Welcome to Geology 218: Environmental Geology

Dr. Ralph Dawes, InstructorToday’s plan.

IntroductionsSyllabus

Active learning is key.Geology learned by reaching out, taking part. HP Compaq tc4200

tablet computer and Earth, ca. 2005

Image Source: http://www.dell.com

Talk to another student and introduce her or him to the rest of the

class in terms of…First and last nameTown where they live Geologic hazard or environmental issue most interested in

Image Source: http://www.k5geosource.org/content/esimage/sea.html

Thinking about Earth / Environment1. Scientific Method 2. Empirical, experimental, &

theoretical approaches3. History of science/geoscience 4. Evolution and environment5. Population growth and

humanEarth interactions6. Earth systems science 7. Dynamic Earth Systems 8. Links & Cycles Among Earth

Systems: Matter and Energy

Image Source: http://www.nasa.com

The Scientific MethodIdeas about nature in terms that are logical, rational, verifiable, repeatable, and yield manipulative/predictive powerMathematical: most elegantly logicalMeasurable, observableHypothesis (what most people mean when they say “theory”)Theory: Verified, repeatedly confirmed, powerful, insightful, predictive.Some common misconceptions…

Image source: http://courses.ncssm.edu/math/CPTA/data/DECAY/decay.gif

Empirical, experimental, & theoretical

Empirical: based on many careful measurements and observationsExperimental: controlling the variablesTheoretical:

may or may not be mathematically expressedprovides explanations that account for the evidencemakes predictions that prove true

E = mc2

Image Source: http://www.stevespanglerscience.com/product/1274

Image Source: http://www.science.smith.edu/departments/Geology/Structure/fieldphotos/4_03/

History of science/geoscienceGeology was one of the leading sciences that arose from the EnlightenmentRanks with physics, chemistry, biologyIn 1800…

Chemistry still separating from alchemyAstronomy separate from astrology for ~200 years (since Copernicus, Kepler, Galileo)Biology post-Linnaeus, pre-DarwinPhysics 100 years since NewtonGeology still over 200 years old, but age of Earth not resolved

Image Source: http://www.scottishgeology.com/history/people/james_hutton_image.html

Evolution and environment

Given that natural selection favors those most well-adapted to the environment, changing environments are a key factor in evolution10,000 years ago wooly mammoths, mastodons, giant elk, etc. existed, but soon after became extinct, probably due to environmental change

At that time the earth warmed up from the last glaciation of the Pleistocene ice ages, driving rapid environmental change

Changes in future earth environments will also change ecosystems and cause extinction of species

Image source:http://www.cr.nps.gov/seac/mam-mis.htm

Population growth and humanEarth interactions

As populations grow and societal infrastructure expands, so does exposure of society to earth hazards

Hurricanes striking increasingly populated coasts is just one example

More humans require more resources (or do they?)Population growth causes:

More land developedMore air, water, and soil pollutionMore floods (why?)Climate change (why?)etc. Image Source:

http://blog.frogbody.com/frogblog/2005/01/

Earth systems science

Geosphere

HydrosphereBiosphere

Atmosphere

Dynamic Earth SystemsFollow a molecule of water in the oceanInto an altered basalt on the ocean floorDown a subduction zoneInto magma (molten rock)Up a volcanoOut with a steam-exploded eruptionInto the atmosphereDown as rainEtc…One tiny example.

Image Source: http://www.island-air.com/ScenicTours/Mt%20St%20Helens.htm

Links & Cycles Among Earth Systems: Matter and Energy

The earth’s surface gets much of its energy from the sun:

WindRainRiversErosionHurricanesEtc.

The earth’s interior gets its energy from remnant heat of earth formation plus natural radioactivity in the rocks:

VolcanoesMountain range upliftEarthquakesPlate tectonics

Image Source: http://www.noaanews.noaa.gov/stories2005/s2372.htm

Image Source:http://www.lbl.gov/Science-Articles/Archive/Phys-earth-core.html

Earth Systems4 main systems:

AtmosphereBiosphereHydrosphereLithosphere (Geosphere)

Lithosphere also has other meanings

Each OtherBoundaries arbitraryEnergy and matterReservoirs and fluxesImage Source:

http://seis.natsci.csulb.edu/rbehl/300i-L01.htm

Earth systems compositionsAtmosphere

Biosphere

Hydrosphere

Lithosphere (Geosphere)

Image Source:http://seis.natsci.csulb.edu/rbehl/300i-L01.htm