Boat gas on pontoon boat carpet

[Little Bear]

I had a gas tank erupt on the stern of my pontoon boat. I closed the vent prior to Irene's arrival, and left it closed while I was gone. When I returned I found that the tank had apparently erupted due to heat, which spewed gas all over the carpet on the stern.

It's discolored the carpet some, but the smell is really bad. Any ideas on how to remove this smell other than time and air?