ermslides4
DESCRIPTION
Class presentation slides for the fourth quarter of ERM 150, Spring Semester 2009TRANSCRIPT
Climate ChangeChanges in water distribution
Changes in Weather Patterns
Extremes
Sahara
Dust Bowl1934 - 35
Causes7 years drought
Overworked soil
Extensive rangeuse
Drought
Dust Bowl
Dust Bowl
Civilian Conservation Corps (CCC)
Shelter Belt
Dust Bowl AftermathEmergency Farm Mortgage ActFrazier-Lemke Farm Bankruptcy ActTaylor Grazing ActEmergency Relief Appropriation
ActSoil Conservation ServiceShelter Belt Project
Consequences of Drought
California
Oakland 1991
San Joaquin Delta2006 (Maurer)
Floods in winterDrought in summer
Fall 2007
Spring 2009
Fargo, ND
Fargo, ND & Moorhead, MN
Midwest 1988
Mississippi 1993
Katrina 2005Erosion
Runoff
Mold
Tree loss
Moche
The Weather
$$ Disasters $$
!Kung Sanhxaro
Ancient Floods5600 BC
Ancient FloodsVishnu
Gilgamesh
Target: Earth
Extraterrestrial Impact
Evidence
Our Moon
Comet Shoemaker - Levy July 1994
Jupiter’s Moon Ganymede
Terrestrial Impact Sites
The Solar System
Geocentrism
Piazzi 1801
CeresVestaPallasJuno
Asteroid Belt10,000+ objects
All < 500 km
Irregular in shape
AsteroidsFragments
OR
Remnants of early solarSystem?
Earth crossers
Kuiper Belt
Kuiper Belt Objects
Oort Cloud
Comets
Omens
Mark Twain & Halley’s Comet
“I came in with Halley's Comet... It is coming again ... and I expect to go out with it... The Almighty has said, no doubt: 'Now here are these two unaccountable freaks; they came in together, they must go out together.”
Comet Composition
Cometary Orbits
Meteor Showers
Meteor ShowersLyrids Apr 24 Comet
186115/hr
Eta Aquarids May 4 Halley 20/hrDelta Aquarids July 30 ? 20/hrPerseids Aug 12 Comet 1862 60/hrDraconids Oct 9 Giacobini 15/hrOrionids Oct 21 Halley 20/hrLeonids Nov 17 Comet 1866 15/hrGeminids Dec 13 Phaeton 50/hr
Meteor Shower 1833
Meteorites
October 2008 (2008 TC3)Entered Earth’s Atmosphere
2008 TC3
Feb 2009
Tunguska 1908
Tunguska
Force = 40 Megatons
Pressure wave
Lake Cheko?
Impact Craters
KT Event
Luis & Walter Alvarez
Iridium anomaly
Soot
Where did it Hit?<-250 km->
65 million years ago
Shocked Quartz
ChondrulesCarbon + silicates
Meteoric
Microspherules
Microscopic glassdroplets produced by rapid cooling
ApproachAsteroid
VS
Comet
Mass Extinction Event
ImpactImmediate:
10+ earthquaketsunamishockwavefirestorm
200 trillion tons TNT
Nuclear Winter http://www.atomicarchive.com/Movies/Movie6.shtml
Long Term Changes50 year cloud cover
Loss of Photosynthesis
Emergence of Mammals
Permian extinction275 million years ago
Large scale insect and marine event
Pangaea
Methane Hydrate Release?
CH4 trapped in watermatrix (low temp,high pressure)
Lake Nyos 1986
Camerooncaldera
CO2 release
Flaming IceExposure to Oxygen:
flammability
Results
Mass Extinctions
The Next Collision?
Apophis
ApophisApproach:
2029
Return Apr 13, 2036
Impact Trajectory
1950DA2880
B612 FoundationLocate & deflect
Earth crossingasteroids
Rusty Schweikart
Risk
Alternative ExplanationsSupernova?
Megavolcano(es)
Marine Regression
Pathogens
SupernovaProduces Pt-244
2 million years agoFe-60 deposits
MegavolcanoesDeccan Traps
60-68 x 106 years ago
Shiva Crater
Marine Regression
PathogensT. rex coprolites
Parasite InfectionsSandflies roundworms
Greatest Threat
Triumph of Survival