Earthquakes And Volcanos 3

Front 1

MORs account for ____ of the total volume activity on earth.

Back 1

about 75%

Front 2

Melting of the mantle beneath MOR occurs because

Back 2

rising mantle undergoes decompression melting.

Front 3

During circulation of ocean water through the ocean crust close to MOR

Back 3

The water becomes very hot and mineralized. (A and B)

Front 4

The ecosystems that exist around MOR hydrothermal vents are sustained by energy from

Back 4

Chemosynthesis

Front 5

Which focal mechanism in the diagram below would be for an earthquake on a spreading center on the MAR.

Back 5

cats eye white center

Front 6

Which type of volcano characterizes subduction zones?

Back 6

stratovolcano

Front 7

The source of the magma generated in subduction zones is

Back 7

peridotite of the mantle wedge

Front 8

Compared to continental volcanic arcs, in oceanic volcanoes arcs there is erupted a

Back 8

greater proportion of basalt and lesser proportion of rhyolite.

Front 9

The difference between the compositional spectrum of oceanic arc and continental arc lavas is because...

Back 9

there is a greater amount of crystal fractionization of rising magma in the continental arc setting and there is interaction of magma with the continental crust in the continental arc setting (B and C)

Front 10

Which volcano had an historic eruption that produced the year without summer in Europe and N. America?

Back 10

Tambora

Front 11

The 1985 eruption of a volcano in Colombia produced lahars that killed over 20,000 people.

Back 11

Nevado del Ruiz

Front 12

Over the last 4000 years the Cascade Range volcano that has erupted most frequently is

Back 12

Mt St Helens

Front 13

In the 1980 eruption of Mt St Helens

Back 13

All of A to C

Front 14

Mt St Helens was triggered by

Back 14

a moderate earthquake under the volcano.

Front 15

After the major eruption of Mt St Helens in May 1980

Back 15

the lava dome grew in the crater through 1986

Front 16

As of March 2013, the eruption of Mt St Helens that began in 2004

Back 16

Had officially been declared to have ended.

Front 17

Mt Pinatuba had a major eruption in 1991. Research done i n the build up to the eruption showed that the response time of Mt Pinatubo is about

Back 17

500 years.

Front 18

In the Build up to the major eruption of Mt Pinatubo in 1991 there was

Back 18

an increase in both the number and magnitude of earthquakes occurring beneath the volcano.

Front 19

The 1991 eruption of Mt Pinatubo was

Back 19

successfully predicted. and many lives were saved because the authorities did act on the prediction and evacuated people.

Front 20

Compared to the 1980 eruption of Mt St Helens, the 1991 eruption of Mt Pinatubo was about ___ times the about of pyroclastic deposits and was a VEI ____

Back 20

10;6

Front 21

The eruption that began in 1995 on the caribbean island of Monstserrat was triggered by

Back 21

intrusion of basalt magma into the magma chamber

Front 22

During the Montserrat eruption there have been periods of lava dome growth separated by periods when lava was not being erupted. As of now...

Back 22

lava is not being erupted; quiescence

Front 23

Of the total energy released globally by earthquakes what percentage is released by MOR and transform fault earthquakes?

Back 23

2%

Front 24

The largest magnitude earthquakes in subduction zones are of

Back 24

shallow focus and occur on the mega thrust boundary between the subducting and over riding plates.

Front 25

The shallow part of teh Cascadia sub zone has produced very few earthquakes over the last 50 years. This is because...

Back 25

the boundary between the two plates is completely locked.

Front 26

On the Cascadia sub zone

Back 26

the recurrence interval for M9 earthquakes is about 500 years.

Front 27

The December 2004 Great Sumatra earthquake...

Back 27

All of A to C

Front 28

A tsunami warnign system was in place in the Indian Ocean before the December 2004 Great Sumatra quake but it malfunctioned and failed to detect tsunami.

Back 28

False

Front 29

Which focal mechanism would be for an earthquake on a right lateral transform fault on the MAR

Back 29

BMW black on right

Front 30

On transform faults there is volcanic activity

Back 30

only on transform fault segments where there is transtension.

Front 31

There is a very high seismic hazard to the large city of Istanbul. This is because of

Back 31

All of A to C

Front 32

The San Andres Fault System

Back 32

Started to develope about 25 million years ago when the East Pacific Rise began to be subducted and has since progressively increased in length.

Front 33

The seismic hazard to the Bay Area

Back 33

All of A to C

Front 34

The 1906 San Fan quake

Back 34

ruptured a greater than 400km length of the San Andres Fault

Front 35

The 1906 San Fran quake was the first quake to which the overwhelming response was a rational one and the study of the cause of the quake marked the beginning of modern seismology

Back 35

true

Front 36

Which focal mech best represents the 1906 San Fran quake

Back 36

BMW white on right

Front 37

On the creeping segments of the San Andreas, Calaveras, and Hayward faults...

Back 37

The creep rate is significant but is less than the rate of plate motion across these fault segments. consequently both the magnitude and recurrence interval of quakes are decreased on these fault segments.

Front 38

The Hayward Fault last produced a large quake in 1868. The present day seismic hazard to the Bay Area from the Hayward Fault is

Back 38

very serious because the average recurrence interval for large earthquakes on the Hayward is 140 years. large quake likely.

Front 39

The 1989 Loma Prieta quake was predicted the year before the earthquake occured

Back 39

False

Front 40

At the Big bend in the san andres fault there is

Back 40

transpresson and therefore a component of reverse/thrust faulting.

Front 41

The M7.1 Loma Prieta quake had an epicenter close to Santa Cruz. In this quake

Back 41

the worst damage and all of the fatalities occured in the Bay Area because of the collapse of structures built on sand/mud/gravel/land fill

Front 42

Consistent with their plate tectonic setting, both the Northridge quake and the Kobe quake occurred on strike slip faults

Back 42

false

Front 43

there were many more deaths and much greater damage in the Kobe quake than in the Northridge quake because

Back 43

the 2 quakes were of similar magnitude but fault rupture occurred right under densely populated Kobe and there was major liquefaction.

Front 44

The 2010 Haiti quake

Back 44

Killed more than 200000 people

Front 45

The 2010 Chile quake

Back 45

Was a great quake and occurred on the megathrust boundary between the .... (Both A and B)

Front 46

The 2011 Japan quake

Back 46

All of A to C

Front 47

the two great earthquakes that occurred in 2012 had epicenters offshore of Sumatra. These quakes occurred on

Back 47

transform faults of the Indo Austrailian plate.

Front 48

In terms of the lethality of the Haiti, Chile, and Japan quakes...

Back 48

The Haiti quake was lower in magnitude than the Chile and Japan but had an epicenter close to a densely populated area.

Front 49

The large volcano on the Italian island of Sicily that has had numerous eruptions in historic time is

Back 49

Etna