LAB 5 2020

Create a diagram illustrating a drainage basin with valleys, interfluves, and the drainage divide identified.

*insert Drainage Basin picture here*

Create a diagram illustrating the following intrusive igneous features: batholith, laccolith, and dike.

*insert Intrusive Igneous Features picture here*

Create a diagram illustrating how the stream-load is transported in a stream.

*insert Stream Load Transportation picture here*

What are the three classes of rocks, and how do they form?

- Igneous: These types of rocks are formed through the cooling of molten rock. There are two types of igneous rocks: extrusive (formed on Earth's surface) and intrusive (formed within Earth's surface). - Sedimentary: These types of rocks are formed through the conglomeration (no pun intended) of sediments. There are three types of sedimentary rock: Clastic, Chemical, and Organic. - Metamorphic: These types of rocks are formed when a parent rock is treated until it forms a different rock. There are two types of metamorphic rock: foliated (showing prominent orientation) and nonfoliated (no distinct pattern).

Discuss the factors responsible for landslides in Oregon and Sierra Leone.

A few of the factors include gravity, rainfall, and vegetation.

What is flood basalt and where does it occur in the continental US?

A flood basalt is where basalt-rich lava is poured out of a divergent boundary fissure and covers a large area of land and seafloor.

Discuss how valleys lengthen in an essay of 200-400 words. Give examples.

A stream can lengthen a valley in two distinct ways, either by Headward Erosion or Delta Formation. Headward Erosion can occur at the upper ends of the valley while Delta Formations occur at the lower ends of the valley. Valley lengthening seems to primarily stem from fluvial processes, and it seems to be more integral than noting the distances of these valleys. Headward erosion occurs towards the top of stream valleys, these cause the stream origin to erode and move away from the stream flow's direction. The result of Headward Erosion is an increase in surface area in the valley as well as a decrease in area between the two valleys. Delta Formations occur at the base of stream valleys, utilizing deposition more than erosion due to their place where little erosion occurs. Streams often slow their flow once they reach a large body of water, such as a lake or an ocean, and deposits the sediment it carries. The majority of its deposit is dropped at the mouth of a river, or like its namesake, a delta. A delta's rather unique shape causes the stream to essentially funnel out and slow down it's flow, dropping off its sediments throughout the channels within it.

Define the following terms: Alluvium: Perennial streams: Intermittent streams: Ephemeral streams:

Alluvium: Stream-deposited sediment from rivers and streams Perennial streams: Permanent large rivers and tributaries in humid areas Intermittent streams: Streams and tributaries that occasionally carry water and are found primarily in arid areas. Ephemeral streams: Dry stream beds that flow water after an influx of constant rainfall.

In an essay of 200-400 words, explain Davis's Geomorphic Cycle.

Davis's Geomorphic Cycle essentially breaks down into landscape development and the cycle of erosion, but today, his geographical theory is regarded as the "geomorphic cycle". According to his theory, Davis suggests that we can interpret the structure, processes, and stages in any landscape. In the structure of a landscape, the underlying rock formations and surface material are arranged in a specific kind of way. The process of a landscape implies how the landscape came to be. In other words, what factors caused the formation to be shaped that way? Lastly, the "stage" of a landscape means how long the formations took to form that specific landform. Davis's theory also suggests that there are four stages within his geomorphic cycle: Youth, Maturity, Old Age, and Rejuvenation. The Youth stage focuses on how flat surface areas are shaped into a valley due to stream activity, shaping it into the next stage of its cycle. The next stage, the Maturity stage has the streams developed into smooth profiles after weathering away all of its other stream-based formations and forming into meandering streams within floodplains. The next stage, the Old Age stage, has erosion transform the area into a floodplain completely and roughly have all of the streams converge into one large meandering stream. The final stage, Rejuvenation, involves the stream being covered over by the surrounding land due to regional uplift, starting the cycle all over again.

From your readings and examination of Figure 14-7 on page 403, explain the pattern of earthquakes across the globe.

Earthquakes are linked to plate tectonics, when epicenters were recorded, it was discovered that they were linked to where the edges of plate tectonics were.

Describe the following: Faulting: Strike-slip fault: Horst: Graben: Rift Valley:

Faulting: An occurrence where one fault becomes displaced from the other. Strike-slip fault: A fault where one converging plate sinks while the other rises as a result of the compression. Horst: A block of crust that has been uplifted from two parallel faults. Graben: A block of crust that has been downthrown by two parallel faults. Rift Valley: A depression in Earth's surface caused by continental diverging plate boundaries.

Describe Figure 16-39 on page 488.

Figure 16-39 displays the many different kinds of landforms that can form in a floodplain such as oxbow lakes, alluvial deposits, and natural levees.

