Natural Disasters Pt. 2

What are some significant pandemics in the last century?

- 1918 Flu Pandemic ("Spanish Flu")-- worldwide - 1900 Smallpox-- worldwide - Malaria (20th century - present)-- worldwide - Tuberculosis (20th century - present)-- worldwide - AIDS (1960 - present)-- worldwide

What is the cause of the K-Pg mass extinction, and what is the main evidence to support the event?

- 64,980,000 years ago, an asteroid with a diameter of about 10 km (~6 mi.) hit Earth along the northern shore of what is now the Yucatan Peninsula - Walter and Luis Alvarez studied iridium in the thin clay layer that marks the K-Pg boundary in Italy - They found that the extinction of many species occurred abruptly in that clay layer - Found way more iridium than expected - The iridium might be the remains of a single asteroid impact - Crater found by Mexican Geologists in 1991 - When drilling the crater, geologists found glassy melt rock, interpreted to be impact breccia, below a massive layer

What were the main purposes of the experimental floods through the Grand Canyon in 1996?

- A "test flood" was released from the dam as an experiment to redistribute sand - The experimental flood formed 55 new beaches and added sand to 75% of the existing beaches - It also helped rejuvenate marshes and backwaters, important habitats for native fish and endangered species

Why are wind speeds the highest in the right forward quadrant of a hurricane?

- A combination of wind-driven waves on top of the storm surge - Coriolis effect and rotation of the hurricane

Describe the differences between an asteroid, meteor, comet, meteoroid, and meteorite

- A meteoroid is any object which orbits the Sun in interplanetary space - A meteor is a bright streak of light in the sky-- "shooting star"-- produced as atmospheric friction burns up the outer layers of a meteoroid. - A large, bright meteor is called a fireball. - A meteorite is a solid fragment of one body that lands on another.

Explain how our solar system formed.

- A supernova occurs when a star is no longer capable of sustaining its mass and collapses inward, resulting in a high-energy explosion that scatters its mass into the void of space, creating a vast nebula. - Ultimately, the force of gravity wins out, and the matter within the nebula begins to collapse back inward on itself, forming new stars in what is called a solar nebula - Our sun formed from this kind of nebula 5 billion years ago - The solar nebula condensed under gravitational forces, and our sun formed at the center - The remaining mass of our solar system became trapped in solar orbits as rings

Historical Record

- A variety of historical records go back several hundred years. - People's written recollections (books, newspapers, journal articles, personal journals, etc.) of the Medieval Warm Period and the Little Ice Age, as well as ships' logs, travelers' diaries, and farmers' crop records. - Qualitative Data

What is the difference between stable and unstable air?

- Air is stable if parcels of air within it resist vertical movement or return to their original position after they have moved. - Alternatively, an air mass is considered unstable if parcels within it are rising until they reach air of similar temperature and density - Atmosphere becomes unstable when lighter warm/moist air is overlain by denser cold or dry air. - The instability causes parcels of air to sink and others to rise like hot-air balloons.

What characteristic of a volcano controls its shape, and how?

- Differences in flow characteristics affect the shape of the volcano formed by different lava types

Explain the relationship between magma composition, viscosity, and gas content

Rhyolitic (Felsic)-- high silica content Andesitic (Intermediate)-- medium silica Felsic (Basaltic)-- low silica content

Risk Analysis

Risk = (probability of event) x (consequences)

What is the tropopause? How high is it above Earth's surface?

- The upper boundary of the troposphere - Clouds won't rise past the troposphere - About 16 km above the surface of the earth

What are the two main channel patterns? How and why do these differ?

Meandering: - A single-thread channel similar to the curves of a moving snake Braided: - A multithread channel where there are two or more channels that unite and divide as the river flows downstream

What scale is most objective when discussing earthquake intensity?

Moment Magnitude

How is land surface monitoring used to detect volcanic activity?

Monitoring ground movements such as tilting, swelling, opening of cracks, or changes in the water level of lakes on or near a volcano, can identify movement that might indicate an eruption

Why is there no volcanic hazard on the East Coast of the United States and Canada?

