Natural Disasters Exam #3

4. Know our six cyclone ingredients.

1. Warm ocean water 2. Pre-existing disturbed weather (Tropical Disturbances) - tropical thunderstorms 3. High humidity - release of latent heat, high pressure area vents system and draws more warm, moist air in at lower levels, powering storm 4. Rapid cooling - air rises and cools fueling storm 5. Low wind shear - hurricanes get organized 6. The Coriolis Effect - causes fluids to turn as they travel

3. How are barrier islands oriented relative to the coast, and are they stationary islands?

3. How are barrier islands oriented relative to the coast, and are they stationary islands?

7. Could you make a deep-water wave in a coffee cup?

Yes

2. What happened during the 1974 superoutbreak?

a. 148 tornadoes in 18 hours b. 315 people died c. As many as 20 tornadoes were on the ground at any single time d. April 3-4, 1974 e. 95% of tornadoes were "significant"

9. What happened during the 2005 hurricane season? You should know about Hurricane Katrina and Hurricane Wilma.

a. 2005 season had a record of 28 tropical storms, and 15 were hurricanes. It was the first season to use Greek letters to name tropical storms b. Hurricane Katrina - most costly hurricane ever, devastated Louisiana, close to 2000 deaths c. Hurricane Wilma - First storm to use "w" since creating the list, third category 5 of the season, second most intense hurricane ever, hit Florida

6. How rapidly has sea level been rising from 1993-2016?

a. 3.4 mm/yr

2. How many states in the United States have coastlines, and what is the average rate of coastal erosion?

a. 30 states b. Average rate of coastal erosion is 2-3 ft/yr

9. How do dams impact river systems?

a. Can stop small floods by regulating flow

4. Know our wave anatomy diagram for deep water waves.

a. Circular orbits b. Waves don't move anything anywhere c. Water depth has to be more than ½ in wavelength

2. What kinds of sediments are there in streams and rivers?

a. Dissolved - minerals in solution from chemical weathering b. Suspended - small rock pieces held aloft by turbulence c. Bed load - course material dragged by traction or rolled/bounced by saltation

7. What is storm surge and how is it generated?

a. Dome of water hitting coast, generated by high winds, piling up ocean water and extremely low atmospheric pressure causing sea level rise

7. If you get caught in a rip current, what should you do?

a. Escape parallel to the shoreline

8. Where else in the world do tornadoes occur?

a. Europe - 170/yr, Netherlands, usually low-intensity b. Bangladesh - 84 in 50 years, more deaths than anywhere else due to dense population and poor construction

11. Know the parts of hurricane anatomy discussed in class and their characteristics (eye, eye wall, spiral rain bands)

a. Eye - region of calm winds at center of hurricane b. Eye wall - right of most intense convection and highest velocity winds surrounding the storm center c. Rain bands - bands of heavy convection (thunderstorms) spiraling inward towards the storm center

2. How can we permanently lose sand from a beach system?

a. Finer sediment is transported offshore out to shelf. Sediment piles up at head of submarine canyon, then slides, forming a "turbidity current."

3. Where do tornadoes most commonly occur?

a. Flat topography, Southern/Midwest United States

10. How is flood damage changing with time and what steps do we take to mitigate for it?

a. Flood damage is growing because of the increase in population around flood-prone areas b. Continue structural measures supplemented by federal subsidized flood insurance existing structures and more near-actuarial rates on new structures

4. What are some landforms associated with rivers?

a. Floodplains - flat, low-lying area along channel subject to floods b. Natural levees - deposition, accumulation of sediment along banks during low-velocity flood

11. Given a coastline with projecting headlands and sheltered bays, where will erosion and deposition occur?

a. Headlands get eroded, sheltered bays get protected and deposition occurs there.

7. Describe what happened in the Iowa City flood of 2008.

a. Heavy rain and snow in preceding fall and winter, intense rainfall in June, 2.7 billion dollars in damage, 24 killed, major systematic infrastructure problems, crop loss

1. What hurricane made landfall on October 10th, 2018, in Florida, and how strong was this hurricane?

a. Hurricane Michael, Category 4

1. How might warming oceans impact hurricane frequency and strength?

a. Hurricane strength correlates with SST, sea surface temp. Most energy derived from heat stored in ocean water. Warm water increases hurricane frequency and strength.

