ERSC 1P92 Extreme Earth

Final Exam:

Wednesday, December 3, 2008

1400h – 1600h

WCIBDS - Ian D. Beddis Gym

110 multiple choice or “figure” questions to be answered on SCANTRON sheets

Questions will be based on material covered over the entire course.

The nature of scientific ideasSpeculation

HypothesisTheory

Law

Geology 001: the basics

Igneous RockSedimentary Rock

Metamorphic Rock

Fossils

The geologic cycle

A Brief History of GeologyHerodotos Aristotle Theophrastus St. Thomas Aquinas

Leonardo da Vinci James Ussher

Neptunism versus Plutonism

Abraham Werner

James Hutton and the Principle of Uniformitarianism

Georges Cuvier Charles Lyle

Catastrophism in the 20th Century

The Origin of the Solar System

Nebular Hypothesis

The Planets of the Solar System

The early history of the Earth

How did the Moon form?

Comets, Asteroids and Meteoroids

Asteroids (rocky bodies)

Meteoroid

Meteor

Meteorite

Bolide

Comets: dust and ice.

The Risk of Space Objects to Humans

K/T boundary impact

Tunguska Event

Comet SL-9 impact on Jupiter

What happens when a meteoroid or asteroid reaches the Earth?

Heat wavePressure wave

Impact crater formation

What is the frequency of impacts with Earth?

Near Earth Objects

Evaluating the risk of asteroid impacts.

Impact craters on Earth

How they form.Crater anatomy.

Major craters on Earth.

Plate Tectonics defined.

What did Plate Tectonics replace?

Alfred Wegener and Continental Drift.

  Evidence

Theory

Outcome

Contracting Earth Theory

Geomagnetism

Earth’s Magnetic Field

Geodynamo

magnetic declination

secular variation

Orientation of the Earth’s magnetic field.

Magnetization of rocks

Remnant magnetic signature (RMS)

Magnetic Anomalies

Apparent Polar Wandering

Apparent polar wandering paths pointed to continental drift.

Sea Floor Stripes and Sea floor Spreading

Polar reversals

Plate TectonicsStructure of the Earth

USGS

Plate Boundaries

Transform Margins – Horizontal slip

Oceanic Trench– Convergence

Oceanic Ridge– Divergence

But what drives plate tectonics?

Anatomy of an Earthquake

Earthquakes

What is an Earthquake?

Shockwaves generated by energy released as adjacent rock bodies suddenly move.

Types of Shockwaves

L-waves (surface waves)

S-waves(secondary or shear waves)

P-waves (primary waves)

Intensity

Magnitude

Damage due to earthquakes

Surface vibration

Landslides

Liquefaction

Tsunamis

Distribution of Earthquakes

1. Along oceanic trenches.

2. In regions of continental collision.

4. Within plates, well away from plate margins.

3. Along oceanic ridges and transform faults.

Predicting earthquakes

Long term prediction

Recurrence rates

Seismic Gaps

Short term prediction precursor events

Seismic wave velocities Ground level deformation

Groundwater Chemistry Microearthquake swarms

Direct Sensors Animal warnings

The Great Canadian Earthquake???(Evidence for a southern BC megaquake)

Early evolution of the Earth and its atmosphere.

Formation of the Earth’s core and crust.

The Earth’s atmosphere and the evolution of early life.

Climate versus Weather

Weather: the condition of the atmosphere at a particular point in space and time.

Climate: the average weather for a defined region.

Climatic Radiative Balance and Radiative Forcing

Climate Change Over Geologic Time

Climatic fluctuation over the Tertiary and Quaternary periods.

Conditions in the Cretaceous

Much warmer as CO2 levels were elevated due to an increase in volcanic activity.

4 glacial periods

Global warming and glaciers

Mild winters, abundant snow and cool summers.

Cold, dry winters, hot summers.

Glaciers will not develop.

Glaciers develop.

Milankovich Cycles

Carboniferous/Permian

Cooling due to CO2 removal by extensive weathering.

Snowball Earth

That 600-700 million years ago the Earth was effectively covered by glacial ice, including 500 to 1500 m thick sea ice cover.

Volcano: A mound of material that is extruded to the Earth’s surface from a vent that is connected to a magma chamber via a feeder conduit.

SiO2 content controls viscosity of the magma which in turn controls the amount of gas in the magma and its explosivity.

Types of volcanic deposits

Lava: very fluid, low viscosity magma at the Earth’s surface.

Pahoehoe

Aa

Pillows

Tephra: Ash, lapilli, blocks and bombs.

Pyroclastic material

Tuff

Ash fall

Lahar

Nuée Ardente

Shield volcanoes:

dominated by lava flows.

Cinder cones:

Isolated cones dominated by

pyroclastics.

Stratovolcanoes:

mixture of lavas and

pyroclastics.

Prediction of Volcanic Eruptions

Short-term prediction

Surface tilting: recognition of changes in the land surface due to building pressure in the conduit.

Gas emissions: rates of emission and type of gas changes in some volcanoes.

Earthquakes: generated as the magma moves up the feeder conduit to the vent.

Identify the distribution, frequency, style of eruption, etc.

Determine local risks to specific hazards.

Long-term prediction

The impact of volcanic eruptions

Global Climate Change

Volcanic Explosivity Index

Mt. Pelée (1902)

Major Historic Eruptions

Tambora (1815)

Krakatoa (1883)

Krakatoa (535 AD)?

Super Volcanoes (>1,000 km3 of ejecta)

Toba

Yellowstone

Volcanoes in Space