VOLCANOES AND THEIR IMPACTS
                                                                                        BY:DJ

HERE IS SOME VOLCANOES AND THEIR IMPACTS ON SEVERAL PLACES
 

WHEN MOUNT SAINT HELENS ERUPTED LAVA  DIDN'T RUN DOWN ITS BACK OR SIDES.
MOST PEOPLE PRECIEVE VOLCANOES AS THEY ARE PORTRAYED BY THE MEDIA WHILE AS OTHERS WHO LIVE NEER VOLCANOES SAY THE CAN BRING LIFE AND PURGE THE WORLD.HAWAII IS KNOWN FOR ITS MANY VOLCANOES. THE ERUPTIONS IN HAWAII ARE ALSO KNOWN AS HAWAIIN VOLCANISM  THESE ERUPTIONS ARE LESS DANGERUOS THAN THOSE ON MOUNT SAINT HELENS. IT' VERY IMPORTANT TO KNOW THE KIND OF VOLCANOE AND TO SEE WHAT KIND OF ERUPTIONS IT CAN PRODUCE.
 

THERE IS TWO CATEGORIES A VOLCANOE CAN BE CLASSIFIED AS. THERE ARE THE EXPLOSIVE ONES SUCH AS  MOUNT ST. HELENS FOR INSTANCE  AND THERE ARE EFUSIVE SUCH AS THOSE IN HAWAII FOR STARTERS. THE MOST ACTIVE VOLCANOE IN ALL OF THE WORLD IS KILAUEA MOUNTAIN ON YOU GUESSED IT HAWAII. KILAUEA IS GENERALLY SUPPOSED TO BE A NON EXPLOSIVE VOLCANOE. ALTHOUGH KILAUEA HAS BEEN KNOWN TO HAVE PRODUCED SOME EXPLOSIVE ERUPTIONS. THERE IS ANOTHER TYPE OF NON EXPLOSIVE ERUPTION KNOWN AS "FLOOD BASALTS"  LAVA FLOWS OUT THROUGH  FISSURES AND COVER LARGE AREAS IN MY OPINION CAN PROVE TO BE VERY DESTRUCTIVE.
 

GENERALY MOST ERUPTIONS IN NATURE ARE MOSTLY EXPLOSIVE. THEY ARE CAPABLE OF PRODUCING FRAGMENTAL ROCKS VIA ERUPTING LAVA AND SURROUNDING ROCK {COUNTRY}. SOME BUT NOT ALL ERUPTIONS ARE HIGHLY EXPLOSIVE AND ARE CAPABLE OF PRODUCING  FINE VOLCANIC ASH THAT RISES IN COLUMNS HIGH INTO THE ATMOSPHERE. WIDE SPREAD ASH FALL , PYROCLASTIC FLOWS' DEBRIS AVALANCHES AND ETC... ARE THE PRODUCT OF EXPLOSIVE ACTIVITY IN VOLCANOES.
                                                              VOLCANIC HAZARDS

THIS IS A PARAGRAPH ON THE HAZARDS OF VOLCANOES. A VOLCANIC HAZARD IN OTHER WORDS IS THE PROBABILITY THAT AREA OR CITE WILL BE AFFECTED. ONLY SOME AREAS ARE AT HIGER RISK THAN OTHERS. A HOUSE BUILT ON A SUMMIT OR A CLIFF WILL BE IN THE SAME RISK RANGE AS A HOUSE BUILT IN A VALLEY 60KM FROM THE VOLCANOE. TILLING AND LIPMAN PRODICT 500 MILLION PEOPLE WILL BE AT RISK FROM A VOLCANOE HAZARD BY THE YEAR 2000. HERE IS A GOOD LINK IF YOU ARE MORE INTRESTED WWW.GEO.MTU.EDU/VOLCANOES/HAZARDS/PRIMER
 

                                                          CAUSES OF VOLCANOES
DEEP WITHIN THE EARTH THERE ARE ROCKS SLOWY BUT SURELY MELT AWAY.THEN THOSE MELTED ROCKS BECOME MAGMA. BECAUSE MAGMA IS LIGHTER THAN THE SURROUNDING ROCKS IT RISES AND COLLECTS IN MAGMA CHAMBERS.EVENTUALLY THE IS PUSHED THROUGH A FISSURE IN THE EARTH'S SURFACE OR A VENT.AND THEN AN ERUPTION OF THE VOLCANIC KIND OCCURS. FOR MORE INFORMATION YOU CAN GO TO HTTP://VULCAN.WR.USGS.GOV/OUTREACH/ABOUTVOLCANOES/HOW_DO_VOLCANOES_ERUPT.HTML

