Transcript hazards_disasters_end_of_course_review_new

Define Disaster.
A major hazard event that
causes widespread disruption to
a community or region that the
affected community is unable to
deal with adequately without
outside help.
Modified Mercalli Scale
To what extent were the citizens of Tohoku, Japan
prepared for the earthquake and tsunami that
struck on March 11, 2011?
Plus side:
-Tsunamui warning sirens and emergency broadcast
in place to go to higher ground; some heeded this
- Some communities heeded ancient landmarks
warning to not build below a certain elevation
Negative side:
- Inadequate tsunami breakwater protection – most
geologists, engineers, and gov. officials did not
expect such a large earthquake (9.0) and tsunami
would be possible in the Tohoku region due to
previously held theory that only young subducting
crust could generate a megathrust e-quake +
largest e-quake recorded in the region had been
8.2.
Tsunami – vertical
movement of the
oceanic floor due
to an earthquake
(i.e. megathrust
e-quake in a
subduction zone)
which displaces a
large volume of
water generating a
wave or series of
waves
Type of earthquake
hazard?
Secondary
Plate boundary and Margin?
Transform Plate Boundary;
Conservative or passive
eg San Andreas fault
Liquefaction – The process by which wet sediment
becomes a slurry; may be triggered by earthquake
vibrations. Type of earthquake hazard?
Secondary
What type of fault was involved in the Jan. 1994
Los Angeles earthquake and a similar one with
the Jan. 1995 Kobe earthquake?
Blind Thrust Fault
Identify two key factors which led to a dramatically
higher death toll in the Kobe quake (6000) vs. the
LA Quake (60)?
- In Kobe, older wood frame homes shaken to
pieces + heavy tile roofs built for protection
against typhoons + heavy stone ornaments fell
on individuals
- in Kobe, the fault line extended underneath the
city whilst LA it extended away
What factor contributed to potentially
fewer casualties in both cases?
- Early morning + LA Quake occurred on a
holiday
Describe three management techniques to deal with
earthquakes in Tokyo and some other major
Japanese cities?
-When p wave detected, bullet trains shut down
- gas lines to individual homes will shut down
during major shaking; monitored using smart
meters
- earthquake simulation rooms to experience Kobe
magnitude quake
- emergency supplies de-centralized to schools
throughout Japan
Identify three ways in which the residents of
Port-au-Prince Haiti were extremely vulnerable to the
7.0 quake that struck in Jan. 2010 killing over
220 000 people.
- Many buildings not constructed to
withstand such an earthquake
- LEDC government ill prepared and ill
equipped to deal with such a hazard event
- Existing widespread poverty as Haiti =
poorest nation in W. Hemisphere
- Shallow e-quake (focus depth – 13 km)
along a strike slip fault similar to the San
Andreas
Identify two specific adjustments made in China
to avoid similar casualties and damage to the 7.9
magnitude Sichuan quake that struck in May 2008
killing over 68 000.
- Investing close to $100 billion in reconstruction in
the quake zone using stricter building codes (1.45
million homes and about 3000 schools)
- May 12 = declared “Disaster Prevention and
Reduction Day” = education measure
What air mass is associated
with the formation of
hurricanes? Maritime Tropical (mT)
Ocean temperatures must be at
least at what temperature range at
depth to help fuel a hurricane?
26-28°C
To at least what depth (+/- 5m)
must these temperatures occur?
60m
During the formation of a hurricane there
must be a lack of what in the atmosphere
in order to sustain the growth of a
hurricane? In contrast, this is absolutely
necessary for the formation of tornadoes.
Also explain what it is.
Wind shear: winds approaching at different
directions and levels in the atmosphere
produce horizontal rolling of the air;
would disrupt the vertical rising of air in
the developing eye wall.
Describe three key processes involved
in the formation of a hurricane?
Convection: Warm air rising from tropical
waters adds tremendous amounts of
moisture to the air.
Condensation: As warm air rises, it
eventually cools, condenses, and forms
clouds.
Latent heat release: Condensation is an
exothermic reaction releasing heat adding
further buoyancy to the air and moisture
carrying capacity.
What is the deadliest part of the
hurricane and why?
Eye wall; specifically the east side (in
the northern hemisphere) where there
is the lowest air pressure (i.e. where
the air is converging and rising most
violently) and the strongest pressure
gradient = strongest winds + heaviest
rains and possible tornadoes.
What cloud produces the torrential
rainfall with a hurricane?
Cumulonimbus
Why is the eye of the hurricane relatively
calm and clear?
As the violent updrafts in the eye wall
approach the top of the troposphere, some
of the air is forced to turn downwards into
the eye; this gently subsiding air does not
promote the growth of clouds.
Which one of the following air pressures
would most likely be associated with a
hurricane?
a) 1200 mB
b) 1030 mB
c) 1013 mB
d) 950 mB
d) 950 mB
e) 730 mB
f) 510 mB
What scale is used to express hurricane
intensity? Saffir-Simpson Scale?
