Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
44 Cards in this Set
- Front
- Back
|
What was the first line of evidence that led to early investigators to suspect that the continents were once connected |
Similarity between coastlines on opposite sides of the Atlantic Ocean. (South American and Africa) |
|
|
What was the prevailing view of how land animals migrated across vast expenses of open ocean? |
It was believed that the continents were once joined together as fossils of identical organisms have been discovered in rocks of similar age |
|
|
What two aspects of Wegner's continental drift hypothesis were object able to most earth scientist? |
His inability to identify a credible mechanism for continental drift. He proposed tidal forces as a mechanism for the motion of continents plowing their way through weaker oceanic crust |
|
|
Compare and Contrast the lithosphere and the asthenosphere |
The Lithosphere is earths OUTERMOST rocky layer that is broken into plates, which is relatively stiff and deforms from breaking and bending. Beneath is the asthenosphere, which is relatively a weak layer that deforms from flowing |
|
|
Three type of plate boundaries and relative motion of each of them |
Divergent plates move apart from one another Convergent plates move towards each other Transform plates move laterally past each other |
|
|
Compare a continental volcanic arc and a volcanic island arc |
A line of volcanoes that erupt through continental crust is termed a continental volcanic arc, while a line of volcanoes that erupt through an overriding plate of oceanic lithosphere is a volcanic island arc |
|
|
Describe the process that leads to the formation of deep-ocean trenches |
Deep ocean trenches are the surface manifestation produced as slabs of oceanic lithosphere descends into the mantle at angles that vary from a few degrees to nearly vertical |
|
|
How are mountain belts such as the Himalayas formed |
Continental-Continental Convergence took place, where one landmass moves towards the margin of another because of subduction of the intervening seafloor. (A COLLISION TOOK PLACE) |
|
|
Differentiate between transform faults and the other types of plate boundaries |
Transform fault plates slide horizontally past one another without producing or destroying lithosphere |
|
|
What is the age of the oldest sediments recovered using deep-ocean drilling? How do the ages of these sediments compare to ages of the oldest continental rocks? |
Deep sea drilling found that the age of the oldest sediment, the oceanic lithosphere, was no older than about 180 years old. By comparison, most continental crust exceeds several hundred million years in age, and some have been located that exceeds 4 billion years in age |
|
|
What is an Earthquake? Under what circumstances do most large earthquakes occur? |
Vibration of Earth produced by the rapid release of energy. An earthquake is ground shaking caused by the sudden & rapid movement of one block of rock slipping past one another along fractures in Earth's crust called faults where internal stresses have caused the crustal rock to rupture or break into two or more units |
|
|
How are Faults, Hypocenter and Epicenter related? |
They are all related to earthquakes and how they are being produced. Hypocenter is the zone at depth where the initial displacement occurs. The epicenter is the surface location directly above the hypocenter. |
|
|
Who was the first person to explain the mechanism by which most earthquakes are generated? |
H.F. Reid conducted a landmark study following the 1906 San Francisco earthquake |
|
|
What are P waves in reference to earthquakes? |
P Waves are "push/pull" waves they momentarily push (compress) and pull (stretch) rocks in the direction the wave is traveling |
|
|
What are S waves in reference to earthquakes? |
S waves "shake" the particles at right angles to their direction of travel |
|
|
What are the two types of surface waves? |
One type causes Earth's surface and anything resting on it to move, much as ocean swells toss a ship.The second type of surface waves causes Earth's material to move side-to-side Surface waves cause the greater ground shaking, and hence greater property damage, than either P or S waves |
|
|
What type of faults tend to produce the most destructive earthquakes? |
Megathrust faults |
|
|
What type of seismic waves tend to cause the greatest destruction to buildings? |
Surface waves that have a side-to-side motion |
|
|
What does the Modified Mercalli Intensity scale tell us about an earthquake? |
It is a tool for measuring an earthquakes intensity at different locations. The scale is based on verifiable physical evidence to quantify intensity on a 12 point scale |
|
|
What information is used to establish the lower numbers on the Mercalli scale? |
The numbers were determined based off of damage, along with feeling minor vibrations |
|
|
How much more energy does a magnitude 7.0 earthquake release than a 6.0 earthquake? |
Each unit of increase in Richter Magnitude equates to roughly a 32 fold increase in energy released |
|
|
What is a Tsunami? How are Tsunami's generated? |
Tsunami is a major undersea earthquake which occasionally set in motion a series of large ocean waves. Most Tsunamis are generated by displacement along a mega thrust fault that lifts a large slab of seafloor |
|
|
What type of plate boundary is associated with Earth's largest earthquake? |
Most earthquakes in the circum-Pacific belt occur along convergent plate boundaries where one plate slides at a low angle beneath another. The contact between the subducting and overlying plates are megathrust faults along which Earth's largest earthquakes are generated |
|
|
What is viscosity? |
Viscosity is a measure of a materials resistance to flow (How sticky magma is) |
|
|
What are three factors influence the viscosity (its stickiness) of magma? |
