Páll says that it is obvious that Eyjafjallajökull and Katla are connected. These siblings sit side by side and influence each other, although Katla is much more dangerous.
Good to have a natives input. It seems I've made many misstakes and I'm not sure I understood you right...
Should it be: "Páll says that it clearly looks like Eyjafjallajokull and Katla are connected. These siblings sit side by side and they influence each other, although Katla is much more dangerous."
juhlstein/ Lilian, I guess I've got it wrong... sorry.
What about to write: "Páll says there's a posibility that Eyjafjallajokull and Katla are connected. These siblings sit side by side and they influence each other, although Katla is much more dangerous."
Or maybe (to highlight the doubt): "Páll points out, Eyjafjallajokull and Katla may be connected. These siblings sit side by side and they influence each other, although Katla is much more dangerous"
I would go for : Páll says that it is obvious that Eyjafjallajökull and Katla are connected. These siblings sit side by side and influence each other, although Katla is much more dangerous.