Define the following terms: Geomorphology: Topography: Relief: Uniformitarianism:

Geomorphology: The study of landforms as well as their characteristics and how they're developed. Topography: The specific height of certain landmasses and areas in regards to how high they are from the sea level. Relief: The difference in levels between specific heights. Uniformitarianism: The concept that revolves around the "present is the key to the past" ideal.

In reference to stream orders, what predictions can be made in a well-developed drainage basin?

In well-developed drainage basins, there will be numerous first-order streams and valleys, more so than other types of streams. Each higher order of streams will be fewer as time goes on.

Discuss the difference in intensity between small earthquakes and large earthquakes in terms of magnitude.

Intensity, in terms of earthquakes, is measured through how powerful an earthquake is through determining how much damage one caused. Magnitude is measured through how much energy is released. Smaller earthquakes tend to happen often, causing minimal damage and hardly felt by others. Larger earthquakes tend to cause considerable damage, from cracking roadways to destroying bridges.

What is the difference between the internal and external geomorphic processes?

Internal geomorphic processes primarily function within the Earth and are considered the "constructive" processes. External geomorphic processes primarily function above Earth's surface and are considered the "destructive" processes.

Explain the phenomenon of knickpoint migration with special reference to Niagara Falls.

Knickpoint mitigation occurs when the harder material erodes away, smoothing out the channel gradient. The Niagara Falls is a good example of knickpoint mitigation because of how the Niagara River drops over a knickpoint formed by the Niagara Escarpment.

Discuss the conditions that facilitate mechanical weathering.

Mechanical weathering is eroding rock material without altering it chemically. For example, larger rocks may break off into smaller rocks due to stress natural elements.

Explain Penck's theory in 100-200 words.

Penck himself was known to be a critic of Davis and his theories regarding landform development, arguing that slopes maintain a constant angle instead of continuously being worn down at a lower angle. Penck's theory, the theory of Crustal Change and Slope Development, states that slopes can adjust depending on the geological conditions in a given area. In adjusting the slopes of a given landscape, there needs to be an equal amount of energy in order for everything to go smoothly. Because of its influence and validity, Penck's theory of equilibrium has become the focus of fluvial geomorphology since the 1960s.

Describe the following: Rockfall: Landslide: Creep: Solifluction:

Rockfall: A common form of mass wasting that involves rocks falling downslope. Landslide: A type of slope failure that involves the collapse of a slope on a flat plane. Creep: The slowest form of mass wasting that gradually moves downhill. Solifluction: A type of creep that creates a specific surface appearance.

From your readings and examination of Figure 14-8, explain the phenomenon of seafloor spreading.

Seafloor spreading is when two plates separate within the ocean and magma emerges from the fissure.

Equilibrium Theory refutes Davis. What are reasonable arguments to support Equilibrium Theory and rebut the Geomorphic Cycle?

Some arguments that support the equilibrium theory are that it focuses more than the other theories surrounding geomorphic processes and surface forms.

Discuss the factors responsible for the Oso Landslide in an essay of 200-400 words.

The Oso Landslide itself was a devastating natural disaster that led to property damage and loss, as well as more than 40 deaths. The landslide occurred on March 22, 2014 at 10:37 A.M in the area of Oso, near the Steelhead Lane community in Washington. The landslide originated from the northern bank of the North Fork Stillaguamish River, burying the community roughly under 40 ft of mud. One of the many underlying factors that caused the landslide in the first place is the area's geological history. The Oso region was once covered by glacial ice sheets back during the Pleistocene Epoch, causing the area to house more water and sediments than it does currently. Many of its river valleys were dammed by ice sheets at one point, leading the way to the formation of its inland lakes and unstable riverbanks. There are four main factors that have contributed, in one way or another, to the cause of the Oso Landslide: gravity, amount of water in the soil, loading or destabilizing influences, and the lack of support at the bottom of the slope. The lack of stability as a result of logging activity as well as an increase in rainfall around the area were also primary causes of the Oso Landslide.

What is the significance of the Ring of Fire?

The Ring of Fire is a line of tectonic plate edges along South and North America, Asia, Indonesia, and New Zealand. This "ring" is where many earthquake epicenters have been located and volcanoes have formed.

In the section marked, The Study of Landforms, what might be considered the basic elements of landform study?

The basic elements of landscape study are structure, process, slope, and drainage.

Explain the phenomenon of folding in the Ridge and Valley province of the Appalachian region.

The compression that forms these ridges and valleys causes them to have more density and resistance to erosion. These types of formations are known as anticlinal valleys and synclinal ridges.

The Mississippi River Flood of 2011 had different impacts on marshes in the Atchafalaya River, Delta, and the Mississippi River Delta. Why? Explain in an essay of between 400 and 600 words.