Not on a plate boundary/the ring of fire

From a planetary perspective, which gas in Earth's atmosphere is unusual?

Oxygen

What are the two ways we can layer the earth?

Physical-- Lithosphere, Asthenosphere, Mesosphere, Outer core, inner core Chemical-- crust, mantle, core

Epicenter

Point on the Earth's surface directly above the hypocenter

How and where do debris flows occur?

- Debris flows occur through flowage, the downslope movement of unconsolidated material in which particles move about and mix within the mass - Occur in arid and semiarid climates - They move down established stream valleys, flow from channels filled with colluvium, or take long narrow tracks or chutes on steep hillsides.

Where is Tunguska? What happened there? Why is it important to our discussion of natural hazards? How often do events like this one occur?

- Airburst that exploded ~ 7 km above the Tunguska River Valley in Russia - 1908 - 10 megatons of TNT—equivalent to 10 hydrogen bombs - If the fireball had exploded over a large metropolis such as London, Paris, or Tokyo, millions of people would have died - Smaller but regionally significant events are sometimes called "Tunguska-type" events - Studies of comets and asteroids and their interaction with planets enable us to make straightforward predictions of their return times

Define glacier and list the main hazards associated with glaciers

- An accumulation of ice, snow, rock, sediment, and liquid water that flows from high to low areas due to gravity acting on the weight of this accumulated ice - Glaciers expand, surge and overrun villages, fields, roads, or other structures - Can advance and cross a stream valley, producing a dam or temporary lake-- Dams can cause downstream flooding - Blocks of ice may fall off in avalanches into the valley below, destroying property and taking human lives

Compare and contrast ash falls and pyroclastic flows.

- Ash flows cover large areas with carpets of cool ash that can destroy some structures and ruin agricultural land, but loss of life is less common. - Pyroclastic flows travel at very high velocities, are extremely hot, and destroy and kill everything in their path.

Where do comets and asteroids originate?

- Asteroids are found in the asteroid belt, which is a region between Mars and Jupiter - Asteroids are composed of rock material, metallic material, or rock-metal mixtures - Comets are composed of a rocky core surrounded by ice and covered in carbon-rich dust - Comets are believed to have originated far out in the solar system, beyond the planet Neptune, and to have been thrown into an area called the Oort Cloud

What is the main evidence supporting the hypothesized Younger Dryas impact event?

- At Clovis sites, archaeologists identified a "black mat," a thin layer of carbonaceous, dark, organic-rich clays associated with YDB - The discovery of a variety of markers that resulted from this cosmic impact - magnetic grains with high levels of iridium - high-temperature magnetic microspherules - carbon spherules - charcoal and soot - Evidence of intense wildfires - An abundance of nanodiamonds (those thought to be formed only by cosmic impact) were discovered from the impact layer where the YDB occurs - Analysis of glacial ice from the Greenland ice sheet at the beginning of the Younger Dryas identified a major platinum (Pt) anomaly

Why might high-magnitude debris flows occur following wildfire?

- Because fires leave a water-repellent layer - Debris flows result from high-intensity rainfall on a landscape that had been stripped of vegetation by a fire

How are Icelandic-type and Hawaiian-type eruptions different and the same?

- Both fissure eruptions that occur in shield volcanoes-- basaltic magma, less dangerous and explosive - Icelandic-type eruption is when basaltic lava erupts from an elongate fissure rather than from a central vent, producing what is called a "curtain of fire." - Absence of central vent means that shield volcanoes constructed from Icelandic-type eruptions are typically smaller and characterized by a broad and flat upland surface - Icelandic-type eruptions are often dangerous because they can cause flood basalts

What are the major gases and solid particles produced by a wildfire?

- Carbon dioxide, water vapor, and heat are released when plants burn - Carbon dioxide and water vapor are the most abundant

Lava Domes

- Characterize by highly viscous felsic magma - Common along the Ring of Fire - Form at subduction zones, and in vent of stratovolcanoes - Relatively small and have low to moderate volatile content - Pelean-type eruptions - Can be explosive, less so than stratovolcanoes

For a model of solar system formation to be viable, it must be consistent with what constraints?

