Editing v0.34:Glacier

{{Quality|Exceptional|15:49, 12 May 2013 (UTC)}}
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'''Glaciers''' are extremely cold [[biome]]s, usually found in the northern or southern extremes on larger world maps. The first few layers of any glacier are solid [[ice]].

There are few resources on an ice tile; no [[tree]]s, [[plant]]s, [[water]], [[animal]]s, [[stone]], or [[ore]]s are typically included. In addition, the [[ice]] can be several z-layers thick, which can make getting to any stone underneath even more challenging.

Due to being freezing and lacking of soil layers, above ground seeds cannot be used, meaning that all farming must be done underground.

These factors make a glacier a very difficult biome to build a successful [[fortress]] in, although many players try it as a challenge. 

Also, because of a glacier's isolation (generally), it is entirely possible that you won't see a caravan from the Mountainhomes for anywhere up to 3 years. Migrants may be even more rare. On the plus side, though, no hostile nations should bother you for a while.

== Starting on a Glacier ==

Take a lot of wood, food and drink. Consider bringing extra [[domestic animal]]s ([[dog]]s are recommended) as an emergency food source, and/or to jump-start a long-term [[breeding]] program.

Dump your wood cutter and axe in favour of another miner and pick. Alternatively, find a glacier near a forested taiga and enjoy the best of both worlds.

Trading is '''essential'''. An easy source of income is rock crafts. All that rock you cut out making wells and farms you can sell to merchants who visit.  Begin as soon as you can because you need to import a lot of wood if you plan on having beds or fuel for making metal objects.

[[Ice]] is everywhere, so read up on it before you make any major plans. One difference between regular ice and glacier ice that you may want to know before you head out is that, unlike ice from other biomes, glacier ice constructions and workshops do not melt when above ground in the "summer".  The disadvantage, however, is that it is more difficult to use the ice as a potential water source.  Note that mined out chunks of ice, when melted by being brought underground, will '''not''' produce usable water. {{Bug|360}}

=== Digging down to the rock layers ===

Due to a bug, down-[[stair]]s and up-down-stairs can't be carved out of ice if the layer immediately below the ice is stone. {{Bug|358}} This makes it impossible to get from the surface down to the stone layers using only stairs.  Instead, use [[ramp]]s.

You can, however, construct ice up-down stairs from above after the carved up-down stairs have melted.

=== Farming and getting water ===

Since glaciers contain no [[soil]] layers you have to use [[irrigation]] in order to [[farm]], and that requires [[water]], which isn't to be found on the surface of a glacier.  Also, water is needed at [[hospital]]s for cleaning and to give the wounded something to drink.  There are two ways to get water on a glacier.

==== Underground pools ====

All regions of the world have vast underground [[caverns]] (unless the world was [[world generation|generated]] without them), and caverns almost always have large pools of water.  Further, if the pool abuts the edge of your embark area, new water will fill in from the edge, giving you an infinite source of water.  On the down side, it can take a while to find the caverns, since digging straight down isn't guaranteed to breach them, and there's a small chance of aquatic monster escaping from the cavern.

To safely (without having to wander around inside the cavern) tap into an underground pool, consider the following diagram:

{{diagram|spaces=yes|\
WWWWWWWWW
▓▓▓▓X▓▓▓▓
▓▓▓▓B▓▓▓▓
▓▓▓▓.▓▓▓▓
▓▓▓▓.▓▓▓▓
▓S......▓
▓.......▓
▓.......▓
▓.......▓
▓.......▓
▓F▓▓▓▓▓▓▓
}}

* W = water
* ▓ = stone wall
* X = last wall to dig out
* B = floor with [[floodgate]] or [[bridge|drawbridge]]
* F = wall or optional floor with floodgate (for [[irrigation]])
* . = floor with optional paved [[road]]
* S = up stairs or ramp

Then do the following steps:

# Dig down to the same level as the pool (not to the surface of the pool) and dig out the reservoir (rectangular region) with stairs (or ramp) leading out.   
# If you're going to use the reservoir for [[irrigation]] then dig an outlet from the reservoir at the F, install a floodgate at its mouth, and hook it up to a [[lever]].
# Dig a tunnel to the pool, leaving one tile's worth of stone between the tunnel and the water (the X in the diagram).
# Install a [[floodgate]] or a south-raising [[bridge|drawbridge]] at the end of the tunnel and hook it up to a lever.
# Have a dwarf dig out the X.

