glacier - n. a very large area of ice that moves slowly down a slope or valley or over a wide area of land

hydroelectric - adj. of or relating to production of electricity by waterpower

rush - v. to move very quickly

evacuate - v. to remove (someone) from a dangerous place

muddy - adj. filled or covered with mud (soft, wet dirt)

layer - n. a covering piece of material or a part that lies over or under another

advance - v. to move forward

seismic - adj. of, relating to, or caused by an earthquake

dramatically - adv. sudden and extreme

due to - adj. because of

instability - n. the state of being likely to change

region - n. a part of a country, of the world, etc., that is different or separate from other parts in some way