Deck 6: Volcano Case Histories : Killer Events

Question 1

Volcanic weather refers to _______________________.

A) the electrical charge carried in violent thunderstorms which trigger eruptions
B) the tornadoes triggered by the violent updrafts of ash and gases associated with eruptions
C) the hurricanes triggered by coastal volcanic eruptions
D) the heavy rainfall triggered by steam blown high into the atmosphere where it cools and condenses

Answer 1

D

Question 2

The eruption of Mount Meager in southwest British Columbia 2,350 years ago (VEI = 5)was similar to that of ___________.

A) Mount Mazama,5,677 BCE
B) El Pinatubo,1991
C) Mount St Helens in 1980
D) Tseax Cone

Answer 2

C

Question 3

The age of volcanoes along the Cascade Range _____________.

A) increases from north to south
B) increase from south to north
C) increase from the centre symmetrically to the north and south
D) are all approximately the same

Answer 3

D

Question 4

The majority of deaths caused by volcanic eruptions are the result of _________________.

A) pyroclastic flows
B) lava flows
C) lahars
D) poison gases
E) all of the choices are correct

Question 5

Deaths caused by volcanic eruptions include _________________.

A) pyroclastic flows
B) tsunami
C) lahars
D) poison gases
E) all of the choices are correct

Question 6

The two most active Cascade Range volcanoes over the past 4,000 years are _________________.

A) Mt.Rainier and Mt.Adams
B) Mt.Meager and Mt.Garibaldi
C) Mt.Baker and Mt.Hood
D) Lassen Peak and Newberry Volcano
E) Mt.St.Helens and Mt.Shasta

Question 7

On 8 May 1902,a massive eruption of this volcano killed 30,000 people in the town of St.Pierre.The volcano was _________________________.

A) Mont Pelée,Martinique
B) Vesuvius,Italy
C) Krakatau,Indonesia
D) Mt.St.Helens,Washington
E) Nevado Del Ruiz,Colombia

Question 8

The volcanoes of the Cascade Range including Mt.Garibaldi in British Columbia and St.Helens in Washington result from ___________________.

A) heat generated by friction on the San Andreas Fault
B) the subduction of the Juan de Fuca plate beneath North America
C) the subduction of the Pacific plate beneath North America.
D) spreading of the Juan de Fuca ridge
E) None of these are correct.

Question 9

The most explosive of Canada's volcanoes in the Cascade Range is(are):

A) Mount Garibaldi
B) WhistlerMountain
C) Mount Baker
D) Mount Meager
E) Mount Garibaldi and Mount Meager

Question 10

The majority Earth's volcanic activity occurs in which of the following tectonic settings?

A) Hot spots
B) Transform faults
C) Spreading centres
D) Subduction zones
E) Continent to continent collision zones

Question 11

The greatest volcanic hazard to the city of Vancouver is due to ______________.

A) Mount St Helens
B) Mount Baker
C) Mount Meager
D) Mount Garibaldi

Question 12

The Mt.St.Helens eruption on May 18,1980 provides a good example of the hazards associated with volcanic eruptions.Which of the following did not occur as a result of this eruption?

A) A massive release of toxic gases
B) Earthquake
C) Lahars
D) Landslide
E) Pyroclastic flow

Question 13

Ways of generating pyroclastic flows include ________________.

A) dome collapse as at Mt.Unzen,1991
B) overspilling of crater rim as at Mont Pelée,1902-1903
C) directed blast as at Mt.St.Helens,1980,and Mt.Pinatubo,1991
D) eruption column collapse at Mt.Mayon,1968
E) all of these are correct

Question 14

The jokulhaup that occurred in 1996 in Iceland _________________________.

A) released poisonous gases that killed most of Iceland's cattle and sheep,leading to famine
B) triggered a major tsunami
C) melted part of the ice cap,releasing a flood that at its peak flowed as the second largest river in the world
D) was triggered by a magnitude 9 earthquake
E) produced a lahar that buried 5 small towns

Question 15

Volcanoes in Canada result from ____________.

