Reference no: EM132865994

QUESTION 1

Sediment Cores and learning about past environments. Watch this 2-minute video about the Horsebarn Hill Core:

Answer the following questions:
Collecting cores is a way to look at which change as a result of varying climate and environment through time.

• a insolation
• b earthquake frequency
• c minerals
• d sediment layers

QUESTION 2

Spruce or Pine cone was Identified in the core at about 3.5 meters deep. According to the video, how old are these features?

• 12.000-13,000 years old
• 150,000 to 160,000 years old
• 2,000-3,000 years old
• 100-200 years old

QUESTION 3

Based on the content of the core, what did Horsebarn Hill look 12,500 years ago? In other words, what type of vegetation dominated the landscape at that time?

0 Deciduous hardwoods (oak, maple, hickory)
0 Coniferous (spruce, pine, fir)
0 The environment could not support much vegetation.
0 Grasslands

QUESTION 4

Based on what you see at Horsebarn Hill today, is the dominant vegetation the same as as -12,500 years ago? What is different or similar?

QUESTION 5
Now it's your turn to describe observations and interpret what you see in the Horsebarn Hill Core. Below is a link to download some slides which contain an image of the core, and a core description with dates. The core length Is about 4 meters. The deeper the layer in the core. the older It is (recall Principal of SuperposMon from the geologic One lab). Look at the image of the core (zoom ins. Use the slides to help you answer the next few questions.

The first step In I nterpretlng a core Is to make observations about what you see in the core. After your observations are made, you can begin to make Interpretations. It is important to make the distinction between observation and interpretation. Observations answer the simple question -What do you seer (e.g. - leaves at 10 cm below the surface, coarse sand at 40 cm below the surface act) Interpretations answer more complex questions like, 'What does this mean about the environment represented by the layer? What kinds of vegetation were present; what events occurred (flood, drought); what environment was present (wetland, lake)?

In order to describe what climate and environments were like in the past, geologists will make a sketch of what they see in their core, and list Important observations. Then, they will interpret their observations based on what they see.

Study the Image of the core provided. List 3 interesting observations, and the approximate depth in cm) where they are present (e.g. pine needles, coarse sand, clay, peat).

QUESTION 6
To make interpretations, we must think about what the observations mean. Think back to your -rocks" lab, where we talked about grain size and how grainsize of sediment relates to the environment. Coarse sands and gravels were associated with high energy environments, like fast Bowing streams or wave action at a shoreline. Fine grained sediments like clays and silts were associated with low energy environments like lakes, or deep ocean basins. Also think about what the organic content of our sedimentary rocks told us. If we found shells, we know that animals, like clams and oysters, could live in the environment-so we might be looking at ancient ocean sediment. If find had coal - which we know comes from peat-we are looking at ancient wetland sediment. Although we are not working with a bedrock core here, the concept is the same. Below is a sketch of the sediment core made by a scientist in training. Based on some of the observations you have made, match the sediment facies (aka, layers) with the environment they most likely represent.(note: yBP 6 years before present)

QUESTION 7
The dates shown for the core by depth were acquired using radiocarbon dating. This Is how we know how old the layers are, and therefore, how long ago different environments existed in Storrs. By looking at the distribution of dates by depth - do you think sediment accumulates at a constant rate at this site?
 Yes
 No

QUESTION 8
Based on the order of the layers, from past to present, tell the story of landscape change through time at Horsebarn Hill. (around 3.5 sentences)

QUESTION 9
Past Climate: Vostok Ice Core

Ice Cores collected from glaciers have layers just like sediment core from Horsebarn Hill does. Again, scientists can use these layers to interpret past environment and climate. Besides looking at changes in sediment, scientists can also look at the molecular composition of the ice and of air bubbles trapped in the ice. These bubbles may be ancient, and therefore, the ancient atmospheric composition is preserved in them.

It is known that the rano between different hydrogen isotopes (i.e., hydrogen and deuterium) in the atmosphere is related to temperature. Using this concept, scientists can reconstruct past temperature by analyzing the hydrogen isotope ratios in the ancient bubbles trapped in the ice. The ratio between different hydrogen isotopes is usually expressed as delta-deuterium (60).

For the next section you will use real climate data collected form the Vostok Ice Core. Download the Excel spreadsheet or google sheet version on the Lab 10 page for the information about the Vostok Ire core.

To answer the next two questions, calculate the ancient temperature based on the hydrogen isotope composition (6D) of the ice. The hydrogen isotope composition (6D) may be used to estimate temperature using the following empirical relationship. Use this formula to fill the 'Temperature' column on the spreadsheet:

Now look at the plot of the calculated temperature vs. age of ice and answer the following questions: Describe the pattern indicated in the plot. How has temperature changed over time?

