Complex sentence: On Great Bakkungan Island, gray mud quietly flows from the vent in a pulsating manner accompanied by gas bubbling, while on Boan Island, mud extrusion have already ceased for a number of years.
Split into simpler sentences: On Great Bakkungan Island, gray mud quietly flows from the vent in a pulsating manner accompanied by gas bubbling. On Boan Island, mud extrusion have ceased for a number of years.