[Francesca Lingo]

Discussion Prompt – Due no later than Friday 2/26/2020 11:59 pm

Now that you have made and recorded your observations, write a brief summary to share your boundary classifications with your group. Your post should include 4 sets of classifications, one for each map, i.e., the V, E, T, and S boundaries. If you had lingering questions or observations you felt you could not properly classify, make note of those in this post.

This topic was also posted in: EAS 10600 #M Group B, EAS 10600 #M Group C, EAS 10600 #M Group E, EAS 10600 #M Group F, EAS 10600 #M Group A.

[Kevin Cardenas]

1. Volcanoes are found at almost all the plate boundaries on Earth, however there is a significantly larger amounts at some plate boundaries over others. Where volcanoes are very common, they tend to be distributed linearly along the line of the plate boundary and are relatively close together. There are some volcanoes that form a bit farther from the plate boundary, and there are even some that form towards the middle of the plate such as where Hawaii is in the Pacific Plate. There is also an occurrence of a cluster of volcanoes near Iceland in the Atlantic region. Some unique boundaries I have found are:
   V1: Linearly distributed volcanoes along the plate boundary such as in the west coast of the US
   V2: Clustered volcanoes on the plate boundary such as where Iceland is
   V3: Volcanoes that are very far apart along the plate boundary such as in the Atlantic
   V4: Volcanoes located in areas far form plate boundaries such as Hawaii
2. Earthquakes occur at every plate boundary on Earth. Some boundaries have a large number of Earthquakes that are distributed in a linear fashion, while others have a small number of Earthquakes distributed in a linear fashion. At one boundary in Europe there is a cluster of Earthquakes that occur, some very close to the boundary and others a bit further inwards. The Earthquakes seem to produce a pattern that looks very similar to the plate boundaries. Unique boundaries that I can identify are:
   E1: Abundant earthquakes distributed linearly along the plate boundary such as on the west coast of the US
   E2: Small number of earthquakes distributed linearly along the plate boundary such as in the mid atlantic
   E3: Large number of Earthquakes clustered and going inward from the plate boundary such as in Europe
   E4: Earthquakes that are very far apart from one another along a plate boundary such as in northeast Russia.
3. At some plate boundaries in the ocean, the elevation is higher than the area near it. It looks similar to a mountain chain but it is in the ocean. At other plate boundaries where oceans and continents meet, the oceans get very deep close to the continent-ocean border forming a trench, and the continents have very high elevations forming a mountain range like formation. At other plate boundaries that is located on land, elevations get very high also forming mountain like formations. Unique boundaries are:
   T1: Ocean-Ocean boundaries that have high elevations at the boundary
   T2: Ocean-Continent boundaries with high elevations on the continental part of the boundary, and very low elevations on the ocean part of the boundary
   T3: Continent-Continent boundaries that have high elevations at and near the boundary.
4. The seafloor is youngest at some plate boundaries and is older at others. At boundaries where the seafloor is older, when going away from the boundary the seafloor tends to get progressively younger until another plate boundary is reached. At some plate boundaries the seafloor age is symmetrical on both sides, whereas on others the seafloor seems to spread faster on one side than the other. Unique boundaries are:
   S1: Youngest seafloor at the boundary and symmetrical age change on both sides of the boundary such as in the Atlantic.
   S2: Youngest seafloor at the boundary and faster spreading on one side than the other such as in the Pacific.
   S3: Older seafloor at boundary and progressively younger seafloor away from the boundary until another one is met such as the border between the ocean and South America.
   S4: Oldest seafloor is near the continents on the side that is closest to a boundary that has the youngest seafloor on it, such as the eastern US.

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[Rajwinder Singh]

<li style=”font-weight: 400;” aria-level=”1″>Open the map of plate boundaries and the map of volcanoes. Spend 3-5 minutes examining the pattern of volcanoes relative to the tectonic boundaries and consider the following questions:

Volcanoes are found across all plate boundaries, some having a heavier concentration of them than others such as the pacific and australian plates.

Volcanoes form along the edges or the connection point between two plates such as the plates along the western coastlines of South and North America. For the most part, these volcanoes are in bunches but there’s enough of them to create a linear pattern among the boundary edges, along with those occurring near coasts of Japan and Australia. Ofcourse, there are volcanoes that form completely by themselves in clusters such as those in Iceland and those near East Africa by Ethiopia and Kenya. The pattern for other volcanoes is quite random that formed all over each of the five oceans. From my observation, most volcanoes occur on top of the boundaries with some forming on both sides of the boundary. It would make sense if the volcanoes that occur in cluster such as in East Africa, the Atlantic Ocean, and around the Pacfic Ocean act as divergent boundaries.

