FDSCI 201 W3

Which of these is not a cause of damage in an earthquake?

Lahars

How much of the development (buildings and roads) at Kobe is located on bay fill?

Maybe 30-50%

How much of the shoreline of the bay in this region is fill? (Also check elevations; fill is everything at sea level.)

Most

What type of fault forms where the crust is being extended?

Normal

If a fault is vertical, where will an earthquake epicenter be located?

On the fault

Which of these is an important earthquake-fire mitigation measure homeowners should take?

Strap gas-fueled water heaters and other gas appliances to the structure of the home.

Which type of seismic waves do the most damage in an earthquake?

Surface waves

Look nearby at other buildings. How would you summarize the fault rupture hazard here?

high - many structures are in harm's way

What do we call the area underground on the fault where an earthquake starts?

hypocenter

What effects did the tsunami have here?

It destroyed buildings and tore out vegetation.

How high did the tsunami get on the hills here?

40 to 100 feet

If you were the engineer in charge, what would you have to take into account to increase safety of the stadium?

A major fault cuts through the stadium

Each of these Mw 9 and greater earthquakes caused a tsunami. Why did you think they did that?

An earthquake that large causes large displacement on the fault, which moves the seafloor to cause a tsunami

What is the general relation between tsunami damage and proximity to coasts, bays, and rivers?

Closer to them and lower elevation means more damage

Choose one Mw 9 earthquake and double click on it to see where it occurred. What type of plate boundary is closest to it?

Convergent

How many earthquakes of Mw 9 or greater have occurred in the world over the past 100 years?

Five

Which of these is not an element of good seismic structural design?

Heavy, sturdy roof materials

What is the level of seismic hazard in the Bay Area?

High and widespread

What is likely to be the effect on the East Bay when the Hayward fault ruptures?

High disruption of structures, roads, and utilities

After months of searching, you find and accept a job in a community built on an active fault. You learn that seismologists say there is a high probability of a damaging (Mw > 7) earthquake on the fault in the next 50 years. The elementary school that your children attend is not seismically safe and is built on an old lake bed. What would you do personally? What would you recommend the community do to help prevent a possible disaster at the school? Is it worth the expense and effort?

In this situation, I think that there are many factors to consider. Personally, I would push the community to make the school safer. I would lobby and campaign to make the school safer by relocation and or renovation of the school in the community. Once a backing of the community had been established, it would be much easier to raise funds for preventable measures and other expenses that may occur in order to keep the children and other people in the community safe. However, before any fundraising could be done, we would first need to decide on one of the many preventable measures that have been tested and used by engineers all around the world. There are numerous disaster measures that could be taken, and have already been taken by numerous schools, businesses, and homeowners around the world. In many buildings, engineers have used shock absorbers to help absorb the shock from the earthquakes which help to diminish structural damage and any possible damage to the people within the buildings. Preventable measures are not cheap, but I believe that when it comes to the safety of mine or any other children that the expense and effort is completely worth it. It is possible that not everyone in the community is aware of the seriousness of the situation. By educating the entire community a coalition of community members can work to make the school safer. Tragedies happen every day, all around us, and I would hope that the community that I live in would feel that keeping our schools safe from at least one potential tragedy is worth while. Making the schools earthquake safe is a smart, responsible action to better the community and bring us together for the common good.

What role will bay fill play in future earthquakes in this area?

Increased shaking and liquefaction will be widespread

Which of these statements is false about tsunamis?

They are caused by strong seismic waves (like surface waves or s-waves)

Which of these is a good characterization of the faults in southern California (from the Google Earth tour)?

They form a web and many are along mountains

Which of these is the smallest Mercalli intensity in which things start to be damaged (like dishes and windows)?

V

So what do you conclude? How can people avoid tsunami property damage?

You must be high above sea level

Which of these is moment magnitude (Mw)?

the amount of energy released during the earthquake