# Closest point to the Earth's centre. **URL:** \ **Category:** Factual Questions\ **Created:** [October 8, 2014, 5:29pm UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779 "2014-10-08T17:29:25Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [October 15, 2014, 12:34pm UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779/41 "2014-10-15T12:34:53Z")
> [@Colophon](#): > > That and the Kola borehole was only [nine inches in diameter](http://www.mnn.com/lifestyle/eco-tourism/stories/the-worlds-deepest-hole-lies-hidden-beneath-this-rusty-metal-cap). But it highlights the problems… so poorly defined question, and so much territory for it to be in… what sort of place can it be ? a crack ? something filled with methane ? a (impossible to navigate) long cave ? What if there is a trench filled with mud… a suitably designed submarine could go into the mud… but we don’t know it exists because no on bothers to investigate all the oceans looking for mud filled trenches… Oh well that just means the definition has to be "the deepest (as measured by distance from centre) KNOWN part of the ocean " ---
**Author:** ![Geekausaurus](https://avatars.discourse-cdn.com/v4/letter/g/6de8d8/32.png) [@Geekausaurus](https://boards.straightdope.com/u/Geekausaurus)\ **Post date:** [September 11, 2018, 7:44am UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779/42 "2018-09-11T07:44:43Z")
The closest point is not necessarily the deepest point since earth is an oblate spheroid, first reported by Sir Isaac Newton. I believe that the difference in the semidiameters from the poles and the equator is 13 km. Litke Deep is located at 82.4N and 20E. At this latitude the difference between the pole and Litke Deep is negligible, and the Deep is 5,450 metres deep. As such, it is the closest known point to the centre of the planet. And it is accessible. Can we put this to bed? > [@Isilder](#): > > But it highlights the problems… so poorly defined question, and so much territory for it to be in… what sort of place can it be ? a crack ? something filled with methane ? a (impossible to navigate) long cave ? What if there is a trench filled with mud… a suitably designed submarine could go into the mud… but we don’t know it exists because no on bothers to investigate all the oceans looking for mud filled trenches… Oh well that just means the definition has to be "the deepest (as measured by distance from centre) KNOWN part of the ocean " Sent from my F160 using Tapatalk ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 11, 2018, 8:41am UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779/43 "2018-09-11T08:41:19Z")
(Yes, I realize this is a zombie) > [@pdunderhill](#): > > Prior to humanity reaching the bottom of Lake Vostok I’ll propose a canyon under the Arctic Ice cap. How the heck is that “accessible to man”? ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [September 11, 2018, 9:04am UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779/44 "2018-09-11T09:04:46Z")
You can use an [online calculator](https://planetcalc.com/7721/) to compute the Earth’s radius by latitude. Challenger Deep is at 11.373N and the radius 6377.312 km. Litke is at 82.4N with a sea level radius of 6357.129 km. This is already 20 km below Challenger, so it wins easily. The radius at depth is 6351.679 km. The radius at 90N is 6356.752, or 377 m below Litke. There’s nothing on [this list](https://en.wikipedia.org/wiki/List_of_submarine_topographical_features#List_of_oceanic_trenches) north of Litke but deeper than 5073 m. There are a few intermediate trenches in the list that could have been in the running. The most promising: Kuril–Kamchatka Trench 47.5N 10,542 m depth 6356.09 km radius at depth South Sandwich Trench 55.42S 8,428 m depth 6355.249 radius at depth So quite a lot better than Challenger Deep, but not as deep as Litke. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [September 11, 2018, 5:53pm UTC](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779/45 "2018-09-11T17:53:49Z")
> [@Geekausaurus](#): > > The closest point is not necessarily the deepest point since earth is an oblate spheroid, first reported by Sir Isaac Newton. First _theorized_ by Newton. It wasn’t actually [shown](https://en.wikipedia.org/wiki/French_Geodesic_Mission) until a few hundred years later. [Previous page](https://boards.straightdope.com/t/closest-point-to-the-earths-centre/700779.md?page=2)