V1) Volcanoes occurring in clusters near the eastern part of the African plate.

V2) Volcanoes forming in a linear yet in abundance along the coastlines of the American continents near the Pacific ocean.

V3) The volcanoes formed at the boundaries of the Eurasian plate and North American plate in Iceland in clusters.

V4) Volcanoes occurring at random and isolated areas of the oceans, notably around islands and the length of the equator.

<li style=”font-weight: 400;” aria-level=”1″>Open the map of plate boundaries and the map of earthquakes. Spend 3-5 minutes examining the pattern of volcanoes relative to the tectonic boundaries and consider the following questions:

<li style=”font-weight: 400;” aria-level=”2″>Are earthquakes present at ALL boundaries?

Earthquakes are found at all boundaries, despite some boundaries faintly having any.

<li style=”font-weight: 400;” aria-level=”2″>Where earthquakes do occur at or near a plate boundary, how would you describe their
distribution? Do they occur in a linear pattern? A clustered pattern? Are there many earthquakes occurring in a small area? Are the earthquakes spread out? Is there no discernable pattern at all? How does the location of the earthquakes relate to the boundary itself? Do they occur on top of the boundary? On both sides of the boundary? Just one side of the boundary? Is the depth of the earthquakes the same at all locations near the boundary? If not, how does it change in relation to distance from the boundary? Is there a pattern you can describe? Keep in mind that the patterns or trends you observe may not be the same at all boundaries.

I see earthquakes copying the exact outline of where the plate boundaries are, although about 10% of the boundary near Russia and near Antarctica not having a huge frequency of earthquakes. The earthquakes occur right above or on the boundaries, with most earthquakes staying closer to the boundaries. It’s rare to see an earthquake to occur inland or further away from the boundary. Earthquakes in the ocean follow a linear pattern whereas those near prominent plates such as the one responsible for most volcanoes, occur in clusters. Surprisingly,unlike volcanoes besides the occurrences over the coastal American and Japanese boundaries, I see a huge concentration of them in the Mediterranean Sea.

 

<li style=”font-weight: 400;” aria-level=”2″>Based on your observations, how many “unique” plate boundaries can you identify on the basis of these observations? Make a list of these unique boundaries, labeled E1, E2, etc., and write a brief description that summarizes the expected pattern of earthquakes (or lack of earthquakes) corresponding to each.

E1) Earthquakes forming in a linear yet in abundance along the coastlines of the American continents near the Pacific ocean. This also includes Japan coastline.

E2) Earthquakes forming in clusters on the boundaries of the northern Arabian plate and the northern African plate.

E3) Earthquakes occurring at a lower concentration, outlining a faint line over the plate boundaries that are in the oceans.

E4) Earthquakes occurring inland via a random pattern in parts of North America, Australia, and SouthEast Asia.

3)  Open the map of plate boundaries and the map of Earth’s topography and bathymetry. Spend 3-5 minutes examining the pattern of elevation relative to the tectonic boundaries and consider the following questions:

<li style=”font-weight: 400;” aria-level=”2″>Are there any distinct patterns in elevation that occur at or near a plate boundary? If so, how would you describe these patterns? Is there a mountain chain? A trench? Be sure to look at both sides of the boundary. Where distinct features like mountains or a trench occur, are they observed on both sides of the boundary or just one? Are there some boundaries where more than one distinct change or pattern in elevation occurs? Be sure to look at both the ocean floor and the continent. In your descriptions, be sure to discuss the pattern of any distinct features. Are features linear? Clustered? Random?

The elevation is highest near the boundaries along the parts of the Western North American and South American plates as they connect with the Pacific plate.The yellow color here indicates the presence of mountainous regions. However the Pacific plate represents low elevation colored in dark purple. Those boundaries that include both land and water such as the African, Eurasian, and North America have both high  elevation in the form of mountains and low elevation regions such as coastal oceans. High elevation occurs in parts of Greenland and Antarctica since there’s a cluster of mountainous regions expanding across the entire lands. Most of the Earth’s crust is colored green representing close elevation to the ceiling of the sea, but high elevation occurs only on one side of most plates. There’s a random occurrence of high elevation in parts of Western Europe, Northern African, and Eastern American continents.

 

<li style=”font-weight: 400;” aria-level=”2″>Based on your observations, how many “unique” plate boundaries can you identify on the basis of these observations? Make a list of these unique boundaries, labeled T1, T2, etc., and write a brief description that summarizes the expected pattern of topography and bathymetry corresponding to each.

