The Emergency Alert System (Eas) Quiz

A disconformity is an erosional surface between horizontal layers of sedimentary rock. This means that there is a break in the rock layers where erosion has occurred, resulting in a gap in the geological record. The layers above and below the disconformity are parallel to each other, indicating that there has been no significant tectonic activity or folding. Disconformities can be difficult to identify as they often appear as flat, smooth surfaces, but they provide important clues about the geological history of an area and the processes that have shaped the Earth's surface over time.

Erratics are large boulders that have been deposited randomly by glaciers. As glaciers move, they pick up rocks and boulders from the ground and carry them along. When the glacier eventually melts, it leaves behind these boulders in different locations, often far away from their original source. These erratics can vary in size, from small rocks to massive boulders, and their presence is evidence of past glaciation in an area. They are an important geological feature that helps scientists understand the history and movement of glaciers.

Gneiss is the correct answer because it is a common type of rock found in the Georgia Tech campus. Gneiss is a metamorphic rock that forms from the transformation of pre-existing rocks under high temperature and pressure. It is characterized by its banded appearance and is often found in areas with extensive metamorphism, such as the campus. Therefore, if one were to dig a deep hole almost anywhere on the Georgia Tech campus, the rock they would most likely find is gneiss.

As the rate of cooling decreases, the size of the crystals that form in an intrusive igneous rock increases. This is because slower cooling allows more time for the atoms to arrange themselves into a regular pattern, resulting in larger crystals. On the other hand, rapid cooling leads to smaller crystals or even a glassy texture, as there is not enough time for the atoms to arrange themselves properly. Therefore, the correct answer is "increases".

The bedrock in the Sierra Nevada Mountains in California is described as granite; batholiths. Granite is a type of igneous rock that is commonly found in mountainous regions, and batholiths refer to large masses of intrusive igneous rock that have solidified deep within the Earth's crust. This combination accurately describes the composition and formation of the bedrock in the Sierra Nevada Mountains.

The presence of crossbeds in a well-sorted quartz sandstone suggests that the sediment was deposited by wind. Crossbeds are formed when wind or water transports and deposits sediment in inclined layers. In this case, the well-sorted nature of the sandstone indicates that the sediment was sorted and transported by wind, rather than water. Therefore, the best interpretation for the depositional environment of this sandstone is a sand dune, where wind-blown sand accumulates and forms distinct crossbeds.

Chemosynthesis is the process by which organisms use chemicals, such as hydrogen sulfide or methane, to produce organic molecules like proteins and carbohydrates. This process occurs in deep sea hydrothermal vent systems where sunlight is not available for photosynthesis. Unlike photosynthesis, which uses sunlight as an energy source, chemosynthesis relies on the energy obtained from chemical reactions. Therefore, chemosynthesis is the correct answer for the given question.

Granite is the correct answer because it is a common rock type found in the continental crust. The continental crust is primarily composed of granite, which is a type of igneous rock made up of minerals such as quartz, feldspar, and mica. This composition is consistent with the average composition of the continental crust, making granite the most closely approximated rock type.

Long Island, New York and Nantucket Island, Massachusetts are examples of a terminal moraine. A terminal moraine is a type of moraine that forms at the furthest point reached by a glacier during its advance. As the glacier retreats, it deposits debris and sediment, creating a ridge-like landform. Long Island and Nantucket Island were both formed by the movement and retreat of glaciers during the last ice age, leaving behind terminal moraines that now shape their landscapes.

Plankton refers to organisms, such as algae and bacteria, that drift with ocean currents. These organisms are unable to swim against the current and rely on the movement of water to transport them. Plankton play a crucial role in marine ecosystems as they form the base of the food chain, providing food for larger organisms.

Liquefaction refers to the phenomenon where a foundation material loses its internal cohesion and fails mechanically during earthquake shaking. This occurs when loose, water-saturated soil experiences rapid shaking, causing the water pressure between soil particles to increase. As a result, the soil loses its strength and behaves like a liquid, leading to the failure of structures built on top of it. Liquefaction can cause significant damage to buildings, bridges, and other infrastructure during earthquakes.

By the close of the Paleozoic era, all the continents had merged together to form a single supercontinent called Pangea. This process, known as continental drift, occurred over millions of years as the tectonic plates shifted and collided. Pangea was a massive landmass that included present-day continents such as North America, South America, Africa, Europe, and Asia. The formation of Pangea had significant geological and biological implications, including changes in climate and the evolution of new species.

