1. VOLCANOES BY DIANA &NATALIE

2. HOT SPOT VOLCANOES  IT IS AN AREA WHERE MATIREAL FROM DEEP WITHIN THE MANTLE RISES AND THEN MELTS,FORMING MAGMA.  A VOLCANO FORMS ABOVE A HOT SPOT WHEN MAGMA ERUPTS THROUGH THE CRUST AND REACHES THE SURFACE.

3. A VOLCANIC ERUPTION WHEN A VOLCANO ERUPTS,THE FORCE OF THE EXPANDING GASES PUSHES MAGMA FROM THE MAGMA CHAMBER THROUGH THE PIPE UNTIL IT FLOWS OR EXPLODES OUT OF THE VENT. WHEN A VOLCANO ERUPTS,THE FORCE OF THE EXPANDING GASES PUSHES MAGMA FROM THE MAGMA CHAMBER THROUGH THE PIPE UNTIL IT FLOWS OR EXPLODES OUT OF THE VENT. AS MAGMA RISES TOWARD THE SURFACE, THE PRESSURE OF THE SURROUNDING ROCK ON THE MAGMA DECREASES.THE DISSOLVE GASES BEGIN TO EXPAND FORMING BUBBLES. AS MAGMA RISES TOWARD THE SURFACE, THE PRESSURE OF THE SURROUNDING ROCK ON THE MAGMA DECREASES.THE DISSOLVE GASES BEGIN TO EXPAND FORMING BUBBLES.

4. QUIET ERUPTIONS  A VOLCANO ERUPTS QUIETLY IF ITS MAGMA IS LOW IN SILCIA.  QUIET ERUPTIONS CAN PRODUCE TWO DIFFERENT TYPES OF LAVA THAT DIFFER IN TEMPERATURE.  ONE OF THE VOLCANOES THAT ERUPTS QUIETLY IS THE HAWAIIAN ISLANDS.

5. EXPOLSIVE ERUPTIONS  A VOLCANO ERUPTS EXPLOSIVELY IF ITS MAGMA IS HIGH IN SILCIA. SILCIA.  AN EXPLOSIVE ERUPTIONS BREAKS LAVA INTO FRAGMENTS THAT QUICKLY COOL AND HARDEN INTO PIECES OF DIFFERENT SIZES.  THE SMALLEST PIECES ARE VOLCANIC ASH –FINE ROCKY PARTICLES AS SMALL AS A SPECK OF DUST.

6. LIFE CYCLE OF VOLCANO  GEOLOGISTS OFTEN USE THE TERMS ACTIVE DORMANT OR INSTINCT TO DISCRIBE A VOLCANO STAGE OF ACTIVITY.  IN CALIFORNIA A LASSEN PEAK AND MOUNT. SHASTA ARE CONSIDERED ACTIVE VOLCANOES

7. SHIELD VOLCANOES  SUCH LAVA FLOWS GRADUALLY BUILD A WIDE, GENTLY SLOPING MOUNTAIN CALLED SHEILD VOLCANO.  SHEILD VOLCANOES CREATED THE HAWAIIAN ISLANDS AND THE MEDICINE LAKE VOLCANO IN NORTHERN CALIFORNIA.

8. CINDER CONE VOLCANOES CINDER CONE VOLCANOES  IF A VOLCANO’S LAVA IS HIGH IN SILICA, IT MAY PRODUCE ASH, CINDERS AND BOMBS.  THESE MATERIALS BUILD UP AROUND THE VENT IN A STEEP, CONE SHAPED HILL OR SMALL MOUTAIN CALLED A CINDER CONE.

9. COMPOSITE VOLCANOES  SOMETIMES LAVA FLOWS ALTERNATE WITH EXPLOSIVE ERUPTIONS OF ASH CINDER AND BOMBS.  THE RESULT IS A COMPOSITE VOLCANO.  COMPOSITE VOLCANOES ARE TALL, CONE SHAPED MOUNTAINS IN WHICH LAYERS OF LAVA ATERNATE WITH LAYERS OF ASH.

10. THE END MUHAHAHAHAHA THE END MUHAHAHAHAHA