Exam #1 Environmental Hazards

Definition of hypothesis:

an explanation that can be tested repeatedly

A hypothesis is…

not proven yet

Definition of Theory:

results from extensive experiments and evidence

A theory is NOT a…

guess

Definition of Principle or Law:

scientific theories that are considered correct and experimentally verified

Definition of Hazard:

a natural even that can potentially threaten life and property

Definition of Disaster:

a hazard that actually causes damage to people, property, and infrastructure

Requirements to identify a Disaster:

10 or more people killed, 100 or more people affected, state of emergency, or requires international assistance

Definition of Catastrophe:

a massive disaster that requires significant time and money for recovery

Scale of natural disasters from least to greatest:

hazard, disaster, and catastrophe

All disasters start as…

hazards

What is the natural hazard annual cost worldwide?

$120 billion and 80,000 lives

What are the fundamental concepts?

magnitude and frequency, environmental unity, acceptable risk, and loss

What shapes landscape the most overe time?

magnitude and moderate frequency

What affects magnitude and frequency of events?

land use

Land use increases what?

hazard severity

What concept explains why one environmental change leads to multiple hazards?

environmental unity

Why does deforestation increase flooding?

because it removes vegetation that stabilizes soil and absorbs water

What is acceptable risk?

the amount of risk that an individual or society is willing to take

What is the current population of the planet

7.9 billion people

What is the current population in the U.S?

332 million people

What is the current population in Texas?

29.5 million people

What conflicts does population growth add to?

water, energy, food,open space, transportation infrastructure, and school rooms

What is the major cause of poverty and poor health in developing countries?

large family size

What year did annual population growth rates peak?

1962

What is commonly associated with reduced rates of population growth?

high levels of economic growth

What is population aging?

when a country has more older people and fewer young people

Why does population aging happen?

declining birth rates and rising longevity

What is the result of population aging?

the median age increases

What are the effects of population aging?

crowding in major cities, shortage of young workers, problems with social security and healthcare, and raising the retirement age

The rate of natural increase includes:

births and deaths

What is the rate of natural increase equation?

r= b-d

Birth rates and death rates are usually measured per…

1,000 people and in decimals and percentages

What is the population equation?

(0.69/r=t)

Doubling time in the U.S 115 years variables:

time: t= 0.6/r and r=0.006

What is the big bang theory?

the dominant scientific theory about the origin and evolution of the universe

What does Mars feel like?

cold

What kind of surface did early earth have?

cratered, molten

What did early earth lack?

oceans and a stable atmosphere

Because the Earth was molten, what process occured?

differentiation

What is differentiation?

where dense materials, such as metallic iron, sink toward the center of the planet

When did oxygen begin to accumulate?

after the development of algae

What contributed to the origin of water?

the gravitational capture of icy comets and the release of water stored within minerals

Earths internal structure chemical layers:

crust, mantle, and core

What distinct layers is Earth’s internal structure divided into?

chemical composition and mechanical properties

What is the crust of the Earth?

the thin, rocky outer shell

What is the crust divided into?

continental and oceanic crust

What is the mantle of Earth?

a solid rock layer of iron-magnesium silicates

The iron-magnesium silicates makes up how much of Earth’s volume?

82%

Earth’s internal structure mechanical layers:

lithosphere, asthenosphere, mesosphere, outer core, and inner core

Lithosphere:

the rigid, outermost layer

Asthenosphere:

a hot, "soft plastic" layer that flows slowly

Mesosphere:

a "stiff plastic" layer located below the asthenosphere

Outer core:

a liquid layer where temperature and pressure allow iron to remain molten

Inner core:

a solid center

Energy source in earth’s internal structure:

internal heat, the sun, gravity, and the impact of bolides

P waves ( primary):

the fastest seismic waves and can travel through all phases of matter, including gases, liquids, and solids

S waves (secondary):

these waves have a higher amplitude than P waves but can only travel through solids

Which waves helped scientists identify the outer core?

s waves

Between continental and oceanic crust, which one is thicker?

continental

What is the San Andreas Fault?

the Pacific Plate and the North American Plate slide past one another at a rate of approximately 6 cm per year

DIfferent Plate Boundaries:

divergent, convergent, and transform

How do divergent boundaries move?

apart

How do convergent boundaries move?

together

How do transformed boundaries move?

sideways past each other

What is the divergent boundaries geological setting?

mid-ocean ridges and continental rifts

What is the convergent geological setting?

depends on crust involved

What hazards are linked to plate boundaries?

earthquakes and volcanoes

Definition of minerals:

building blocks of rocks. must be solid, natural, and consistent formula

Definition of rocks:

made of minerals

Different types of rocks:

igneous, sedimentary, and metamorphic

How do igneous rocks form?

the crystallization of molten rock material

Types of igneous rocks:

intrusive and extrusive

How are intrusive igneous rocks formed?

from magma that cools slowly beneath the Earth's surface

How are extrusive igneous rocks formed?

from lava that cools quickly at the surface

How are sedimentary rocks formed?

in horizontal layers called beds through two main processes

Types of sedimentary rocks:

clastic and biochemical/chemical

How are clastic sedimentary rocks formed?

from weathered pieces of pre-existing rocks

How are biochemical/chemical sedimentary rocks formed?

by direct precipitation from aqueous solutions

How are metamorphic rocks formed?

when a pre-existing rock undergoes physical or chemical changes to adapt to new pressure, temperature, and chemical conditions

What is the hydrological cycle?

the continuous movement of water on, above, and below the surface of the earth

What are the key processes of the hydrological cycle?

evaporation, transpiration, precipitation, infiltration, and runoff

What are some hydrological cycle hazards?

flooding, landslides, erosion, and earthquakes

What has turned what was once a disaster into a catastrophe?

increasing population and poor land-use planning

An event is considered a natural disaster if…

10 or more people are killed

Why do high-income countries suffer the lowest number of deaths in natural disasters despite having relatively high populations?

improved warning systems, disaster preparedness, and sanitation post-disaster

A landslide resulting from the clearing of natural vegetation that in turn

causes flooding due to the slide mass damming a stream, which then

damages and destroys homes is an example of…

environmental unity

Why are warnings issued even if the forecast is not 100% for a

predicted hazard?

an informed public is better able to act responsibly than an

uninformed public

The risk society or an individual is willing to take depending on the

situation is called…

acceptable risk

A massive forest fire that causes more damage than a small, contained one but occurs less frequently is an example of…

the magnitude-frequency concept

Most of the more developed countries have…

low death rates and low birthrates

Possible increases in the flooding of the Yangtze River due to

the basin losing about 85 percent of its forest to timber harvesting and conversion of land to agriculture is an example of…

land-use changes affecting the magnitude and frequency of an event.

Natural hazards in worldwide take about an average of _________ lives every year over the last 20 years.

80,000

Over the last 20 years, natural disasters cost an average of_____ US

dollars per year in worldwide.

$120 billion

Assuming the rate of natural population increase is 0.006, how
long does it take for a population to double?

115 years

The processes that produce the earth materials, land, water, and

atmosphere necessary for survival are collectively known as the…

geological cycle

Which of the following is NOT part of the tectonic cycle?

A. Mountain building

B. Continental formation

C. Earthquakes

D. Hurricanes

E. Volcanoes

hurricanes

How do igneous rocks form?

crystallization of magma

What is the correct order of the layers of the Earth

from inside to outside?

inner core, outer core, mantle, and crust

Why is the rock cycle considered a "cycle"?

rock material is constantly being recycled into different forms or

back to magma