Shared Flashcard Set

Details

study guide and quiz questions
Test #1
52
Geology
Undergraduate 3
09/21/2008

Additional Geology Flashcards

 


 

Cards

Term
Why does the # of the world-wide deaths due to natural disaster change dramatically from year to year
Definition
the reporting was inaccurate
Term
Why are the costs of natural disasters increasing
Definition
there are more human infrastructure as time goes on
Term
What % of the earth’s population is at risk of earthquakes
Definition
10-20%
Term
What continent has historically had the largest loss of life due to natural disaster
Definition
Asia
Term
Earth’s population will double again in:
Definition
in our life time
Term
Earth loses most of its heat by:
Definition
convection
Term
Since it formed, earth has used up almost this % of its radioactive fuel
Definition
80%
Term
In continental drift theory
Definition
continental crust slides over the ocean crust
Term
In plate tectonic theory:
Definition
Term
Carbon-14 used to:
Definition
date things that are 1000's of years old
Term
Most abundant element in the earth
Definition
iron
Term
Most abundant element in the crust
Definition
oxygen
Term
Chemical layer made of iron is:
Definition
lithosphere
Term
oldest crust
Definition
continental
Term
Fast plates move
Definition
10 cm/yr
Term
Continental collision produces
Definition
mountains
Term
Ocean plate subduction produces:
Definition
deep trenches
Term
The main force driving plate motion is:
Definition
slab pull
Term
The history of plate motion is known as
Definition
magnetic anomilies
Term
Most earthquakes occur on
Definition
convergent
Term
The most powerful earthquakes occur on
Definition
convergent
Term
Deep earthquakes occur on
Definition
convergent
Term
Compared to normal lithosphere divergent plate boundaries are:
Definition
hot and weak
Term
The Izmit earthquakes occurred on a
Definition
transform boundaries
Term
**KARL POPPER
Definition
said scientific theories must contain statements that can be proven false observe theorize predict test prediction
Term
what 2 leaders account for a majority of the natural disasters
Definition
earthquakes and hurricanes make up 77%
Term
earth's origin KANT's theory
Definition
initial state: cloud of gas, ice, & dust contraction: gravity flattening into a disk formation: collapse to orbiting spherical clusters
Term
history of earth
Definition
initial state: homogeneous mass bout b.y. ago heating: compaction, impacts, & radioactivity core formation: iron catastrophe internal & external structure: desity layers form 4 b.y. ago
Term
what are the 2 most abundant resources in the whole earth?
Definition
iron and oxygen
Term
what are the two most abundant elements in the earth's crust?
Definition
silicon and oxygen
Term
principles of isostasy
Definition
mantel flows under loads earth surface sinks and rises weight of overlying rock equal all over the earth
Term
Airy model of isostasy
Definition
uniform, density, variable thickness layer underlain by denser material
Term
compositional layers of the earth
Definition
crust: oxygen and silicon; 7 km mantel: oxygen, silicon, magnesium, & iron 40 km core: iron 2,880 km
Term
physical layers of the earth
Definition
lithosphere: rigid; 0-125 aesthenophere: weak plastic; 125-350 mesosphere: strong plastic; 350-2880 outer core: liquid; 883-5140 inner core: solid; 5140-6371
Term
brittle deformation
Definition
is permenant by fracturing -brittle strength increases with confining pressure -its insensitive to temperature
Term
ductile deformation
Definition
permenant by plastic flow -it decreases with increasing temperature -if rich w/silica= low ductile strength
Term
high geotherm
Definition
-higher temps at shallower depths -decrease in overall strength -thinner brittle zones
Term
low geotherm
Definition
-lower temps for greater depths -increased overall -thicker brittle zones
Term
radioactive deacy
Definition
-spontaneous break up -half-life
Term
continental drift (Wegener)
Definition
-pangea: one large continent that broke into several ones over time -strong points: expain mountains and such -weak point: driving force? -evidence: fossils,glaciers and mountains
Term
weak points of the continental drift
Definition
-there's not a strong enough force to slide contental crust over oceanic crust -slip mechanism: continents couldn't move intact and both crust would deform
Term
theory of tectonic plates
Definition
13 large plates that include both oceanic and contiental -motion: slide over each other, collide,or move apart
Term
sea floor amanomilies
Definition
are linear belts of altering high and low magnetic field strength
Term
you date the sea floor by...
Definition
-base it on reversal history -matching sea floor magnetic anomilies
Term
hot spot tracks
Definition
along chains of volcanos with consistant age progression
Term
slap pull
Definition
cold ocean plate sinks into subduction zones uinder its own wieght -submerged plate pulls remaining plate
Term
ridge push
Definition
-ocean plate seperates at spreading ridges -aesthenophere flows upward to fill the viod - upwelling asthenosphere melts and boyancy uplifts the ridge -ocean plates slide off the ridge (lava lamp demonstration)
Term
ring of fire
Definition
80% of the earthquakes
Term
mederteranean belt
Definition
15% of earthquakes
Term
divergent boundaries
Definition
have few and not as severe earthquakes -high temp decreases ductile strength at geotherm -size 5 sometimes 6 or 7
Term
transform boundaries
Definition
plates slide over each other -temp is normal -bends influence the size of the earthquakes -size some 5-6 while others 7-8
Term
convergent boundaries
Definition
oceanic lithosphere sinks beneath the continent
-causes formation of mountains
-high number of these
-biggest kindsare here
-temp here is cold and has brittle rock
Supporting users have an ad free experience!