4. What characteristics do you need to generate and sustain tornadoes?

a. Intense low pressure, sharp pressure gradient, strong wind speed

8. Why are hurricane damage costs increasing?

a. Intensive buildup of low-lying coastal areas

1. What records were set/unique occurrences happened during the 2017 Atlantic hurricane season? Know where Harvey and Maria made landfall and their impacts.

a. It was the first time that two Atlantic Basin Category 4 hurricanes have made landfall in the U.S. since 1851. Irma and Jose sustained winds greater than 150 mph, the first time that was observed in the Atlantic. For the first time on record, three consecutive category 4 storms occurred: Harvey, Irma and Jose. b. Harvey - Southeast Texas, one of the costliest disasters in U.S. history with $190 billion in damage, was the most extreme rainfall event in U.S. history. c. Maria - Puerto Rico, max strength with category 5, 3,000 deaths, in affected areas, it took nearly a year to get power back for many communities.

5. When does the north Atlantic hurricane season run from?

a. June 1 - November 30

9. What is a beach?

a. Loose sand along shore deposited by waves

8. Why is low wind shear important for hurricane formation?

a. Low wind shear allows the storm to get organized and form, high wind shear breaks up the clouds.

1. When are tornadoes most likely to occur - both during the year and during the day.

a. May-June, 3-7 p.m.

3. Describe the different stream types.

a. Meandering streams - low sediment load, low velocity, one main channel b. Braided streams - high sediment load, high velocity, many channels

7. What does warm water provide, in terms of hurricane formation?

a. Means for energy to travel faster and gain intensity.

5. Understand what a mesocyclone is and what it has to do with a radar hook echo.

a. Mesocyclone - forms when horizontally circulating winds reach warm updraft of a developing thunderstorm and are lifted into a vertical rotation vortex 10-20km in diameter b. Mesocyclone spins counterclockwise and provides strong updraft, generating radar hook echo

10. Does a hurricane have more or fewer closed isobars than a tropical depression, and what is the pressure at the center of a hurricane? Similarly, how does decreasing pressure relate to hurricane strength?

a. More closed isobars, low pressure at center, lower pressure at center means greater hurricane strength because velocity increases.

6. Describe what happened in the Johnstown Flood of 1889.

a. Most devastating flash flood in U.S. history. Human's fault destroyed dam from fishing & hunting club, 2000+ killed

11. What are the benefits of flood plains?

a. Natural flood & erosion control b. Water quality maintenance c. Groundwater recharge d. Richer harvests e. Recreational opportunities f. Scientific and outdoor education g. Biological productivity h. Fish and wildlife habitats

4. Know the different hazards associated with hurricanes.

a. Ocean waves b. High winds and heavy precipitation c. Storm surge

6. Explain the different stages of development of a tornado.

a. Organizational stage - Mesocyclone developed by wind shear, major updrafts causing wall cloud, wall cloud begins to rotate and short funnel descends b. Mature stage - Visible funnel extends from thunderstorm, funnel is condensed water vapor caused by cooling due to low pressure, dust cloud at base c. Shrinking stage - supply of warm air reduced, tornado thins and begins to tilt, conservation of momentum as funnel width decreases and winds increase, upward-spiraling air comes in contact with downdrafts and tornado begins to move erratically, beginning of end

5. What are the different types of floods?

a. Regional floods - when a river overflows its banks on a large scale, flooding entire regions b. Flash floods - intense local rainfall causes stream to suddenly flood small area, usually local watershed c. Ice-jam floods - melting ice-floes dam a portion of a river, normally in spring, causing it to flood upstream from ice blockade d. Storm-surge floods - sudden rise in sea level inundates coastal areas usually during intense hurricanes or "northeasters." e. Dam failure floods - more often than not result of faulty engineering, people-induced f. Mudflow floods - lahars, when ash from volcanic eruption washes into rivers and creates mudflow-like conditions

