Why do you say (a) "En Santa Marta no hay aeropuerto" instead of (b) "En Santa Marta no hay ningún aeropuerto," or is the latter correct as well?
In fact, one would most often say (a) En Santa Marta no hay aeropuerto.
However, it would be natural to include "ningún/ninguna" in cases that require emphasis. For example, let's say two travel agents are arguing about whether Santa Marta has one airport or two. Let's imagine now that a native of Santa Marta happens to be visiting their office, and is sitting waiting his turn to speak with Travel Agent #3. This visitor might correct them by saying
Yo soy de Santa Marta, y les puedo asegurar que en Santa Marta no hay ningún aeropuerto.
(I'm from Santa Marta, myself, and I can assure you that there are no airports in Santa Marta.)
The most common uses of ningún/ninguno/ninguna are a bit different from your sentences:
Ningún hotel en esta calle te cobrará muy caro. Todos son buenos y económicos. No dudes en quedarte en cualquiera de ellos.
(No hotel in this block will charge you an arm and a leg. They are all nice hotels, economically priced. I can recommend any of them to you without hesitation.)
Ninguno te dirá otra cosa.
(No one will tell you otherwise.)
En Santa Marta no hay aeropuertovs
En Santa Marta no hay ningún aeropuerto, the meaning is basically the same, only that the second is a little bit more stressed. So the person who says it either wants to make it perfectly clear that there are no airports in Santa Marta or it's a strong reply to someone stating otherwise.