It's impossible to answer that question without knowing which Icelandic volcano you're referring to. Iceland has many active volcanoes, and their impacts can vary significantly depending on the eruption's size, location, and type.

To help me give you a more accurate answer, please tell me:

* Which specific volcano are you asking about? (e.g., Mount Hekla, Grímsvötn, Fagradalsfjall)

* What kind of effects are you interested in? (e.g., air travel disruptions, ash fall, climate change, tourism)

Once I have this information, I can provide you with a more informed response.