Solifluction is the correct answer because it is a process that specifically occurs in regions with permafrost. Solifluction is the slow movement of saturated soil or sediment over a frozen layer, which is characteristic of areas with permafrost. The freezing and thawing of the ground in these regions creates a saturated layer that is unable to drain properly, causing the soil to flow downslope. This process is not commonly observed in regions without permafrost.

Fossil fuels are formed from the remains of plants and animals that lived millions of years ago. The Precambrian period refers to the time before the emergence of complex life forms, such as land plants and certain animals. Therefore, it is expected that fossil fuels would be notably absent in Precambrian rocks.

The angle of repose refers to the maximum angle at which a pile of material remains stable without sliding or collapsing. Generally, smaller particles have a lower angle of repose compared to larger particles. Since quartz sand consists of smaller particles than quartz gravel, the angle of repose for a pile of quartz sand would be less than that of a pile of quartz gravel.

The correct answer is slate, phyllite, schist because this order follows the principle of increasing grain size and increasing grade of metamorphism. Slate has the smallest grain size and lowest grade of metamorphism, followed by phyllite with slightly larger grain size and higher grade of metamorphism, and finally schist with the largest grain size and highest grade of metamorphism.

The movement of sand parallel to the shore can be achieved by longshore currents, which are currents that flow along the coastline. These currents can transport sand and sediment along the shore, causing it to move in a parallel direction. This movement of sand can also create spits, which are elongated ridges of sand that extend from the shoreline into the water. Additionally, the movement of sand parallel to the shore can be created by waves approaching at an oblique angle, meaning the waves are not directly perpendicular to the shoreline. Waves approaching at an angle can cause the water and sediment to move in a parallel direction along the shore. Therefore, all of the given options are correct explanations for the movement of sand parallel to the shore.

Pahoehoe is a type of basaltic lava flow that has a fairly smooth, unfragmented, and ropy surface. This type of lava flow forms when the lava is very fluid and flows slowly, allowing it to cool and solidify in a smooth, undulating surface. The ropy texture is a result of the movement and folding of the still-molten interior of the lava flow as it cools. Pahoehoe lava flows are commonly found in areas with low slope gradients and can create unique and visually striking landscapes.

The carbonate compensation depth refers to the ocean depth at which the rate at which carbonate is supplied to the sediments is equal to the rate at which it is dissolved. This means that below this depth, calcite and aragonite accumulate in ocean sediments, while above this depth, diatoms dissolve and do not accumulate in marine sediments. It is important to note that the carbonate compensation depth is not related to the concentration of dissolved carbon dioxide or the profitability of mining carbonates from the ocean floor.

When the depth of water is equal to one-half the wavelength, waves begin to "feel bottom". This means that the waves start to interact with the bottom of the body of water, causing changes in their behavior. At this depth, the wavelength is significant enough for the waves to be affected by the bottom, but not so deep that the waves are fully submerged and unaffected. Therefore, when the depth is equal to one-half the wavelength, the waves start to feel the bottom.

The correct answer is "the start of a temperature increase with increasing altitude." The boundary between the troposphere and stratosphere is defined by a change in temperature with increasing altitude. In the troposphere, temperature generally decreases with altitude, while in the stratosphere, temperature increases with altitude. This temperature inversion is caused by the presence of the ozone layer in the stratosphere, which absorbs and traps solar radiation, leading to a temperature increase. Therefore, the point where the temperature starts to increase marks the boundary between the troposphere and stratosphere.

Basalt is the correct answer because it is the most abundant igneous rock in the Earth's crust and is found underneath the floors of the ocean. Basalt is formed from the solidification of molten lava and is characterized by its dark color and fine-grained texture. It is commonly found in volcanic areas and is a major component of oceanic crust.

A fjord is a drowned glacial valley. This means that it was once a U-shaped valley carved by a glacier during the ice ages. As the glaciers melted and sea levels rose, the valley became flooded with seawater, creating a long, narrow inlet with steep sides. Fjords are typically found in areas where there was significant glacial activity, such as Norway, New Zealand, and Alaska.