Temperature: Hotter magma are less viscous Composition: Silica content High Silica = High Viscosity (e.g., Rhyolitic lava) Low Silica = More Fluid (e.g., Basaltic lava) Disolved Gases: (Volatiles) Mainly water vapor and carbon dioxide Gases expand near the surface Provide the force to extrude lava Violence of eruption depends on escaping gas
|
|
|
Explain how the viscosity of magma influences the explosiveness of a volcano |
As magma rises, the pressure reduces, and the dissolved gases begin to separate from melt, forming tiny bubbles. When fluid basaltic magmas erupt, the pressurized gases readily escape. The gases can quickly expand to occupy hundreds of times their original volumes. Highly viscous magma expels particles of fragmented lava and gases at nearly supersonic speed. |
|
|
What is aa lava flow? |
Aa lava flows have rough, jagged blocks with dangerously sharp edges and spiny projections |
|
|
What is Pahoehoe lava flows? |
Pahoehoe exhibit smooth surfaces that sometimes resemble twisted braids of ropes. (means "on which one can walk on") |
|
|
What main gases are released during a volcanic eruption? |
The gases most commonly emitted by volcanoes are water vapor and carbon dioxide. Upon reaching the surface, these gases rapidly expand, resulting in explosive eruptions that generate an eruptive column and produce a mass of lava fragments called Pyroclastic Materials |
|
|
How do volcanic bombs differ from blocks of pyroclastic debris? |
Somewhat larger pyroclasts that range in size from small beads to walnuts are known as lapalli (little stones). Particles larger than 64 millimeters (2.5 inches) in diameter are called blocks when they are made of hardened lava and bombs when they are ejected as incandescent lava |
|
|
Describe the composition and viscosity of the lava associated with shield volcanoes |
Shield volcanoes consist of many successive layers of low-viscosity basaltic lava and lack significant amounts of pyroclastic debris. Lava tubes help transport lava far from the main vent, resulting in very gentle, shield like profiles |
|
|
Describe the composition of cinder cones |
Cinder cones are steep-sided structures composed mainly of pyroclastic debris, typically having a basaltic composition. Lava flows sometimes emerge from the base of a cinder cone but typically do not flow out of the crater |
|
|
How do the size and steepness of slopes of a cinder cones compare with those of a shield volcano? |
Cinder cones are small relative to the other major kinds of volcanoes, reflecting the fact that they form quickly, in single-eruptive events. Because they are unconsolidated, cinder cones easily succumb to weathering and erosion |
|
|
How do the composition and viscosity of lava flow differ between composite volcanoes and shield volcanoes? |
Composite volcanoes are much larger than cinder cones and form from multiple eruptions over a million years or longer. Because the andesitic or rhyolitic lava erupted from composite volcanoes is more viscous than basaltic lava, it accumulates at a steeper angle than does shield volcanoes |
|
|
Describe pyroclastic flows and explain why they are capable of traveling great distances |
Pyroclastic flows is one of the most destructive volcanic forces. Driven by gravity and the reduction of friction from the hot gases, these pyroclastic flow deposits are found many miles from their source |
|
|
Pyroclastic flows are associated with what volcanic structure that is not a cinder cone? |
Calderas-forming eruptions are of colossal proportions, ejecting huge volumes of pyroclastic materials, mainly in the form of ash and pumice fragments |
|
|
Describe dike and sill, using the appropriate terms from the following list: massive discordant, tabular, concordant. |
Tabular intrusions may be concordant (sills) or discordant (dikes) igneous bodies are said to be discordant (discordare = to disagree) if they cut across existing structures and concordant (concordare = to agree) if they inject parallel to features such as sedimentary strata. Dikes are discordant bodies that cut across bedding surfaces or other structures the country rock. By contrast, sills are nearly horizontal, concordant bodies that when magma exploits weaknesses between sedimentary beds or other structures. In general, dikes serve as tubular conduits that transport magma, whereas sills tend to accumulate magma and increase in thickness. |
|
|
Compare and contrast batholiths, stocks, and laccoliths in terms of size and shape. |
Massive Intrusive Bodies:Batholiths, stocks, and Laccoliths. By far the largest intrusive igneous bodies are batholiths. Smaller plutons are termed stocks. Blister-like intrusions also exist (laccoliths) which are forcibly injected between sedimentary strata so as to arch the beds above while leaving those below relatively flat |
|
|
Are volcanoes in the Ring of Fire generally described as quiescent or explosive? |
Convergent plate boundaries that involve the subduction of oceanic crust are the sites where explosive volcanoes of the Pacific "Ring of Fire" are most prevalent. Here, release of water from the subducted plate triggers melting in the overlying mantle. The resulting magma interacts with the lower crust the overlying plate during its ascent and results in the formation of a volcanic arc at the surface. |
|
|
What type of plate boundary is associated with Earth's largest earthquakes? |
Convergent plate boundaries |
|
|
What is the former of oxygen that combines 3 oxygen atoms into each molecule? |
Ozone |
|
|
What is Climate |
Is the generalization of atmospheric conditions over a long period of time |
|
|
What is weather? |
Is the state of the atmosphere at a particular place for a SHORT period of time |
|
|
What are the most important elements- quantities or properties that are measured regularly of weather and climate? |
Air temperature Humidity Type and amount of cloudiness Type and amount of precipitation Air pressure The speed and direction of the wind |
