Chapter 01

SC1150 ENVIRONMENTAL GEOLOGYQUIZ 0 RESULTS

This group:- Needs a science course (27%)- Finds geo interesting (33%)- Feels the info is necessary (27%)- Does not expect EnvGeo to be easy

…

Where should we spend our money in MN?

Ranked answers

need to know

sounds easy

interesting

need a

science

other: told I had to;

needed elective; important for

career

SC1150 ENVIRONMENTAL GEOLOGY

Jeff Bartlett [email protected]

QUIZ 0 RESULTS: most people already know some geology

Just one sticking point !

T F

water = over half Earth’s surface 93% 7%

water = over half the Earth’s volume 75% 25%

rocks are made of minerals 100%

there’s more oil than coal 25% 75%

drought is a MN concern 81% 19%

glaciers were important in MN landscape 88% 13%

Your news items: ripped from the headlines

The Basic Idea

This course includes the examination of Earth processes that influence human activities.

Topics include Earth development, rocks and minerals, internal Earth processes, surface Earth processes, Earth resources, pollution, and waste disposal.

Environmental Geology [email protected]

Environmental Geology: the‘environmental’ part

Connects the lithosphere to the hydrosphere, atmosphere, biosphere & human sphere

You

are

here


Scientific MethodHypothesis is formed to explain

observations or dataMakes predictions to test repeatedly and systematically

Conclusion includes direction for further questions - actually continues a cycle


But really – is this how our investigations work?

wired.com

Chaos – accidents and dead ends are very very common

Mysteries drive curiosity Practical issues drive projectsEconomics is important for

stakeholders

Scientific Method


Actual hypothesis – experiment – result type process

‘Beauty is in the eye of the beer holder’: People who think they are drunk also think they are attractive

Examples of traditional experimental science

Geology and the Scientific MethodGeology has unique issues A pressing environmental

issue: Tuvalu and sea level change

“Tuvalu is growing” USGS, 2010

“Sinking feeling in Tuvalu” BBC, 2002

Geology is an environmental scienceRocks record how earth has changedControl of erosion and sedimentationExtraction of resourcesRecognition and mitigation of hazardsIssues with scaleA river is not easily fit within a laboratoryPlate tectonics involves the whole EarthProblems with timeGeologic processes take millions of yearsGeologists are limited by human timeProblems with resolution of dataNew technology and proceduresWe can see more details now


Anyone can be a geologist

What it really takes :

Observation– either natural or controlled

circumstances

Reasoning drive curiosity

Evidence to collect and assess important step!


Progress includes both conclusions and new questions

Formation of the solar systemFormation of the earthComposition of the earth

Interaction with humanityGeologic hazardsPopulation

An Overview of Our Planetary EnvironmentChapter 1

Environmental Geology looks at interactions between

humans and geologic environments


Setting the stageThe Big Bang Theory is the dominant scientific theory about the origin of the universe. widely accepted, but hard to prove

The universe was created 10 - 20 billion years ago from a cosmic explosion that hurled matter and in all directions.[latest estimate = 13.8ish]

Very smallest particles were forced into larger particles, then basic atoms of lightest elements: 1H, 2He, 3Li, and so on up to 16O


Stellar furnacesBigger elements had to be fused in stars themselves… that gets up to iron , 56Fe


What about very heavy elements like gold, 197Au?

Elements have to form during solar collapse, and resulting supernova explosions

The only known process with energy that can form these elements…

Solar systemFormed ~5 billion years ago, out of swirling mass of gas and dust - the ‘solar nebula’Planet compositions dependedon distance from the hot sunnear = rocky / metallic far = gaseousNearest planets: metallic iron, few very high temp minerals, little water or gas. Farther from the sun: lots of low temp minerals, water, & condensed gases.


1.4

5.6

g/c

c

Planet #3:• >4 billion years old• 15 o C, not really

too hot or cold• Tilted >20º• Rocky with gases

Earth – planetary formation

One impact made our moonAs cooling progressed, dense materials [Fe] sanklighter, low-density minerals [Si] floated out toward the surface

Early Earth – a barren world with a cratered surface Earth was target of many impacts

Asteroids MeteorsComets Dust Particles


= =

Earth – differentiation and change

Heat from core escapes by convection, keeping the planet constantly changing

Figure 1.4

Differentiation Core: dense, hot

Ni + FeMantle: thick zone that

surrounds the coreMushy, hot ultramafic rocks

Crust: Zone of interactionOceanic (mafic)continental (felsic)


Composition

Crust has loads of Si, O, and Al

Atmosphere lacked free oxygen (O2)Dominated by N, CO2 & SO2

A

Heating and differentiation of the early earth formed crust, atmosphere and oceans. Minerals released gasesImpacts brought extraterrestrial elements!


Early environment

Very early in the world, life began and interacted with the earth

Earliest fossils show that bacteria used ancient atmosphere and ‘polluted’ the seas with O2 Iron rained out of seas

Result – oxygen in the atmosphere, and iron in the rocks!This is a great example of a feedback between biosphere, lithosphere and atmosphereEcological interactions were responsible for changing the world: We would not exist if they hadn’t


Curiosity Rover Finds No Sign of Methane

Geologic Hazards

Rising tide of acid mine water

threatens Johannesburg

Fig 1.6-1.9

A dangerous place!

Partly because of us:- Choosing to live near hazards- Poor understanding- Contributing to risk

Residents on edge over eroding bluff


Population GrowthExponential growth:

• Possibly 9 billion people by 2050

• Life span & birthrate up, mortality down

• Mass mobility

Inflection [change] point:• Acceleration is

slowing to zero• Population decline

in many countries


Overcrowding? Nah — the World’s

Population May Actually Be Declining

Global population density

Figure 1.18

Figure 1.15


Density is highly variable and depends on resources, space, culture, economics etc


The Earth has some time left before the sun gets too hot. Based on their models, the scientists calculate that the planet will fall out of the habitable zone some time in the next 1.75bn to 3.25bn years. Then, the habitable zone will start beyond Earth's orbit, and make Mars more earth-like

Earth Expected to Be Habitable for

Another 1.75 Billion Years

Technology

Chapter 01