Thursday, October 31, 2013

Non-renewable vs. Renewable Resources


A nonrenewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption.


A renewable resource is a natural resource that can be replenished in a short period of time.







Wednesday, October 16, 2013

EarthQUAKE

What is an earthquake?

labeled fault
An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter.


 

 

What causes earthquakes and where do they happen?

Earth cross-section The earth has four major layers: the inner core, outer core, mantle and crust. (figure 2) The crust and the top of the mantle make up a thin skin on the surface of our planet. But this skin is not all in one piece – it is made up of many pieces like a puzzle covering the surface of the earth. (figure 3) Not only that, but these puzzle pieces keep slowly moving around, sliding past one another and bumping into each other. We call these puzzle pieces tectonic plates, and the edges of the plates are called the plate boundaries. The plate boundaries are made up of many faults, and most of the earthquakes around the world occur on these faults. Since the edges of the plates are rough, they get stuck while the rest of the plate keeps moving. Finally, when the plate has moved far enough, the edges unstick on one of the faults and there is an earthquake.

Why does the earth shake when there is an earthquake?

tectonic plates While the edges of faults are stuck together, and the rest of the block is moving, the energy that would normally cause the blocks to slide past one another is being stored up. When the force of the moving blocks finally overcomes the friction of the jagged edges of the fault and it unsticks, all that stored up energy is released. The energy radiates outward from the fault in all directions in the form of seismic waves like ripples on a pond. The seismic waves shake the earth as they move through it, and when the waves reach the earth’s surface, they shake the ground and anything on it, like our houses and us! (see P&S Wave inset)

ALL INFORMATION TAKEN FROM: USGS - EARTHQUAKES

EARTHQUAKE IN THE CLASSROOM








DENSITY!!

Here are some photos from today's activity for Periods 1 and 4. The class looked at how different liquids behaved when you poured them into the same container.






Wednesday, October 2, 2013

New Land is Formed After Earthquake in Pakistan

Image: Earthquake island

Continental Drift Theory & Plate Tectonics Theory

In 1915, the German geologist and meteorologist, Alfred Wegener, first proposed the theory of Continental Drift, which states that parts of the Earth's crust slowly drift atop a liquid core. The fossil record supports and gives credence to the theories of continental drift and plate tectonics.

Wegener hypothesized that there was a gigantic supercontinent 200 million years ago, which he named Pangea, meaning "All-earth".







Photos of Student Presentations!




Pangaea started to break up into two smaller supercontinents, called Laurasia and Gondwanaland, during the Jurassic period. By the end of the Cretaceous period, the continents were separating into land masses that look like our modern-day continents.

Wegener published this theory in his 1915 book, On the Origin of Continents and Oceans. In it he also proposed the existence of the supercontinent , and named it (Pangaea means "all the land" in Greek).

Piece of Evidence #1:  The coasts of the continents surrounding the Atlantic ocean could, if the continents were moved closer, fit together like a jigsaw puzzle.

Piece of Evidence #2:  Living animals in widely separated lands are similar. For example India and Madagascar have similar mammals, which are quite different from those in Africa, even though it is now near to Madagascar.
 
Piece of Evidence #3:    Fossil plants in India, South Africa, Australia, Antarctica and South America are similar to each other. This so-called Glossopteris flora is quite different from plants found in other parts of the world at the same time.






Piece of Evidence #4: There are numerous geological similarities between eastern South America and western Africa.

Piece of Evidence #5: Apparent Polar Wandering: Paleomagnetism tells us how far from the poles rocks were when they formed, by looking at the angle of their magnetic field. The story told by different continents is contradictory, and can only be explained if we assume the continents have moved over time.

Paleomagnetism shows that the sea floor has spread away from these ridges. Distinct patterns of stripes can be seen in the magnetism of rocks on either side of the ridges.




Plate Tectonics Theory
Plate tectonics is the theory that the outer rigid layer of the earth (the lithosphere) is divided into a couple of dozen "plates" that move around across the earth's surface relative to each other, like slabs of ice on a lake.



THE PLATES
     Simplistically, the earth consists of the plates, and plate boundaries, those zones where the plates contact and interact. Observe that 7 different plates are labeled in the cross section. Plates are combinations of two units, continents and ocean basins. A plate may be an ocean basin alone, or a continent alone, or a combination of ocean basin+continent (common).
      It is possible a plate could be a continent alone, but for this to occur all edges of the continent would have to be a plate boundary (very rare, perhaps not practically possible). Note that in the cross section several different ocean basin/continent combinations are present, but that it is difficult to get a continent with all plate boundaries.