The last glacial maximum occurred approximately 20,000 years ago. This refers to a period in Earth's history when ice sheets were at their maximum extent during the last ice age. The Earth's climate was much colder during this time, with large portions of North America, Europe, and Asia covered in ice. The glacial maximum eventually gave way to a warming trend and the retreat of the ice sheets.

The correct answer is 2 centimeters per year. This rate is considered typical for seafloor spreading in the Atlantic Ocean. This means that the oceanic crust is spreading apart at a rate of 2 centimeters per year, leading to the formation of new crust. This slow but continuous process contributes to the widening of the Atlantic Ocean over geologic time.

A transform plate boundary is characterized by a deep, vertical fault along which two plates slide past one another in opposite directions. This type of boundary is also known as a conservative plate boundary because there is no creation or destruction of crust. Instead, the plates are simply sliding past each other, causing earthquakes as the stress builds up and is released along the fault line. This type of boundary is commonly found in areas such as the San Andreas Fault in California.

When waves reach shallow water, they undergo a process called refraction. Refraction occurs when waves change direction as they pass from one medium to another, in this case from deep water to shallow water. The change in direction is caused by the difference in wave speed between the two mediums. In shallow water, the bottom of the wave slows down, causing the top of the wave to move faster and bend towards the shore. This results in the waves becoming parallel to the shore.

Thick turbidite layers are typically associated with deep-sea fans at the base of a continental slope. Deep-sea fans are sedimentary deposits formed by the accumulation of sediment transported by turbidity currents. These currents are triggered by the downslope movement of sediment-laden water, often due to gravity-driven processes such as submarine landslides. As the sediment-laden water flows down the continental slope, it slows down and deposits the sediment in thick layers on the deep-sea fan. Therefore, it is most likely that thick turbidite layers would be found in this environment.

A dike is an intrusive, igneous rock body that is tabular and cuts across the surrounding rock. It is formed when magma is forced into a fracture or fissure in the Earth's crust and solidifies underground. Dikes can vary in size and shape, but they are typically vertical or near-vertical in orientation. They are commonly found in areas of volcanic activity and can be composed of various types of igneous rock, such as basalt or granite. Dikes are important geological features as they provide insights into the history and processes of Earth's crust formation.

Radioactive decay is a spontaneous process that is not influenced by external factors such as temperature, chemical reactions, pressure, or coriolis forces. The rate of radioactive decay is determined solely by the inherent properties of the radioactive material and is not affected by any external factors. Therefore, none of the options provided can change the rate of radioactive decay.

A scarp is a steep slope or cliff that forms when a slump occurs. A slump is a type of mass movement where a block of material slides down a slope, leaving behind a crescent-shaped rupture surface at the head. Therefore, a scarp is the correct answer as it best describes the exposed, crescent-shaped rupture surface at the head of a slump. A horst refers to an uplifted block of crust between two parallel faults, a ledge is a narrow, horizontal shelf-like projection, a sole is the bottom surface of a sedimentary layer, and a laccolith is a dome-shaped intrusion of magma.

After each half-life, the amount of parent isotope remaining is reduced by half. So, after the first half-life, there will be 6000 atoms remaining. After the second half-life, there will be 3000 atoms remaining. And after the third half-life, there will be 1500 atoms remaining.

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An earthquake with a magnitude of 6.5 releases approximately 30 times more energy than one with a magnitude of 5.5. The Richter scale is logarithmic, meaning that each increase of one magnitude represents a tenfold increase in the amplitude of seismic waves and approximately 31.6 times more energy release. Therefore, the difference between a magnitude 6.5 earthquake and a magnitude 5.5 earthquake is approximately 30 times in terms of energy released.

The law of superposition states that in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it. This means that the layers of sedimentary rock are deposited in a chronological order, with the oldest layers at the bottom and the youngest layers at the top. This principle is fundamental in understanding the relative ages of rocks and fossils in geological studies.

Oxygen is the correct answer because it was not part of Earth's original atmosphere. The early atmosphere consisted mainly of nitrogen, carbon dioxide, and water vapor. Oxygen began to accumulate in the atmosphere through photosynthesis by early organisms, eventually leading to the oxygen-rich atmosphere we have today.

The geologist correctly interprets that the land containing the river has been uplifted. This is because the presence of large bends and meanders in the river indicates that the river has been flowing for a long time and has eroded the surrounding land. The steep-walled valley suggests that the land has been uplifted, as erosion alone would not create such deep valleys. Therefore, the uplift of the land is the most plausible explanation for the observed features.