- Chronology - Chemistry and Physics - Composition of planets and asteroids (meteorites) - observed spin and orbital motions of planets, asteroids, moons

Distinguish weather from climate

- Climate refers to the characteristic atmospheric conditions of a given region over long periods of time, such as years or decades - Weather refers to the atmospheric conditions of a given region for short periods of time, such as days or weeks

How do clouds form?

- Clouds develop when very small water droplets or ice crystals condense from the atmosphere.

Suspended Load

- Composed of small silt and clay particles that are carried above the stream bed by the flowing water - Accounts or nearly 90% of the total load Makes rivers look muddy

What are the three processes of heat transfer in a wildfire?

- Conduction, Convection, Radiation - Convection is a dominant process in atmospheric transfer of heat, radiant heat also plays a role - Transfer of both convective heat and radiant heat increases the surface temperature of the fuel

Dissolved Load

- Consists of electrically charged atoms or molecules, called ions, which are carried in chemical solution - Most dissolved load derived from chemical weathering of earth materials in the drainage basin

Bed Load

- Consists of sand and gravel particles that slide, roll and bounce along the channel bottom in rapidly moving water - Makes up less than 10% of the total load

Chicxuclub Crater

- Crater was identified in 1991 in Yucatan Peninsula - K/T extinction - Another impact of this size would mean mass extinction probably for humans and other large mammals - Impacts of this size occur once every ~50 to 100 million years

Explain how cyclones are linked with other natural hazards.

- Cyclones linked to coastal erosion, flooding, mass wasting, as well as tornadoes, severe thunderstorms, snowstorms, and blizzards. - In coastal areas, the cyclone hazard is directly linked to climate change

What is the primary natural service function cyclones provide the western United States?

- Cyclones, and the weather fronts associated with them, are the primary source of precipitation in most areas of the United States and Canada - Equalizing the temperatures of our planet-- Hurricanes elevate warm air from the tropics and distribute it toward polar regions - Winds from these storms carry plants, animals, and microorganisms long distances, helping populate volcanic islands with flora and fauna once the islands rise above sea level

What are atmospheric rivers and megafloods?

- Discrete zones of high moisture in the atmosphere that could move for thousands of kilometers - Some atmospheric rivers contain as much water as the Amazon or 10 to 20 times as much water as carried by the Mississippi River - Sometimes a series of atmospheric rivers arrive for a month or longer, bringing prolonged moderate-intense rainfall that can cause catastrophic flooding. - When this occurs, it's a Megaflood

Explain the Coriolis effect. How does it influence weather?

- Earth rotates beneath the flowing air masses, causing a deflection of the wind to the right or to the left - Westerly flow of Jet streams is due to the Coriolis effect -

Why are volcanoes commonly linked with earthquake activity?

- Earthquakes commonly accompany or precede volcanic eruptions as magma rises through Earth's crust - Shallow earthquakes and tremors are produced below a volcano as upward-moving magma fractures surrounding rock and gas bubbles in the magma burst

What distinguishes a tropical cyclone from an extratropical cyclone?

- Extratropical cylones develop in the midlatitudes within the band of westerly winds - Tropical cyclones form within the equatorial easterly winds - Extratropical cyclones are associated with fronts and have cool central cores - Tropical Cyclones are not associated with fronts and have warm central cores

Explain the atmospheric factors needed for the formation of an extratropical cyclone.

- Extratropical means "outside of the tropics." - Extratropical cyclones develop over land or water in temperate regions, typically between 30° and 70° latitude - These midlatitude cyclones are generally associated with fronts and have cool central cores - Obtain their energy from the horizontal temperature contrast between air masses on either side of a front

What are the three main ways that materials on a slope may fail?

- Falling, Sliding, Slumping - Falling refers to the free fall of earth material, as from the free face of a cliff - Sliding is the downslope movement of a coherent block of earth material along a planar slip plane - Slumping of rock or soil is sliding along a curved slip plane producing slump blocks

How is climate classification useful to understanding natural hazards?

