ACT Science › How to find synthesis of data in earth and space sciences
Scientists studying historical trends in climate change have a number of tools at their disposal. One method of analyzing paleoclimate data involves the use of fossilized pollen spores embedded in sediment. Pollen spores are specific to the plant that produced them. Because the spores are resilient and are widely-distributed by wind, they provide a snapshot of the vegetation that was widespread at a particular point in time. By identifying the age of a sample and the composition of the various spores, scientists can identify the prominent vegetation and use this information to gain insight into the climate at the time the spores were deposited.
Scientists took sediment samples from various depths of a lakebed. They found that five types of pollen spores make up the majority of spore deposits in each sample. In Table 1, plants are listed along with the respective temperature ranges and levels of precipitation for the areas in which they are commonly found. Table 2 shows the composition of the assortment of spores in each of the four samples taken by the scientists.
A fifth sample is taken at a different depth. If it contains few spores from any of the 5 plants, which is the most likely explanation for their absence?
The temperature and/or precipitation at the time was outside of the optimal ranges for each plant.
The spores did not survive from the time they were deposited.
The spores were poorly distributed.
The scientists used poor sampling procedures.
According to the passage, plant populations and the concentrations of deposited spores are largely dictated by climate conditions. Therefore it is most likely that the _absence_of spores is also attributable to climate conditions.
The passage also states that pollen spores are resilient and widely-distributed. This makes it unlikely that they did not survive or were poorly distributed. Lastly, no changes in sampling procedures were listed besides the change in depth. Because the scientists did not find similarly low numbers in Samples 1-4, it is unlikely that their sampling procedures were the cause of the absence of spores in Sample 5.
A scientist has observed a new planet, Planet H. It was discovered that Planet H has water on its surface. As a result, it is being investigated to determine if it is possible for Planet H to sustain human life. Futhermore, observations revealed that Planet H has four moons: Moon J, Moon K, Moon L, and Moon M. Each moon's radius, distance to Planet H, and time to orbit Planet H have been recorded in the provided table.
According to NASA, it takes Earth's Moon 27.3 or 29.5 Earth days to orbit the Earth depending upon the period. If the first settlers on Planet H established a lunar calendar similar to Earth's lunar calendar, then which moon would be the best to use (assume all of the moons go through the same cycles as the Earth's Moon)?
Moon L
Moon K
Moon J
Moon M
It cannot be determined from the given information
The lunar calendar is based on the phases of the moon, which depends upon the time it takes the moon to orbit its respective planet. Moon L has an orbit time of 29.6 days, which is most similar to the given orbit time for Earth's Moon. Therefore Moon L is the best moon to base the lunar calendar on so that it is the most similar to Earth's lunar calendar.
Researchers have discovered a new planet, Planet Z. This planet is orbited by several comets, A, B, C and D. Researchers have calculated the time it takes each comet to orbit Planet Z, the closest the comet gets to Planet Z and the diameter of the comet.
If the researchers wanted to visit Planet Z to conduct further researcher, where is the best location to set up a space station in millions of miles from Planet Z's surface? The space station is to be located at the point where all comets reach there minimum distance to Planet Z.
If a space station was to be setup, it should not be located in the path of any of the comets. The closest the comets come to the surface of Planet Z is 2.2 million miles and the farthest the comets are at the minimum is 4.1 million miles. Since it is undesirable for one of the comets to collide with the space station the space station should not be located within the range of 2.2 million miles to 4.1 million miles to Planet Z's surface. The correct answer is the only option not in this range, 6.2 million miles.
In a specific region, a scientist recorded the rainfall, in inches, during the months of May, June, July and August. The scientist recorded this data in the same spot each month over four years. The purpose of this study was to see how the new factories built in the area impacted the rainfall in that location.
What are the potential impacts if the trend in rainfall continues?
All of these
Flooding of crops
Increased water/irrigation for crops
Cannot be determined from the given information
The trend in the data is that each year the rainfall increases. In year 1 there is a total of 11.8in, in year 2 a total of 13.8in and the trend continues for the recorded years and months. An increase in rainfall could flood crops if the area already has plenty of water. However if the area is dry, the increase in rainfall could help with irrigation. Both of these answers are correct. Additionally, an increase in rainfall would cause more water to runoff into the environment.
One night there was a meteor shower and scientists in four different regions, A, B, C and D, observed and counted the number of meteors seen. The scientists noted the duration of the meteor shower and the visibility of the stars.
What is the relationship be the number of meteors seen and the duration of the meteor shower?
The longer the duration of the meteor shower, the less meteors were seen
There is no relationship
The shorter the duration, the less meteors seen
The longer the duration, the more meteors seen
It depends on the location
It can be seen in the data table that the most meteors seen were in Region B for a 12 minute period. While in Region D the least amount of meteors were seen and had the longest duration of 33 minutes. Region C had no meteors seen and a duration of zero and therefore is not to be included in this data trend. It is noticed that as the duration of the meteor shower increased, less meteors were seen.
Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.
Scientist 1
Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.
Scientist 2
Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.
What is a potential cause for an increase in greenhouse gases since 1750?
Production of greenhouse gases during the industrial revolution and population growth
An increase in the number of plants producing carbon dioxide
An increase in gas released from melting ice caps
An increase in clorofluorocarbons resulting in depletion of the ozone layer
During the early 1900s, the Industrial Revolution resulted in burning coal for energy, which caused an increase in production of greenhouse gases. Additionally, the increase in population has caused rapid deforestation, reducing the number of plants and trees that consume carbon dioxide. To date, there is no strong link between depletion of the ozone layer and climate change.
Scientists have long debated the origin of organic molecules on Earth. Organic molecules are those based on the atom carbon, which can form four distinct bonds in contrast to the fewer number allowed in most other non-metals. As a result of this property, carbon can give rise to the enormously complex molecular shapes necessary for life to arise.
Some scientists argue that organic matter was dissolved in water ice on comets, and brought to Earth early in its history. These comets crashed into the early Earth, and deposited carbon-based molecules in copious quantities to the Earth’s surface as their water melted.
In 2014, the first space probe landed on the comet 67P/Churyumov-Gerasimenko. Suppose that scientists find the following information from 5 distinct samples after landing on the comet. Each sample was taken at a single geographical location, but 5 meters deeper than the last. Sample 1 was taken at a depth of 1 meter below the surface.
Sample # | Water Ice? | Concentration of Organics |
---|---|---|
1 | No | N/A |
2 | Yes | 1 mg/L |
3 | No | N/A |
4 | Yes | 4 mg/L |
5 | Yes | 10 mg/L |
These samples were compared to 5 similar samples from the surface of Mars. Scientists posited that this comparison would be meaningful because we know that life does not exist on Mars the same way that it does on Earth. Thus, they are comparing a known non-biological celestial body, Mars, with another celestial body, the comet, which may be seeding life on suitable plants.
Sample # | Water Ice? | Concentration of Organics |
---|---|---|
1 | No | N/A |
2 | No | N/A |
3 | No | N/A |
4 | No | N/A |
5 | Yes | 1 mg/L |
The purpose of the sample from Mars as described in the passage is most likely to act as:
a negative control group for the experimental sample from the comet.
an experimental group for the negative control group from the comet.
a standard group to allow for standardization of data from the comet.
a balancing group to balance data from the comet.
The passage indicates that Martian soil was chosen as it is known to be non-biological. As a result, it is being used as a negative control to compare the concentration of organic molecules on comets to known non-biological samples from another celestial body.
Since the early 1900s, there has been a steady increase in the earth’s atmospheric temperature, resulting in a phenomenon called “Global Warming.” While the steady temperature change has been well documented, the cause of global warming remains controversial.
Scientist 1
Scientist 1 believes that “external forcings” are the cause of increased temperature over the past century. “External forcings” can direct the change in temperature over thousands of years. One example of an external force is variation in the earth’s orbit around the sun. The earth orbital cycle lasts 26,000 years and causes general trends in warming and cooling.
Scientist 2
Scientist 2 believes that global warming is a man-made phenomenon due to an increase in greenhouse gases such as carbon dioxide or methane. Greenhouse gases have a natural warming effect, however, an increase in the amount of atmospheric greenhouse gases many enhance that effect. Since 1750, the concentration of carbon dioxide has increased 36 percent while the amount of atmospheric methane has increased 148 percent.
In the year 2438 another ice age occurs, supporting which scientists' theory?
Scientist 1
Scientist 2
Both Scientists
Neither Scientist
Scientist 1 believes that global warming is a result of cyclical changes in the earth's orbit; therefore, periods of global warming should be followed by periods of global cooling, which can result in another ice age. On the other hand, Scientist 2 believes that as the world's population continues to grow, global warming will also continue. Because there was no data presented to suggest an abrupt change in population growth, scientist 2's theory is incorrect.
Scientists have recorded data in Region A, Region B, Region C and Region D. The data collected include the average daily temperature, the annual rainfall for the past year and the number of fresh water reservoirs. The scientists want to perform an experiment on wild life migration patterns.
Which of the regions most probably represents a desert?
Region A
Region B
Region C
Region D
A desert is an area that has very little rainfall and typically has high temperatures. Region A has 1.3 inches of rainfall, which is the smallest recorded amount. This region also has the highest average temperature indicating that Region A is a desert.
One night there was a meteor shower and scientists in four different regions, A, B, C and D, observed and counted the number of meteors seen. The scientists noted the duration of the meteor shower and the visibility of the stars.
In which of the regions is there the least amount of light pollution?
Cannot be determined from the given information
A
B
C
D
Light pollution will reduce visibility of the night sky. The scientists do not note the weather conditions in their respective regions. It can be cloudy in Region C or it could have a large amount of light pollution. It cannot be determined which region has the most light pollution. Be careful when the question is asking for inference leaps that are too far outside the scope of the information presented in the table and passage.