Noun and の adjective
ちかく
日本列島は、千年に一度の大地殻変動期に突入しています。
The Japanese islands appeared after thousands of years of deformation of the Earth’s crust.
The earth's shell is called the earth's crust. You should have learned that in earth science. And if you didn't, at least you know now!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.