- Familiarity with Earth's climate zones is a step toward recognizing the threat from natural hazards - Flooding is partly dependent on rainfall amount and intensity - Landslides may be more common in areas with rainy climates - Wildfires are more likely to occur in dry areas.

How are wildfires related to plant photosynthesis and decomposition?

- Fire essentially reverses the process of photosynthesis - During a wildfire, plant tissue and other organic material (biomass) are oxidized and broken down by combustion, or burning - These systems establish a balance between plant productivity and decomposition. - Microbes alone don't decompose plants fast enough to balance plant growth - Wildfire helps in this decomposition

How is wildfire linked to climate change?

- Fires increased ozone levels in parts of Canada and the northern United States by 25% - Climate change in this century increases the intensity and frequency of wildfires - Climate change likely to increase the number and intensity of wildfires in NorCal - Regional climatic conditions are projected to become warmer, drier, and windier—three factors that promote wildfires

What are the four requirements for a tropical disturbance to become a hurricane?

- First, warm ocean waters of at least 26°C (~80°F) must extend to a depth of 46 m (~150 ft.) or more - The atmosphere must cool fast enough from the surface of the ocean upward to allow moist air to continue to be unstable and convect (uplift), causing condensation - There must be little vertical wind shear (a change in wind speed between the ocean) surface and the top of the troposphere - The disturbance must be far enough away from the equator so Coriolis effect is strong enough to cause rotation around the low pressure region

Flaming Combustion

- Flaming combustion is the rapid, high-temperature conversion of fuel to thermal energy - Is characterized by a large amount of residual unburned material. - Flaming combustion dominates during the early stages of a fire as fine fuel and volatile gases produce rapid oxidation reactions.

What are flash floods and where are they likely to occur?

- Flash floods typically occur in the upper part of a drainage basin (zone 1) - Generally produced by intense rainfall of short duration over a small area

Contrast the alluvial fans and delta flows of zone 3 with zone 2 river flows.

- Floods on alluvial fans and deltas are particularly hazardous because of uncertain and changing flow paths - The main channel of a fan or delta during one flood may not be the same channel in a subsequent flood.

Preignition

- Fuel is brought to both a temperature and water content that favors ignition Preheating: - Fuel loses a great deal of water and other volatile chemical compounds Pyrolysis: - Means "heat divided." - Group of processes that chemically degrade the fuel. - Heat divides, or splits, large fuel molecules into smaller ones. - Preignition processes absorb energy

What is relative soil profile development, and how is it useful in evaluating hazards?

- Geologists recognize differences among weakly developed, moderately developed, and well-developed soils (dating) - Provides info about recent history of a landscape and site stability when locating such facilities as waste disposal operations or a large power plant - useful in evaluating rates of processes and recurrence of hazardous events such as earthquakes and landslides

Describe the three types of fire.

- Ground, Surface, and Crown. - Ground fires creep along slowly under the ground surface, with little flaming and more smoldering combustion. - Surface fires move along the ground and vary greatly in their intensity. - Low intensity surface fires burn grass, shrubs, dead limbs, leaf litter, and other debris. - They burn relative slowly with glowing or smoldering combustion and limited flaming combustion. - Extremely intense surface fires release large amounts of heat energy as they move swiftly across a landscape. - Crown fires are those in which flaming combustion is carried through canopies of trees - Large crown fires are generally driven by strong winds and are aided by steep slopes.

How does road construction increase the occurrence of landslides?

Roads can interrupt surface drainage, alter subsurface movement of water, and adversely change the distribution of earth materials on a slope by cut-and-fill or grading operations

Explain the USGS alert notification system for volcanic eruptions.

- Ground-based volcano alert levels, and aviation-based color coding levels - The hazard posed to those on the ground may differ to those in the air, and higher alerts/codes will be issued Ground Levels: - Normal (noneruptive state) - Advisory (elevated unrest) - Watch (potential of eruption) - Warning (Hazardous eruption imminent) Aviation Levels: - Green(noneruptive state) - Yellow (elevated unrest) - Orange (potential of eruption) - Red (Hazardous eruption imminent)

Eons and Eras of time

- Hadean Eon - Archean Eon - Stromatolites - Proterozoic Eon - Phanerozoic Eon: - Paleozoic Era - Mesozoic Era - Age of reptiles - Ended in the K-Pg extinction - Extinction of all dinosaurs - Cenozoic Era (66 mya - present) - Age of mammals - Ice age 2.6 mya, humans prevailed

3 Components of Risk

- Hazard - Vulnerability - Exposure

Describe the weather conditions that are most favorable for wildfires.

