard Glacier. It's

http://ak.water.usgs.gov/glaciology/hubbard