# A submarine, an ice cap, a question.

**URL:** <https://boards.straightdope.com/t/a-submarine-an-ice-cap-a-question/438839>\
**Category:** Factual Questions\
**Created:** [February 23, 2008, 11:55am UTC](https://boards.straightdope.com/t/a-submarine-an-ice-cap-a-question/438839 "2008-02-23T11:55:54Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![motomoon](https://avatars.discourse-cdn.com/v4/letter/m/a9adbd/32.png) [@motomoon](https://boards.straightdope.com/u/motomoon)\
**Post date:** [February 23, 2008, 11:55am UTC](https://boards.straightdope.com/t/a-submarine-an-ice-cap-a-question/438839/1 "2008-02-23T11:55:54Z")

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If a submarine was under a thick ice cap and _really_ needed a hole punched in the ice above, could it fire a torpedo to do the trick? How thick of ice can a submarine handle?

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**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\
**Post date:** [February 23, 2008, 12:26pm UTC](https://boards.straightdope.com/t/a-submarine-an-ice-cap-a-question/438839/2 "2008-02-23T12:26:47Z")

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How thick? [This page](http://ice-glaces.ec.gc.ca/App/WsvPageDsp.cfm?ID=11703) indicates that ice thickness is less than 3 metres, but that’s around Canada; [this article](http://news.bbc.co.uk/1/hi/england/devon/7046366.stm) indicates that we don’t really know how deep the ice is. I don’t know if even the 300 kg in a [Spearfish torpedo](http://en.wikipedia.org/wiki/Spearfish_torpedo) could break through 3 metres of ice: ice is pretty tough.

Of course, a torpedo with a nuclear warhead should do the job easily.

Fortunately **casdave** and **robby** should be along shortly.

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**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\
**Post date:** [February 23, 2008, 12:47pm UTC](https://boards.straightdope.com/t/a-submarine-an-ice-cap-a-question/438839/3 "2008-02-23T12:47:09Z")

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\<channeling mraru\>

You can fire a torpedo at an ice cap from underneath … if you want to kill yourself [hydrostatic shock is a bitch]

The current break record for 18 feet of icepack is held by the San Juan SSN 751, however whenever a sub is under ice, it tracks the location of polyanas [areas where the icepack has melted for one reason or another] so the breakthrough points are known.