- Hot, dry conditions are most favorable for fires to burn - Wildfires burn more vigorously when humidity is at its lowest point - Winds greatly influence the spread, intensity, and form of a wildfire

Why is soil erosion a serious problem?

- Human agricultural practices are mining the soil - Soils are being eroded faster than they are being produced by soil-forming processes - Soil erosion leads to loss of soil resources and decreased quality of water due to sedimentation. - Problem in urban environments, where vegetation is removed prior to development.

How do hurricane watches and warnings differ?

- Hurricane watches issued when a hurricane is likely to strike within the next 36 hours - Hurricane warnings given when the storm is likely to make landfall within the next 24 hours or less

What is the primary way that hurricanes are classified? Give an example.

- Hurricanes are classified by their wind speed on a damage-potential scale - A hurricane's category typically changes as it intensifies or weakens - Meteorologists describe Category 3 through 5 hurricanes as major hurricanes A category 5 hurricane would mean: - Complete roof failure on many residences and industrial buildings. - Complete building failures with small utility buildings blown over or away. - All shrubs, trees, and signs blown down. - Complete destruction of mobile homes. - 2005, Hurricane Wilma was a Category 5 hurricane at peak intensity-- is the strongest Atlantic tropical cyclone of record.

What methods have been used to control lava flows?

- Hydraulic chilling and wall construction have been used to deflect lava flows away from populated areas - Hydraulic chilling is attempting to cool down lava flows with vast amounts of water hoses

How might the hazard of an extraterrestrial impact be minimized?

- Identifying hazards - Spacewatch programs identify potentially hazardous objects several thousand years before they are likely to collide with our planet - Blowing up huge extraterrestrial objects isnt' an option-- would cause way more damage - Gently diverting object so that they miss Earth is one option - Evacuation theoretically possible with smaller objects

What is the role of water in soils?

- If pore spaces in soil are completely filled with water, the soil is saturated; otherwise, it's unsaturated - Water content determines strength of soil and its potential to shrink and swell - Water in soil is related to many processes, including slope stability and subsidence

Why does Earth apparently have so few impact craters?

- Impact craters involve extremely high velocity, energy, pressure, and temperatures normally not experienced or produced by other geologic processes

Describe the general characteristics of an impact crater. How can it be distinguished from other types of craters?

- Impacts involve high velocity, energy, pressure, and temperatures, normally not experienced/produced by other geologic processes - Kinetic energy of the impact is transferred to Earth's surface through a shock wave that propagates into Earth - The shock can metamorphose some rocks in the impact area (breccia) while others are melted and mixed with the materials of the impacting object itself

Explain the significance of Comet Shoemaker-Levy 9

- In 1993, Gene and Carolyn Shoemaker and David Levy discovered a comet - Less than a year and a half later, astronomers watched Shoemaker-Levy 9 explode in one of the most tremendous impacts witnessed - The comet's orbit was tied to Jupiter - After years of orbiting the planet, it separated into 21 fragments-- "string of pearls." - Huge rings developed in Jupiter's atmosphere around the impact sites. - Rings exceeded diameter of Earth! - Sobering event for those who consider that impacts such as this might one day occur on Earth - After Shoemaker-Levy 9 and investigations of the Barringer Crater, the idea that there could be a catastrophic impact on Earth was finally accepted

Subsidence/ Volume Change

- In contrast to mass wasting, which originates on slopes, subsidence and changes in the volume of the soil occur on slopes and flat ground - Subsidence is a type of ground failure characterized by nearly vertical deformation, or the downward sinking of earth material

What are some similarities and differences between causes of deaths in rich vs. poor countries?