Divergent Boundaries: At divergent boundaries new crust is created as wo or more plates pull away from each other. Oceans are born and grow wider where plates diverge or pull apart. As seen below, when a diverging boundary occurs on land a 'rift', or separation will arise and over time that mass of land will break apart into distinct land masses and the surrounding water will fill the space between them. Jump to 'Birth of an Ocean'
Diverging Plate Boundaries Iceland offers scientists a natural laboratory for studying - on land - the processes that occur along submerged parts of a divergent boundary. Iceland is splitting along the Mid-Atlantic Ridge - a divergent boundary between the North American and Eurasian Plates. As North America moves westward and Eurasia eastward, new crust is created on both sides of the diverging boundary. While the creation of new crust adds mass to Iceland on both sides of the boundary, it also creates a rift along the boundary. Iceland will inevitably break apart into two separate land masses at some point in the future, as the Atlantic waters eventually rush in to fill the widening and deepening space between.


Convergent Boundaries: Here crust is destroyed and recycled back into the interior of the Earth as one plate dives under another. These are known as Subduction Zones - mountains and volcanoes are often found where plates converge. There are 3 types of convergent boundaries: Oceanic-Continental Convergence; Oceanic-Oceanic Convergence; and Continental-Continental Convergence.

Oceanic-Continental Convergence
Oceanic-Continental Converging Plates When an oceanic plate pushes into and subducts under a continental plate, the overriding continental plate is lifted up and a mountain range is created. Even though the oceanic plate as a whole sinks smoothly and continuously into the subduction trench, the deepest part of the subducting plate breaks into smaller pieces. These smaller pieces become locked in place for long periods of time before moving suddenly and generating large earthquakes. Such earthquakes are often accompanied by uplift of the land by as much as a few meters.
Oceanic-Oceanic Convergence
Oceanic-Oceanic Converging Plates When two oceanic plates converge one is usually subducted under the other and in the process a deep oceanic trench is formed. The Marianas Trench, for example, is a deep trench created as the result of the Phillipine Plate subducting under the Pacific Plate.

Oceanic-oceanic plate convergence also results in the formation of undersea volcanoes. Over millions of years, however, the erupted lava and volcanic debris pile up on the ocean floor until a submarine volcano rises above sea level to form an island volcano. Such volcanoes are typically strung out in chains called island arcs.
Continental-Continental Convergence
Continental-Continental Converging Plates When two continents meet head-on, neither is subducted because the continental rocks are relatively light and, like two colliding icebergs, resist downward motion. Instead, the crust tends to buckle and be pushed upward or sideways. The collision of India into Asia 50 million years ago caused the Eurasian Plate to crumple up and override the Indian Plate. After the collision, the slow continuous convergence of the two plates over millions of years pushed up the Himalayas and the Tibetan Plateau to their present heights. Most of this growth occurred during the past 10 million years.

Transform-Fault Boundaries: Transform-Fault Boundaries are where two plates are sliding horizontally past one another. These are also known as transform boundaries or more commonly as faults.
Most transform faults are found on the ocean floor. They commonly offset active spreading ridges, producing zig-zag plate margins, and are generally defined by shallow earthquakes. A few, however, occur on land. The San Andreas fault zone in California is a transform fault that connects the East Pacific Rise, a divergent boundary to the south, with the South Gorda -- Juan de Fuca -- Explorer Ridge, another divergent boundary to the north. The San Andreas is one of the few transform faults exposed on land. The San Andreas fault zone, which is about 1,300 km long and in places tens of kilometers wide, slices through two thirds of the length of California. Along it, the Pacific Plate has been grinding horizontally past the North American Plate for 10 million years, at an average rate of about 5 cm/yr. Land on the west side of the fault zone (on the Pacific Plate) is moving in a northwesterly direction relative to the land on the east side of the fault zone (on the North American Plate).

Source: http://www.platetectonics.com/book/page_5.asp

Tuesday, September 24, 2013

Constructing a Topographic Profile

Aim: How do we map the surface of the Earth?

profile is a picture of what the landscape would look like from the side. It is a cross section of the landscape. You should be able to identify a correct profile, as well as draw one.


Given the topographic map above, which of the four choices below accurately depicts the correct profile between points X and Y?


Easy Peazy Steps to Constructing a Topographic Map Profile:

A profile may be constructed quickly and accurately across any straight line on a map by following this procedure:
a. Lay a strip of paper along a line across the area where the profile is to be constructed.b. Mark on the paper the exact place where each contour, stream and hill top crosses the profile line.
c. Label each mark with the elevation of the contour it represents. 
d. Prepare a vertical scale on profile paper by labeling the horizontal lines corresponding to the elevation of each index contour line.
e. Place the paper with the labeled contour lines at the bottom of the profile paper and project each contour to the horizontal line of the same elevation.
f. Connect the points.




