Earth's Crust
noun, の adjective
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.
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 archipelago is entering a once-in-a-millennium period of significant tectonic upheaval.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.