# The structural integrity of islands without the surrounding water **URL:** \ **Category:** Factual Questions\ **Created:** [October 25, 2012, 7:32pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857 "2012-10-25T19:32:37Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [October 26, 2012, 3:39pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/21 "2012-10-26T15:39:56Z")
> [@wheresmymind](#): > > This. Here is a relevant [XKCD](http://xkcd.com/1040/large/), note the inset that shows Mauna Kea and the Marianas Trench with true horizontal scale. While Hawaii looks like a precipitous mountain jutting up from the sea floor on most maps/globes it’s actually more like a wide, gently sloping hill. Most islands will have similar, if not flatter profiles. Wow! Is this picture accurate? The Wikipedia article on the Deepwater Horizon says it only went to 10 685 m. But it makes me wonder, if we can drill to that deep, why can’t we dive that deep easily? And what’s that bit about Freddie Mercury? ---
**Author:** ![leahcim](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@leahcim](https://boards.straightdope.com/u/leahcim)\ **Post date:** [October 26, 2012, 3:44pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/22 "2012-10-26T15:44:58Z")
> [@AaronX](#): > > And what’s that bit about Freddie Mercury? Him and David Bowie are… …Under Pressure ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [October 26, 2012, 3:49pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/23 "2012-10-26T15:49:50Z")
> [@leahcim](#): > > Him and David Bowie are… > > …Under Pressure Goddammit, I’ve got that cartoon as [a large poster](http://store.xkcd.com/), and I have the song on my iPod - and I never made the connection. :smack: ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [October 26, 2012, 3:52pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/24 "2012-10-26T15:52:57Z")
> [@AaronX](#): > > Wow! Is this picture accurate? The Wikipedia article on the Deepwater Horizon says it only went to 10 685 m. But it makes me wonder, if we can drill to that deep, why can’t we dive that deep easily? It’s not terribly hard to dangle a drill bit that deep in the water; it’s much more difficult to build a large, hollow vessel that doesn’t implode when exposed to several thousand psi of water pressure on its hull. It’s been done, but not for practical purposes. In other words: possible, but not profitable. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [October 26, 2012, 3:55pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/25 "2012-10-26T15:55:22Z")
Aww, I thought they were buried at that depth. My current practical dream burial is to have my cremated remains sealed in a tungsten tube and dropped over the Marianas Trench. The impractical one is shot into a black hole. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [October 26, 2012, 3:59pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/26 "2012-10-26T15:59:19Z")
> [@Machine\_Elf](#): > > It’s not terribly hard to dangle a drill bit that deep in the water; It’s not? I’ve heard that that depth, the drill bit is like a strand of spaghetti. Or was that an analogy for something else? Hmm… ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [October 26, 2012, 4:49pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/27 "2012-10-26T16:49:50Z")
> [@AaronX](#): > > Wow! Is this picture accurate? The Wikipedia article on the Deepwater Horizon says it only went to 10 685 m. The cartoon depicts a bore hole roughly 10,500 meters long starting from the bottom of the ocean (which in turn is roughly 1500 meters below the surface of the ocean). That’s fairly close to reality. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [October 26, 2012, 5:26pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/28 "2012-10-26T17:26:35Z")
> [@Chronos](#): > > A glance at that xkcd link will show that the slope gets a lot steeper, right at the waterline. This suggests that the buoyancy increases the stable angle of repose, and that if the water went away, it’d be carved down to the above-water slope everywhere. Perhaps that’s caused by higher erosion above the surface, or underwater growth (coral). I don’t know about Mauna Kea in particular, but I do know that for atolls, the mountain has long since eroded, and what remains is primarily coral growth on top, covered by residue from upslope erosion, plus whatever the local ecology adds. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [October 26, 2012, 5:30pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/29 "2012-10-26T17:30:38Z")
> [@AaronX](#): > > It’s not? I’ve heard that that depth, the drill bit is like a strand of spaghetti. Or was that an analogy for something else? Hmm… A steel rod that length would be like a strand of spaghetti, regardless of where it was – it doensn’t have to be underwater or under pressure. So it’s not THAT easy, but it’s certainly a lot more profitable than sending someone down there. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [October 26, 2012, 6:14pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/30 "2012-10-26T18:14:40Z")
RE: the XKCD cartoon. there’s an unlabelled white line below the gap between Titanic and Aircraft Carrier. Any idea what that is? ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [October 26, 2012, 6:23pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/31 "2012-10-26T18:23:23Z")
Bin Laden in a sheet? ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [October 26, 2012, 6:24pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/32 "2012-10-26T18:24:14Z")
> [@Peter\_Morris](#): > > RE: the XKCD cartoon. there’s an unlabelled white line below the gap between Titanic and Aircraft Carrier. Any idea what that is? Weird. That little line is not present on the full-size poster print. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [October 26, 2012, 7:33pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/33 "2012-10-26T19:33:30Z")
The water lapping at the shore of an island may be eroding it, but it is not holding it up. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [October 26, 2012, 8:48pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/34 "2012-10-26T20:48:28Z")
> [@Little\_Nemo](#): > > **A warning for people. I got a virus alert when I clicked on that link.** WTF?! I tried the same link again and still didn’t get any virus alerts, maybe it only happens with a particular AV because it was detected as a threat in the past (I have MSE). Either from the Google image link ([http://www.google.com/imgres](http://www.google.com/imgres)…) or the actual web site (a link to Google should be safe, shouldn’t it?). ---
**Author:** ![Moonlitherial](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@Moonlitherial](https://boards.straightdope.com/u/Moonlitherial)\ **Post date:** [October 26, 2012, 10:22pm UTC](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857/35 "2012-10-26T22:22:39Z")
> [@AaronX](#): > > Aww, I thought they were buried at that depth. That would be incredibly unpopular with David Bowie since he’s still alive. [Previous page](https://boards.straightdope.com/t/the-structural-integrity-of-islands-without-the-surrounding-water/638857.md?page=1)