kelp vs wrack

kelp

noun
  • Any of several large brown algae seaweeds (order Laminariales). 

  • The calcined ashes of seaweed, formerly used in glass and iodine manufacture. 

verb
  • To gather kelp. 

wrack

noun
  • Any marine vegetation cast up on shore, especially seaweed of the family Fucaceae. 

  • The remains; a wreck. 

  • A high flying cloud; a rack. 

  • Weeds, vegetation or rubbish floating on a river or pond. 

verb
  • To execute vengeance; avenge. 

  • To wreck, especially a ship. 

  • To worry; tease; torment. 

How often have the words kelp and wrack occurred in a corpus of books? (source: Google Ngram Viewer )