Exam 3 Flashcards
(224 cards)
The human population is about ______ people.
7 billion
Without hydrocarbons (oil, gas, coal), the carrying capacity of the earth is about _____ people.
2 billion
When the hydrocarbons run out, the survival of some _____ people will be threatened.
5 billion
The use of hydrocarbons has exaggerated the earth’s carrying capacity by _______.
5 billion
After N half-lives, the number of daughter isotopes is ____.
1-(2^-N)
After N half-lives, the number of parent isotopes is ____.
2^-N
A body excavated in a floodplain contains about 25% (= ¼) of the atmospheric 14C concentration. Thus, it has been dead for some ____ years assuming a 14C half-life of about 6,000 years.
12,000
Your investment is doubling every 2 years. What is your investment’s rate of return.
35%
Since the beginning of 2013, some ____ species have gone extinct.
51,000
poodwaddle number: 25,775
Volcanic rocks erupted into the air.
tephra (XIII-22)
The catastrophically explosive eruptions of Mt. St. Helens in southern Washington involve ______, _______ magma.
high-viscosity?
Why are most active volcanoes associated with plate tectonic boundaries?
(1) plate tectonic boundaries are created by volcanism
(2) spreading or sinking plates interact at plate boundaries with other materials to produce magma
(3) earthquakes at plate boundaries bring large amounts of magma to the surface
(4) in reality, most volcanoes are in the plate interiors rather than at plate boundaries
(2) spreading or sinking plates interact at plate boundaries with other materials to produce magma
Volcanoes produce _____ rocks.
(1) sedimentary (2) metamorphic (3) igneous (4) evaporite
(3) igneous
Viscosity of a magma is controlled by _______.
(1) the eruptive processes at work (2) the types and amounts of gases dissolved in the magma (3) the water content of the magma (4) temperature and silicon content of the magma
(4) temperature and silicon content of the magma
Granitic magmas have densities ______ those of basaltic magmas.
(1) lower than (2) higher than (3) equal to (4) none of above
(1) lower than
Basaltic magmas have specific gravities ______ those of granitic magmas.
(1) lower than (2) higher than (3) equal to (4) none of above
(2) higher than
Magma type typically producing Pahohoe lava.
(1) basaltic (2) granitic (3) evaporite (4) none of above
(1) basaltic
Magma type typically producing Aa lava.
(1) basaltic (2) granitic (3) evaporite (4) none of above
(2) granitic
Plate margin setting where pillow lavas predominate.
(1) subduction (2) spreading (3) transform fault (4) none of above
(2) spreading
The abbreviation ‘asl’ stands for ‘________.’
(1) as little (2) above surface level (3) above sea level (4) none of above
(3) above sea level
The shape of shield volcanoes is a function of the _______.
(1) lava viscosity (2) proportion of pyroclastic debris included in the edifice (3) local variations in the tilt of the land surface (4) the explosive nature of the eruptions that produce the shield
(1) lava viscosity
Type of lava that flows most readily.
(1) Pahohoe (2) Aa (3) evaporite (4) granitic
(1) Pahohoe
Basaltic lava flows ______ granitic lava.
(1) faster than (2) slower than (3) at the rate as (4) none of above
(1) faster than
The relatively benign fluid eruptions of the Kilauea volcano in Hawaii involve ______, _______ magma.
Pahohoe, basaltic?