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70 Cards in this Set
- Front
- Back
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phreatomagmatic |
water mixes with magma and creates small eruptions |
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hotspot |
hot rock rises and melts the lithosphere, often creating volcanoes |
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pahoehoe lava |
lava that makes rivers, wrinkles itself; smooth |
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a'a lava |
looks like rubble, not smooth; comes from pahoehoe after it loses gas and cools |
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vesicles |
holes in lava formed by escaping gas (found in pumice) |
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pillow lava |
caused by underwater eruptions; very round shapes, cools very quickly |
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calderas |
formed by collapse of overlying rock into an evacuated magma chamber |
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fumaroles |
vents where volcanic gases escape |
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fissure eruption |
eruption along rift zone; magma forces its way up through the cracks that it formed |
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cinder cones |
small, steep-sided volcanoes built of mafic ash, scoria, and lava; explosive |
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pumice |
frothed glass |
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tuff |
volcanic fragments commonly welded together; a product of explosive volcanism |
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lahars |
volcanic ash mixes with water and flows |
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obsidian |
volcanic glass; felsic lava flows; no crystalline structure |
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hydrothermal alteration |
rocks are chemically changed and often weakened through interaction with hot water |
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mudpots |
the rock is altered to clay and water flow is low, therefore the composition is not clean |
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weathering |
rock is broken down at or near the earth's surfact to form sediment |
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mechanical/physical weathering |
rocks are physically broken apart |
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chemical weathering |
minerals are changed into more stable components due to interaction with water rich in carbonic acid |
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leaching |
the removal of soluble components into water |
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oxidation |
chemical combination of an element with oxygen |
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erosion |
the incorporation and transportation of material (sediment) by a mobile agent |
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rounding |
indicates how far the material was transported; smoothness of sediment |
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sorting |
often indicates the mechanism of transport (water, wind, ice); the range of grain size within a material |
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fluvial environment |
the erosive capability of streams is directly related to the velocity, which is primarily dependent upon the gradient and discharge |
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differential weathering/erosion |
different rock units weather and erode at different rates; this is what creates a stair-step pattern in the grand canyon |
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the inner gorge |
steep gorge in the Grand Canyon that the river is between--igneous intrusive and metamorphic rock |
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active margin |
plate boundary is basically the edge of a continent |
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passive margin |
continental edge is a central part of a plate; not on a boundary |
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percentage of Hawaiian species found nowhere else in the world |
90% endemic species |
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types of volcanoes that form from mafic |
shield volcanoes and cinder cone volcanoes |
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direction of pacific plate |
northwest |
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direction of |
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Hawaiian hazards identified by NPS |
1. Volcanism 2. mass wasting (slump:slow, slide:quick downslope movement) due to gravity 3. costal erosion due to rising sea level 4. seismic activity and tsunamis formed at convergent boundaries (subduction zones) 5. added by professor: volcanic gases |
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land forms of mafic lava flows |
lava tubes, skylights |
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How do we monitor volcanoes? |
1. What happened in the past? 2. What are the changes in the volcano's shape? 3. How do earthquakes affect the volcano? 4. What kind of gases are released and how much? ( fresh magma=more gases released; so2:co2 ratio higher |
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how are Hawaiian tsunamis formed |
when large pieces of land fall into the ocean (because the islands are gravitationally unstable) |
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describe the life cycle of a Hawaiian island |
volcanoes move off the hotspot, cool and subside, often becoming a sea mount |
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what causes the continential volcanic arc? |
subduction of the Juan de Fuca plate |
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what are cascade range volcanoes made of? |
lava flows and pyroclastic materials |
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what is significant about the Mt. St. Helens volcanic research center |
it was the first time the US geographic survey got to monitor all processes of volcanism |
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describe the differences between a caldera and a crater |
calderas are a collapse feature that are generally larger while craters are explosive destruction features that are typically smaller |
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examples of composite/stratovolcano activity |
ash column, pyroclastic flow, and lahars |
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why was the Mt. St. Helens Sediment Dam built? |
to capture lahars |
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why was crater lake misnamed |
it is actually a caldera |
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Mt. Ranier |
14,410 ft tall, capped by snow and glaciers, ~2 million visitors/year, largest single-peak glacier system, likely the most dangerous volcano in the Cascade Range |
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Yellowstone National Park |
first NP, created in 1872, ~3 million visitors/year, 60% of the worlds geysers |
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issues in Yellowstone |
bison: brucellosis virus--bison who leave the park are killed snowmobiles: 95% of Yellowstone is affected by noise or air pollution because of snowmobiles, 318/day are allowed in the park wolves: reintroduced as a form of elk control; removed from endangered species list in 2009 |
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how are calderas formed |
rising magma bulges the surface, cracks form and propagate down, intersecting the magma chamber and causing eruption. Then, overlying rock collapses, forming the caldera |
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volcanic products of Yellowstone |
tuff, obsidian |
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geothermal features |
geysers, hot springs, and mud pots caused by superheating of water; hot springs have an open conduit, continuous flow; geyser eruption driven by gas expansion WATER VAPOR! Geysers require a restricted conduit and storage chambers |
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products of weathering |
sediment, soil, ions in water |
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examples of physical weathering |
frost wedging, roots |
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examples of chemical weatherin |
leaching, oxidation |
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main controls on the rate of weathering |
1. climate: temperature and rainfall 2. parent material: mineral solubility and rock structure ( interlocking vs. clastic) 3. erosion: transportation of a material |
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examples of mobile agents of erosion |
wind, water, ice |
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best and worst sorters |
wind is the best and ice is the worst |
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what does a coarse material reflect |
a high energy environment |
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examples of clastic sedimentary rocks (named by texture/grain size) |
conglomerate: coarse sandstone: medium shale: very fine |
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examples of chemical sedimentary (named for mineral precipitated |
limestone: calcite gypsum: gypsum |
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what is the main type of rock that composes the Colorado Plateau |
sedimentary |
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what resources have been taken from the Colorado Plateau |
copper and gold logging and grazing uranium hydrocarbons coal water |
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What was the Colorado River developed for? |
Flood control, irrigation, electricity generation |
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Benefits of Colorado River Control |
hydroelectricity for 30 million people, irrigation, recreation |
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Consequences of Colorado River control |
apportionment exceeds capacity, dams disrupt geological processes and natural environment (sediment is not being transported) |
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Describe the air and water quality in the Grand Canyon. |
air: anitiquated coal plants create thick haze over the canyon water: dissolved ions and pollution have doubled |
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Due to differential weathering, which types of rocks create a diagonal slope, and which create a cliff? |
Soft rocks create a diagonal shape, while hard rocks form cliffs |
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What were the reasons for sea level change in the Permian? |
Primary: the creation of Pangea Others: glaciers, water temperature, sea floor spreading |
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How was the Grand Canyon formed? |
D: depostion--sediment underwater U: uplift--high and flat D: downcutting-- Colorado River E: erosion--snow, ice, water |
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steps of formation of arches |
1. rocks are jointed (cracked) -this is caused by salt domes pushing up from underneath 2. differential weathering occurs along joints creating fins 3. erosion along geologic contacts causes collapse of overlying rock |
