Transcript Geology 102: Historical Geology August 23, 2006

November 18, 2009
How to Make Pumpkins Fly
"It's a redneck thang. You wouldn't understood."
(Nov. 14) -- Start with one delightfully warped science
project contest for grown-ups. Add a touch of county fair
and a whole lot of tailgating. What do you get? Flying
pumpkins. Every year on the first weekend after
Halloween, competitors bring catapults, trebuchets, air
cannons and all sorts of other pumpkin-launching
contraptions to a vast cornfield near Bridgeville, Del. The
World Championship Punkin Chunkin draws fans from
all over the country to rural Sussex County, where a
pumpkin is a "punkin" and "chunkin" rolls off the tongue
so much easier than "chucking" after "punkin." This year,
there were 109 machines in the competition, and 70,000
spectators.
 Reading Ch. 13
 YES, there is class on FRIDAY
Permian
Mass
Extinction
(251mya)
 Devastated 90-95%
all species
• < 5% sea life survived
• ~1/3 of large land
animals survived
• Trees almost
obliterated
http://evolution-textbook.org/content/free/figures/ch10.html
http://ngm.nationalgeographic.com/ngm/0009/feature4/index.html
Proposed Causes
 Global cooling?
• Caused other extinctions
• Reduced marine habitats
 Support
• Pangaea formation
Glaciers at poles
• Siberian traps
Flood basalts
 Likely cause?
• Probably not
mid-Permian cooling
Climate instability
http://www.emporia.edu/earthsci/student/kaczor1/rk.htm
http://earthobservatory.nasa.gov/Features/SiberiaBlog2008/page9.php
Proposed Causes
 Volcanic activity
• Ash would block sunlight
• Acid rain generation,
followed by greenhouse
• Support
Siberian traps
 Asteroid impact
• Support
Possible impact crater
– Anarctica
http://researchnews.osu.edu/archive/erthboom.htm
http://science.nasa.gov/headlines/y2002/28jan_extinction.htm
http://earthsci.org/fossils/space/craters/permian/permian.html
http://www.scientificamerican.com/article.cfm?id=geologists-link-the-great
Proposed Causes
 Ocean anoxia
• Oxidation of organic matter
Created dead zones
• Bicarbonate burp
CO2 upwelling
• Sulfide production
Phototroph blooms
– fed by nutrient input from eroding land
– Chlorobium (GSB)
http://www.msnbc.msn.com/id/30563213/
http://www.bio.ku.dk/nuf/projects/index.htm
http://waterresearch.blogspot.com/2007/06/bule-green-algae-bloom-in-dianchi-lake.html
Exam 3 (before curve)
10
9
8
7
6
5
Series1
4
3
2
1
0
90-100
80-89
70-79
60-69
50-59
40-49
Exam 3 (after curve)
12
10
8
6
Series1
4
2
0
90-100
80-89
70-79
60-69
50-59
40-49