The dwarf who dug the X should be able to get back to the stairs/ramp in time to not [[swimming|drown]].  To make extra sure of not drowning, ensure at least one dwarf is idling and have him/her pull the lever to the floodgate/drawbridge as soon as the wall is breached, then lower it again to let the reservoir fill.  To make extra, ''extra'' sure, embark with a dwarf with a single point in the [[swimming]] skill, and have him/her carve the fortification.

Use a drawbridge instead of a floodgate at the end of the tunnel to prevent [[building destroyer]] aquatic/amphibious monsters from swimming into the reservoir and enter the rest of your fortress.  A floodgate wouldn't stop a building destroyer, and monsters can swim through fully submerged [[fortification]]s. {{Bug|3327}}  If you're going to use this reservoir for a [[well]] then closing off it off with a drawbridge is very important, since some building destroyers can swim ''and'' fly.  If you're only going to use it for irrigation then you can use a floodgate and then simply [[wall]] off the reservoir once you're done with it, since building destroyers can't affect walls.

If you're going to use the reservoir for a well you should cover its floor with a paved [[road]] to prevent [[tree]]s from growing, because in some circumstances trees can grow underwater. {{Bug|1139}}

==== Cave-in some ice ====

This may not work, beware.

One quirk of [[dwarven physics]] is that a [[cave-in]] will transform an ice [[wall]] into liquid water.  This can be used to generate water in the following fashion:

To begin, it is best to clear out a large section of the rock underneath all the ice.  Then cut out a 6x6 section of ice (it is easiest to cut out two squares around the part you want to drop so that you won't have any fatalities while channeling out the section of ice).  Channel out the entire piece of ice and it will fall into that cleared out section, immediately defrosting and flooding the area.  Now you can farm!

Before you run out of starting booze, do the same again, but this time do it further away and open 3-4 levels of rock (channel everything away) so that you create a well.  Make sure you make it deep enough or you will create an ice zone that will kill any dwarf that tries to dig it out.  

Continue to cut out chunks of ice, dropping them a few stories, and reaping the benefits as you continue in the fortress.  Be careful channeling as the dwarves are all idiots and like to strand themselves while channeling, and they like to drop their buddies down the hole (which pollutes the future water and creates a huge mess).

Diagram of Ice cutting:

{{diagram|spaces=yes|\
OOOOOOOOOO
OCCCCCCCCO
OCIIIIIICO
OCIIIIIICO
OCIIIIIICO
OCIIIIIICO
OCIIIIIICO
OCIIIIIICO
OCCCCCCCCO
OOOOOOOOOO
}}

O = Open area, no channeling, just an area for dwarves to walk

C = Channel area, first dig it out, then channel once every layer is ready.

I = Future water source, now ice.

Once you have dug deep enough to see rock, channel out the entire level (make sure you have an escape route for the miner).  Also, when channeling a large room, do it layer by layer.  Start at the one end and do the entire left side, then the next.  If you just select the entire thing dwarves will die.

Don't drop water anywhere near other tunnels; the ice will break through, and it will be messy.  You can cut off entire sections of fortress to flooding or caved-in sections by doing this, and it wastes a lot of work and ice.

== Wildlife ==

'''On neutral glaciers appear:'''

* [[Polar bear]]
* [[Yeti]]
* [[Weasel]]

'''On evil glaciers appear:'''

* [[Blizzard man]]
* [[Ice wolf]]

== Some Hints and Ideas ==

Flowing sources of [[water]], such as [[river]]s or [[brook]]s, don't ever seem to be present in glacier [[biome]]s.  So getting [[water]] for wounded dwarves early on may prove a challenge.  Usable water may be present in the underground [[cavern]]s.

Ice that is underground melts, but creates only useless puddles of water (marked as a cyan double tilde) identical to water dumped from a [[bucket]].  These puddles can only be cleaned.  They cannot form usable water (blue tilde with depth attribute).  Dumping block after block of mined ice blocks indoors will simply result in a huge stack of useless "water".

[[Aquifer]]s are sometimes present, and magma can be used to melt ice - if that's present. Seaside glaciers can allow you to bring some water in underground, but [[Water#Salt_Water|desalinating]] the water will be necessary before it is drinkable by dwarves (or even before it can be designated as a [[Activity_zone#Water_Source|water zone]] for filling ponds).

Glaciers are very unlikely to have a source of [[shell]]s.  Thus, you may want to mod the game so that some other material can be used in place of shells for the occasional [[strange mood]]s which call for them; see [[Shell]] for details.

Some glacier biomes have such low temperatures that your dwarves and animals may die if exposed aboveground for too long.

Water in [[bucket]]s does not freeze above ground so you can designate an area as a pool, tell dwarfs to fill it, then smooth and engrave your new ice fort.

{{World|Biomes}}