Science 8 Final Exam Studyguide

The universe began about ___________________________________.

14 billion years ago

A sample is brought to the laboratory and it is determined that onesixteenth of the original parent isotope remains in the sample. Use Figure 122 to determine the age of the sample if the halflife of the material is 60 million years.

240 million years

What is the half life of Strontium90?

28.1 years.

Using the halflife of Carbon14, determine the original mass of the remains of a piece of petrified wood with a final mass of 300g and a total of three half lives. How old would this piece of petrified wood be?

300g x 2 = 600g 600g x 2 = 1200g 1200g x 2 = 2400g original mass = 2400g C14 half life = 5,730 years 5,730 x 3 = 17,190 years old

What is the currently accepted age of Earth?

4.6 billion years

Our solar system began to form about ______ years ago.

5 billion

If the halflife of an unstable isotope is 2,000 years, and only 6.25% of the radioactive parent remains in a sample, how old is the sample?

8,000 years

Name the three climate zones in the diagram to the right. Why would point A have the warmest climate?

A - Tropics B - Temperate Zone C - Polar Zone Because the sun's rays are more direct on average at this location

Based on the weather map below, describe how the weather will change within the next 24 hours at stations A, B, & C?

A - precipitation moves in with warmer temperatures B - skies clearing & cooler temps. C - stormy & colder air

Name and describe each of the volcanoes.

A Cindercone explosive eruptions of pyroclastic materials B Composite (Stratovolcano) alternating explosive and quiet eruptions of pyroclastic materials and lava flows C Shield quiet eruptions of lava flows

According to the impact hypothesis, dinosaurs became extinct when __________________.

A giant asteroid or meteorite crashed into the Earth near the Yucatan Peninsula in Mexico

Why did many plants die at the end of the Mesozoic?

A giant meteorite or asteroid hit the Earth incinerating many plants. A global cooling period following killing off many of the remaining plants.

What is global warming and what is the cause?

A gradual increase in average global temperatures. The cause may be from an increase in the concentration of greenhouse gases resulting from human activity.

A tornado watch means that the conditions are favorable for a tornado to form, while a warning means that __________________.

A tornado has been spotted or detected on radar

The mass extinction at the end of the Permian Period led to ____________________ in the Mesozoic & Cenozoic Eras.

Abundant new life in the Mesozoic & eventually the Cenezoic Eras

What is the difference between the following: dormant, active, & extinct?

Active the volcano is currently or has recently erupted Dormant the volcano has not erupted recently but expected to again Extinct the volcano will never erupt again

How has warmer ocean temperatures affected oceanic algae growth?

Algae growth has increased

Figure 131 shows the times of appearance and relative abundance of major groups of organisms. According to Figure 131, the fossils of which type of organism would be characteristic of the Precambrian era?

Algae, fungi, some invertebrates

How did Earth change about 2.5 billion years ago when some organisms began using photosynthesis to make food?

An oxygen rich atmosphere began to form

What is a recharge zone?

Anywhere that water from the surface can travel through permeable rock to reach an aquifer

What is a body of rock or sediment in which water can flow and be stored?__________________________

Aquifer

Describe how contaminated groundwater can reach the surface?

As groundwater is recharged, the water table rises to become surface water in wetlands, lakes, etc.

. Describe the relationship between hurricane category, wind speed, change in sea level, and change in air pressure.

As hurricane category increases: winds increase, air pressure decreases, & sea level rises.

Which point on the timeline most correctly identifies the Sun's current point in its lifecycle?

B

Why are recharge zones sensitive areas?

Because this is where groundwater in an aquifer is replenished and can become contaminated by pollutants

Put each of the letters in the correct order of formation.

C, D, E, F, G, H, 10 ,5, X, Y, A, Z

What three factors cause climate change according to the Milankovitch theory?

Changes in the tilt of Earth's axis, changes in the shape of Earth's orbit, & changes in the wobble of the Earth

What event may have triggered the great Paleozoic extinction?

Climate change possibly due to the formation of Pangaea as the interior of continents dried up

The weather behind a cold front is dominated by which type of air? ___________________________________

Cold & typically dry air

How is the weather produced in a cold front different from that of a warm front?

Cold fronts - more violent & faster moving Warm fronts - less violent, precip is more widespread, & slower moving

What is happening to the coral reef as a result of climate change?

Coral bleaching as a result of the warmer ocean temperatures

The graph to the right indicates what type of relationship between carbon dioxide levels and global average temperature?

