Show:
Walter Alvarez
K-T boundary
Meteor
Crater
Miscellaneous
100
Who was Walter's father?
Luis Alvarez
100

What interesting observations did Alvarez make about the KT boundary that originally sparked his interest. 

1) He found no fish fossils  

2) The forams in the older layer were bigger than the younger layer 

100

What was the size of the meteor?

10 ± 4 km in diameter.

100

What Texan riverbed provided the biggest clue about the crater’s location?

The Brazos River.
100

What interesting work did Luis Alvarez work on during WWII?

He worked on the Manhattan Project, specifically made detonators for the atomic bombs. 

200
While studying the formation of Gubbio, what did Walter find throughout the limestone?
fossilized shells of tiny creatures called Foraminifera (forams for short)
200

What periods did the Gubbio formation spanned parts in?

Cretaceous and Tertiary

200

How much more powerful was the K-T impactor than the largest fission bomb ever detonated?

100 million.

200

What is the size of the crater?

180 km in diameter.
200

What was the largest extinction on record?

The Permian-Triassic transition which caused nearly 90% of species to disappear which happened about 251 million years ago

300
Who was Walter's colleague that he spent several years studying the Gubbio formation with?
Bill Lowrie
300
After discovering the abrupt change in the Gubbio forams and the K-T extinction what did Walter want to answer?
How long did it take for that thin layer to form?
300
What was the energy of the meteor strike?

108 megatons of TNT

300

Where is the impact site located?

Underneath Chicxulub, Mexico.
300

How close was earth coming to being hit by an asteroid on March 23 1989? How big of an explosion would it have caused.

1,000-foot diameter asteroid missed earth by 400,000 miles.  The asteroid was about 6 hours late.  It would have produced an explosion more than 1000 megatons, which would be the largest in recorded history. 

400
What did Al Fischer point out to Walter that sparked interest in him studying the little forams and the K-T boundary?
the K-T boundary was about the same age as the most famous extinction of dinosaurs
400

What was the original isotope Luis suggested they measure, and why was that isotope a poor option? 

Beryllium-10  

The half life was shorted than previously thought. After 65 million years there would not be enough to measure. 

400

What other groups of organisms perished besides the dinosaurs?

Belemnites, ammonites, and marine reptiles.


80-90% of marine species went extinct. All terrestrial organisms in excess of 25 kg of body weight survived.

400

What were three of the clues that pointed to the impact site?

Gravitational anomalies, Haitian tektites, Haitian shocked quartz grains, Brazos River riverbed.

400

How many confirmed impact sites are there on our planet?

170 confirmed impact sites 

(at the time this was written)
500
What did Walter give his father Luis that got him hooked and interested in helping his son?
Walter gave him a small polished cross section of Gubbio K-T boundary rock and explained the mystery within it. 
500

What element did they finally use to measure levels in the KT boundary?   How do the levels of this element in the Gubbio KT boundary compare to areas around it? 

Iridium  

30 times more 

500

What was the primary cause for the K-T extinction? Be specific.

Atmospheric dust deposited by the meteor blocked sunlight and shutdown photosynthesis across the globe, eliminating global food webs.

500

Why was the theory of a meteor impact causing the K-T extinction initially disregarded by the geological community?

Established conventions asserted that all changes to Earth’s crust were gradual. Cataclysms were regarded as unlikely and unscientific.

500

Why was the identification of the impact site bittersweet for Walter Alvarez? 

Luis had passed away in 1988, just before the Chicxulub discovery