GOPH 375 - Midterm 1

"___ growth" is a kind of mathematical curve that best fits the human population data from the past several centuries

exponential

World wide, and as we noticed just last week in Canada, glaciers ___ leaving research huts, artifacts, and ancient drainage surfaces exposed

retreat due to atmospheric warming

Wildfire, possibly due to power lines downed under high winds, burned most of the town of Lahaina on Maui island, and is a relatively new disaster risk to the Hawaiian Island chain in addition to ___ and ___

volcanic eruption; earthquake

The decrease in the worldwide fertility rate is likely linked to urbanization and increased opportunities for women

True

The ___ of a disaster is the average number of years between same sized events

return period

Since the adaptation of waste water systems in urban areas, and with the advent of science-based medicine, birthrates ___

have changed a little, while death rates have plummited

A natural disaster with a large return period is a low-frequency event

True

In the USA, a tornado killing 10 people is less likely than an earthquake killing 10 people

False

Hurricane Lee, now approaching our Maritime provinces, began as ___ 13 in the eastern ___ ocean just above the ___

tropical storm; Atlantic; equator

If we could decrease the global human population, the death toll from natural disasters would be expected to ___

decrease

As of Thursday, September 7, 2023, ___ 13 grew to become named Hurricane ___, and was predicted to bring heavy rain and dangerous storm surge to ___

tropical storm; Lee; Nova Scotia

Social media misinformation peddlers might have us believe, falsely, that Earth's early heat came primarily from ___

dark energy

Smashing a rock with a hammer into fragments give one the experience of ___ deformation

brittle

A typical molecule in an oceanic plate gets recycled every ___ years, approximately

200 million

In a collision between oceanic plates, the ___ subducts the ___

older, colder plate; younger, warmer plate

Astronomers theorize how our solar system formed ___

by the gravitational accretion of matter

Earth's magnetic and rotational axes don't necessarily coincide

True

What differentiated Earth into a mantle and core?

Fe catastrophe

Below the Curie point of approximately ___ C, Fe-rich minerals align (magnetize) with Earth's magnetic field

550

Storm Daniel crossed Greece, crossed the Sahara desert, and killed thousands of people in Libya. Why might Daniel be considered an anthropomorphic (human-made) disaster?

dam failures due to negligence and no plan to evacuate citizens

Hurricane Lee struck Nova Scotia having followed the ___ predicted path ___

NOAA; almost exactly

The transverse ___ waves apply shear forces to rocks in a direction perpendicular to their propagation direction

Love and S

Can the same fault be classified as both a strike-slip and a transform fault?

Yes

In normal faulting, the hanging wall moves ___ relative to the footwall

down

Sedimentation (deposition following suspension in water) of sand, gravel, and mud in horizontal layers occurs according to the law of ___

original horizontality

Thursday, Sept 21, we notices an Oklahoma earthquake with a hypocentre of about 18 km - why don't we think it is associated with oil-filed production?

hypocentre too deep, oil production EQs associated with about 4km

The frequency of a wave is ___

the number of passing a sensor per second

The supercontinent ___ is thought to have existed about 220 million years ago

Pangea

The sediment layer on the sea floor is ___

thinest near the volcanic ridges

___ waves travel only through solids; on reaching liquids or gas, the wave energy is reflected back into rock or is converted to another form

S

For every ___ times increase in seismic amplitude, the Richter magnitude value increases one integer

10

A building foundation that slides or rolls with an earthquake uses ___ to reduce earthquake-induced damage

base isolation

The seismic-gap method of earthquake forecasting works by identifying ___

segments along a fault that not moved for the longest amount of time

The last major earthquake and tsunami on our west coast occurred on or about 26 January 1700 because:

annual growth rings in drowned trees have no rings after 1699, and a 2m tsunami hit Japan on 26 January 1700

Which of the following does NOT improve a building's resistance to earthquakes?

match its period to the expected seismic waves

In the 1989 Loma Prieta quake, the Marina District building collapses were extensive, and numerous destructive fires broke out, due to all but which one of the following?