QUESTION 10
How long ago did the maximum temperature occur?

QUESTION 11
How long ago did the minimum temperature occur?

QUESTION 13
Multiple factors could have affected the temperature pattern in the past. Such as:
• Greenhouse gas
Today, rising levels of greenhouse gasses, CO2 (carbon dioxide) and CH4 (methane), are associated with increasing global temperatures. Does this pattern exist in the past? To find out, scientists can measure the CO2 and CH4 of air bubbles trapped in the ice, and compare the CO2 and CH4 levels with the temperature reconstruction.
• Solar insolation
Periodic variations in Earth's orbit change the intensity and distribution of solar energy across the Earth's surface. Scientists can calculate the solar insolation changes through time and investigate how these changes may be related to the temperature.

To quantitatively access how strongly each factor influences the temperature, we can plot these factors with the temperature difference from present, and observe how well they are correlated. For the following questions, consult the scatter plots to answer. These datasets are available in the Vostok Ice Core data spreadsheet for those of you who are interested. You can refer to the plots provided here to answer the following questions:

QUESTION 14

Temperature difference from present (CC)
4.0
2.0
0.0
2.0
-4.0
-6.0
-8.0
-10.0
The 112 value is (to 3rd decimal), indicating a (moderate to weak moderate to strong)

correlation between CH4 concentration and temperature.

QUESTION 15
Solar insolation (langleys per day)
The R2 value is (to 3rd decimal), indicating a (strong, weak) correlation between solar
insolation and temperature. This correlation is (much less, much more, no difference) than those between temperature
and greenhouse gas concentrations.

QUESTION 16
Look at the graph showing variations in CO2 and CH4 as a function of time of the Vostok Ice Core records. The record of temperature difference is also included on this plot with a second axis.

how well does the temperature record match with the CO2 and CH4 record?

QUESTION 17
Now look at the graph showing variations in solar insolation as a function of time

-Solar Insolation (langleys per day) -Temperature difference from present CC)

Bred on the plots, do you think solar Insolation exerts any Influence over long-term dime& changes? Why or why not?

QUESTION 18

Modern Climate
For the next section, read the information provided in the Climate Change reader about modern climate data. The following plots were generated using modern temperature data (1880-2016) and CO2 levels recorded at the Maua Luna station in Hay aii (1956-2016).

The curve continuously (remains steady, oscillates), but the long term trend is (upward, downward, not apparent), with (a dramatic increase, a dramatic decrease, no change) during the past few years.

QUESTION 19
What is the difference between the highest and lowest temperature on record?

QUESTION 20
The 3 warmest years for the entire globe in this record are The 2 coldest years are

QUESTION 21

Which year of your life was the coldest? Have we come anywhere close to having one of the coldest years in the record during your lifetime?

QUESTION 22
Look at the graph showing how annual CO2 concentrations have changed with time to answer the following questions:

QUESTION 23
What is the range of CO2 concentrations in this data set?

QUESTION 24
Use the plot below to answer the following questions:

Based on the R2 value, there is a very strong correlation between CO2 concentrations and global temperature. (remember, 122 = 1 means perfect correlation; R2 = o means absolutely no correlation)

QUESTION 25
The B2 value shown is

QUESTION 26
The recently released report by the Intergovernmental Panel on Climate Change concludes that CO2 levels in the year 2030 will be somewhere between 410 and 480 ppm. Using the regression equation from the trendline, calculate the temperatures that correspond to these CO, values.

These temperatures (in celcius) are and . (Answer in numbers only. You do not need to include the units. Answer to the nearest 3rd decimal.)

QUESTION 27
Consult the plot below of global annual temperature vs. time to answer the following questions. The blue line is for the last 50 years (1966-2016), and the shorter orange line is for the last 10 years (2006-2016). The slopes and R2 values for these curves have been calculated and are shown on the plots.

How does the slope of the full dataset compare; the toolbar. AIT lniPn or AIT N tnt

QUESTION 28

Look at the figure below showing the temperature history of Earth. The the vertical axis Is average surface temperrature relative to the 1960-1990 average, and the horizontal axis is time in years before 2015. The red dots on the righthand side of the figure indicate the temperatures that climate scientists predict we may experience in 2050 and 2100.

Do you think the trend of warming tomparatur. bah.. 1960 and today is an issue we need to worry about, Why or Why not? Your answer, which should be several .ntences long. must include your interpretations of the data displayed by this figure. You will be graded based on the clarity and thoughtfulnes in your explanation regardless of whether your answer is yes or no.