A) subduction
B) a hot spot
C) rifting
D) all of these

Question 16

There are more than 200 dormant volcanoes in Canada they are concentrated in _____________.

A) British Columbia and Alberta
B) British Columbia and Yukon
C) British Columbia and Newfoundland
D) British Columbia and the Canada Shield
E) All of the choices are correct.

Question 17

Table Mountain (southern British Columbia)represents a classic ___________.

A) stratovolcano
B) tuya
C) subglacial volcano
D) cinder cone
E) tuya and subglacial volcano

Question 18

How many volcanic eruptions have occurred in the Cascade Range in the past 4,000 years?

A) 10
B) 49
C) 1,000
D) 2,500

Question 19

Tuyas are _________ with a characteristic flat top.

A) flood basalts
B) lava dome
C) submarine volcanoes
D) stratovolcanoes
E) none of these

Question 20

Mount Garibaldi in southwest British Columbia is a _____________.

A) classic Tuya
B) shield Volcano
C) scoria Cone
D) lava Dome
E) stratovolcano

Question 21

Which of the following statements regarding the lahars of Nevado del Ruiz in Columbia is true?

A) The 1985 lahars that killed 22,000 people in the city of Armero were unprecedented and a complete surprise.
B) The potential danger to Armero was not included in a hazards map published before this tragic event.
C) The 1985 lahars were a virtual rerun of the events of 1845 and 1595 with the same places buried by the same types of lahars.
D) The 1985 lahars that buried the city of Armero were the result of volcanic weather due to an ultra-Plinian eruption.

Question 22

If a volcanologist installs a sensitive seismometer besides a volcano and it detects longer-period seismic waves this means that:

A) magma is still in the mantle zone
B) magma eruption is imminent
C) only gases will erupt from the volcano
D) no eruption is expected since short-period waves are the precursor for imminent eruption
E) none of these choices are correct,we still don't know the meaning of these signals

Question 23

Death came quickly to those in the path of the pyroclastic flow that destroyed St.Pierre.Which of the following is not one of the possible causes?

A) Physical impact of the 190 km/h super-heated ash cloud
B) Inhaling the superhot gases
C) Burns from the hotter-than-700°C ash cloud
D) Burns from the low-viscosity lava that flowed rapidly down the volcano's slope and buried the city in a matter of minutes

Question 24

The chain of volcanoes in the Cascade Range like those of the Hawaiian Chain located above a hot spot;vary in age from young to old in an orderly progression.

Question 25

In August 1986,a gigantic volume of gas belched forth from Lake Nyos in Cameroon and swept down the adjacent valleys asphyxiating 1,700 people.The gas was _______________.

A) sulfur dioxide
B) carbon dioxide
C) hydrogen sulfide
D) carbon monoxide
E) a mixture of all of these

Question 26

In March 1991,Mount Pinatubo awoke after 500 years,causing the following:

A) thousands of small earthquakes
B) emitting thousands of tonnes of SO₂ rich gas
C) creating three small steam-blast craters
D) none of these choices are correct
E) all of these choices are correct

Question 27

Volcano Mountain,Ruby Mountain,Tsaex Cone,Lava Fork,Hoodoo and Iskul (Northern British Columbia and Yukon)are all associated with:

A) subduction zones similar to Cascade Range
B) continental hot spot zones
C) oceanic hot spot zones
D) continental rifts
E) oceanic ridges

Question 28

In this figure the sign shows:

A) the direction towards the volcano.
B) the route for evacuation.
C) the direction parents should take their kids towards the active volcano site.
D) that the volcano is active,so please follow the route.
E) both the route for evacuation and that the volcano is active.

Question 29

The plate-tectonic process responsible for volcanoes in the Pacific Northwest region of North America is identical to the cause of the region's great earthquakes-subduction of the Juan de Fuca plate.

Question 30

In Icelandic-type eruptions,low viscosity,low-volatile content lava erupts peacefully.