T1)  Mountains  forming in a linear yet in abundance along the coastlines of the American continents near the Pacific ocean.However, unlike earthquakes, mountains spread more inland.

T2) Lowest elevation is in an obvious pattern indicated by purple in plates that encompass the ocean. These occur on the outline of the plate boundaries.

T3) Highest elevation is found on the meeting point of the Indian and Eurasian plate, indicated by the Himalayan mountains.

T4) Colder regions such as Iceland and Antarctica show a cluster or high elevation ranges. 

4. Open the map of plate boundaries and the map of seafloor age. Spend 3-5 minutes examining the pattern of seafloor age relative to the tectonic boundaries found in the ocean basins and consider the following questions:

<li style=”font-weight: 400;” aria-level=”1″>Is the age of the seafloor the same at all boundaries? If not, where is it the youngest? Where is it the oldest?

No for most boundaries the age is not the same, although the red color across the boundaries represents a young sea floor. The oldest seafloor indicated by the blue color is further away from the North American plate, African Plate, and Pacific plate. I see some random specs of blue near Mexico and near Antarctica. 

<li style=”font-weight: 400;” aria-level=”1″>Is there a discernable pattern relative to the position of different boundaries? For example, does age increase/decrease in the same way on both sides of the boundary or does it only change on one side of the boundary? 

Yes as you further away from the boundary lines, the age changes similarly almost like a graph of parabola. The age starts young near the boundaries and gets older as you expand out from the boundary.

<li style=”font-weight: 400;” aria-level=”1″>Based on your observations, how many “unique” plate boundaries can you identify on the basis of the age of the seafloor? Make a list of these unique boundaries, labeled S1, S2, etc., and write a brief description that summarizes the patterns corresponding to each.

S1) The eastern side of the Pacific plate boundary starts off as young and gets older as you move west and surprisingly a very older ocean floor near the most western parts of the boundary.

S2) Most plate boundaries show an even growth pattern despite the Pacific plate which seems very young, and after a long distance, the ocean floor becomes older.

S3) The North American and African plates show random areas of the oldest seafloor regions.

 

[Jaemin An]

1. Although volcanoes are present at nearly all boundaries, there are some plate boundaries in which volcanoes are more commonly found. For example, there are more volcanoes running along the Pacific Plate than there are volcanoes running along the African Plate. The distribution of the volcanoes in high-concentrated areas such as the Pacific Plate occur at a linear pattern whereas they occur in clustered patterns in low-concentrated areas like the African Plate. In addition, some volcanoes occur in small areas as seen in the center of the African Plate while volcanoes are spread out in the Antarctic Plate. Further, there are volcanoes which run along both sides of the plate boundary such as the Pacific Plate in which volcanoes are commonly found linearly running along the west and east side of the Pacific Plate. However, volcanoes are not found on all sides of the boundary in the Australian Plate in that volcanoes are not evident on the top of the boundary.

 

Unique boundaries:

V1. Volcanoes are linearly distributed along the west and east side of the Pacific Plate.

V2. Volcanoes occur in clustered patterns as seen in the African Plate.

V3. Volcanoes are spread out and scattered in the Eurasian Plate.

V4. Volcanoes are linearly distributed along the west of the South American Plate whereas they are spread out on the east side of the South American Plate.

V5. Volcanoes are distributed in clustered patterns in the small area of Iceland.

V6. Volcanoes are linearly distributed where the northern border of the Australian Plate and the southern border of the Eurasian Plate meet whereas there are almost no volcanoes running along the southern border of the Australian Plate.

 

2. Earthquakes are present at all boundaries, but there are some plate boundaries in which more earthquakes are found more than others. For example, there are more earthquakes running along the west and east side of the Pacific Plate whereas there are fewer earthquakes running along the northeast side of the Eurasian Plate. Like the distribution of volcanoes, the distribution of the earthquakes is uneven based on the plate boundary. Earthquakes run linearly along the Pacific Plate whereas they occur in clusters in small areas as seen in the north of the African Plate. Although the distribution and the concentration of earthquakes differ depending on plate boundary, earthquakes occur on all sides of the plate boundary. Overall, the earthquakes display a very similar pattern to the volcanoes.

Unique boundaries:

E1. Earthquakes are linearly distributed along the west and east side of the Pacific Plate.

E2. Earthquakes occur in clusters in small areas such as the north boundary of the African Plate.