The flood of the Mississippi River in 2011 is considered one of the most destructive floods along the river since 1993. In the spring of 2011, heavy rainfall caused by two distinct storm systems. The increase in precipitation as well as the inclusion of the recent snowmelt has caused the river water to overflow and flood the landscape beyond the levees. A few states along the Mississippi River have experienced some forms of flooding, including Louisiana, Arkansas, Kentucky, Tennessee, Missouri, Illinois, and Mississippi. It has been stated that the flood that took place in 2011 may have even been greater than the Flood of 1927, and of course 1993. It is because of this devastating flood that new measures have been implemented for those that live or do business near the Mississippi River. Such measures include highlighting areas that could be susceptible to flooding, the impact of those said floods for its inhabitants, and taking estimations to predict whether or not an area is vulnerable for a flood. Many counties in the states that surround the Mississippi have already declared some areas as being "unsafe" in terms of possible flooding. The flood in 2011 has caused the communities surrounding the river to start considering how they can be more prepared for possible future disasters. The various branching rivers and deltas that are connected to the Mississippi River have, in some form or another, impacted the 2,000 mi long river itself. Many deltas near the Mississippi river provide carbon and nutrients from the sediment it carries throughout its streams. The marshes near the river have been known to provide these sediments from outside water sources. A few of its deltas, like the Mississippi River Delta, is known to be the largest and most productive when it comes to marine ecosystems from various surrounding bodies of water. Because of the flood, the deltas have sustained massive damage, primarily the loss of land surrounding it. The rivers that connect to the Mississippi have also sustained some damage as a result of the 2011 flood. As some can assume, the flooding of any given area can severely impact the local fishery productions, disrupting the ecosystem in general. Aside from the land loss it sustained from the flood, the ecologies and oceanography from other bodies of water that also connect to the surrounding rivers have also been impacted. Floods are a natural disaster that, often times, cannot be avoided. However, just like with any other destructive force of nature, it can be studied and, through analysis, prevented.

What are the fundamental questions of geographic inquiry?

The fundamental questions of geographic inquiry are: - What? The form of the feature or features - Where? The distribution and pattern of the landform assemblage - Why? An explanation of origin and development - So what? The significance of the topography in relationship to other elements of the environment and to human life and activities

What is the internal structure of the earth?

The internal structure of Earth consists of 4 broad layers: the Crust, the Mantle, the Outer Core, and the Inner Core. The crust and upper mantle are known as the lithosphere and just below that is the asthenosphere.

What is the most common type of rock on the earth's continents?

The most common type of rock on Earth's continents is sedimentary.

Figure 13-17 on page 388 displays a map of rock classes in the US. What is the most widespread type of rock in the US?

The most widespread type of rock in the U.S is sedimentary.

In an essay of 200-400 words discuss how plate tectonics occurs.

The theory of plate tectonics has been used to explain the phenomenon known as the "continental drift" and how the continents became who they are. According to the theory, the continents were once a single, large landmass at one point, only for it to separate into multiple parts as the years went by. Plate tectonics have been cited as a way to explain various natural disasters around the globe, such as volcanoes and earthquakes. Even though scientists can't definitively explain what processes go on in the Earth's interior, they continue to improve their models and hypotheses regarding the subject. The plate tectonics are described as slabs of rock that are primarily made up from the lithosphere layer that drift along the molten asthenosphere below it. These plates can move in virtually any direction along the surface of the Earth, that is primarily due to the convective heat flow below them. As stated before, volcanic and seismic activity, as well as a few other natural disasters have been linked back to plate tectonics. Movements such as subduction zoning, where one plate dips below the converging plate due to having a higher density, are often the causes of tsunamis and volcanic formations. Transform plate boundaries are also credited with producing the more destructive earthquakes than any other boundary type.

Discuss the eruption of Mt. Mazama and its aftermath in an essay of 200-400 words.

To start off, the composite volcano, Mount Mazama, is located in the Cascade Range in Oregon in the United States. Composite volcanoes are known to be formed through a mixture of molten rock and pyroclastic material over a given period of time. Roughly 7,700 years ago. Mount Mazama underwent a massive eruption caused by a buildup of gas concentrations within the magma, the magma rises and caused the gases to be fully released after sustaining a ton of pressure, resulting in an explosive eruption. Composite volcanoes are known for being the most explosive and destructive in terms of volcanic types. In the aftermath of Mazama's eruption, the walls surrounding the volcano became so weak after masses of pyroclastic material were ejected from it that it collapsed soon after the dust settled. Another reason why the entire volcano collapsed is probably due to the complete emptying of the magma chamber below it, leaving it completely vulnerable. The aftermath of the explosion has caused the 12,000 ft volcano to collapse 4,000 ft into a shell of its former self, as well as one of the deepest lakes in North America. Despite that, the newly formed caldera has produced a smaller volcanic cone known as Wizard Island.

Explain the distribution of volcanoes, which are illustrated in Figure 14-26 on page 416.

Volcanoes are primarily formed through divergent boundaries and subduction zones. Depending on the type of fault, volcanoes form on plate tectonics.