Flashcards in Lecture #3 Deck (47):
What does Tsunami mean in Japanese?
How are tsunamis produced?
By the sudden displacement of water
What are the 2 ways in which earthquakes can cause tsunamis?
-Displacement of sea floor
-Triggering landslides which fall into the water
What magnitude of an earthquakes is required to produce a tsunami event as well?
What is the 1st stage of tsunami development?
Displacement of the seafloor pushes the water up and when it hits the surface it spreads outward
What is the 2nd stage of tsunami development?
Waves move rapidly across the open ocean, but are asmall
-spacing between waves in large
What is the 3rd stage of tsunami development?
As the tsunami approaches land the water depth decreased
-causes the water to pile up and decrease wave speed, decrease in spacing of the waves and an increase in wave amplitude
What is the 4th stage of tsunami development?
As the tsunami hits land, waves get taller
-wave speeds up
What is a run up?
The max horizontal and vertical distances that the largest waves of tsunami reaches as it travels inland
-basically describes the geographic area impacted by a tsunami
What is a distant tsunami?
Also called tele-tsunamis
-Travels thousands of kilometres across the open ocean
-has a lessened impact
what its a local tsunami?
A tsunami that affects shorlines a few kilometres to about 100 km from its source
Which areas are at a greater risk of being affected by tsunamis?
-coasts located near or across the ocean from subduction zones
What are primary effects of tsunamis?
Floodin+ erosion destroys vegetation adn infrastructure
How do most deaths occur from tsunamis?
What are secondary effects of tsunamis?
These effects generally occur after the event is over
-fires, contaminated water
What are the natural service functions of tsunamis?
-Carry fertile sediment onto the land that can then be used for agriculture
When did the Indian Ocean Tsunami of 2004 happen? What was the magnitude of the earthquake that caused it?
Where did the Indian ocean tsunami occur?
At subduction zone between burma and indo-australian plate
-3rd strongest quake in world history
How many and why did so many people die?
because they didn't have a proper warning system in place in the pacific ocean
-people weren't familiar with tsunamis and ignored the warning signs
Why isn't a warning system enough?
Need an evacuation plan
tsunami education is also needed
How do you detect tsunamis?
Seismographs are connected to buoys that verify if a tsunami was produced from the quake.
What are Tsunameters?
Sensors that rest on the sea floor and measure changes in water pressure paling over them
What are some structural controls for tsunamis?
- better building regulations
- off shore barriers
What are inundation maps?
Shows the run up of previous tsunamis which help to plan for future events
Why is vegetation important in the protection of land?
Dense vegetation protects areas farther inland
When did the Japan Tsunami occur and what magnitude?
March 11th 2011
9M quake which produced the tsunami
Was there a warning issued for the Japan tsunami?
Yes, just an hour before it hit land
Midterm Question: Why are tsunamis rare in the Atlantic Ocean?
Because earthquakes aren't common in the Atlantic ocean because there isn't a plate boundary there to create one. So no quake=no tsunami
What are the 3 categories of Adjustment?
1. Modify the Loss Burden
2.Modify the Design
3. Modify Human Vulnerability
What does it mean to modify the loss burden?
-spreading the burden well beyond immediate victims
Ex: insurance and relief aid
What does it mean to modify the design?
-requires a knowledge base of the hazard
Ex: retrofitting buildings
What does it meant o modify human vulnerability?
Adjusting the population to the possible events
Ex: land planning warning systems, preparedness programs
What are the 2 scenarios of loss?
1. Accepting Loss
2. Sharing loss
How do people accept loss?
This is the 'free choice' it is a no action response.
-people choose to live how they want regardless of the hazard risk
how do people share loss?
This is the government action response
-may be laws in place to prevent people from lung in certain areas
-if government doesn't intervene after a disaster there is often political ramifications
What external sources can aid come from?
UNICEF, government, insurance, local
What is the problem with sharing loss?
-Donor fatigue can set in if there are many disasters
-Recovery can take a long time
-Aid and enthusiasm to donate eventually fades
What are the 3 factors affecting individual adjustment choices?
2. Material Wealth
What does it mean by experience when looking at factors that affect individual adjustment choices?
More experience with a hazard results in more likelihood of adjustment
What does it mean by material wealth when looking at factors that affect individual adjustment choices?
More resources result in more information and more options
What does it mean by personality when looking at factors that affect individual adjustment choices?
Some people are more likely to take risks, some people have more confidence than others
What is the prospect theory
Generally, people are more willing to protect against a loss than than they are willing to gamble on an equivalent gaini
What is purposeful adjustment in terms of human responses to hazards?
This is an adjustment that is specifically designed to reduce loss or damage
-Ex: designing building to withstand high magnitude quakes
What is incidental adjustment in terms of human responses to hazards?
These are not primarily hazard-related but they have the effect of reducing potential loss
-Ex: Improved warning systems
What is absorptive capacity in terms of human responses to hazards?
measure of the ability of people to sustain impacts from a hazard
-results from cultural purposeful and incidental adjustments
The likelihood of a 100 year tornado touching down in 2016 is considerably less than 0.01 because one struck in 2015. true or false?
False: just because it happened last year inset relevant to the year we are looking at, we don't cary over the weather from last year over. We reset every year