The origins of Hurricane Ismael were from a northward bulge of the Intertropical Convergence Zone ( ITCZ ) in early August , which resulted in Causation the formation Coming_to_be of a tropical depression on August 8 .

The eruption Catastrophe was preceded Process_start by a two-month series of earthquakes Catastrophe and steam-venting episodes , caused Causation by an injection Motion of magma at shallow depth below the volcano that created Creating a large bulge and a fracture system on the mountain 's north slope .