Google Earth and the Arctic Circle

When I look at Google Earth, the Arctic circle seems to be non-existent, or perhaps I should say it appears to be melted. The only thing white I see anywhere near there is Greenland. What gives?

I can’t really find and good explanation for this at any of the links I have found.

Any ideas?

There are a few possibilities, but the most likely one IMO is this:

When you look at a 3D object on a computer, the surface detail is generally done via a technique called texture mapping. The idea is simple; you take a 2D picture and “wrap” it around the 3D object.

However, texture mapping has the same fundamental problem that ordinary mapping has, which is that flat surfaces can’t wrap around curved objects without some distortion. The kind of distortion you get is dependent on the exact type of mapping.

In this case, it appears that they use a technique called cylindrical mapping. You can imagine a cylinder just enclosing the Earth, where each point on the texture corresponds to the point on Earth with the same longitude and the same distance along the axis of rotation.

What this means, though, is that the poles end up with less detail. Suppose one pixel on the equator corresponds to 1 mile on the texture. But as you get closer to the poles, it starts flattening out, and the same pixel might stretch out to 10 miles, 100 miles, or more. When you finally get to the pole, there’s essentially no detail at all.

That’s seems to be what I’m seeing as explanations. However the Antarctic is clearly visible.

Yeah, it does look like something extra is going on in the arctic. I wonder if they simply delete floating ice in favor of undersea terrain. Remember that there is no land at the north pole.

That makes sense. I think you’re on to something.

It’s the ocean, so you’re seeing the bathymetric data instead of aerial photos on all but the lowest zoom level. The arctic sea ice changes all the time, so there wouldn’t be much point of maintaining imagery up there, so they just treat it like they do the rest of the oceans. The continental ice pack on Antarctica doesn’t change as much over human time scales, so they do have imagery there.

Sorry, but your question just doesn’t make any sense. Are you by chance mistaking the Arctic Circle with the ice cap around the North pole?

Seems like others got the gist of it. But thank you, I stand corrected. Should I reword it perhaps? I’ll wait for further instructions. Moving on to less acuteness until I have further direction on my obtuseness.

You are speaking as though you are the OP :confused:

I also got the gist of it, but nevertheless, the question is nonsensical.

How about this one then: Why can’t I see the South Pole research base on Google Earth?

Because satellites aren’t allowed to take pictures too close to the poles., it would reveal the secret of the polar openings!

(yes this guy seems to be serious)

I don’t know how my post got in here. Sorry. Even stranger is that my response seems to fit in here too. Now If I can remember where I was supposed to post that. That’s what happens when you don’t stay on top of things.

Two guesses:

One is that Google Earth has put extensive effort into modelling the earth’s undersea terrain, and covering the Arctic ocean with a solid model of sea ice would undermine a considerable portion of that effort.

Another is that northern sea ice is so highly variable that it would be very difficult to depict it in any meaningful way; any map of sea ice would show only how the Arctic Ocean looked at that minute. For that reason Google may have chosen to omit the sea ice altogether.

If seeing the extents of sea ice is something that really interests you (as it did for me), the National Snow and Ice Data Center has a great downloadable plug-in for Google Earth that places a white bitmap on the earth, representing the sea ice on the date you select for it.

Ah ok, no worries.

Thanks, Hyperion89. That is really cool. And yes, that is something that interests me. On another note, I guess I’ll have to cancel my tropical vacation to the North Pole. Damn… Already bought the cabana clothes too. Complete with pictures of Polar bears in shades and Santa on the beach sipping Pina Coladas and tanning.

Just wait a few years… :wink:

To reiterate the question above: are you talking about the Arctic Circle or the polar ice cap? They are entirely different things. Most (if not all) of the Arctic Circle region will only be snow covered in winter.