E3. Earthquakes are highly concentrated and run linearly on the north of the Australian Plate where the Australian Plate and the Eurasian Plate meet whereas there are fewer concentration of earthquakes along the south of the Australian Plate.

E4. Earthquakes occur more on the west side of the Eurasian Plate whereas they are fewer on the east side of the Eurasian Plate.

 

3. The elevation that occur at a plate boundary is higher than the area located near the plate boundary. For example, the elevation at the Pacific Plate, specifically the west of the United States Is higher than the rest of the country. In addition, the ocean gets deeper at the plate boundary. Trenches which are formed by the subduction of divergent plates are seen in these areas where the ocean and land meet as evident in the Pacific Plate.

 

Unique boundaries:

T1. On the west side of the North American Plate, there is high elevation whereas there is low elevation on the east side of the plate.

T2. The elevation in Greenland increases as it moves inland.

T3. The elevation along the east side of the Eurasian plate where it meets the Pacific Plate is higher than the west side of the plate.

 

4. The age of the seafloor is not the same at all boundaries because the age is young along the Pacific Plate near North America whereas the age is older along the Pacific Plate located near Asia. In addition, the age seems to relatively be younger at the plate boundary and get older as it moves away from the boundary. For example, in the African Plate and the South American Plate, the age is young where the two plates meet, but gets older as it moves away from the boundary. The pattern is common in almost all plate boundaries because the age is younger nearer the boundary and older away from the boundary.

Unique plate boundaries:

S1. The age is younger along the Pacific Plate near North America and older along the Pacific Plate near Asia.

S2. The age along the border of the African Plate is younger and gets older as it moves closer to the center.

[Diego Silva]

1. Volcanoes seem to be present along all boundaries but not evenly distributed, there are regions with lots of them and some where there are barely any. Parts where the plate boundaries lie under islands or the continents seem to have the most volcanoes, while the sea parts are mostly empty. the thing I did notice is that the volcanoes appear slightly to the side of the plate boundaries, in the case of America’s west coast, the volcanoes mirror the plate boundary but moved slightly to the right.

V1= volcanoes that form alongside a plate boundary linearly like japan or the American west coast

V2= small patches of volcanoes around specific areas, east Africa and Iceland

V3= lack of volcanoes along boundary like india or Russia

V4= single or few volcanoes in the oceans.

2. Earthquakes are present alongside every part of the boundaries except some parts have a higher and a lower concentration. The majority of earthquakes just follow a linear patter along the boundary but there are regions such as Japan or Europe where there is a cluster. And some empty spots along the map, its very clear that the plates have a direct relationship to earthquakes just by looking at the graphs

E1= light linear earthquakes along boundary

E2= clusters of earthquakes in specific places near the plate boundaries like japan or europe

E3= light spread out earthquakes far from the boundaries like in Australia

E4= empty spots such as Greenland or majority of Russia

3. The plate boundaries can actually be seen at the topography map in the ocean as they have a different elevation as the ocean. And in the parts where the boundaries are under land there are usually mountains, such as in south America and the US west coast. You can also see the outline of a plate on the Himalayas as in one side we have the mountain range and the other is flat land.

T1= Boundaries in the ocean with a slightly higher elevation

T2= Boundaries on land where there are mountain ranges

T3= tranches in some parts of the boundaries like next to Alaska

4. The age is the same in almost the same in all of the boundaries, there are a few exceptions such as next to Alaska and right of India where it’s very young compared to the rest where it is the oldest. It looks like the age is equal on both sides of the boundary is equal.

S1= oldest seafloor alongside the boundaries

S2= young seafloor along boundary such as alaska’s left side

S3= large portion of seafloor including entire plates like next to south America, theyre old as well

[Rose Crisostomo Cabrera]

Volcanoes

We can see that there are volcanoes at the edges of most continents and follow a pattern of being at the very edges. This makes sense since we know that a significant chunk of volcanoes occur at the boundary of tectonic plates. The ones that are close together and at the border of continents are likely from subduction zones.

V1) There is a cluster of volcanoes that makeup Iceland.
V2) Almost the entirety of Japan is made up of volcanoes.
V3) The Andes range has a cluster of volcanoes.
V4) There is a small line-cluster in Africa near present-day Saudi Arabia.

Earthquakes

Earthquakes occur at plate boundaries all over the earth. We can see that, for this reason, they tend to coincide with a lot of the volcanoes pointed out above.

E1) Earthquakes line the entire western boundary of the Americas (North and South continents).
E2) Earthquakes are present near the lower Antilles in the Caribbean basin.
E3) There are many earthquakes present in Europe, particularly near the Mediterranean.
E4) Earthquakes

Elevation – the different altitudes present on earth.

