# Shared Flashcard Set

## Details

EQ final
EQ final
115
Physics
05/07/2011

Term
 isoseismal lines
Definition
 contour lines drawn to separate one level of seismic intensity from another -used to determine the center of the eq shaking and id source of seismic waves -indicated rate at which the skaing effects diminished with distance and provides him with an estimate of the relative size of the eq
Term
 intensity
Definition
 measure of ground shaking obtained from the damage done to structures built by humans, changes in the earth's surface, and felt reports
Term
 Intensity scales
Definition
 1st developed from I to X by M.S. de Rossi and Francois Forel in 1880 -more refined scale from I to XII in 1902 by italian seismologist and volcanologist G. Mercalli - versoin called the abridged modified Mercalli developed by H.O. Wood and Frank Neumann to fit construction of CA
Term
 Problem with Mercalli intensity scales
Definition
 the measure using the greatest intensity ex.. landslides = X
Term
 harder rock =
Definition
 lower damage
Term
 filled lands =
Definition
 greater damage
Term
 VI on mercalli scale
Definition
 eq is felt by all, most people are frightened, many run outdoors, shifts heavy furniture, causes plaster to fall, damages some chimneys
Term
 soft, sandy soil =
Definition
 higher intensity/damage often cause building foundations to move, crack, or subside
Term
 moment magnitude
Definition
 1931 by K. Wadati in Japan and developed by the late Professor Charles Richter in 1935 in CA - uses seismic wave amplitudes measured by a seismograph
Term
 3 main ways eq magnitudes are used
Definition
 1. recognized by the general public, scientists, engineers, and technicians 2. magnitudes are important in the ongoing efforts to monitor a comprehensive nuclear test ban treaty -best way to determine diff between nuclear explosion and natural eq 3. mags of pervious eqs are used in an approx. way to predict what the greatest acceleration of the ground shaking may be in an eq -used to design structures that will withstand
Term
 Ms
Definition
 surface wave magnitude
Term
 Mw
Definition
 moment magnitude -improve the uniform coverage of eq size
Term
 Ml
Definition
 Richter magnitude -developed for southern california -used the wave with the highest amplitude
Term
 Mb
Definition
 measures p wave- not affected by the focal depth
Term
 force couple
Definition
 equal and oppposite forces pushing on faults. the size of this couple is called the moment
Term
 3 factors that directly effect the intensity of an eq at a particular geographic location
Definition
 1. degree of damage to structures of human origin 2. amount of disturbance to the surface of the ground 3. extent of human and aminal reaction to shaking
Term
 subduction zones
Definition
 surface layers of rocks plunge into the earths interior, temp and pressure go up and sinking lithosphere is gradually reworked until it becomes mixed and absorbed into the rocks of deeper interior
Term
 seismic gap
Definition
 area in an eq prone region where there has been a below average level of seismic energy release
Term
 chile vs haiti eqs
Definition
 chile feb 27 2010 mag 8.8 deaths 550-800, very strong building codes, subduction  dip slip zone haiti jan 12 2010, mag 7, 100,000 to 220000 deaths, many many weak buildings, strike slip fault
Term
 tectonic plates
Definition
 fairly stable slabs of solid, rigid rock
Term
Definition
 mid-oceanic ridges and rises
Term
 subduction zones
Definition
 burial ground of plates
Term
 charles lyell
Definition
 the presnet is the key to the past - the causes of mountains, volcanoes, and earthquakes are the same today as they were in the deep past. principles of geology
Term
 driving mechanism of tectonics
Definition
 heat incessantly produced from the decay of radioactive elements in the rocks throughout the interior of the earth
Term
 intraplate earthquakes
Definition
 the most difficult eqs to explain using plate tectonics theory
Term
 until the 1960s there were only two serious global hypotheses for the formation of mountain ranges and ocean deeps. they were _________ and _________
Definition
 the earth was cooling and thus contracting and large-scale convective movements of the rocks of the earths mantle
Term
 describe a prediction which can be made to test the plate tectonic theory
Definition
 if the theory of plate tectonics is true then scientists would be able to predict when eqs would occur. for example, there is a seismic gap in the alutian islands where considerable strain has built up and scientist predict that theyre will be an eq occuring in that area. also eqs can be predicted to occur at subduction zones because the plates are converging
Term
Definition
 regular, downward dipping seismic zones
Term
 most of the largest magnitude eqs (near chile and japan) are
Definition
 in subduction zones
Term
 which of the following is NOT an example of a famous intraplate eq
Definition
Term
