Create an account
natural process on earth that can potentially threaten humans in some way; not all their impacts are negative- volcanic soil, floods and hurricanes deposit nutrients
natural hazards that cause massive negative impacts to society in some way; measures by fatalities and economic loss
where are disasters with highest economic loss occurring?
in countries like the U.S. where there is a lot of infrastructure; urbanization-can make a disaster in a city like ny much worse
crust (chemical property)
outermost layer of the earth, includes the oceans and oceanic crust and continental crust; least dense and most thin
earth is separated into a series of concentric layers based on their...
chemical and physical properties
refers to the way in which material behaves in response to an applied force and determines the way the earth's physical properties are split up.
lithosphere (physical property)
contains to chemically distinct layers-the crust and upper mantle; it acts like a solid, rigid layer
asthenosphere (physical property)
weaker part of the mantle that s solid but relatively plastic; more viscous and can flow like "soft plastic" over long periods because of increased heat
mesosphere (physical property)
contains part of the mantle that behaves like a solid, "stiff plastic"; boundary btwn mesospere and outer core is a physical and chemical boundary
Bishop James Ussher
calculated the age of the earth by adding up several generations in the Bible; his creation date: Oct. 23, 4004 BC
19th century; his creation date: earth approx. 24-400 million years old; neglected to account for radioactive decay
how is the earth's age calculated?
by determine the age of rocks by measuring the amt of radioactive decay since the rock was crystallized
push/pull pulses of compression and extension in the direction the wave is traveling; behave like sound waves and will travel through solids, liquids, or gases; travel fastest
move up/down perpendicular to the direction that the wave is traveling; can't travel through liquids or air; 2nd fastest
when waves are passing through materials with different physical properties the waves will change velocity and bend (refract)
discovered by Andrija Mohorovicic(Moho); it marks the boundry between the Earth's crust and mantle which was discovered by studying seismic waves; it effects how waves move in the earth
recognized that the composition of the inner core (a solid) differs from that of the outer core (a liquid)...discovered the inner core
when materials are subject to too much stress; deform by flowing and not return to original shape
materials are subject to too much stress; will break and become permanently deformed from original shape
on either side of the fault, force accumulate and start to cause increasing amounts of strain
the plane across which the fault occurs, including both rupture area and the part of the fault which did not rupture
increase in temperature with increasing depth which weakens the rock making it more ductile
theory of plate tectonics
the rigid lithosphere on the Earth's surface is divided into several pieces or plates that sit on the denser, plastic asthenosphere
the asthenosphere will flow away from an area where the lithosphere is thicker to counterbalance the added mass; balace btwn the two spheres
give evidence of seafloor spreading; gives a record of when earth's magnetic orientation changed, generated by the outer core; currently in a positive magnetic orientation
topographically high ridges or underwater mountain ranges; i.e. the mid-Atlantic ridge
the temperature at which the rock cools and leaves a lasting record of the Earth's magnetic orientation
divergent plate margins
occurs where two plates are moving away from each other where lithosphere is being created; hot material rises out of the mantle through a rift; aka accretionary margins
process where the oceanic plate sinks down because it is cooler and therefore denser than the mantle; a type of convergence
transform plate margins
occur where two plates slide past each other; it can connect faults, convergent or divergent plate margins and is a place where lithosphere id neither created nor destroyed
San Andreas fault
example of a transform plate boundary and a right lateral strike-slip fault with a triple junction in northern California
devised the Richter scale in the 1930s to quantify the earth's magnitude; it uses whole numbers and is logarithmic
process by which material is heated becomes less dense, and then rises away from the heat source; it modifies the plates but does not create or destroy them
what are significant contributors to the increase in economic loss due to natural hazards over time?
population growth, increase in concentration of people into urban areas, increasing complexity of infrastructure
characteristics of basin and range province?
distributed deformation resulting from shearing along the san andreas plate boundary; numerous large earthquakes in the last 2 centuries; north-south oriented mountains and intervening valleys
why do great earthquakes occur primarily at convergent plate boundaries?
the dipping geometry of subduction zones keeps large rupture area above ductile conditions
volcano in Martinique; located on a subduction plate which produces explosive/deadly volcanoes
in Cameroon; volcanic gas asphyxiation; carbon dioxide remained dissolved in the water until something (possibly an earthquake) shook the lake
a topographic depression in the earth caused by the motion of a strike-slip fault; as the earth moves sediment material washes into the depression and is deposited
and area along the fault where earthquakes have not happened recently but have happened in adjacent locations
these are buried faults that cannot be detected on the surface; the Northridge earthquake in 1994 occurred on one
sand-saturated water layer formed when water is under high pressure in an area of unconsolidated, loose sediment
a type of landslide that occurs when forces acting on a pile of earth build up to a point where internal cohesion fails and the ground is pulled downslope
when the ground compresses ad sinks beacuse liquids like oil or water have been removed from under it
circular depressions in the ground where the ground has fallen in; they commonly form in areas where acidic groundwater eats away at bedrock composed mainly of calcium carbonate
made up of ice and dirt; when they travel close to the sun the ice melts and debris is blown away creating a trail
sites of past meteor impacts
Chesapeake Bay; Meteor Crater in Arizona; Sudbury, Canada (positive effects); Chixculub area in the Gulf of Mexico
potential deadly extraterrestrial hazards
coronal mass ejections, supernovas, black hole, gamma ray burst, extraterrestrial microbes, the death of the sun
narrow column of intense winds that passes over land and water created by a collision of air masses with different temperatures and levels of moisture; 330 feet with wind 224mph
very small vortices; 3.3 feet in diameter and up to 22mph; very weak winds that move vertically
vortices that occur over water; 33 feet in diameter and up to 112mph ; formed by small thunderstorm that first is on land then water, can form from hurricanes, in the great lakes
places where tornadoes are usually formed when cold, sinking masses of air move with warm, moist air forcing warmer air into the atmosphere
used to rank the intensity of a tornado and is based on surveys about the amount of damage that a tornado has caused to an area's structures and vegetation
a piece of solid particulate matter that is suspended in the atmosphere i.e. carbons (soot) and sulfates; have a cooling effect on the earth's temp.
an imbalance between the amounts of radiation coming in and out of the Earth system that causes the Earth's radiation budget to diverge from its natural state of equilibrium; caused by an increase of carbon dioxide and greenhouse gases
where changes to one part of a system produce effects that amplify that change even further
1st stage in hurricane development
an appearance of a cluster of thunderstorms over the tropical oceans known as a tropical disturbance
2nd stage in hurricane development
tropical depression-when the sustained wind speeds of the storm system reach 23 mph
conditions for hurricane formation
1. warm sea surface temp above 79 degrees Fahrenheit
2. considerable moisture available at lower levels of the Earth's atmosphere
3. light winds throughout troposphere
4. needs to be a convergence of air masses with different pressures and temperatures to trigger the storm
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together