BTM I don't know about a fault, but I did read that this is unusual for that area.
Something is going on below the surface of the earth that not one of us, including the scientists, are aware of. I think the entire structure, and underlying foundation of the planet is shifting. I believe the Indonesia area is the main eruption area for what is like a big infection. Soon we will have others areas with major eruptions (earthquakes - volcanoes) when the infection hits a critical point.