 scottish naturalist james hutton was the first influential proponent of the view that geological processes take place in
Definition
 millions of years
Term
 moment magnitude is abbreviated
Definition
 Mw
Term
 damage to structures during an eq is due more to ________ than to _________
Definition
 the duration of strong ground shaking that to the peak or maximum ground acceleration
Term
 the maximum allowable value on the modified mercalli intensity scale is
Definition
 XII
Term
 It is uniformitarianism that leads us to expect that the next large eq will occur in a seismic gap in an otherwise already eq prone region
Definition
 T
Term
 the earth is constantly creating new crust and consuming old crust
Definition
 T
Term
 magnitude scales haveno upper limit, but the upper limit on the size of an eq is limited by the strength of the rocks of the earths crust
Definition
 T
Term
 magnitude scales were created because scientists, engineers, and the general public use them as a measure of the relative size of eqs and as a rough estimate of the eqs severity
Definition
 T
Term
 body wave magnitude, Mb, uses the p wave amplitude and it not affected by the focal depth of the eq
Definition
 T
Term
 surface wave magnitude, Ms, uses the largest amplitude of surface waves with a period near 20 seconds
Definition
 T
Term
 when the surface wave magnitude Ms inceases by 1 unit, the amount of seismic energy E released increases by a factor of about 30
Definition
 T
Term
 ground acceleration is usually reported as a percentage oft the acceleration due to gravity becasue this is a value with which everyone is familiar, at least intuitively
Definition
 T
Term
 generally, the vertical ground acceleration in an eq is less than the peak horizontal acceleration
Definition
 T
Term
 experience has shown that it is the horizontal motions of the ground that topple structures and even throw people to the ground, rather than vertical motions
Definition
 T
Term
 one of the most reliable methods for distinguishing between natural eqs and nuclear blasts is the unusually shallow focus of a nuclear blast
Definition
 T
Term
 the following geographic region(s) has (have) been hit by notable and deadly tsunamis in the last 200 years; iceland, hawaii, japan, a and b, a and c, b and c
Definition
 b and c (hawaii and japan)
Term
 a tsunami, in the open ocean, travels about the same speed as:
Definition
 a jet plane
Term
 the only official eq prediction ever made in the US was in the late 1980s for the region around
Definition
 Parkfield
Term
 according to the CA panel of eq prediction, there are four essential elements required for a valid eq prediction. which of the following is not one of the essential elements a. the magnitude range b. the odds that the type of eq predicted would occur by chance alone c. the max ground accelerations that would be expected d. the location for the eq
Definition
 c. the max ground accelerations that would be expected
Term
 in the open ocean, tsunamis are often several meters in height and have a wave length of 5 to 10 m
Definition
 F
Term
 the run up height of a tsunami is the horizontal distance of water run up on the shore compared to the normal waters edge
Definition
 F
Term
 even very large eqs on strike-slip faults like the san andreas rarely produce a seismic sea wave
Definition
 T
Term
 mt. st. helens is a composite volcano made up of tephra (ejected fragments of older rocks) and lava flows
Definition
 T
Term
 no one was killed in the may 1980 explosion of mt. st. helens
Definition
 F
Term
 volcanic activity can cause an eq or an eq can cause volcanic activity. it works both ways
Definition
 T
Term
 eqs associated with volcanic eruptions are always volcanic tremors (more or less continuous shaking) volcanic eqs do not produce P and S waves
Definition
 F
Term
 reasonably often, seismographs can be used to predict eruptions of active volcanoes
Definition
 T
Term
 at the summit of most composite volcanoes there is a caldera
Definition
 T
Term
 seismic sea wave, tsunami, and tidal wave are equally acceptable terms (scientifically correct) for what Darwin called great waves
Definition
 F
Term
 The eruption and subsequent collapse of Krakatoa Is in the east indies in 1883 created one of the largest tsunamis in recorded history
Definition
 T
Term
 A large reservoir of molten rock, waiting to make its way to the surface via a volcanic vent, is called a ________ _________
Definition
 magma chamber
Term
 An avalanche of hot gasses, steam, and rock debris, accompanying a volcanic eruption, is called a _________ flow
Definition
 pyroclastic
Term
 Name the four countries that became heavily involved in the study of earthquake prediction, beginning in the 1960's
Definition
 Japan, Soviet Union, US, China
Term
 which effort will do society more good: learning to predict the time and location of eqs or predicting seismic intensity (seismic risk) for particular areas? Explain why. contrast advantages and disadvantages of each option and explain why you prefer one or the other.
