ancient ice

• glacierSlow-moving ice mass
• permafrostPerpetually frozen earth layer
• frozenSolidified by extreme cold
• prehistoricBefore documented civilization
• coreCentral essential portion

tundra · mammoth · ice age · millennia · Arctic · Antarctic · pristine · crystals · preserved · eternal · drilling · layers · climate · samples · bubbles · trapped · melt · primordial

• cometscomet, Halley's Comet, comet tail, Hale-Bopp, dirty snowball