- In high income countries, the highest causes of death are almost all non-communicable diseases - In low income countries almost all the top causes of death are communicable diseases, and several of them are diseases that have already been cured in high-income countries

Combustion

- In the combustion phase, external reactions involving flaming or glowing liberate energy in the form of heat and light - Ignition repeats time and time again as a fire moves

Describe the five stages of tornado development.

- In the first stage of tornado development, funnel-shaped vortices called funnel clouds that do not reach to the ground form below the thunderstorm - mature stage-- visible condensation funnel extends from the thunderstorm cloud to the ground as moist air is drawn upward - shrinking stage--the funnel thins and begins to tilt. As the width of the funnel decreases, the winds increases, making the tornado more dangerous - In the decaying stage, or rope stage, the upward-spiraling air comes in contact with downdrafts and the tornado begins to move erratically.

Assuming that the hypothesized Younger Dryas impact is correct, what would the consequences be if such an event were to happen in the future?

Should such an event occur in the future, civilization as we know it would likely disappear

What is herd immunity? Why is it important?

- Insurance that a community will be free of a virus if everyone who can get vaccinated does get vaccinated - If fewer than 92-95% of people receive vaccines, a community can lose its "herd community," and an outbreak can occur. - Loss of herd immunity can affect people who cannot be vaccinated: • Infants that are too young • people allergic to egg proteins • Older adults with complicated health issues • Anyone with compromised immune system

Gradualism

- Introduced by Scottish Doctor James Hutton in 1785 - Other term for Uniformitarianism - Present geological processes may be studied to learn the history of the past—"the present is the key to the past." - Earth must be much older than 6000 years to allow gradual processes of erosion, deposition, and uplift to form mountain ranges and other features on Earth's surface

List the different natural service functions of landslides.

- It is difficult to imagine any good coming from landslides except the creation of new habitats in forests and aquatic ecosystems - For some old-growth forests, the disturbance increases plant and animal diversity - In aquatic environments, landslide-dammed lakes create new habitat for fish and other organisms

Why was Barringer Crater controversial, and why is it important?

- It was the first impact crater identified on Earth - Wasn't identified as an impact crater until 1947 - Barringer Crater eventually shown to be the result of an asteroid impact, probably with air-bursts - Since then, more than 175 other large impact features have been identified on all the continents and on the ocean floor - These observations have led to punctuated uniformitarianism.

Calderas

- Known as the ultra-Plinian type - Largest Caldera eruptions known as the Super-Volcanic type - High silica and volatile content suggests that continental crust has been mixed with the magma - Most violent eruptions occur when calderas form due to collapse of the land surface or volcanic edifice following partial emptying of the magma chamber. - LOTS of ash

Explain how large landslides are related to flooding and tsunamis

- Landslides themselves may be responsible for flooding if they form an earthen dam across a river - A large landslide may also cause a tsunami or widespread flooding if it displaces water out of a lake or bay

What are the conditions necessary for both thunderstorms and severe thunderstorms to form?

- Large changes in wind shear, high water vapor content in the lower troposphere, updraft of air, and the existence of a dry air mass above a moist air mass

Describe how wildfire affects air and water quality.

- Large wildfires create their own clouds and release smoke, soot, and invisible gases that contribute to air pollution - Increase in particulates in the atmosphere - Significant quantities of toxic mercury into the environment - Fires lead to floods, debris flows, and erosion, which produce large quantities of sediment and plant debris that affect the water quality

Why might levees, flood walls, and dams produce a false sense of security?

- Levee construction doesn't remove land from the floodplain or eliminate flood risk - Levees cannot withstand high-magnitude floods for a long time. - By constructing a levee, there is less floodplain space to "soak up" floodwaters. - Floodwalls were built in St. Louis, Missouri before the 1993 flood - Flood walls produce a bottleneck effect—they force floodwater through a narrow channel and cause it to back up. - This effect contributed to the 1993 flooding upstream of St. Louis

What are squall lines?

- Long lines of individual storm cells - Commonly develop parallel to cold fronts 300 to 500 km (~180 to 310 mi.) ahead of the front

What are the two types of snow avalanches, and how do they differ?