Direct relationship. As CO2 concentrations go up, so does the average global temperature

What ultimately leads to a thunderstorm's dissipation?

Downdrafts preventing updrafts

What short term climate change is being demonstrated in the diagram? What happens as a result?

El niño....typhoons, cyclones, & floods in the Pacific Ocean region & southeastern U.S....and droughts in Indonesia & Australia

A hurricane hits land with wind speeds of 225 km/h and sea level changes of 5.5 m. What damage classification would it be labeled as according to the SaffirSimpson Hurricane Scale?

Extreme

Identify the following in the rock cycle diagram.

F - Metamorphic Rock G - Sedimentary Rock H - Igneous Rock I - Sediments J - Melting K Magma

A tornado lasts 9 minutes, is 2 km wide and has wind speeds of 135 km/h. What intensity level would it be classified?

F1

If a tornado followed a path of 50 kilometers and uprooted most of the trees in a nearby forest and threw several heavy cars, it would be classified as a _____________________.

F3

Which climate graph would be a city near an ocean and which would be farther from the ocean? Explain.

Farther away because there are temperature extremes Closer because there aren't temperature extremes

How do humans impact groundwater quality?

Fertilizers & pesticides from agriculture Waste dumps and underground storage tanks for toxic chemicals Leaking sewer systems

List any contaminants that can affect the water quality in groundwater

Fertilizers, pesticides, sewage, hazardous chemicals, salt water

What are the two states that have the potential to lose the most area due to a rise in sea level caused by global warming?

Florida and Louisiana

Figure 131 shows the times of appearance and relative abundance of major groups of organisms. The wider the band, the more dominant the group. According to Figure 131, which plant group dominates the Cenozoic era?

Flowering Plants

Clues about animal adaptations to climate change have been found in the study of ________________________.

Fossils

How is it possible for global warming to lead to an increase in the number and intensity of hurricanes?

Global warming causes an increase in ocean temperatures which could possibly make hurricanes stronger & more frequent

What force draws the matter in an interstellar cloud together to form a star?___________________________

Gravity

The increase and decrease of CO2 within each year is a result of ___________________.

Human activity (burning fossil fuels)

Describe how each of the following types of rocks form: igneous, sedimentary, & metamorphic

Igneous rocks - cooling & solidifying of molten rock Sedimentary - compaction & cementation of rock particles Metamorphic - when existing rock is exposed to heat & pressure inside Earth

What can be inferred from the information in the passage?Scientists think that Earth began as a melted mixture of many different materials. These materials underwent a physical change as they cooled and solidified. These became the first igneous rocks. Igneous rock continues to form today. Liquid rock changes from a liquid to a solid, when lava that is brought to Earth's surface by volcanoes hardens. This process can also take place far more slowly, when magma deep beneath the Earth's surface changes to a solid. At the same time that new rocks are forming, old rocks are broken down by other processes. Weathering is the process by which wind, water, and gravity break up rock. During erosion, broken up pieces of rock are carried by water, wind, or ice and deposited as sediments elsewhere. These pieces pile up and, under heat and pressure, form sedimentary rock—rock composed of cemented fragments of older rocks.

Igneous rocks formed early in Earth's history from a mixture of many different materials. New rocks continue to form & get broken down.

If a flash flood warning is issued, you should ________.

Immediately move to higher ground

Is the concentration of CO2 in the atmosphere increasing or decreasing?

Increasing

What can be inferred from the passage below about the sustainability of the Ogallala Aquifer? The Ogallala Aquifer, part of the High Plains Aquifer System, is a vast yet shallow underground water table aquifer located beneath the Great Plains in the United States. One of the world's largest aquifers, it covers an area of approximately 174,000 mi² (450,000 km²) in portions of the eight states of South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico, and Texas. It was named in 1898 by N.H. Darton from its type locality near the town of Ogallala, Nebraska.[1] About 27 percent of the irrigated land in the United States overlies this aquifer system, which yields about 30 percent of the nation's ground water used for irrigation. In addition, the aquifer system provides drinking water to 82 percent of the people who live within the aquifer boundary.[2] While groundwater is a renewable source, reserves replenish relatively slowly. The USGS has performed several studies of the aquifer, to determine what is coming in (groundwater recharge from the surface), what is leaving (pumping and baseflow to streams) and what the net changes in storage are (rise, fall or no change — see figure above). Simply put, water in, minus the water out, is equal to the change in water stored in the aquifer. This type of massbalance "accounting" is how hydrologic budgets are performed, and is a crucial first step in sustainable management of any natural resource. Withdrawals from the Ogallala Aquifer for irrigation amounted to 26 km3 (21,000,000 acre·ft) in 2000. As of 2005, the total depletion since predevelopment amounted to 253,000,000 acre feet (312 km3).[5] Some estimates say it will dry up in as little as 25 years. Many farmers in the Texas High Plains, which rely particularly on the underground source, are now turning away from irrigated agriculture as they become aware of the hazards of overpumping.

