| Question | Answer |
| active volcano | a volcano that currently vents lava or gases |
| dormant volcano | a volcano that is not currently erupting but is likely to erupt in the future |
| extinct volcano | a volcano that is no expected to erupt again |
| cinder cone volcano | a volcano that is composed of both solidified lava and pyroclastic materials |
| shiield cone volcano | huge, built mainly from lava, sloping sides |
| volcanic neck | solidified magma that originally filled the vent or neck of an ancient volcano and has been exposed eruption |
| lava dome | roughly circular mound shaped protrusion resulting from the slow extrusion of viscous lava from a volcano |
| lava | rock that in its molten form (magma) issues from volcanoes, lava is what magma is called when it reaches the surface |
| tephra | solid material thrown into the air by a volcanic eruption |
| aa lava | blackly basalt lava |
| pahoehoe lava | smooth unbroken lava |
| fissure eruption | volcanic eruption where lava wells up through fissures in the earth's crust |
| quiet eruptions | eruptions that are quiet |
| explosive eruption | volcanic term to describe a violent, explosive type of eruption |
| basalt plateau | an extensive, thick, smooth flow or succession of flows of high temperature, fluid basalt erupted from fissures, flooding topographic lows, and accumulated to form a plateau |
| crater | the cup shaped depression or cavity on the surface of the earth or other heavenly body marking the orifice of a volcano |
| vent | an opening, as in a wall, serving as an outlet for air, smoke, fumes |
| fumarole | a hole in or near a volcano, from which vapor rises |
| sill | a tabular body of intrusive igneous rock, ordinarily betweens beds of sedimentary rocks or layers of volcanic ejects |
| dike | a long narrow cross cutting mass of igneous rock intruded into a fissure in older rock |
| laccolith | see lopolith a dome shaped body of igneous rock between to layers of older sedimentary frock: formed by the intrusion of magma, forcing the overlying strata into the shape of a dome |
| dome mountain | magma cooled and hardened beneath the earth's surface to become later exposed |
| batholith | a large body of intrusive igneous rock believed to have crystallized at a considerable depth below the earth's surface; pluton |
| magma chamber | a reservoir of magma in the earth's crust where the magma may reside temporarily on its way from the upper mantle to the earth's surface |
| geyser | a hot spring that intermittently sends uup fountain ike jets of water and steam into the air |
| hot spring | a natural spring of mineral water found in areas of volcanic activity |
| viscosity | the property of a fluid that resists the force tending to cause the fluid to flow |
| granitic magma | a coarse grainded igneous rock |
| basaaltic magma | fluid rock material of basaltic origin |
| hot spot | (land and sea floors) under continents |
| hot spot volcano | region on the earth's surface that has experienced volcanism for a long time |
| what is a volcano | a volcano is a weak in the crust where moten material, or magma comes to the surface |
| a molten mixture of rock-forming substanses,gases, and water from the mantle is referred to as | magma |
| when magma reaches the surface, it is called | lava |
| what is the ring of fire | one major volcanic belt formed by many volcanos that rim the pacific ocean |
| where do most colvanoes form | colvanic belts form along thhe boundaries of earth's plate |
| descrive how volcanoes form along the mid-ocean ridges | lava pours out of the cracks on the ocean floor |
| true or false? volcanoes can form along diverging plate boundaries on land | true |
| true or false? many volcanoes form near converging plate boundaries where oceanic crust returs to the mantle | true |
| how does subduction at converging plate boundaries lead to the formation of volcanoes | volcanoes may form where tow oceanic plates collide or where an oceanic plate collides with a continental plate |
| volcanoes at boundaries where two oceanic plates collide creat a string of islands called an | island arc |
| what are three major island arcs | japan, new zealand, indonesia, philippines, aleutians, carribean islands |
| what types of plates collide to form the andes mountains on the west coast of south america | continental plate and an oceanic plate |
| what is a hot spot | an area where material from deep within the mantle rises and melts, forming magma |
| how did the hawaiian islands form | pacific plate drifited over a hot spot |
| true or false? hot spots form only under oceanic crust | false |
| a substance that cannot be broked down into other substances is called an | element |
| true or false? when forzed water melts, it is undergoing a physical change | true |
| the great the viscosity, the......a liquid flows. the....... the viscosity, the more easily a liquid flows | slower, lower |
