24 Volcanoes have a positive service function by a Replenishing soil with nutrients b Lava flows creating ghost forests for us to marvel Allowing fluorine in water that is ultimately good for our teeth Volcanoes serve no positive function just ask the people at Pompeii d 25 A lahar can best be described as Flow of gas and hot ash Hot lava flow moving very fast A flow of hot mud with the consistency of wet cement d A rain of volcanic ash whose weight can cause roofs to collapse 26 Shield cones are most likely to form from Effusive eruptions from a central vent b Explosive eruptions from a central vent C Culminating pyroclastic eruptions d Lahars 27 Calderas form when A fissure C a b C erupt happens b Mafic magmas are heavy and sink Magma chamber empties and volcanic edifice collapses Lava flows are greater than pyroclastic flows during an eruptive episode a a C C d a 28 The distance inland that a tsunami travels is known as A local tsunami event b A distant tsunami event a Tsunami run up d Hydraulic displacement 29 A normal fault occurs as a result of Tensional stress the hanging wall moves down relative to the foot wall b Tensional stress the hanging wall move relative to the footwall c Compressive stress the hanging wall moves down relative to the footwal d Compressive stress the hanging wall move up relative to the footwall