geology 2

"Describe the three factors that affect a magma's viscosity."

"The three factors are temperature, silica content, and dissolved gas content.";

"Explain the characteristics of volcanic bombs."

"Volcanic bombs are rubbly, blocky lava with a steep front flow, made from fluid basaltic flows that are slightly cooler than pahoehoe flows."

"Define volcanic ash and its significance in eruptions."

"Volcanic ash consists of fine particles of rock and glass that are ejected during a volcanic eruption, contributing to air pollution and affecting climate."

"How does pahoehoe lava differ from aa lava?"

"Pahoehoe lava is hotter and more fluid, resulting in a smooth, ropey surface, while aa lava is blocky and brittle."

"List the main gases released during a volcanic eruption."

"The main gases are water vapor, carbon dioxide, and sulfur dioxide."

"Describe the characteristics of pumice."

"Pumice is a light-colored, highly vesicular rock formed from felsic lavas, appearing glassy and threadlike in texture, and it may float on water."

"What is scoria and how does it differ from pumice?"

"Scoria is a red or black, highly vesicular ejecta material formed from basaltic to andesitic lavas, and it usually does not float, unlike pumice."

"Explain the structure of a shield volcano."

"A shield volcano is broad and low-sloped, characterized by low viscosity lava that flows great distances, primarily composed of basalt."

"Identify a well-known shield volcano in the United States."

"Mauna Loa and Kilauea are well-known shield volcanoes located in Hawaii."

"Describe the composition and eruption characteristics of cinder cone volcanoes."

"Cinder cone volcanoes are primarily composed of scoria fragments, tend to be basaltic, and usually erupt for a short interval of time."

"Where is Huerfano located and what type of volcano is it?"

"Huerfano is located in Colorado and is classified as a cinder cone volcano."

"What are composite volcanoes and how are they formed?"

"Composite volcanoes are formed from layers of fluid lavas that are low enough in viscosity to flow away from the vent, creating gentle-sloped flanks."

"Describe the characteristics of lava domes."

"Lava domes are formed from the slow extrusion of viscous lava, which can become over steepened and collapse, potentially triggering pyroclastic flows."

"Explain the nature of pyroclastic flows."

"Pyroclastic flows are hot gases mixed with ash and larger lava fragments that can travel down volcanic slopes at speeds of up to 60 MPH, driven by gravity."

"Define calderas in the context of volcanic landforms."

"Calderas are very large summit depressions of volcanoes, typically with diameters greater than 1 kilometer."

"Describe the role of fissures in volcanic activity."

"Fissures are linear volcanic vents through which lava erupts, allowing magma to reach the surface."

"Explain the relationship between volcanic activity and plate tectonics."

"Volcanic activity globally is primarily caused by the interactions of tectonic plates, which can lead to the formation of volcanoes."

"Describe the destruction caused by the eruption of Mount Pelee in 1902."

"The eruption of Mount Pelee resulted in a pyroclastic flow that killed 28,000 people in St. Pierre, Martinique."

"Explain the impact of the eruption of Mount Vesuvius on Pompeii."

"The eruption of Mount Vesuvius in C.E. 79 buried Pompeii under ash and pumice, with hot ash and gases causing many deaths."

"List and describe the hazards associated with volcanic eruptions."

"Volcanic hazards include pyroclastic flows, which are fast-moving flows of ash and lava, and lahars, which are destructive mudflows formed when volcanic ash mixes with water."

"Define the term 'pipe' or 'neck' in relation to volcanoes."

"A pipe or neck is the circular conduit through which magma travels to the surface, culminating in the vent where lava and other materials are released."

"Describe the composition of lava flows in composite volcanoes."

"The lava flow in composite volcanoes is typically silica-rich, with andesitic to rhyolitic composition."

"Describe how tsunamis can be generated."

"Tsunamis can result from violent submarine explosions, caldera collapses, tectonic movement from volcanic activity, flank failure into a water source, or pyroclastic flow discharge into the sea."

"Define an earthquake."

"An earthquake is ground shaking caused by a sudden release of energy from the slipping of crustal blocks along a fault."

"Explain what faults are in the context of earthquakes."

"Faults are fractures in Earth's crust along which slippage occurs, causing earthquakes."

"Describe the function of a seismograph."

"A seismograph is an instrument designed to measure the amount of displacement caused by a seismic wave, using a weight suspended from a support attached to bedrock."

"How do P-waves differ from S-waves?"

"P-waves, or Primary waves, travel fastest and move materials in a push-pull motion, while S-waves, or Secondary waves, are slower and move materials at a right angle to the direction of travel."

"Explain the characteristics of surface waves."

"Surface waves travel along the Earth's surface, moving materials up and down and side-to-side, and they arrive last at a seismic station."

"Describe the Modified Mercalli intensity scale."

"The Modified Mercalli intensity scale is a subjective scale that measures the amount of shaking an earthquake produces based on human perception and damage to physical structures."

"What does the Moment Magnitude scale measure?"

"The Moment Magnitude scale measures the overall strength or size of an earthquake based on fault slip, surface area, size of the rupture, amount of displacement, and energy released."

"List some types of destruction caused by earthquakes."