| what liquids that have a relatively low viscosity | milk, orange juice |
| what factors determine the viscosity of magma | depends upon it's silica content and temprature |
| what is true about silica | it makes magma thicker, produces light-colored lava |
| the rock.....forms from light-colored lava | chyolite |
| low-silica magma forms rocks like | basalt |
| what happens to viscosity as temperature increases | hotter-lower, cooler-slower |
| hot, fast-moving lava is called | pahoehoe |
| cool, slow-moving lava is called | AA |
| true or false? magma forms in the lithosphere | false |
| true or false?liquid magma rises until it reaches the surface, or until it becomes trapped beneath layers or rock | true |
| what features do volcanoes share | pocket of magma beneath the surface, side vents, craters |
| what is lava flow | the area covered by lava as it purs out of a vent |
| where does a crater form | on the top of a volcano around central vent |
| true or false?the pipe of a volcano is a horizontal crack in the crust | false |
| how does a volcano erupt | carbon dioxide dissolved in soda pop rushes out when the pop is opened |
| what happens during a volcani eruption | dissolved gases are trapped in magma, then as magma rises toward the surface, the pressure of the surrounding rock of magma decreases |
| what factors determine the force of a volcanic eruption | expanding gases |
| true or false?a volcano erupts quietly if its magma is thick and sticky | false |
| volcanic ash | fine rocky particles as small as a speck of dust |
| cinders | pebble sized particles |
| bombs | particles ranging from the size of a baseball to the size of a car |
| what is pyroclastic flow | it is something that happens when an explosive eruption hurls out a mixture of hot gases ash cinders and bombs |
| true or false?volcanic eruptions cause damage only when they are close to the crater's rim | false |
| what kidns of damage can colvanoes cause | can bury everything in itsd paths and can cover large areas with lava, burty towns, bleach out hot clouds of deadly gases as well as ash cinders, and bombs |
| true or false?the activity of a volcano may last from less thatn a decade to more thann 10 million years | true |
| true or false?most long-lived volcanoes erupt continuously | false |
| extinct | unlikely to erupt ever again |
| active | erupting or showing signs that it soon will erupt |
| dormant | no longer active buy may become active again |
| rank the volcanic stages from least likely to erupt to most likely to erupt | extinct,dormant,active |
| true or false?the length of time beetween eruptions of a dormant volcano is always less thatn a thousand years | false |
| why might people living near a dormant volcano be unaware of the danger | because since it has erupted a long time ago they don't thing of it erupting again and hurting people and things |
| how can we predict eruptions | geologists are more successful in predicting volcanic eruptions than earthquakes, geologists cannot predict what type of eruption a volcano will produce |
| list four landforms created from lava and ash | sheild volcanos,cinder cone volcano, composite volcanos, lava plateaus |
| true or false?the hawaiian islands are cinder cone volcanoes | false |
| name two examples of composite volcanoes | mount fiji and mount st. helens |
| true or false?a composite volcano has both quiet and explosive eruptions | true |
| sheild volcano | gently sloping mountain formed by repeated lava flows |
| cinder cone | fone shaped mountain formed from ash, cinders, bombs |
| composite volcano | mountain formed by lava flows alternating withh explosive eruptions |
| lava plateau | high, level area formed by repeated lava flows |
| caldera | hole left by the collapse of a volcanic mountain |
| when volcanic ash breaks down, it realses.....and.....both of which are needed by plants | potassium, phosphurus |
| list five features formed by magma | volcanic necks, dikes, sills, batholiths,bome mountains |
| dikes are.. | across rocks |
| sill is... | inbetween rocks |
| a mass of rock formed when a large body of magma cools inside the crust is called | batholith |
| what is an example of a btholith in the united states | half done in yosemite national park |
| true or false?a dome mounain forms when hardened magma is uplifted and pushes up horizontal layers of rock | true |
| true or false?some types of volcanic activity do not invlove the eruption of lava | true |
| when groundwater heated by a nearby body of magma rises to the surface and collects in a natural pool, it is called | hot spring |
| a fountain of water and steam that erupts from the ground is referred to as a | geyser |
| how can geothermal energy be converted to electricity | steam can be piped into bines and creates energy |
