Unfortunately I just read an article that answers my question.
A whale expert in the Bahamas is linking beachings to ear damage
caused by U.S. Navy sonar. 
Coincidently a live whale was in the process of trying to beach
itself directly in front of Ken Bocomb's home. He runs 
Earthwatch. He was a Sonar expert when he was in the Navy in the
70's and is an expert on both sonar and whales.

This may explain the unprecidented number of whale beachings
along the Pacific coast, and area where sonar testing has been 
done extensively in the past year.