"Types of earthquake destruction can include building collapse, landslides, tsunamis, ground rupture, and liquefaction."

"Describe how seismographs determine the location of an earthquake's epicenter."

"Seismographs use a travel-time graph to determine the distance to an earthquake's epicenter by analyzing the difference in travel time for the first P- and S-waves received at a seismic station."

"Explain the characteristics of short-range earthquake predictions."

"Short-range predictions must have a small range of uncertainty regarding location and timing, and they should produce few failures or false alarms. Currently, no reliable method exists for making these predictions."

"How do long-range earthquake predictions assist in disaster preparedness?"

"Long-range earthquake predictions, based on historical and paleoseismic data, indicate where large earthquakes may occur, aiding in strengthening building codes, land use planning, and reinforcing existing structures."

"Define the composition and characteristics of oceanic crust."

"Oceanic crust is composed of basalt and is formed at mid-ocean ridges."

"Distinguish between oceanic crust and continental crust."

"Continental crust is less dense than oceanic crust, variable in composition with many rock types, and generally thicker on average than oceanic crust."

"Explain the structure of the lithosphere."

"The lithosphere is the rigid, relatively cool outermost shell of Earth, consisting of the Earth's crust plus the uppermost mantle."

"Describe the asthenosphere and its properties."

"The asthenosphere is located beneath the lithosphere and is characterized as a soft, relatively weak layer."

"What are the differences in damage caused by the San Francisco 1906 earthquake and the Alaskan 1964 earthquake?"

"The San Francisco 1906 earthquake (magnitude 7.7-8.3) caused most damage from fires that started after the shaking, while the Alaskan 1964 earthquake (magnitude 9.2) resulted in significant ground movement, landslides, and a massive tsunami affecting multiple regions."

"How did the magnitude of the Alaskan 1964 earthquake compare to the San Francisco 1906 earthquake?"

"The Alaskan 1964 earthquake had a magnitude of 9.2, making it significantly larger than the San Francisco 1906 earthquake, which had a magnitude between 7.7 and 8.3."

"Describe the three major components of magma."

"The three major components of magma are: 1) Liquid (melt) - the fluid portion of the magma; 2) Solid - any silicate minerals present; 3) Volatiles (gases) - dissolved gases in the melt."

"Define the four basic igneous compositions."

"The four basic igneous compositions are: 1) Felsic - low temperatures, includes granite and rhyolite, characterized by pink/light colors; 2) Intermediate - low to mid temperatures, includes diorite and andesite, characterized by light gray color; 3) Mafic - high to mid temperatures, includes gabbro and basalt, characterized by light green color; 4) Ultramafic - high temperatures, includes peridotite and komatiite, characterized by dark colors."

"Explain the six major igneous textures."

"The six major igneous textures are: 1) Aphanitic - fine grained; 2) Phaneritic - coarse grained; 3) Porphyritic - large crystals in a finer-grained matrix; 4) Glassy - lacks a crystalline structure due to rapid cooling; 5) Vesicular - contains abundant cavities; 6) Pegmatitic - some mineral crystals are larger than 2.5 cm."

"How does Bowen's Reaction Series describe the relationship between temperature and igneous rock composition?"

"Bowen's Reaction Series indicates that ultramafic rocks form at the highest temperatures and have the darkest colors, while felsic rocks form at lower temperatures and are lighter in color."

"Do igneous rocks vary based on composition and texture?"

"Yes, igneous rocks vary based on composition (silica content) and texture, with examples including: Felsic - Phaneritic Texture (Granite), Aphanitic Texture (Rhyolite), Porphyritic Texture (Granite porphyry), Glassy (Obsidian), Vesicular Texture (Pumice), and Pyroclastic Texture (welded tuff). Intermediate examples include Diorite (Phaneritic) and Andesite (Aphanitic). Mafic examples include Phaneritic (Gabbro) and Aphanitic (Basalt), as well as Vesicular (Scoria)."

"Describe the process of magma generation from solid rock."

"Magma generates from solid rock by heating the rocks above their melting point."

"Explain the characteristics of Felsic igneous rocks."

"Felsic igneous rocks are characterized by low temperatures, high silica content, and lighter colors, with examples including granite and rhyolite."

"What distinguishes Intermediate igneous rocks from Felsic and Mafic rocks?"

"Intermediate igneous rocks are distinguished by their low to mid temperatures and light gray color, with examples including diorite and andesite."

"How do Mafic igneous rocks differ in temperature and color from Felsic rocks?"

"Mafic igneous rocks form at higher to mid temperatures and are characterized by light green colors, contrasting with the lower temperatures and lighter colors of Felsic rocks."

"What is the significance of texture in igneous rocks?"

"Texture in igneous rocks is significant as it provides information about the cooling history and formation process of the rock, influencing its appearance and mineral composition."

"Describe the Pegmatitic texture in igneous rocks."

"Pegmatitic texture in igneous rocks is characterized by the presence of some mineral crystals that are larger than 2.5 cm."

"Explain the Vesicular texture found in some igneous rocks."

"Vesicular texture in igneous rocks is characterized by the presence of abundant cavities, which are formed by gas bubbles trapped in the lava as it cools."