Widespread looting and arson

In general, tall buildings have a ___ resonant period

longer

All but which of the following characterize the moment magnitude of and earthquake?

Modified Mercalli Intensity

Recent work in Switzerland suggests that Swiss ___ will retreat completely by ___

glaciers; 2100

As of Thursday, Sept 28, tropical storm Philippe struggled to organize itself around a central eye due to:

strong wind shear high in the atmosphere

Decreasing the pressure on hot rock generates magma

True

Which of these decrease within a rising plume of subduction-zone magma?

percentage of Fe

West Texas earthquake with its hypocentres of less than 10km depth occurred this semester - why might we associate this seismicity with oil-field production?

production facilities near epicentres; oil production seismicity associated with fluid injection at about 4km

___ is a rough volcanic landform

aa

What shape describes the most important mineral building block made of Si and O2?

tetrahedron

Rock melts if ___

• temperature increases

• pressure decreases

• water content increases

As a magma cools, which of these is the correct sequence of mineralization?

olivine, pyroxene, amphibole, biotite mica, and quartz

The volcanic process in this image from Italy is best described as a ___

lahar

Pyroclastic debris is ___

flying lava chunks and rocks

Number of classes so far:

10

Sites for daily disasters:

• Earthquake roundup: USGS

• Hurricane Hootenanny: NOAA

Daily disaster 1 (Sept 5)

• DD: peyto glacier losing ice mass

• ER: plate boundaries: iceland, chile, puerto rico, vancouver island, NOT hawaii

• HH: Tropical depression 13: energized by hot water

Daily disaster 2 (Sept 12)

• DD: 10,000 missing after floods in Libya. Sun heat -> climate heat -> water to atmosphere -> falling -> flood

• ER: Morocco 4.0 -> internal heat

• HH: Storm west africa. oceans get rid of heat quickly via hurricanes

Daily disaster 3 (Sept 14)

• DD: Libya floods, man-made.

• ER: Morocco, Texas-Gulf coast

• HH: Lee gonna hit Nova Scotia.

Difference between storm surge vs storm watch

• Surge: swarm of water

• Watch: watching for high winds and rainfalls

Daily disaster 4 (Sept 19)

• DD: Lee hits Nova Scotia (expected)

• ER: Morocco issues (same as Libya), Texas 4.0

• HH: hurricane nigel

Daily Disaster 5 (Sept 21)

• DD: no

• ER: oklahoma, too deep for fracking

• HH: nigel (affected by upper jet streams), tropical cyclone sixteen (highwinds)

Daily Disaster 6 (Sept 26)

• DD: river swept Guatemala's capital city (poverty again)

• ER: plates middle east

• HH: Hurricane philippe -> cant form eye due to upper sheer winds

Daily Disaster 7 (Sept 28)

• DD: Swiss glaciers get 10% smaller. things exposed. no water = no well mantainance

• ER: Russia, Africa (failed rift/triple junction)

• HH: Philippe, going contrary direction

What is a Glacier?

reservoir of water

Daily Disaster 8 (Oct 3)

• DD: dry summer in alberta

• ER: West texas, fracking -> pump water into subsurface = EQ

• HH: philippe going strong but losing shape, hard to predict path

Daily Disaster 9 (Oct 5)

• DD: India rainfall -> open damns -> flash flooding

• ER: Texas (fracking), Puerto Rico (cluster)

• HH: Philippe prob will hit maritime provinces and disappear

Daily Disaster 10 (Oct 10)

• DD: Afghanistan, big EQ (corruption and poverty again)

• ER: Alaska (surface), Oklahoma (not fracking), Texas (fracking)

Most frequent mega-killers:

earthquakes and hurricanes

Where do most mega-killers occur?

densely populated belt through Asia and Indian Ocean

number of ___ is proportional to ___

fatalities; density population

Economic losses from natural disasters:

• damage structures, loss wages

• more population/urbanization = losses

• insurance loses from storms

Natural hazards:

Risk evaluation -> mitigation before and after event

___ correlation between ___ and ___

inverse; frequency; magnitude

return period

recurrence interval of event

Overview of Human Population:

• more people = more cost

• exponential growth

Last 10,000 years of history:

• agriculture -> domestication -> better shelter and supplies -> growth rate up

Human population today:

• +7 billion

• Growth rate: 1.2% p/year

• Doubling time = 58 years

• GR = fertility rate - mortality rate

• +80 million p/year

Demographic Transition:

• before: high DR and BR (maintain population)

• during: low DR and high BR (increase)

• after: low DR and BR (stabilize)

Urbanization and Earthquake Fatalities:

• more population = more deaths

• more deaths in developing countries (poor infraestructure, MIL-death EQs)

Disease Pandemics:

• spread of deadly diseases

• more people + animals + airplanes

• black death, influenza A, CV-19

Carrying Capacity:

• average population size in a place

• Ireland 1840s

• potatoes -> more population (increases capacity)

• potato death -> many deaths (decreases capacity)

Origin solar system:

rotating spherical cloud of gas/ice/dust/debris -> particles accrete w/ gravity -> contracts, speeds and flattens

Origin of Sun

• most of disk matter (H, He)

• temp increases

• nuclear fusion (H -> He + heat)

Origin of Planets

• gravity -> cloud to rings -> planetesimals -> planets

• solar heat: no gas/liquids for closer planets (close/rocky)

• giant planets get gas/liquids (distant/gassy)

What is IAU?

International astronomical Union

IAU definition of a planet:

1- Eliptical orbit 2- Large and dense enough to become spheroidal 3- No planets/planetesimals in its orbit

Why is Pluto not considered a planet?

• Eccentric orbit

• Crosses Neptune

Origin of Moon

• Mars-sized body collapses w/ Earth and chunk comes off

• Moon = chemically similar to Earth's crust + mantle

• Gases/liquids bye

• Less dense than Earth (no Fe-core)

What is Accretion?

cohesion of matter due to gravity

Origin of Earth:

• accretion ceases

• planet formation (= heat): impact energy -> decay of radioactive elements -> frictional energy from layers

Differentiation of Earth:

• Liquid Fe = denser -> descends to center cuz gravity

• Low density melt left -> rises -> forms solid crust, oceans and atmosphere

Layered Earth:

differentiated in layers (deeper = denser)

Terms that describe layers:

• density (chemical): crust over mantle

• strength (compositional): litosphere rigid, asthenosphere plastic

Behavior of materials:

• Elastic: recovers (glacial rebound)

• Ductile: deforms (shear in asthenosphere)

• Brittle: breaks (EQ fault)

Behavior of materials in Layers

• surface: elastic, brittle

• asthenosphere: ductile, soft plastic

• deep mantle: ductile and stiff plastic

Athenosphere:

• 250km thick

• visible in mid-ocean ridges

• facilitates oblate-spheroid shape

• continents float by isostasy (asthenosphere accommodates it)

Isostasy

gravitational and buoyant equilibrium between lithosphere and asthenosphere

Examples of Isostasy:

• lake mead behind Hoover Dam

• Scandinavia rose: down force from ice sheet -> rebound

Internal Sources of energy:

• impact energy: impacts of bodies

• energy diff under gravity: pull dense mass = release heat

• radioactive isotopes: radioactive decay = heat

Result of internal heat:

• plate tectonics

• EQs

• volcanic eruptions

Age of Earth

• less than 4.57 billion years (we know cuz of the moon)

Tectonic cycle:

• divegent = magma rises -> new oceanic crust -> old diverges

• crust collisions: ocean-ocean, cont-cont, ocean-cont

Plate tectonics

study of movement and interaction of plates

___ is broken into ___ by ___

lithosphere; plates; divergence zones, transform faults, convergence zones