Download Volcanic and Seismic Terms and Definitions and more Quizzes Environmental Science in PDF only on Docsity!
system
defined set of parts that work together to perform a particular function TERM 2
volcano
DEFINITION 2 a vent or series of vents that issue lava and/or pyroclastic material TERM 3
shield volcano
DEFINITION 3 usually vertically exaggerated low silica lava from central vent composition" Basalt known for lava flows Mauna Loa and Mauna Kea TERM 4
composite cones (stratovolcanoes)
DEFINITION 4 made up of layers composed of pyroclastics and lava steep and conical lava has high silica and high velocity andesite- rhyolite (intermediate-felsic) Mt. Fuji (Japan) Mt Kilamanjaro (Africa) Mt Rainier (Seattle) TERM 5
Cinder Cones
DEFINITION 5 cinders or scoria = glassy or vesicular fast, violent eruptions Craters of the Moon National Park (Idaho), Flagstaff (Arizona), Mt. Etna (Italy)
Lava Flows
results when magma reaches the surface, overflows craters or vent and moves down the flanks of a volcano TERM 7
Lahar
DEFINITION 7 hot or cold mixture of water and rock fragments flowing down the slopes of a volcano cement like slurry of debris Nevada del Ruiz (Columbia) TERM 8
Pyroclastic Flows
DEFINITION 8 glowing avalanche of hot pyroclastic debris Mt. St. Helen Mt. Pelee TERM 9
Ash or Tephra falls
DEFINITION 9 hazardous because you are breathing it in TERM 10
Lateral Blasts
DEFINITION 10 explosions of gas and ash from the side of a volcano very explosive and rapid projection of material
Secondary Waves
Slower, travel only through solids TERM 17
Modified Mercalli Intensity Scale
DEFINITION 17 scale measures the effects of quake on man-made objects Keyed to U.S. architectural and building codes Roman Numeral Scale ( I-XII) TERM 18
Magnitude
DEFINITION 18 amount of energy released TERM 19
Richter Scale
DEFINITION 19 based on the maximum amplitude of ground motion caused by the surface waves near the epicenter TERM 20
Direct Hazards (Earthquake)
DEFINITION 20 ground shaking; results from surface waves shaking amount is greatly affected by the frequency of the seismic waves different earth materials respond differently to seismic waves
Ground
Failure
surface rupture or fissures TERM 22
Liquefaction
DEFINITION 22 transformation of water saturated granular material from a solid to a liquid state TERM 23
Indirect
DEFINITION 23 Fire-electric and gas utility lines (water mains are broken and fires cannot be fought) TERM 24
Floods
DEFINITION 24 Failure of levees and dams TERM 25
Paleoseismicity
DEFINITION 25 examines prehistoric seismic activity used to predict the probability of having a quake within a certain time interval and magnitude and potential damage
resisting forces
cohesive and frictional forces that hold "things" in place TERM 32
Angle of Repose
DEFINITION 32 maximum angle at which a pile of unconsolidated material can remain stable about 32-34 degrees for dry sand larger, angular, and moist grains maintain steeper slopes TERM 33
Pore-water Pressure
DEFINITION 33 water does not act as a lubricant increased water pressure leads to less grain to grain contact, decreased soil strength which leads to mass wasting TERM 34
Creep
DEFINITION 34 measured in mm/yr TERM 35
Seasonal Creep
DEFINITION 35 movement of soil by heave caused by expansion and contraction due to freeze thaw and wetting and drying
Continuous Creep
strain response to stress generated by weight and overburden (driven by gravity alone) TERM 37
Creeps
DEFINITION 37 are evidenced by slowly deforming ground, bent fences and utility poles, cracks and rolls on the landscape TERM 38
Falls
DEFINITION 38 abrupt free fall of loosened blocks or boulders of solid rock bedding, jointing and fracturing are important failure initiated by weather, water pressure in joints, and undercutting TERM 39
slides
DEFINITION 39 failure of material at depth and movement along a well defined surface TERM 40
Translational Slides
DEFINITION 40 failure alone a nearly planar surface
Mine Subsidence
underground voids created by human activity TERM 47
Fluid Withdrawal
DEFINITION 47 oil, gas, and water withdrawal reduces sediment cohesion and fluid pressure which leads to sediment composition and subsidence