2. What is the scale that we use to classify hurricanes, and what is this scale based on?

a. Saffir-Simpson Scale - Ranks 1-5 damage potential of land-falling hurricanes based on sustained wind speed

4. You should be able to match our "Armoring the shoreline" methods to their descriptions.

a. Seawalls: vertical walls built on land and parallel to the beach to absorb wave energy b. Revetments: Riprap or interconnecting concrete blocks used to protect dunes and beaches from erosion c. Jetties or groins: Rock walls or piles built perpendicular to the beach. Generally used to block flow of sand and prevent ship channels from filling in. d. Beach nourishment: Placing sand on an eroding beach.

8. How does a shallow water wave differ from a deep-water wave-how are these two wave types defined? Additionally, how do wavelength, wave height, wave velocity and wave period change (or not change) as a wave moves into shallow water?

a. Shallow-water wave - elliptical orbits, 1/20th wavelength, waves break b. Deep-water wave - circular orbits, don't move anything anywhere, more than ½ in wavelength for water depth

8. What is recurrence interval and what are the problems associated with it?

a. Statistical average of number of years between flows of a certain peak b. Paleoflood data can extend record, may change recurrence interval c. Data must be representative d. Conditions affecting stream should remain constant

10. What can we do to help protect against hurricane damage? This includes protection of natural areas.

a. Stop building residential areas near coast, stop destroying natural resources that block hurricane damage.

3. How do hurricanes dissipate energy and die (three ways)?

a. Storm moves over cooler water b. Storm moves over land c. Storm moves into area where large-scale flow aloft is not favorable for continued development or sustainment (wind shear)

1. Understand the basic processes of streams and rivers.

a. Streams - any flowing body of water, large or small b. River - major branches of a large-stream system

3. How do cyclonic storm names relate to their location?

a. The basin they are located in determines which institution names them, and each institution has different lists of names.

9. Why don't hurricanes form at the equator-relatedly, why do hurricanes spin and why does their spin direction differ depending on hemisphere? I want you to know the name of the effect that causes this (you do not need to be able to describe how it works).

a. The water is too cold at the equator. The Coriolis Effect - causes the hurricane to spin. Points on the equator are spinning faster than points on the poles, so the outside of the storm spins faster than the middle.

3. What happened in Pacifica, California (and is still happening)?

a. There were 12 homes constructed along Esplanade Drive in 1949 on a sea cliff. Due to coastal erosion, most homes no longer have a yard and risk being demolished if they haven't already. The cliff retreats 2 ft/yr.

1. What do tides result from? In spring tides, are lunar and solar tides additive or acting in opposition?

a. Tides result from the moon's gravitational pull b. Solar and lunar tides are additive in spring tides

2. What has the highest and lowest wind speeds- a tropical storm, a tropical depression, or a hurricane? You should be able to order these by increasing speed.

a. Tropical Depression, lowest wind speeds b. Tropical Storm, medial wind speeds c. Hurricane, highest wind speeds

6. What kind of pre-existing disturbed weather makes most Atlantic hurricanes (where do they come from)?

a. Tropical thunderstorms, they come from the Inter-Tropical Convergence Zone, air convergence at the end of mid-latitude frontal boundary in the Gulf of Mexico or east coast of Florida, and easterly waves traveling from east to west.

6. What is a rogue wave, and would you expect one to form from constructive or destructive interference?

a. Twice as big as other waves - come from unexpected directions, usually steep b. Destructive interference

7. What is a typical tornado? What are the characteristics of an F5 tornado?

a. Typical tornado F1 b. F5 - Strong-frame houses leveled off foundations and swept away, automobile-sized missiles fly through air greater than 100m

11. How do warmer oceans lead to the potential for stronger hurricanes?

a. Warmer oceans lead to more energy for stronger hurricanes to form.

6. What hurricane hazard does the most damage to buildings?

a. Wind

5. What three factors determine how large our waves will grow?

a. Wind speed b. Fetch (distance over which wind blows) c. Duration