It may not be sustainable because the outputs exceed the inputs preventing if from recharging

Describe the Mt. St. Helens eruption.

It was an explosive eruption that killed people & animals, destroyed railways, destroyed bridges, destroyed highways, and destroyed forests

Tornadoes are most frequent from April to _______________________.

June

What is the difference between the way the sun heats water and land?

Land heats faster than water.

A hurricane begins when warm, moist air rises rapidly and the moisture condenses, releasing energy in the form of _________________________.

Latent heat

Younger layers of undisturbed sedimentary rock are above older layers according to the ________________________________.

Law of Superposition

According to the chart, which source has the longest residence time? Shortest?

Longest - Antarctica Shortest atmosphere

Describe the pressure in a middlelatitude cyclone.

Low....air converges and rises

What feature is labeled A in the volcano diagram?

Magma chamber

In what stage of a thunderstorm would updrafts and downdrafts form hail and separate the charges to allow lightning to form?

Mature

When a bend forms in a cold front, it begins the process of creating an area of low pressure with rotating wind that moves toward the rising air of the central lowpressure region a storm known as a(n) ___________________________

Midlatitude cyclone

What seasonal wind blows toward the land in summer, bringing heavy rains, and blows away from the land in the winter, bringing dry weather? Why does this occur?

Monsoons....because water heats up slower & cools faster than land (higher specific heat)

What is the VEI of the following eruptions: Mt. St. Helens, Yellowstone, & Pinatubo.

Mount St. Helens - 5 Yellowstone - 8 Pinatubo 6

The Atlantic Hurricane Season occurs from June to _________________________.

November

What global wind belt pushes the Gulf Stream toward Europe?

Prevailing Westerlies

How is radioactive decay used to determine the absolute age of rocks?

Ratios of parent atoms and daughter atoms are compared using a known halflife of a certain radioactive isotope

What is the difference between absolute and relative age?

Relative age is the age of an object in relation to the ages of other objects and absolute age is the numeric age of an object

Based on the diagram above, what amount is saltwater? Freshwater?

Saltwater - 97% Freshwater - 3%

Describe how index fossils are used to determine geologic time sequence.

Scientists use known index fossils and the Geologic time periods in which they existed to determine relative ages.

When water masses of differing temperatures & salinity come together in the ocean, the water from the two masses will ______________.

Separate with colder & saltier (more dense) water will sink

A rotating cloud of gas and dust from which Earth's solar system formed is called a(n) _______________________________.

Solar nebula

What are inputs? Give an example using the Great Lakes.

Sources that enter a body of water. Lake Huron's inputs are: groundwater, precipitation, runoff, streams, rivers, Lake Michigan, etc.

What are outputs? Give an example using the Great Lakes.

Sources that exit a particular body of water. Lake Huron's outputs are: St. Clair River, evaporation

In which type of front is the flow of air on both sides of the front almost parallel to the line of the front? ______________________

Stationary Front

What is the most dangerous aspect of a hurricane in terms of being a threat to the loss of human life.

Storm surge

Lowpressure systems are usually associated with _________________________ weather

Stormy

What is residence time?

The average amount of time that a water molecule will spend in a reservoir

What happens as a cold air mass collides with a warm air mass along the boundary of a cold front, __________.

The cold air mass wedges underneath the warm air mass forcing the warm air mass up causing condensation, cloud formation, & precipitation

The Greenhouse Effect The greenhouse effect is Earth's natural heating process, in which gases in the atmosphere trap thermal energy. Earth's atmosphere acts like the glass windows of a car. Imagine that it is a hot day and that you are about to get inside a car. You immediately notice that it feels hotter inside the car than it does outside the car. Many scientists hypothesize that the rise in global temperatures is due to an increase in carbon dioxide that is produced as a result of human activity. Most evidence indicates that the increase in carbon dioxide is caused by the burning of fossil fuels that release carbon dioxide into the atmosphere. Fossil fuels are organic compounds that are formed from the buried remains of ancient plants and animals. These fuels are used by humans for many things, such as heating homes and providing fuel for automobiles. 1. What conclusions can you make about the greenhouse effect based on the passage above?

