Chapter 4

Question 1

What is the difference between forecast and prediction?

Answer 1

A forecast is a general statement about the possibility of something happening. A prediction is a more precise statement about the possibility of a future event.

Question 2

What is the relationship between height, ground oscillation frequency, building oscillation frequency and building damage during an earthquake?

Answer 2

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Question 3

Is it possible to predict and earthquake? why?

Answer 3

No it is not possible to predict an earthquake because there is no direct evidence suggesting that an earthquake will happen at an exact predicted moment. You can forecast an earthquake but understanding the warning signs.

Question 4

Explain how foreshocks may be used to predict an earthquake

Answer 4

Foreshocks are smaller earthquakes that preceded a big one and may be used to indicate another event. For this to work, the earthquake history of this area needs to be known in detail.

Question 5

Explain how changes in ground level and ground water may be used to predict an earthquake

Answer 5

The water table and the movement of groundwater may change as stress causes cracks in the ground. (Porosity and permeability) to open and close.

Question 6

Explain how radon gas may be used to predict an earthquake

Answer 6

Changes in radon gas emissions (Naturally occurring) Th rate of gas escaping from the ground will depend upon the grounds porosity and permeability. Changes in stress that might be related to an earthquake activity may change porosity and permeability and rate of gas escape.

Question 7

Explain how earthquake regularity may be used to predict an earthquake

Answer 7

The regular occurrence of earthquakes at cretin times and places may be useful in predicting their behavior.

Question 8

Explain how paleoseismology may be used to predict an earthquake

Answer 8

The long term earthquakes history of an area as recorded in he rock record. This may include tsunami deposits, and evidence of movement on a fault. This not only provides longer term records, it also provides information from other sources and areas not regularly monitored

Question 9

Explain how animal behavior may be used to predict an earthquake

Answer 9

It is generally accepted that many animals “sense” things differently than humans. These different or strange behaviors have been linked to earthquakes, usually after that fact. ex: Elephants pacing.

Question 10

There have been notable examples of successful earthquake prediction. Describe one. When was it and on what basis was a successful prediction and warning made?

Answer 10

Feb 1975 China. A series of foreshocks, changes in land elevation, changes in the earths magnetic field and strange animal behavior were signs of an upcoming earthquake. Authorities issued a warning. People were ordered to remain outside, shortly after a 7.3 magnitude earthquake happened which caused considerable damage but minimal loss of life.

Question 11

What is seismic gap and why is it significant? Describe in detail

Answer 11

Seismic Gap - a section of fault that has not experienced an earthquake n a significant period of time. Seismic gaps help narrow the search for where the next earthquake may happen.

Question 12

What is a blind fault

Answer 12

A fault that does not show on the surface.

Question 13

Can earthquakes be triggered by the introduction of fluids such as water into a fault zero? Explain your answer. Give an example.

Answer 13

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Question 14

If earthquakes could be deliberity triggered by injectiing fluids (i.e. water) into a fault zone, what are some of the ramifications?

Answer 14

It is not possible to reliably map out a fault, predict where the fluid would go or what it would do. The earthquake you hope for may or may not happen. It may be of a size that was intended or it may take place at a time and location that was not predicted.

Question 15

Describe the earthquake hazard in Turkey.

Answer 15

In Turkey, the main type of plate margin is a right lateral strike - slip or transform margin. Along this North Anatolian Fault earthquake epicenters have been migrating to the west. This means that more recent earthquakes have happened towards the west.

Question 16

Describe the earthquake hazard in Chile. Why is this area so important to British Columbia.

Answer 16

The West Coast of South America includes a continental US Oceanic Convergent plate margin. Along this plate margin there is also a record of large earthquakes. The largest record anywhere was here in 1960. These earthquakes result in significant horizontal and vertical displacement of the crush which has and will cause tsunamis. The earthquake hazard in Chile is very similar to Western North America.

Question 17

What is an intraplate earthquake? Give an example.

Answer 17

Earthquakes that take place not at a plate margin but in the interior of the plate. ex: The New Madrid earthquakes in the Mississippi valley in 1815. This was a series of earthquakes that took place in the failed rift that lies beneath the Mississippi river.