mendenhall recedes

[bottom-dragger]

time lapse over the past 3 years

 

http://www.extremeicesurvey.org/index.php/new_gallery/timelapse_41/

[welly world]

OMG! We were there 4 years ago and were told about the amount it has receded, but to actually see it happen 'before your eyes' is truly amazing. Thank you for sharing!

[PennyAgain]

Thanks for the link. I remember what it looked like about 40 years ago and can also remember when you could easily see Portage from the bi parking lot.

[diverearl]

Great link thanks for posting it.

[lilacbirman]

We were there in July and was surprised at seeing the two waterfalls that were not there the first time we were there 15 years ago. Amazing to see the time lapse!

[Tricia724]

That is a fantastic visual. When you are viewing a glacier and it looks big to you, it's difficult to understand what people are talking about when they say it is receding.

[blakey]

The beginning date is May, and the ending date is sept. Anyone else see a problem here?

[chipmaster]

Nice links, amazing what global warming has done :mad:

 

While we were there we ran into a older couple who talked about how far things have receded in the last 10 years, pictures really put it into prospective.

[tee_harbor]

The beginning date is May, and the ending date is sept. Anyone else see a problem here?

 

Not if you don't tell us. :D

[Budget Queen]

I've been traveling Alaska for 16 years, another glacier which has had a lot of recession is Exit. I noted the that the Reid had some hanging glacier areas, which were new. Global warming is a problem.

[bottom-dragger]

The beginning date is May, and the ending date is sept. Anyone else see a problem here?

 

 

the black helicopters with no markings couldn't fly in to set up until the snow was gone and went to retrieve their gear before it got frozen in. they were going to mount it on a grassy knoll but.......

 

my hairline is receding faster.

[lilacbirman]

The beginning date is May, and the ending date is sept. Anyone else see a problem here?

 

 

It's May 2007 throught September 2010...3 years. But still shocking to see! :eek:

[bottom-dragger]

It's May 2007 throught September 2010...3 years.

 

i think the implication was that it started at the end of a winter and was compared to end of summer ice. but the seasonal change isn't that great.

[tee_harbor]

i think the implication was that it started at the end of a winter and was compared to end of summer ice. but the seasonal change isn't that great.

 

Yeah, he never came back! I wanted to know! Was he implying that like some giant ice cube, the glacier was only receding because it was the end of summer?

 

Er, if that's the case, he needs to check out the displays in the Mendenhall vistors' center and learn how glaciers work.

[BIG_Steve]

It was an interesting video. I hope this thread doesn't turn into a political battle ground.

[blakey]

A serious, credible study would compare May, 2007 to May, 2010 or Sept to Sept. It's like comparing apples to oranges...yes, they are both fruits. And May and Sept. are both months of the year. However, I must question motives when comparing May to Sept. If they have the technology to make the time-lapse shots over several years (3yrs plus 4 mos)...then they have the technology to check that camera at the appropriate times or to post the film/pics/whatever using the appropriate parameters.

Having said all that...I do believe in global warming AND in global cooling. I do believe in sunspots and solar flares AND the lack of them.

So, after watching it over and over, stopping it at various points, the time-lapse video is interesting at best but not credible. Thank you, OP, for posting it! This has been an entertaining thread.

[tee_harbor]

A serious, credible study would compare May, 2007 to May, 2010 or Sept to Sept. It's like comparing apples to oranges...yes, they are both fruits. And May and Sept. are both months of the year. However, I must question motives when comparing May to Sept. If they have the technology to make the time-lapse shots over several years (3yrs plus 4 mos)...then they have the technology to check that camera at the appropriate times or to post the film/pics/whatever using the appropriate parameters.

Having said all that...I do believe in global warming AND in global cooling. I do believe in sunspots and solar flares AND the lack of them.

So, after watching it over and over, stopping it at various points, the time-lapse video is interesting at best but not credible. Thank you, OP, for posting it! This has been an entertaining thread.

