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Science:Geology
Earth Science
Question | Answer |
---|---|
Geology | the study of the earth |
crust | earth's outer layer of rock |
granite | the portion of crust underlying the continents |
basalt | portion of crust under the oceans |
sediment | deposits sand, rock fragments, sometimes organic matter,usually laid water deposited wind glaciers down by water sometimes deposited4 |
oxygen | the most abundant element in the earth's crust |
seismic waves | study of earthquake waves |
Mohorovicic discontinuity or Moho | boundary separates the crust from the mantle |
upper mantle | extends from Moho down to about 400 km |
Transition zone | the zone in between,where the upper mantle merges into the lower mantle |
plastic rock | with some properties of a solid and some properties of a liquid |
Gutenberg Discontinuity | boundary between the earth's mantle and the core |
core | the central part of the earth |
what does the core consist of? | the inner core and the outer core |
the outer core seems to be | liquid as a result of the intense heat at that depth;probably consists of molten iron and nickel |
the inner core seems to be | solid nickel or iron kept in solid state by pressure |
plate | plate tectonics theory, several rock masses of rock float like rafts plastic rock of upper mantle |
plate tectonics | theory earth's crust consists huge plates slowly move result convection currents plastic rock upper mantle |
Pangaea | name given to huge,hypothetical land mass which all the present day continents connected together |
fault | fracture in rock that occurs when rock breaks under the strain of forces upon it |
normal fault | type of fault that occurs when rocks along one side of fault sink vertically |
strike-slip fault | type of fault that occurs when the rocks along one side of a fault move horizontally along fault |
thrust fault | type of fault that occurs when the rocks on one side of a fault are thrust on top rocks on the other side |
fold | formed by buckling of rocks |
syncline | trough-like fold that occurs when rocks bend downward |
anticline | arch-like fold that occurs when rocks bend upward |
volcanic mountains | cone-shaped mountain molten rock erupts from crust |
domed mountains | formed when molten rock collects beneath |
folded mountains | two rock layers pushed together |
fault-block mountains | formed: when 1 side of fault goes up;other side sinks |
earthquake | trembling/shaking earth's crust |
tremors | weak earthquake |
tectonic earthquakes | earthquakes result movements rock beneath surface |
aftershocks | smaller earthquake follows larger earthquake |
seismology | study of earthquakes |
tectonic earthquakes are | result movement rock masses along fault |
elastic rebound theory | rocks either side fault spring position no strain moment earthquake, triggering vibration |
San Andreas Fault | strike-slip fault western California |
focus | point which earthquake begins |
epicenter | point earth's surface directly above focus earthquake |
Primary waves or P waves | waves consist rhythmic push-pull motion direction travel;goes through solids and liquids |
Secondary waves or S waves | waves consisting rhythmic side side motion right angles direction wave travel |
Surface waves | waves that travel across earth's surface |
seismograph | instrument used to record earthquake vibrations |
seismogram | record produced by seismograph |
shallow-focus earthquakes | 85% earthquakes depths 8-65 km(5-40 mi) below surface |
intermediate focus earthquakes | 12% earthquakes depths 65 to 300 km (40-200 mi) |
deep-focus earthquakes | 3% earthquakes depths more 300 km (200 mi) |
deepest focus yet recorded for earthquake | 700 km(435 mi) |
Circum-Pacific Belt | belt bordering the Pacific Ocean along 80% of world's earthquakes occur |
Richter Scale | scale of earthquake strength in popular use |
Volcano | opening earth's surface through gases,ash,and molten rock ejected from earth's interior |
vent | channel gases,ash,and rock are ejected from volcano |
magma | molten rock beneath earth's surface |
cone | conical shaped mountain which is formed from the ejected materials |
crater | bowl-shaped depression which caps the cone |
volcanology | the study of volcanoes |
volcanologists | scientists who study volcanoes |
cinder-cone volcanoes | volcano consists of erupted volcanic ash and cinders(rock fragments) |
shield volcanoes | gently sloping volcano built from mild eruptions of large quantities of highly fluid lava |
composite volcano | steep-sided volcanic cone consisting of alternate layers of lava and cinders |
active volcano | volcano has erupted within past 50 years |
dormant volcano | volcano which erupted more than 50 years ago and is now inactive |
extinct volcano | volcano that will not probably erupt again |
Ring of Fire | narrow zone of active volcanoes bordering Pacific Ocean Basin more 25% world's volcanoes are formed |
viscosity | syrupiness caused by internal friction |
ejecta | any substance emitted by an active volcano |
lava | molten rock that flows from volcanoes |
types of lava | pahoehoe and a a |
Pahoehoe lava | lava that hardens to form a smooth or ropy surface |
aa lava | lava that hardens into rough,jagged rocks with a crumbly texture |
pyroclasts | particles or blocks of solid volcanic ejecta |