                                                     SIGNS OF ERUPTIONS
I BET YOU DIDN'T KNOW EXPLOSIVE ERUPTIONS COULD OCCUR WITH OUT WARNING BUT SOME PREMONITARY  ARE MORE LIKELY TO PROCEDE THE NEXT ERUPTION. STEAM BLASTS CAN OCCUR WITH LITTLE OR NO WARNING AS SUPER HEATED WATER FLASHES TO STEAM. MAGMATIC ERUPTIONS INVOLVE THE RISE OF MAGMA TO THE SURFACE. SUCH AN UPWARD MOVEMENT CAN CAUSE DETECTABLE EARTHQUAKES AND DEFORM THE SURFACE.MAGMATIC ERUPTIONS CAN ALSO CAUSE ANOMALUS HEAT FLOW OR CHANGES IN THE TEMPERATURE AND CHEMISTRY OF THE GROUND AND SPRING WATERS. FOR MORE INFORMATION YOU CAN GO TO HTTP://VULCAM.WR.USGS.GOV/OUTREACH/ABOUTVOLCANOES/WHEN_WILL_A_VOLCANO_ERUPT.HTML

                                                     MOUNT VESUVIUS
MNT.VESUVIOUS IS THE VOLCANOE THAT DESTROYED IN 1631 DESTROYED POMPEII.VESUVIOUS IS SURROUNDED BY A LOT OF PEOPLE WHO ARE IN DANGER BECAUSE IT'S PREPPING FOR IT'S NEXT ERUPTIONS. VESUVIOUS'S NEXT ERUPTION IS GONNA BE A REAL HUMAN CATASTROPHE. THERE ARE SOME OBSTACLES HOWEVER  WHICH WILL IMPEDE ANY ATTEMPT TO AVERT THIS TRADEGY FROM HAPPENING.

VESUVIUS IS AVERY COMPLEX VOLCANO.VESUVIUS IS KNOWN AS A STRATOVOLCANO. THE 79 B.C. ERUPTION WAS THE FIRST  OF ITS KIND TO BE DESCRIBED IN DETAIL.PLINY THE YOUNGER WITTNESSED THIS ERUPTION AND RECORDED IT IN ONE OF HIS LETTERS.HE DESCRIBED THE EARTHQUAKES THAT PROCEDE THE ERUPTION, THE ERUPTION COLUMN,THE EFFECTS OF THERUPTION ON THE POPULUS THE PYROCLASTIC FLOWS AND THE TSUNAMI IT CAUSED!
 

                                                  MOUNT ST. HELENS
ST. HELENS FIRST RECORDED OBSERVATION WAS BY GEORGE VANCOUVER HE WAS CHARTING AN ISLAND VERY CLOSE TO MODERN DAY SEATTLE ON MAY 19,1792. A FEW YEARS AFTERWARD MOUNT ST. HELENS EXPERIENCE A  RATHER SEVERE ERUPTION.ALL KINDS OF DIFFERENT PEOPLE HEARD OF THIS ERUPTION FROM PEOPLE INCLUDING THE SANPOIL INDIANS OFC EASTERN WASHINGTON. LATER OBSERVATIONS CONCLUDED THE ERUPTION OCCURED IN 1800. EVEN LEWIS AND CLARK THE EARLY EXPLORERS SIGHTED ST.HELENS IN 1805 AND 1806 BUT REPORTED NO VOLCANIC ACTIVITY.

A PHYSICIAN AT FORT VANCOUVER NAMED MEREDITH GAIRDNER DESCRIBED THE DARKNESS AND THE HAZE DURING POSIBLE VOLCANIC OR ERUPTIVE ACTIVITY. HE REPORTED TO SEE "LAVA FLOWS" WHICH CUOLD HAVE POSSIBLY HAVE BEEN MUDFLOWS OR PYROCLASTIC FLOWS OF INCANDESENT ROCKS.ON NOVEMBER  22 OF 1842 A REVERAND BY THE NAME OF JOSSIAH PERISH IN OREGAN WITNESSED MT.ST.HELENS ERUPT.THE ASH FALLOUT FROM THE ERUPTION REACHED THE DALLES IN OREGON.MISSIONARIES AT THE DALLES CORROBORATED PARISHES ACCOUNT.