I was referring to the previous question which I wrote, sorry for the confusion.
Re: Dynamic Planet B/C
Posted: January 7th, 2019, 2:20 pm
by LiteralRhinoceros
SciolyHarsh seems to be inactive, so if no one minds, I'll post a question.
What forces are in action during isostatic rebound?
Re: Dynamic Planet B/C
Posted: January 7th, 2019, 5:45 pm
by UTF-8 U+6211 U+662F
LiteralRhinoceros wrote:SciolyHarsh seems to be inactive, so if no one minds, I'll post a question.
What forces are in action during isostatic rebound?
Gravity and asthenosphere pressure?
Re: Dynamic Planet B/C
Posted: January 8th, 2019, 4:41 am
by LiteralRhinoceros
I was looking for buoyancy too, but that works. Your turn!
Re: Dynamic Planet B/C
Posted: January 8th, 2019, 12:22 pm
by UTF-8 U+6211 U+662F
Cool!
Contrast between depositional and erosional features left by glaciers. Give examples.
Re: Dynamic Planet B/C
Posted: January 8th, 2019, 1:51 pm
by JoeyC
Erosional features tend to be carved into rock; examples including roche mountonee, striations, and the carving of U shaped valleys. Depositionals tend to involve till, examples being drumlins, eskers, and other similar structures. Deposition's main agent is the glaciofluvial forces and the glacial movement. Erosional features main force tend to be mainly glacial movement (less so on glaciofluvial, but fluvial is still there)
Re: Dynamic Planet B/C
Posted: January 8th, 2019, 5:10 pm
by UTF-8 U+6211 U+662F
JoeyC wrote:
Erosional features tend to be carved into rock; examples including roche mountonee, striations, and the carving of U shaped valleys. Depositionals tend to involve till, examples being drumlins, eskers, and other similar structures. Deposition's main agent is the glaciofluvial forces and the glacial movement. Erosional features main force tend to be mainly glacial movement (less so on glaciofluvial, but fluvial is still there)
Yep, your turn
Re: Dynamic Planet B/C
Posted: January 8th, 2019, 5:13 pm
by JoeyC
Name the method of formation, differences, and direction of Roche Mountounees, Drumlins, and Crag and Tails.
Re: Dynamic Planet B/C
Posted: January 13th, 2019, 8:08 am
by SciolyHarsh
UTF-8 U+6211 U+662F wrote:
SciolyHarsh wrote:Question: Suppose a large area of continent consists of 30 km of Earth’s crust with a density of 2.6 Mg/m³ over 90 km of material with a density of 3.0 Mg/m³. The asthenosphere density is 3.3 Mg/m³. This region is covered with a 1.5 km thickness of ice of density 0.9 Mg/m³ and is assumed to be in isostatic equilibrium. If the ice melts, how much will the surface of the continent change once isostatic equilibrium is re-established? Answer in kilometers.
cacodemon wrote:Nope, somewhat of a trick question.
Sea level would not change. An ice shelf is floating on water by buoyancy -- sea level rise is proportional to volume of water displaced. So when the ice shelf melts, there is no change in sea level because the water displaced by the ice shelf is filled by the volume of water that ice shelf represents. Sea level changes when ice on land melts and either runs off or sheds directly into the ocean as icebergs.
But it is asking about the surface of the continent, not sea level: the glacier is not in the ocean.
0.41 km?
Sorry about the late response! You were close but you forgot to factor in the top layer offset.
The answer is 1.09 km, it's 1.5km (the top and bottom layer offset combined)-0.419(the bottom layer offset).
JoeyC wrote:Name the method of formation, differences, and direction of Roche Mountounees, Drumlins, and Crag and Tails.
A roche moutonee is similar to a hill, and is smoothed on one side due to the glacier advancing over it, and plucking of rocks on the other side. A crag is a hill which is formed when an ice sheet passes over harder ground such as bedrock or granite, and the ice sheet erodes the surroundings. A drumlin is a hill formed by flowing ice reshaping the underlying ground; it looks like an egg.
Re: Dynamic Planet B/C
Posted: January 13th, 2019, 10:41 am
by JoeyC
Correct! Roche Mountounees face the opposite way of the ice flow, while Drumlins and Crag and Tails face toward the Ice flow
Your Turn!