Page 1 of 5

### Dynamic Planet B/C Question Marathon

Posted: August 28th, 2013, 8:20 pm
Question Marathon for Dynamic Planet B/C.

### Re: Dynamic Planet B/C Question Marathon

Posted: September 1st, 2013, 9:10 pm
I guess I'll start off with an easy question. How can you tell the direction of a glacier's movement by looking at a drumlin? A roche moutonnee?

### Re: Dynamic Planet B/C Question Marathon

Posted: September 2nd, 2013, 9:28 am
For both, the lee side points in the direction of the ice flow. For a drumlin, that is the less steep, sloping side. For a roche moutonnee, it's the opposite--the jagged, steeper side is the lee side and points in the direction of ice flow

EDIT: dang, I'm starting to like these question marathons already

### Re: Dynamic Planet B/C Question Marathon

Posted: September 2nd, 2013, 9:40 am
Correct! I think this means it's your turn to post a question

### Re: Dynamic Planet B/C Question Marathon

Posted: September 2nd, 2013, 9:46 am
Aw pigeon. Um...

Name two factors that cause glaciers to flow.

Also, a somewhat related question...

Name and describe the ways a glacier moves.

This question (the latter) has kinda bothered me in the past, since I had a lot of information on glacier movement and I didn't really know what to put for this question (that is, I couldn't articulate my answer), and I have a decent idea of what I would put for this question, and I want to see what other people would put

EDIT: should we [hide] our answers?

### Re: Dynamic Planet B/C Question Marathon

Posted: September 4th, 2013, 5:48 pm
First year doing this , so I am ignorant , but I'll try without using resources . For part a: A downwards slope, and pressure buildup. For part b: Slowly and unpredictably

### Re: Dynamic Planet B/C Question Marathon

Posted: September 4th, 2013, 6:50 pm
mrburrito wrote:First year doing this , so I am ignorant , but I'll try without using resources . For part a: A downwards slope, and pressure buildup. For part b: Slowly and unpredictably

Um...no...

How about this, try looking up the answer yourself. I'm sure you'll find some good resources in the process from which you can study as well

C'mon, there has to be someone out there who knows this! Fozen? PacificGoldenPlover? (can I please just call you "Plover" from now on for convenience? )

### Re: Dynamic Planet B/C Question Marathon

Posted: September 4th, 2013, 7:04 pm
Crazy Puny Man wrote:there has to be someone out there who knows this! Fozen? PacificGoldenPlover?

From now on, put Pacific's name first, then after thousands of spaces you can put mine... Pacific is uber good at DP

And if the answer isn't posted by the time I finish my HW I will look into it

### Re: Dynamic Planet B/C Question Marathon

Posted: September 5th, 2013, 3:11 pm
Ok, pressure and gravity, so I was partially correct.

And umm basal sliding, which is when glaciers slide over the terrain it's on, lubricated by liquid water.

I think that's right.

### Re: Dynamic Planet B/C Question Marathon

Posted: September 5th, 2013, 3:39 pm
mrburrito wrote:Ok, pressure and gravity, so I was partially correct.

And umm basal sliding, which is when glaciers slide over the terrain it's on, lubricated by liquid water.

I think that's right.

Also, some glaciers move because internal ice crystals move past one another based on conditions (temperature, weight, pressure). Usually, the top layers of a glacier move quicker than the bottom layers.
Is this right? Thanks.

### Re: Dynamic Planet B/C Question Marathon

Posted: September 5th, 2013, 5:45 pm
@Fozen: I'd like to think I'm kinda good at DP, I was 6th...but Pacific won And took medals in two other ID events So of course he owns everyone's ass

@burrito & ScienceOlympian: for the first part, the answer I was looking for was gravity & internal deformation of ice. I think that's on Wikipedia word for word.

For the second part of the answer, I was thinking (1) basal slip (2) plastic flow (includes plastic deformation, creep, & folding & fracturing) (3) subglacial bed deformation and (4) surges <-- I was iffy on this one. I didn't think surges were technically a WAY that glaciers move, but after taking some tests and going to invites last year it seemed like it was. Also, for number 2 I would've also put stress/strain, and supplied equations for that too, but then I reasoned that plastic flow of glacier ice is due to stress/strain -_- Fail moments...

Pacific, can you confirm/explain if surges are technically a way which a glacier moves?

Also, ScienceOlympian, what you described was plastic flow, and that's due to the structure of ice and weak molecular bonds between layers of atoms of ice, and that's why ice flows, blablabla which is what you were saying I think.

Yes, the top does flow faster than the bottom due to pressure/abrasion, & the middle flows faster than the edges because the edges are thinner & more brittle, and are more subject to friction (in mountain glaciers)

### Re: Dynamic Planet B/C Question Marathon

Posted: September 6th, 2013, 1:36 pm
I do not have much experience with Glaciers, but wouldn't pressure be a partial cause of internal deformation?

### Re: Dynamic Planet B/C Question Marathon

Posted: September 6th, 2013, 5:07 pm
Pressure is due to the weight of the ice (gravity), the way I see it. The internal deformation of ice accounts for ice's special property of plastic deformation.

### Re: Dynamic Planet B/C Question Marathon

Posted: September 6th, 2013, 9:12 pm
Crazy Puny Man wrote:@Fozen: I'd like to think I'm kinda good at DP, I was 6th...but Pacific won And took medals in two other ID events So of course he owns everyone's butterfly

@burrito & ScienceOlympian: for the first part, the answer I was looking for was gravity & internal deformation of ice. I think that's on Wikipedia word for word.

For the second part of the answer, I was thinking (1) basal slip (2) plastic flow (includes plastic deformation, creep, & folding & fracturing) (3) subglacial bed deformation and (4) surges <-- I was iffy on this one. I didn't think surges were technically a WAY that glaciers move, but after taking some tests and going to invites last year it seemed like it was. Also, for number 2 I would've also put stress/strain, and supplied equations for that too, but then I reasoned that plastic flow of glacier ice is due to stress/strain -_- Fail moments...

Pacific, can you confirm/explain if surges are technically a way which a glacier moves?

Also, ScienceOlympian, what you described was plastic flow, and that's due to the structure of ice and weak molecular bonds between layers of atoms of ice, and that's why ice flows, blablabla which is what you were saying I think.

Yes, the top does flow faster than the bottom due to pressure/abrasion, & the middle flows faster than the edges because the edges are thinner & more brittle, and are more subject to friction (in mountain glaciers)

Who woke me up?

I guess you could consider surges to be a form of glacial motion, but I see it as more of a result of basal slip that happens to be cyclical and more dramatic, since essentially surges occur because of regular accumulations of subglacial water.

And yeah it's fine to call me plover.

### Re: Dynamic Planet B/C Question Marathon

Posted: September 7th, 2013, 10:22 am
Or because of mass accumulations.

But yeah, that's what I thought. I mean, my partner thought surges WERE a way that glaciers move, and at one of the invites I went to, surges was one of the answers to that type of question...

Whatever. I know what I'll do with that question now