The greenhouse effect is natural, but is being enhanced by the burning of fossil fuels

The big event that marked the end of the Permian Period (Palezoic Era) was a _________________________________.

The largest mass extinction in Earth's history killing 90% of marine species & 70% of the land species

What is happening to the polar bear population? Why?

The polar bear population is decreasing because of a loss of habitat (sea ice) that is utilized for hunting

The Pleistocene Epoch was characterized by _____________________________________.

The repeating advance & retreat of ice sheets ending with the most recent ice age

The main source of energy in the climate system is _____________________.

The sun

What determines the VEI rating of a volcanic eruption?

The volume of pyroclastic materials (tephra) ejected, height of the ash plume, and the explosivity on a scale of 0 8

What is the difference between the damage and destruction produced by tornadoes and hurricanes?

Tornadoes produce damage in a more narrow path. Hurricanes have a much wider path of destruction. Large hurricanes can cause major flood damage

What is the name of the scale to the left that is used to classify a volcanic eruption?

VEI (Volcanic Explosivity Index)

What natural event(s) decrease temperatures by reflecting sunlight back into space?

Volcanic activity

Based on this passage, how do volcanoes impact humans? In 1815, Mount Tambora in Indonesia erupted violently. Following this eruption, one of the largest recorded weatherrelated disruptions of the last 10,000 years occurred throughout North America and Western Europe. The year 1816 became known as "the year without a summer." Snowfalls and a killing frost occurred during the summer months of June, July, and August of that year. A similar, but less severe episode of cooling followed the 1991 eruption of Mount Pinatubo. Eruptions such as these can send gases and volcanic dust high into the atmosphere. Once in the atmosphere, the gas and dust travel great distances, block sunlight, and cause shortterm cooling over large areas of the globe. Some scientists have even suggested a connection between volcanoes and the ice ages.

Volcanic eruptions can lead to climate change. Dust and certain gases can cause global cooling and possibly lead to ice ages.

What is the difference between volcanic igneous rock at convergent vs. divergent boundaries?

Volcanoes at convergent boundaries with subduction zones have a higher silica content and are therefore more explosive

What can be inferred from the passage?In 1815, Mount Tambora in Indonesia erupted violently. Following this eruption, one of the largest recorded weatherrelated disruptions of the last 10,000 years occurred throughout North America and Western Europe. The year 1816 became known as "the year without a summer." Snowfalls and a killing frost occurred during the summer months of June, July, and August of that year. A similar, but less severe episode of cooling followed the 1991 eruption of Mount Pinatubo. Eruptions such as these can send gases and volcanic dust high into the atmosphere. Once in the atmosphere, the gas and dust travel great distances, block sunlight, and cause shortterm cooling over large areas of the globe. Some scientists have even suggested a connection between volcanoes and the ice ages.

Volcanoes can have other sometimes longterm effects besides just the eruption itself.

Along a front, which type of air is always forced upwards?_______________________

Warm air

When moist winds approach a mountain, they often drop rain as they rise over the mountain, and come down the other side of the mountain much ________and _______.

Warmer, dry

Name the five primary greenhouse gases.

Water vapor, carbon dioxide, nitrous oxide, methane, & ozone

What is the Gulf Stream?

a warm surface ocean current driven by global winds that moves along the east coast of the U.S. toward Europe

What type of cloud forms during a thunderstorm?

cumulonimbus

Thermohaline circulation is a deep water current driven by ____ and ____.

temperature and salinity differences

What are fossils

the remains or traces of prehistoric life

Read the paragraph below and describe how tornadoes form. Tornado Alley Although tornadoes are not unique to the area, the violent, rotating, funnelshaped clouds and their trails of destruction are so common in the central United States that the area is called Tornado Alley. Severe thunderstorms and the supercell tornadoes that they spawn are formed when warm, moist air from the Gulf of Mexico becomes trapped beneath hot, dry air from the southwest desert region. Above the hot, dry air, cold, dry air sweeps in from the Rocky Mountains. The interaction between high altitude winds and thunderstorms creates the funnelshaped vortex of highspeed winds known as a tornado. The largest outbreak of tornadoes in this region occurred in April of 1974. Before the storms ended, 148 separate tornadoes roared through 13 different states. More than 300 people lost their lives, and another 5,000 people were injured. More than 1,300 buildings were destroyed.

when high altitude winds meet the rising air in a thunderstorm causing rotation

What are the characteristics of index fossils?

• Widespread • Abundant • Existed in a relatively short period of time • Easily identified