Question 31

In 1977 and 2002 Nyiragongo (Mount Nyiragongo),__________ killed an estimated 340 and 40 people,respectively.

A) low viscous lava
B) a lahar
C) pyroclastic flow
D) high viscous lava
E) none of these choices are correct

Question 32

In 1973 the town of Vestmannaeyjar on the island of Heimaey (off the coast of Iceland),was devastated by pyroclastic flows which completely filled and closed the town's harbor.

Question 33

The energy behind the 1902 pyroclastic flow that destroyed St.Pierre came from ___________________.

A) the blast of the volcano
B) gravity
C) gas escaping from pieces of airborne pyroclastic material
D) all of the choices are correct
E) none of the choices are correct

Question 34

Southwestern British Columbia and the Pacific Northwest region of the United States (Washington and Oregon)have long-term risk for both explosive volcanic eruptions and earthquakes.

Question 35

Canada's volcanoes are concentrated in British Columbia,the western Quebec and the Northwest Territories.

Question 36

Several geologic phenomena are being studied as signs of an impending volcanic eruption.These include seismic waves,________________,and the release of gases.

A) ground deformation
B) flash floods
C) landslides
D) human anxiety
E) unusual animal behavior

Question 37

Which one of the following variables is not needed for volcanism to have an effect on global weather?

A) The size and rate of the eruptions
B) The height of eruption columns
C) The types of gases and atmospheric level they reach
D) Low-latitude eruptions
E) Rainfall at the time of the eruption

Question 38

A genuine success story of advance warning before a large eruption occurred in the Philippines in 1991 before the climactic eruption of ___________________.

A) Mt.Mayon
B) Nevado Del Ruiz
C) Mont Pelée
D) Mt.Pinatubo
E) Popocatepetyl

Question 39

In August 1986,a gigantic volume of CO₂ belched forth from Lake Nyos in Cameroon and swept down the adjacent valleys asphyxiating 1,700 people.The origin of this gas was _____________.

A) a basaltic magma in the subsurface
B) a sub-lake pyroclastic flow
C) an earthquake preceding the volcanic eruption broke a gas pipe running along the bottom of the lake.
D) the calderas collapse of a volcanic dome at the bottom of the lake

Question 40

There are no hot spots under Canada.

Question 41

The Indonesian word lahar refers to the buoyant ash plume associated with Plinian type eruptions.

Question 42

Nazko Cone has had a mixed eruptive history,quiet lava and explosive pyroclastic eruptions.

Question 43

According to the Geologic Survey of Canada,the most important short-term impact of volcanism on the Canadian public is due to airborne ash in Canadian airways.

Question 44

Pyroclastic flows cannot travel down all sides of a volcano simultaneously.

Question 45

John Stix (Human Focus box)is planning to conduct an investigation on volcanoes of the Canadian North since they are not well investigated.

Question 46

Airborne pyroclasts have their finest grains settle down from the atmosphere first,closest to the volcano,followed by progressively coarser material at greater distances away.

Question 47

Volcanic eruptions are relatively peaceful above continental hot spots,such as Hawaii while eruptions above oceanic hot spots,such as Yellowstone National Park may be very explosive.

Question 48

The Tseax Cone is a very young volcano and it never caused any problems to people.

Question 49

Large,explosive Plinian eruptions can blast gas and ash up to the stratosphere where they completely disappear into space.

Question 50

Haze can produce a cooling effect on Earth while excess of carbon dioxide causes warming.

Question 51

At Lake Nyos in 1986,a gas cloud wiped out all plant and animal life,as well as killed 1,700 people.

Question 52

The eruption of Nevado del Ruiz in Columbia in 1985 dropped hot pyroclastic debris onto glaciers,resulting in lahars.

Question 53

Nuée ardente (French for glowing cloud)is another term used to describe a lava flow.

Question 54

Pyroclastic flow can move with higher speed than hurricane wind speed (> 190 km/h)because it is less dense than a hurricane.