STUDENT WORKSHEET CLIMATE DETECTIVES (L/O/A-AP) Name______________________________ ACTIVITY - POLLEN PUZZLE 1. Date___________________ 4. Using the descriptions in the Pollen-Climate Key Sort the foam “pollen grains” in your sample, by color. Each color of foam dots represents a different species of plant. 2. Match the colors of the dots to the colors on the Pollen-Climate Key, to determine the species for each sediment layer. 3. In the table below, for each sediment layer (1, 2, 3) and the species you identified in the pollen analysis on the front of this worksheet, for each sediment layer determine the biome at the time the layer was formed., and record the biome name in the table below . BIOMES vs. SEDIMENT AGE BLACK HAWK LAKE (ybp = years before present) mark an X for each species your team identifies. Sediment Layer POLLEN ANALYSIS BLACK HAWK LAKE Plant Species Sediment Layer 1 2 3 1 150-450 ybp 2 450-650 ybp 3 650-1500 ybp alpine sage bristlecone pine Douglas fir Engelmann spruce limber pine meadow grasses & wildflowers ponderosa pine sedges & mosses Age Biome 5. Based on the biomes recorded in the table above, how did the climate change from 1500 to 150 years before the present? 6. Can you speculate about what might have caused this climate trend? What do you think might have happened? (You may know the answer to this from what you learned in a world history or European history class!) 7. From this single lake sediment core can you make conclusions about global climate trends during 1500-150 ybp? If not, what additional evidence should you investigate? ACTIVITY – FINDING “NEO” 1. 1. For each of the three foram samples (10 thousand, 15 thousand, and 20 thousand years before 2. present), count the total number of Neogloboquadrina forams and record the number in the table 3. below, in the appropriate rows. 2. 2. Next count the number of right-coiling “Neos” in each sample and record these numbers in the 3. table. Sedime TOTAL Rightnt Layer “Neos” coiling “Neos” 3. For each sample, calculate and record the percent of right-coiling “Neos”: percent = number of right-coiling Neos X 100 total Neos in sample 4. Determine the relative ocean temperature (cold, warm, in-between) for each sample, based on the percents you calculated. 1 10,000 ybp 5. What happened to the ocean temperature 2 15,000 ybp 6. What might have caused this temperature 3 20,000 ybp between 20,000 and 10,000 years ago? Percent Relative RightOcean Coiling Temperature “Neos” trend? ACTIVITY – STOMATA SPECTACULAR 1. For each fossil leaf, count and record the number of stomata in the 3 areas of the “microscope slide”. Next calculate the average of the three counts and then divide that average by the area of the microscope’s field of view, to determine and record the stomatal density. 2. From the stomatal density, determine the relative carbon dioxide levels (higher or lower) for each of the two time periods. FOSSIL AGE STOMATA IN 1st AREA STOMATA IN 2nd AREA STOMATA IN 3rd AREA AVERAGE OF THREE AREAS AREA STOMATAL DENSITY = CO2 HIGHER AVG./AREA FIELD OF or LOWER? VIEW OF VIEW) (FIELD 15 million years mm2 13 million years mm2 3. Other scientific field evidence shows that 15 million years ago, the world’s icecaps and glaciers decreased in size, and about 13 million years ago there was major growth of glaciers and icecaps. How might these changes be related to the results of your stomata study? 4. Are the atmospheric changes the result of natural causes or human activities? What factors or phenomena may have caused the changes?