alert vs ear to the ground

alert

noun
  • A notification of higher importance than an advisory. 

  • An alarm. 

  • A state of readiness for potential combat. 

adj
  • Attentive; awake; on guard. 

verb
  • To give warning to. 

ear to the ground

noun
  • The practice or characteristic of carefully gathering information; a state or mindset of attentiveness. 

  • Pursuing the practice or having the characteristic of carefully gathering information; well-informed. 

How often have the words alert and ear to the ground occurred in a corpus of books? (source: Google Ngram Viewer )