Convergent plate boundaries occur when two tectonic plates collide or move towards each other. This collision can cause the subduction of one plate beneath the other, resulting in the formation of deep trenches. These trenches are often the sites of the deepest earthquakes on Earth. Therefore, it can be inferred that the deepest earthquakes occur at convergent plate boundaries.

The broad looping patterns seen in the geologic map of the northwest corner of Georgia indicate a series of plunging anticlines and synclines. Anticlines are upward folds in the rock layers, while synclines are downward folds. The looping patterns suggest a repetitive pattern of folding and bending in the rock layers, which is characteristic of anticlines and synclines. This type of geologic structure is often associated with mountain ranges and can provide valuable information about the history and formation of the region.

Brittle deformation is favored over plastic deformation in cooler temperatures and low confining pressures. In cooler temperatures, the rocks become more rigid and less ductile, making them more prone to brittle failure. Similarly, in low confining pressures, there is less pressure acting on the rocks, allowing them to fracture more easily. Therefore, both cooler temperatures and low confining pressures promote brittle deformation.

During the day, the land heats up faster than the water, causing the air above the land to become warmer and rise. As a result, cooler air from the water rushes in to replace the rising warm air, creating a sea breeze that flows from the water towards the land. This phenomenon is commonly observed in coastal areas during the daytime.

The correct answer is "S waves travel through liquids and P waves travel through solids." This statement is incorrect because it is the opposite of the true statement. P waves, also known as primary waves, are able to travel through both solids and liquids, while S waves, also known as secondary waves, can only travel through solids.

During the Cenozoic era, mammals became the dominant land animals. This era, also known as the "Age of Mammals," began approximately 66 million years ago and continues to the present day. It is characterized by the diversification and evolution of mammals, leading to their dominance over other land animals. This era witnessed the emergence of various mammalian groups, including primates, rodents, carnivores, and ungulates, which eventually occupied various ecological niches and adapted to different environments. The Cenozoic era marked a significant shift in the Earth's biodiversity, with mammals taking the lead as the dominant land animals.

Kaolinite is a typical product of the chemical weathering of feldspar. Feldspar is a common mineral found in many rocks, and when it undergoes chemical weathering, it breaks down into smaller particles and forms new minerals. Kaolinite is one of the minerals that can form from the weathering of feldspar. It is a clay mineral that is often found in soils and sedimentary rocks.

Plastic deformation is favored over brittle deformation when there are high confining pressures and warmer temperatures. High confining pressures help to confine the material and prevent crack propagation, leading to plastic deformation. Warmer temperatures increase the mobility of atoms, allowing for easier dislocation movement and plastic deformation. Therefore, both high confining pressures and warmer temperatures contribute to favoring plastic deformation over brittle deformation.

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In the open ocean far from shore, tsunamis have long wavelengths that can span many kilometers, but their wave heights are often relatively low, typically 3 meters or less. This is because the energy of the tsunami is spread out over a large area, causing the wave to be less pronounced in terms of height. As the tsunami approaches shallower water, its wave heights decrease even further and its wavelengths increase. Therefore, the correct answer is that in the open ocean far from shore, wavelengths are many kilometers long and wave heights are often 3 meters or less.

The thickness of sediments is generally less in the Pacific Ocean basin compared to the Atlantic Ocean basin because there are more submarine trenches, which collect terrigenous sediment, at the margin of the Pacific basin and greater average ocean floor depths in the Pacific basin reduce the accumulation of calcium carbonate.

Coccolithophores are photosynthetic plankton, meaning they can convert sunlight into energy through photosynthesis. They have calcite shells, which are made of calcium carbonate. These shells provide protection and support for the coccolithophores. The calcite shells also play a role in the carbon cycle, as they can sink to the ocean floor and sequester carbon dioxide. Therefore, the correct answer is "Photosynthetic plankton with calcite shells."

Unconsolidated, finely ground material that is sometimes found in fault zones is called "gouge." Gouge is formed through the grinding and crushing of rocks along a fault line, resulting in a mixture of fragmented rock particles. It is commonly composed of various rock types and can have a clay-like consistency. Gouge plays a significant role in fault mechanics and can affect the behavior of earthquakes.