Definition
 It is more important to predict seismic intensity for an area because then proper precautions such as building codes can be established. if you live in an eq prone area then you know the eq is likely to occur. if you predict down to the date people may panic, unnecessary evacuation may occur, housing market prices may decrease, insurance may sky rocket. however, if people can prepare ahead of time and have better building structures, not build near the ocean to avoid tsunamis that would do society more good.
Term
 indicate whether each is a predictor, not a predictor or if they are uncertain if it is or not. foreshocks ground uplift and tilt release of radon gas eq weather tidal pull of sun and moon
Definition
 foreshocks - uncertain ground uplift and tilt - uncertain release of radon gas - uncertain eq weather - not a predictor tidal pull of sun and moon - not a predictor
Term
 which is the more realistic goal: prediction of eqs or prediction or seismic intensity
Definition
 intensity
Term
 coastal dwellers in which of the following areas run a high risk of a tsunami hitting within minutes after a major eq east coast of japan coast of s. ca coast of chile coast of WA west coast of florida coast of brazil
Definition
 east coast of japan coast of chile coast of WA
Term
 magma chamber
Definition
 huge reservoirs underneath volcanic vents, molten fraction of rocks makes its way to the surface -magma moves up from time to time to issue forth as lava
Term
 volcanic tremor
Definition
 can usually be detected only very near vents, useful in forecasting probably imminent eruptions. continuous shaking of the ground that persists for days or hours
Term
 caldera
Definition
 at the summit of a volcanoe crater produced by rock collapse into the depleted magma chamber after a great eruption
Term
 a valid prediction has four essential elements
Definition
 1. the period within the event would occur 2. the area of the location 3. the mag. range 4. a statement of the odds that an eq of the predicted kind would occur by chance alone without reference to any special evidece
Term
 clues for recognizing impending eqs
Definition
 detection of strain in rocks of earths crust by geodetic surveys and id of suspicious gaps in the regular occurrence of eqs in time and space observe foreshocks installed seismograph stations accross continential shelf
Term
 eq prediction - ground tilts
Definition
 ground tilts in eq regions, rapid ground uplift of a consideralbe area
Term
 eq prediction - release of radon
Definition
 radioactive gas into the atmosphere along fault zones particularly from deep wells
Term
 eq prediction - varation in electrical resistivity
Definition
 conductivity of the rocks, electrical resistance or water- saturated rocks, such as granite, changes measurably just before the rocks fracture
Term
 eq prediction- variation in the seismicity
Definition
 large change in normal background eq occurance is noted, up rate of small eqs
Term
 West Coast   East Coast
Definition
 eqs are more frequent, seismic waves propagate shorter distances   eqs are less frequent, seismic waves progagate longer distances
Term
 technically speaking, when describing the danger from eq _________ is the event itself, that is, the ground shaking with a specific force
Definition
 hazard
Term
 On the other hand, eq ________ is the danger eqs present to vulnerable buildings or persons
Definition
 risk
Term
 when fine-grained water-saturated soil is shaken, it loses its resistance to shearing, a condition called ________
Definition
 Liquefaction
Term
 every day americans are at risk (that is, in danger of losing their lives) from five, eqs, and automobile accidents. put these three risks in order from highest to lowest (by number of deaths per million Americans per year)
Definition
 automobile, fire, eqs
Term
 G or B before during and after an eq Store extra food in the basement
Definition
 B
Term
 G or B before during and after an eq Devise a plan for reuniting your family after an eq in the event that anyone is separated
Definition
 G
Term
 G or B before during and after an eq Fasten heavy appliances and furniture to the floor or wall
Definition
 G
Term
 G or B before during and after an eq During an eq, if indoors, immediately proceed outdoors
Definition
 B
Term
 G or B before during and after an eq During an eq, if outdoors, proceed to a doorway of a nearby building
Definition
 B
Term
 G or B before during and after an eq During an eq, if driving, keep driving with caution
Definition
 B
Term
 G or B before during and after an eq During an eq, in a high rise building, head for the nearest elevator to evacuate the building
Definition
 B
Term
 G or B before during and after an eq After an eq, it at home, immediately proceed outdoors, even if your house appears to be undamages
Definition
 I marked it as G but he marked it wrong, and then changed to G Bolt says to leave because building could be damaged
Term
 G or B before during and after an eq After an eq, go into all damaged areas looking for people who are injured
Definition
 B
Term
 G or B before during and after an eq After an eq, immediately call friends and relatives to see if they are okay
