GOL106 Northern Virginia Climate Analysis Using Planktonic Foraminifera Lab Report

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guveqyhk

Science

GOL106

Northern Virginia Community College

Description

You have been given a series of samples containing planktonic foraminifera representing time from the present to 150,000 years ago. You are processing the samples to look at the climatic signal they reveal in Earth’s recent history. You are aware that two particular species of foraminifera, Ammonia beccarii and Elphidium excavatum, are excellent recorders of water temperature through geologic time. Both species live in the shallow water, near-shore environment. When the Earth experiences periods of relatively cold temperatures, ocean waters are cooler and can retain more dissolved oxygen. These conditions favor the species Elphidium excavatum. Alternatively, during periods of relatively warm climatic periods, ocean waters heat up and are unable to retain as much dissolved oxygen. These conditions favor the species Ammonia beccarii. Therefore, you have separated each species from your samples to determine their A/E Index (Ammonia beccarii/Elphidium excavatum Index). Comparing the number of the two species found in each sample will provide the A/E Index by using the following formula:

A/E Index = [#A/(#A+#E)] x 100

where # = number of each species in the sample

As ocean waters heat up, the A/E Index goes up; alternately, as ocean temperatures go down, so does the A/E Index.

Procedure:

1) You will need graph paper or use online graphing software to construct the graph for this exercise.

2) For each time period sample you have counted the number of each species. Your data is recorded in Table 1. Your next step is to calculate the A/E Index for each sample. Complete the worksheet in Table 1 by using the equation provided. The first sample has been done for you.

3) Use graph paper to plot your results. On the vertical axis you should plot the age of the samples with "0" at the top and "-150,000" at the bottom. On the horizontal axis, plot the A/E Index. You should now have a graph representing the climatic signal derived from the comparison of Ammonia beccarii to Elphidium excavatum populations.

4) After completing your calculations and plotting your results, answer questions #4 and #5 found on the next several pages.

Unformatted Attachment Preview

LAB 4A: CLIMATE ANALYSIS USING PLANKTONIC FORAMINIFERA Background: You have been given a series of samples containing planktonic foraminifera representing time from the present to 150,000 years ago. You are processing the samples to look at the climatic signal they reveal in Earth’s recent history. You are aware that two particular species of foraminifera, Ammonia beccarii and Elphidium excavatum, are excellent recorders of water temperature through geologic time. Both species live in the shallow water, near-shore environment. When the Earth experiences periods of relatively cold temperatures, ocean waters are cooler and can retain more dissolved oxygen. These conditions favor the species Elphidium excavatum. Alternatively, during periods of relatively warm climatic periods, ocean waters heat up and are unable to retain as much dissolved oxygen. These conditions favor the species Ammonia beccarii. Therefore, you have separated each species from your samples to determine their A/E Index (Ammonia beccarii/Elphidium excavatum Index). Comparing the number of the two species found in each sample will provide the A/E Index by using the following formula: A/E Index = [#A/(#A+#E)] x 100 where # = number of each species in the sample As ocean waters heat up, the A/E Index goes up; alternately, as ocean temperatures go down, so does the A/E Index. Procedure: 1) You will need graph paper or use online graphing software to construct the graph for this exercise. 2) For each time period sample you have counted the number of each species. Your data is recorded in Table 1. Your next step is to calculate the A/E Index for each sample. Complete the worksheet in Table 1 by using the equation provided. The first sample has been done for you. 3) Use graph paper to plot your results. On the vertical axis you should plot the age of the samples with "0" at the top and "-150,000" at the bottom. On the horizontal axis, plot the A/E Index. You should now have a graph representing the climatic signal derived from the comparison of Ammonia beccarii to Elphidium excavatum populations. 4) After completing your calculations and plotting your results, answer questions #4 and #5 found on the next several pages. Years Before Present Ammonia beccarii Elphidium excavatum A/E Index = [#A/(#A+#E)] x 100 0 260 63 260/(260+63)x100=81 10,000 250 85 20,000 56 245 30,000 44 298 40,000 53 305 50,000 62 384 60,000 40 280 70,000 53 285 80,000 67 271 90,000 106 24 100,000 244 48 110,000 174 90 120,000 103 35 130,000 52 199 140,000 48 333 150,000 49 71 4) Analyze your graph and make an interpretation of the climatic history on our planet during the last 150,000 years. Describe this history below (use words to explain what is displayed on your graph). Don’t forget the question on the next page... 5) Search the Internet for a graph of Earth’s temperature history over the past 150,000 years. Copy and paste that graph below. Compare it with your graph. Note and explain any similarities or differences.
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Explanation & Answer

Attached.

Surname1
Student’s Name
Instructor’s Name
Course Code
Date
Climate Analysis Using Planktonic Foraminifera

Years Before
Present

Ammonia beccarii

Elphidium excavatum

A/E Index =
[#A/(#A+#E)] x 100

0

260

63

260/(260+63)x100=81

10,000

250

85

250/(250+85)x100=75

20,000

56

245

56/(56+245)x100=19

30,000

44

298

44/(44+298)x100=13

40,000

53

305

53/(53+305)x100=15

50,000

62

384

62/(62+384)x100=14

60,000

40

280

40/(40+280)x100=13

70...

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