 

I guess my question is, what are you accusing 'someone' of doing? Faking it? Do you not believe man ever walked on the moon? (My best friend doesn't.)

 

I don't need any time lapse photography. I've just been visiting the glacier my whole life. It has receded. That discussion doesn't have to have anything to do with global warming; there are glacier moving forward in AK too. But because the movement is still fairly small by human time standards, they used three years worth of footage. They probably stopped in September because that's when they posted! No conspiracy going on!

[blakey]

I guess my question is, what are you accusing 'someone' of doing? Faking it? Do you not believe man ever walked on the moon? (My best friend doesn't.)

 

I don't need any time lapse photography. I've just been visiting the glacier my whole life. It has receded. That discussion doesn't have to have anything to do with global warming; there are glacier moving forward in AK too. But because the movement is still fairly small by human time standards, they used three years worth of footage. They probably stopped in September because that's when they posted! No conspiracy going on!

I will assume from your post that you live in Juneau, Alaska near Mendenhall Glacier, therefore what you say bears more weight than the video.

Time-lapse photography is great...if used properly. I would love to see this same footage with a true comparison...May to May, or July to July, or whatever! Because it is showing May, 2007 to Sept. 2010, I must question the motives of the photographer/interpreter or the site that is hosting it.

By the way, it would devastate me if anyone ever proves that Armstrong didn't walk on the moon back in 69. :D

[bottom-dragger]

...

[wolfie11]

I'm not a real glaciologist, but I work closely with one...so here's the deal on glaciers in general, and Mendenhall in particular. Mendenhall is a lacustrine-calving glacier (it terminates in a lake). For calving glaciers in temperate climates, flow is slower in the winter and when the lake is frozen (glaciers move faster when there is liquid water present, like a slip-n-slide). For Mendenhall, the accumulation area is high enough that it receives snow for most of the year, and the ablation area is low enough that melting occurs most of the year. Retreat occurs when the amount of snow falling and not melting is less than the amount of snow falling and melting. A warming climate contributes to this process and around 99% of Alaska glaciers are retreating. Part of this is due to long-term climate change since the Little Ice Age peaked in the early 1700's, but warming has accelerated in the last few decades.

 

Glaciologist don't look as much at the face of the glacier, which can change from year to year, but at the mass balance of the glacier (how much ice the glacier is losing over its entire length and height). Mendenhall has been wasting steadily over the last several years and has a visible trim line (area above the glacier where there is no vegetation because it was recently covered by snow). If you look closely at the hills just beyond the glacier in the video, you can see the changes in the trim line, although most of the shrinkage is below sight line from this camera angle.

 

The long and short of it is that this video is NOT any kind of scientific analysis of glacier retreat. It is a really nice visualization of part of the process. Comparing May to May would be just as unscientific because of seasonal variations (how cold the spring is and how long the lake stays frozen would affect the movement of the glacier) and also because the ice at the face reflects the snow that fell years or even decades ago on the Juneau Ice Field.

[NHsnowpup]

One grade at school is studying landforms and includes an intro. to glaciers. This should be a great discussion starter for me, with a link that should get past our firewall/filter.

 

Once again, thanks guys. Your discussions are so much better than the tired dishrags on "do we REAAAALLLLLY have to dress up to get our lobstas?";)

 

The hubby loved the trip to Mendenhall with the walk out to the falls. He says it was one of the top best of our trip. The lake had a jam up of lots of big blue and little white/clear bergy chunks and pieces between the face and towards the falls trail. Had an urge to wade on out and touch a few, but restrained myself

 

Have a great holiday!

[Beach4me]

Thanks for the link. Very interesting.

 

My first visit to Mendenhall was 31 years ago. I remember standing there along the lake this past September wondering at the change over the years. I'd never have believed it 31 years ago.

[nannygoatjunction]

We got married on top of the Medenhall Glacier, was very interesting to see the changes.