T1) We can see the high mountain elevation present in the Himalaya mountain range.
T2) We can also see the high mountains in the Andes.
T3) We can see the high elevation on the West Coast of the United States.
T4) We see low elevation near the Amazon northern basin (heavy rivers).

Boundaries

S1) The boundary of the South American plate on the western part almost perfectly borders and creates the shape of the South American continent.
S2) The Arabian plate is separate and based on the movements, has been nestled between Africa and Eurasia.
S3) the North American plate contains what we currently identify as North America
S4) The caribbean plate is its own thing.

[Luis Antonio Alchundia Laborde]

Not all the plate boundaries have volcanoes. Volcanoes are common along convergent and divergent plate boundaries, but are also found within lithospheric plates away from plate boundaries. Volcanoes occur on and near a plate boundary. The distribution of the volcanoes depends on the área along the Pacific Ocean basin, on the edges of the Pacific, Cocos and Nazca plates, their distribution is grouped similar to a swarm, in the same way in the upper limit of Australian Plate. In certain areas volcanoes are scattered throughout the Pacific Ocean basin, mainly on the edges of the Pacific, Cocos and Nazca plates. Volcanoes are scattered across the African Plate. In the Antartic Plate the volcanoes present have no discernible pattern. If there is a relationship of the location of the volcanoes in most of the boundaries, they are near or at the boundaries. They can occur on both sides of the plate boundaries. V1: Pacific Plate boundary north and upper northwest. The volcanoes are near the limit and located on the limit, along the northwest limit they do not have a defined distribution and in a section of the northern limit they have a linear distribution. V2: South American Plate western limit, the volcanoes are close to each other located on the limit of the plate, they show a distribution similar to a swarm, in certain areas of the limit there is no presence of volcanoes.  V3: Eurassian Plate southeast limit, the volcanoes are located close to each other in the form of swarms.

 

Yes, earthquakes occur on all edges of the tectonic plates. The distribution of earthquakes varies at each plate boundary; Pacific Plate: In the upper part the earthquakes are grouped together, with depths between 0 to 700km. In the northwest limit many earthquakes occur at depths of 300 to 700km. In the lower part the presence of earthquakes decreases and their depths range from 0 to 33 km. African plate: linear pattern except in the upper limit, in the other limits the presence of earthquakes decreases and has no discernible distribution. The depths of earthquakes range from 0 to 33km. Australian Plate: north and northeast part linear and grouped pattern, with depths between or 700 km. In the following limits the presence of earthquakes decreases and does not have a discernible distribution, the depth of the earthquakes is from 0 to 33 km. South American Plate: on the eastern limit earthquakes occur grouped together with depths between 0 to 33km up to 700km, there is a greater presence of earthquakes with depths between 70 to 300km. Many earthquakes occur between Eursaian Plate and African Plate, with a depth of 0 to 33 km, 70 to 300km. E1: Eurasian plate. In the upper East limit there is no presence of earthquakes.

 

 

If there are patterns with different elevations that occur at and near a plate boundary. Different elevations are presented in: Caribbean Plate, Eurasian Plate southern limit, in the north of African Plate, in the Southwest of the North American Plate different levels of elevations are presented and a mountain range is shown. If there is a boundary where more than one change in elevation occurs, for example North American Plate to the northeast and at the southwestern boundary of the Eurasian plate. On most plate boundaries, elevation characteristics are linear, but on certain plates they are random as in Eurasian and North America. T1:  Eurasian plate east limit, presents bathymetry changes from -2500 masl to 1600 masl. T2: Eurasian plate southern limit, presents bathymetry changes from -2500 masl to 4500 masl. T3: Eurasian plate south west limit, presents bathymetric changes from -3500 masl to 1600 masl. T4: North American Plate east limit, presents bathymetry changes from -3500 masl to 1600 masl.

 

The boundaries of all plates except Arabian Plate, Caribbean Plate show younger seafloor ages. The oldest seafloor age 180 million years is found at the northern boundary of the African Plate. In most limits the age of the seabed remains between 0 and 9.7 million years. In the north pacific plate the age of the seabed varies on one side of a boundary with bottoms ranging in age from 0 to 55.9 million years. In the northern Australian plate, on one side of a boundary, different ages of the seabed occur approximately between 33.1 and 83.5 million years. In North African plate different ages of the seabed are presented on one side from 0 to 180 million years. S1: in Pacific Plate is the youngest seabed. S2: in African Plate is the oldest seabed.

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