volcanic ash | pyroclastic particles less than 4 mm in diameter |
volcanic cinders | ejecta that are larger than volcanic dust particles but less than 32 mm |
volcanic blocks | solid,irregularly shaped lumps of hardened lava,often large and boulder like in appearance |
volcanic BOMBS | almond/tear-shaped pyroclast formed when lava thrown high the air liquid state hardens rock hits ground |
fierce blasts | dangerous part of volcano consisting incandescent ash and superheated gases accompanies eruptions |
nuee ardente | superheated,incandescent cloud of gas and volcanic ash that travels down volcanic slope as avalanche |
calderas | bowel-shaped crater least two miles across,formed underground magma chamber collapses |
lava tunnels | horizontal cave like tube formed surface large lava hardens lava beneath remains molten continues |
igneous intrusions | mass of igneous rock beneath earth's surface |
dike | vertical,sheetlike igneous intrusion formed when magma hardens in vertical crack or fissure |
sill | horizontal,sheetlike igneous intrusion formed magma squeezes horizontal layers of rock solidifies |
laccolith | domelike igneous intrusion,formed by magma that bulges the overlying rocks upward |
batholiths | igneous intrusion similar to laccolith but much larger;commonly forms base of great mountain ranges |
Where is the earth's crust the thickest? | beneath mountain ranges(on the continents) |
where is it the thinnest? | beneath the oceans |
What is the largest known volcanic mountain on earth? | Mauna Kea(part of the island Hawaii) |
What mountain range in South Dakota is an example of domed mountains? | the Black Hills |
What two U.S. ranges are mentioned in the text as examples of folded mountains? | Appalachians and Rocky |
what is a tectonic earthquake? | an earthquake that results from sudden movements of rock beneath the earth's surface |
What is the primary cause of tectonic earthquakes? | the sudden movement of rock masses along a fault(faulting) |
what does the elastic rebound theory state? | rocks on either side of the fault spring back to a position of little or no strain at the movement of a earthquake producing vibrations in the earth's crust |
fault scarp | short cliff sometimes produced along fault as result of earthquake |
slickenslides | a term that refers to smooth-faced fault scarps formed by movement along a fault |
what major strike-slip fault is in western California | San Andreas fault |
what are three categories of earthquakes according to the depths at which they originate? must record an earthquake scientists | shallow-focus earthquakes intermediate-focus earthquakes deep-focus earthquakes |
how many seismograph stations record earthquake scientists pinpoint focus and epicenter? | at least three |
What is the most active earthquake belt in the world and borders the Pacific ocean? | Circum-pacific belt |
what earthquake zone extends from southern Europe into Asia? | Mediterranean-Trans-Asiatic belt |
What scale of earthquake strength rates earthquakes by the damage they produce? | Mercalli scale |
what is a volcano? | opening in the earth's surface through which hot gases,ash,and molten rock ejected earth's interior |
Which type volcano consists alternating layers lava cinders symmetrical,wide-based volcano | composite volcano |
which type of broad,gently sloping volcano is formed when large quantities highly fluid lava solidify | shield volcano |
which type of volcano consists primarily of loose fragments of volcanic rock? | cinder-cone volcano |
What 2 factors determine violence of volcano's eruption? | viscosity of magma and amount of dissolved gas the magma continues |
What is ejecta? | any substance emitted by an active volcano |
Which two U.S. mountain ranges are mentioned in the text as examples of fault-block mountains? | Great Basin and Range Province; Sierra Nevada |
What is nuee ardente | superheated,incandescent cloud of gas and volcanic ash that travels swiftly down volcanic slope as avalanche |
what is huge bowl-shape crater the ground thought formed by the collapse underground magma chamber? | caldera |
what is the general term for masses igneous rock form when magma hardens cracks and fissures beneath surface? | igneous intrusions |
what type of igneous intrusion is formed when magma squeezes into a horizontal fissure and hardens? | sill |
what type igneous intrusion consists sheet-like mass igneous rock,formed magma squeezes vert. and hardens? | dike |
what are two types of domelike igneous intrusions? | laccoliths and batholiths |
what is the second most abundant element in the crust | silicon |
what is the third most abundant element in the crust? | aluminum |
where is the Mohorovicic discontinuity(Moho) located? | at the lower boundary of the crust |
What is an earthquake? | any trembling or shaking of the earth's crust |
what is the cause of most tectonic earthquakes? | the sudden movement of rock masses along a fault |
what are pyroclasts | particles or blocks of volcanic ejecta |
what name superheated incandescent cloud gas volcanic ash travels swiftly volcanic slope avalanche | nuee ardente |
what huge bowl-shaped crater ground, least 2 miles across,thought collapse empty magma chamber | caldera |
what is an igneous intrusion | mass of igneous rock(solidified magma) beneath surface |