Monday, September 23, 2013

Structure of the Earth

Important Ideas

1. How are the layers of the Earth's interior differentiated?
2. How does the composition of each layer
3. How does activity taking place in the interior affect the activity and physical nature of the Earth's surface?









Independent and Dependent Variables (Answers)

 
1.  A group of college students were given a short course in speed-reading. The instructor was curious if a monetary incentive would influence performance on a reading test taken at the end of the course.  Half the students were offered $5 for obtaining a certain level of performance on the test, the other half were not offered money. 
 
Independent variable:  Monetary incentive ($5 or no money)
 
Dependent variable:  Performance on reading test
 
Experimental group:  $5 group (receive monetary incentive)
 
Control group:  $0 group (no monetary incentive)


2.  A social psychologist thinks that people are more likely to conform to a large crowd than to a single person.  To test this hypothesis, the social psychologist had either one person or five persons stand on a busy walking path on campus and look up.  The psychologist stood nearby and counted the number of people passing by who also looked up.
 
Independent variable:  Size of group (5 people or 1 person)
 
Dependent variable:  Conformity (measured by number of people looking up)
 
Experimental group:  People passing 5 person group
 
Control group:  People passing single person.  (This group gets “less” of the independent variable)
 
 
3.  To test a new voice feature in a cockpit design a flight simulator was used.  The simulator was programmed to give visual readings of flight information, or to give visual and auditory (voice) readings of flight information.  All test pilots were put through a simulated emergency landing procedure, but were randomly assigned to the visual, or visual and auditory conditions.  Flight experts rated each pilot’s performance in the simulator on a scale of 1 (very poor) to 10 (excellent).
 
Independent variable:  Presence or absence of auditory (voice) readings.  (All pilots received visual readings, so that is a constant variable.)
 
Dependent variable:  Ratings of pilots’ performance
 
Experimental group:  Pilots in auditory readings condition (visual + auditory)
 
Control group:  Pilots in visual reading only condition (no auditory)

Thursday, September 19, 2013

Independent and Dependent Variables

1.  A group of college students were given a short course in speed-reading. The instructor was curious if a monetary incentive would influence performance on a reading test taken at the end of the course.  Half the students were offered $5 for obtaining a certain level of performance on the test, the other half were not offered money. Based on the situation presented, identify the:

Independent variable:
Dependent variable:
Experimental group:
Control group:


2.  A social psychologist thinks that people are more likely to conform to a large crowd than to a single person.  To test this hypothesis, the social psychologist had either one person or five persons stand on a busy walking path on campus and look up.  The psychologist stood nearby and counted the number of people passing by who also looked up.

Independent variable:
Dependent variable:
Experimental group:
Control group:



3.  To test a new voice feature in a cockpit design a flight simulator was used.  The simulator was programmed to give visual readings of flight information, or to give visual and auditory (voice) readings of flight information.  All test pilots were put through a simulated emergency landing procedure, but were randomly assigned to the visual, or visual and auditory conditions.  Flight experts rated each pilot’s performance in the simulator on a scale of 1 (very poor) to 10 (excellent).

 Independent variable:
Dependent variable:
Experimental group:
Control group:

Monday, September 16, 2013

Density

Densitya measure of the compactness of a substance, expressed as its mass per unit volume.

Density = mass (g) / volume (mL)
 
Mass - a measure of how much matter is in an object.

Volume - the amount of space occupied by a three-dimensional object or region of space.


 

Friday, September 13, 2013

Topographic Maps


Aim: How do we map the surface of the Earth?

Notes Given to Students: Guided Notes: Topographic Maps
Drawing Contours Practice: Drawing Contour Lines 
Calculating Gradient Practice: Calculating Gradients 

Topographic Maps 
maps showing the relief features of the earth's 
surface, usually by means of contour lines to show changes in elevation.

The picture above is an example of a field map. In this example, the numbers on the map represent the concentration of gasoline found at that location. So the map simply shows how much of something (in this case gasoline) is found at many locations.
Isolines are lines that are drawn on a field map to connect all of the points on that map that have the same value.



Contour Line -
 a line joining points of equal elevation on a surface.






Close line =Steep Slope


Contour lines bend upstream when crossing a river.

A contour interval is the difference in elevation between two contour lines that are side by side.

Highest possible elevation of a hill

Depressions are shown by small marks pointing inward off the contour line.

Gradient