Definition
 B
Term
 The National EA hazard reduction act of 1977 emphasized eq prediction research over mitigation of eq hazards
Definition
 F
Term
 Bolting a wood frame house to its foundation is a good way to reduce damage to the house and its contents during an eq
Definition
 T
Term
 In countries like new zealand, japan, and the us, eq insurance is rarely if ever available, except through direct negotations with a specific insurance company
Definition
 F
Term
 More often than not (that is, over 50% of the time) people are at home when damaging eqs occur
Definition
 T
Term
 the collapse of weak houses and buildings is the cause of most casualties from eqs
Definition
 T
Term
 inexpensive modifications to rural and urban housing design are better long-term measures to prevent injury than is eq prediction
Definition
 T
Term
 probabilistic seismic hazard maps which give an idea of the underlying statistical uncertanity of eq shaking are now commonly used in eq prone countries
Definition
 T
Term
 In CA, eq intensity drops off fairly rapidly with distance from the epicenter, this is not true in the eastern US where seismic waves propagate farther
Definition
 T
Term
 One of the problems with eq hazard maps is that the probability statements are given in a way that non-specialists find difficult to understand
Definition
 T
Term
 Mexico has an already tested warning system which could give mexico city 50 to 70 seconds of advance warning for a large eq centered along the pacitic coast of mexico
Definition
 T
Term
 the weight of roofing material is an important consideration in eq safety for one and two story family houses
Definition
 T
Term
 In the great eqs of 1811 and 1812 near new madrid, shaking was great but there was little change in the soil surface in the area
Definition
 T
Term
 circle the items which, according to bolt, you should keep easily accessible in the home if you live in an actively seismic area: first aid kit, flashlight, fire extinguisher, batteries, candles, duct tape, battery-powered radio, iPod
Definition
 First aid kit, flashlight, fire extinguisher, batteries, battery-powered radio
Term
 hazard
Definition
 event itself, the eq ground shaking or the volcanic eruption, dangerous physical effects -landslides and tsunamis
Term
 risk
Definition
 danger the hazard presents to vulnerable buildings or persons- probability of life and property loss within a given time interval and region- must be assessed compared to all other risks -cars, fires, tornadoes, etc
Term
 self protection before - home
Definition
 battery radio flashlight 1st aid kit everyone knows where they are know where fuse box is, where gas and water shut off valves are dont keep heavy objects on shelves, securely fasten appliances, anchor furniture -devise a plan in case of separation
Term
 self protection before - school
Definition
 discuss eq safety in class and secure objeccts, have drills
Term
 self protection before - work
Definition
 find out emergency plan, what is your responsibility
Term
 self protection during - home
Definition
 stay calm, if indoors stay indoors and stand against wall near center of building or get under sturdy table, stay away from windows outdoors- stay in open, keep away from wires or anything that might fall- chimneys dont use candles, matches or other open flame stop car, stay away from bridges, stay in car
Term
 self protection during - work
Definition
 get under desk or sturdy furniture, stay away from windows, evacuate if told to do so, use stairs not elevators
Term
 self protection during - school
Definition
 get under desks, facing away from windows stay away from building if outside, if on bus, stay in seat til driver stops
Term
 self protection after - home
Definition
 check self and others for injuries, provide 1st aid check water and gas and electric lines, if damaged shut off check for leaking gas by odor only-never light match if detected open all windows and doors shut off gas leave immediately report to authorities turn on radio for emergency instructions do not use phone because it is needed for high priority messages dont flush toilets until sewer lines are checked stay out of damaged buildings wear boots/gloves
Term
 self protection after - school/work
Definition
 follow emergency plan/instructions, stay away from beaches/water front in case of tsunamis do not go into damaged areas expect aftershocks
Term
 steps to reduce hazards to homes
Definition
 1. waterproof housing and adequately nailed 2. fasten utilities securley enough to withstand high acceleration 3. brick chimneys reinforced, flues should to be lightweight 4. frame and sill plate reinspected periodicaly to assure it can resist and tied to concrete foundation has not been damaged by termites or fungus 5. all masonry walls should be reinforced and tied to footings 6. roots and ceiling should be light 7. flexible joints should be probided between the inside of utility lines (gas and water) and outside mains 8. closets and heavy furniture should be fastened or strapped to the wall studs   put plastic restraints on shelves - especially hospitals and secure artwork
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