Closest point to the Earth's centre.

Hello good people,
the question should be simple; What is the closest point to the Earth’s centre accessible to Man?

Prior to humanity reaching the bottom of Lake Vostok I’ll propose a canyon under the Arctic Ice cap.

Any more knowledgeable proposals?

Peter

Access on a regular basis, or once for about 20 minutes?

Any access as long as you return alive.
I’m not certain the Marianas Trench is the closest point, if you were about to suggest that:)
Peter

Due to the oblateness, I would say a spot on the floor of the Arctic Ocean. If we can get to Challenger Deep twice we could certainly get there and back.

I assume there are topological maps of the Ocean floor under the Arctic, although they are probably somewhat ‘confidential’.
Are there any deep mines in Northern Russia or Canada that might come close?

BTW, I was thinking of the planet’s centre of gravity, as used to calculate orbits etc and this may be variable, as well as not necessarily the geometric centre of the Earth.

Peter

The maximum depth of the Arctic Ocean is Litke Deep in the Eurasian Basin, at 5,450 m (17,880 ft).
The lowest known point on Earth—the Mariana Trench—lies 10,911 meters (35,797 ft or 5,966 fathoms) below sea level in the Pacific Ocean.

http://www.scientificamerican.com/article/earth-is-not-round/

Brownie points to Saint Cad.

Erm yes I did realize that the Earth was oblate, just didn’t need to state it.
So the question still stands.
Peter

So what was wrong with the answer: http://en.wikipedia.org/wiki/Litke_Deep in the previous post?

Hi there, it’s not really an answer, the Wiki article states that:

Litke Deep is an oceanic trench located to the northeast of Greenland, and approx. 350 kilometers north of Svalbard, in the Eurasian Basin in the Arctic Ocean. The Litke Deep holds the distinction of being the deepest known point in the Arctic Ocean at 5,449 metres (17,881 feet).[1] It is the 20th deepest oceanic trench in the world.

The piece doesn’t state whether that place on Earth is closest to the centre of the Earth.

No offence intended but it’s an incomplete answer.

Peter

That’s where I’d put my money. But if someone wants to do the necessary calculations for all other contenders, they should concentrate on the Arctic. Nothing in the tropics stands a chance.

Actually you have your answer.

Given a feature at latitude L, the distance from the center to the ellipsiod at that point in kilometers (IIRC) is E = 162177731.1568/(161634607.8736cos[sup]2[/sup]L + 162722679.4384sin[sup]2[/sup]L). This assumes the Earth is an ellipse if cut along a line of longitude with the polar radius the semi-minor axis and the equatorial radius the semi-major axis. Distance from the center of the Earth is E+a where a is the altitude above or below the ellipsoid.

Mean Seal level (MSL) follows the geoid and the distance of the feature from the center of the Earth is G+A where A is the altitude above or below the geoid and G is the distance of the geoid at that coordinate from the center of the Earth. The geoid only approximates the ellipsoid, is based on the barycenter of the Earth instead of the orthocenter and suffers from hills and valleys.

Notice the problem?

SaintCad,

I don’t wish to get into an argument…but
However, wtf was that all about?

This is GQ, not a specialized GIS forum.

I too could quote pages of theory, essentially meaningless to most people, there is a time and a place to use them, this is neither.

Again I don’t wish to be rude, and you nay be closer to the answer than other dopers, but can anyone answer the question?

It’s pretty straightforward. The closest accessible place to the centre of the earth is likely going to be at one of the poles. Antarctica is a land mass, so attention turns to the northern pole, and the sea bed of the Arctic Ocean. Litke Deep is, as far as we know, the deepest part of the ocean up there.

It’s kind of like “What part of the world is furthest from the centre?” It’s not Everest, it’s the summit of Chimborazo, in Ecuador.

Isn’t that the apocryphal Diablo stage where you’re attacked by angry pinnipeds?

I’m sure (s)he gets that. The answer still is incomplete. The sounds like a good guess, but perhaps there’s a canyon that’s not quite as deep, but is further north that might pose a challenge.

I’m not sure where the attitude from several of the responders is coming from.

Thank you for your last, question still stands,

What a bunch of idiots, simple question,

Peter

Oh, pdunderhill, and you were doing so well. Well, at least okay.

Yeah. Maybe the attitude was justified. Hmm.

People were getting there, gradually. The math is a part of finding the answer. You’re an asshole. When they find that deepest part, I hope they throw you in there and dance afterward.