What is the minimum sustained
wind speed in km/h (+/- 5 km/h) for
a Category One hurricane? 118 km/h
What categories are considered
“major” hurricanes? 3 and above
What category of hurricane is
evident based upon the following
description?
-Some complete roof structure failures
on small residences
- Shrubs, trees, and all signs are blown
down
-Complete destruction of mobile homes
-Extensive damage to doors and
windows
-210-249 km/h sustained winds
Category 4
Which way do hurricanes rotate in the
northern hemisphere and why?
Counter-clockwise due to the Coriolis
effect caused by the rotation of the earth.
Name four pieces of technology used
to measure and track hurricanes?
Satellite images, doppler radar,
computer models, scientific
research aircraft, ocean buoys
with instrumentation, weather
balloons
What phenomena kills the most people
with hurricanes?
Storm surge
% of deaths due to storm surge?
And, what is it?
90%
A rise of the sea due to the winds of
the storm and low atmospheric
pressure.
What category was Hurricane Katrina
when it struck New Orleans? Category 3
Why did 75% of the city end up flooded?
- Storm surge amplified up the industrial canal
(5.4 to 7.5 m) overtopping and then scouring
the levees = first flood
-Two canals from Lake Pontchartrain
undermined and gave way = second flood
- City shaped like a bowl with an avg. of 2.1 to
3m below sea level; pumps overwhelmed and
no place for the water to go
- Wetlands (flood protection) destroyed
How many people did not leave even though there was a
“mandatory evacuation” order? 100 000
Lake
Pontchartrain
New Orleans
Mississippi r.
Digitate or
Type Foot
of
Bird’s
Delta?
Delta
1300-1800 deaths due to Hurricane Katrina
How many homes declared damaged
beyond repair (+/- 1000)? 60 000
Which way do hurricanes rotate in the
northern hemisphere and why?
Economic Impact
(+/- $10 billion)?
Approx. $125 billion
Hurricane Mitch: 11 000 – 12 000 dead
Economic Impact (+/- $1 billion)?
$5 billion
In Nicaragua, what was a secondary
hazard of the hurricane that caused much
damage and many deaths?
Intense rain filled the crater lake atop
the Casita volcano and part of the walls
collapsed – mud flows / lahars buried
villages.
Which biome is most vulnerable to periods of
extended drought and / or desertification and
especially where? (Horn of Africa + Sahel)
Savanna biome on the edge of the desert.
What % of Somalia’s population has been
displaced by the 2009-2011 drought and
resultant food crisis?
25%
Which two countries have had to deal with
an influx of Somali refugees?
Kenya and Ethiopia
What is a natural factor that contributed to
the drought in Somalia?
La Nina
What is a political factor exacerbating
the impact of the drought?
Al-Qaeda linked Al-Shebab controls
much of southern Somalia and
prevents international aid from getting
to the people.
Define an arid area – two key
characteristics
-Potential Evapotranspiration exceeds
Precipitation for a significant portion of the
year resulting in a large negative water
balance in soil moisture budget.
- Less than 250 mm of precipitation per year
Define a semi-arid area in terms of avg.
annual precipitation.
250- 600 mm
Note: You do not want to say that a desert
area is vulnerable to drought as it is
already in a near perpetual state of
drought. It is those areas near the edges of
large deserts that are most vulnerable to
drought.
List three causes of deserts
- High pressure / Anticyclone dominates (i.e. 30ºN and S)
High = Dry
- Rainshadow / leeward side of mountains
- Continental interior
- Nearby cold ocean current
- Offshore wind
-On the descending branch of a
convection current / hadley cell
What phenomena causes drought in
Australia?
El Nino
How can food aid sometimes increase
vulnerability (for instance, this has became an
issue in Ethiopia?
- Sustained food aid creates dependence
on handouts; shifts focus away from
improving agricultural practices locally
- Ethiopian farmers can’t compete with
free food
What is a potential solution to this dilemma?
- Pay Ethiopians to work on rural public
works projects (eg roads and irrigation);
money can be used to buy local food or if
necessary, food from outside the country
In times of drought, over 9 million
Ethiopians have received food aid from
which specific organization?
United Nations World Food Program
List three US states directly impacted by
the BP Oil Spill?
Louisiana, Mississippi, Alabama,
Florida
1) Periodic drought is a period of at least
_____ consecutive days during which the
avg. daily rainfall does not exceed 0.2 mm.
2) In the Gulf, in terms of employment, which
industry was hit the hardest by the BP Oil
Spill?
3) Approximately, how many barrels of oil
were spilled?
A) 1 000 000
B) 3 000 000
C) 5 000 000
D) 7 000 000
E) 9 000 000
1) 29
2) Tourism
3) 5 000 000