Below is my favorite song about an earthquake. Its actually the only earthquake song that I know of. Let me know if you know of any others.
Uncle Tupelo - New Madrid.mp3
From: Old Town Music School Fest, Chicago, IL, USA, July 25, 1999
The song "New Madrid" is about the New Madrid seismic zone in southern Missouri, and if it ever moves like the Enriquillo-Plantain Garden Fault that demolished Port-au-Prince, the entire central US is fucked.
One more track here about Haiti. Régine Chassagne of the Arcade Fire is of Haitian descent. Her parents immigrated to Canada in the 1970s to escape the totalitarian reign of then "president for life" Jean-Paul Duvalier.
Arcade Fire - Haiti.mp3
Buy: Funeral (2004)
Lots of great humanitarian organizations are helping the relief effort in Haiti. I just donated to Doctors Without Borders/Médecins Sans Frontières (MSF). Others are donating to the Red Cross, OXFAM, and Google Crisis Response has a page of information on how you can help.