- Loose-snow avalanches typically start at a point and widen as they move downslope - Slab avalanches start as cohesive blocks of snow and ice that move downslope-- far more dangerous and damaging

Describe the characteristics of the troposphere. How do meteorologists identify the top of the troposphere?

- Lowest layer of atmosphere - Humans spend all of their lives only in the troposphere - extends about 8 to 16 km (~5 to 10 mi.) - Defining characteristic of the troposphere is a rapid upward decrease in temperature that results from decreasing air pressure with increasing altitude

What is magma and where does it come from?

- Magma is molten rock within Earth - Most magma comes from the asthenosphere - Asthenosphere is weak and able to flow because it's close to melting temperature

What are sources for the initial ignition of wildfires? How often does ignition occur?

- Many sources of ignition, such as lightning, volcanic activity, and human action - Ignition repeats time and time again as a fire moves

Describe the process of sediment flushing following wildfires. How common is the flushing?

- Material accumulates at the base of the slope or in adjacent stream channels after dry ravel takes place. - Remaining material is washed downslope in the first rainfall after a fire because the water-repellent layer is now deeper below the surface. - The voluminous amount of material that moves downslope from dry ravel or surface runoff clogs stream channels with sediment. - In a second moderate rainstorm, the sediment is flushed from the channel, leaving it how it was before the fire

Explain why incoming solar radiation does not overheat the Earth, using the energy balance diagram

- Most energy to Earth from the sun is either reflected or reradiated back into outer space.

What are the hypotheses for the cause of mass extinctions?

- Most hypotheses for mass extinctions involve rapid climate change - Climate change can be triggered by plate tectonics, volcanic activity, or extraterrestrial impact - Plate movements create new patterns of ocean circulation, which have a major effect on climate - Large basaltic eruptions produce huge volumes of flood basalts and release large quantities of carbon dioxide into atmosphere and cause global warming. - In contrast, large volcanic eruptions of silica-rich lava can inject tremendous quantities of volcanic ash into atmosphere and cause global cooling. - Finally, climate change is one of several effects of extraterrestrial impacts or airbursts that contribute to extinctions

What are easterly waves, and how are they related to tropical cyclones?

- Most tropical cyclones develop from easterly waves that form over western Africa. - Easterly waves are troughs of relatively low pressure that extend north-south for 2000 to 3000 km (~1200 to 1800 mi.) - They move westward with the trade winds at a rate of 15-30 km (~10—20 mi.) per hour. - The waves in the trade winds cause local convergence of air east of the axis of low pressure, which encourages air to rise and clouds to form

What is the relationship between plate tectonics and the location of volcanoes?

- Most volcanoes are located near active plate boundaries - ~two-thirds of all active volcanoes above sea level on Earth are located within the Pacific "Ring of Fire" - Relationship exists because spreading or sinking plates at boundaries interact with earth materials to produce magma

How has the risk from an eruption of Mount Vesuvius changed in the past two 2000 years?

- Mount Vesuvius, which devastated the cities of Pompeii and Herculaneum in A.D. 79 is considered one of the most hazardous volcanoes on Earth with nearly 3 million people living in the surrounding area. - In an attempt to minimize the potential for a future catastrophe if another large eruption were to occur, the Italian government is offering 30,000 euros to anyone living within the area willing to relocate

What factors control the path a hurricane takes in the Atlantic Ocean?

- Movement of a hurricane is controlled by the Coriolis effect, which deflects the storm to the right in the Northern Hemisphere - Hurricanes commonly track westward in the trade winds that cross the Atlantic and curve to the north - North Atlantic Hurricanes are also influenced by the Bermuda-Azores High, a persistent high-pressure anticyclone that remains anchored in the North Atlantic during the summer and early fall

Stratovolcanoes

- Mt. Fuji, Mt St. Helens, Mt. Rainer and Mt. Shasta - Conical shape - Occur at Subduction zones - high viscosity - Lavas don't travel far from vent and pile up, giving stratovolcanoes steep sides - Stratovolcanoes responsible for most of the death and destruction caused by volcanoes - Plinian Type eruption (Mt. Vesuvius)

How might near-Earth objects (NEOs) be identified?

- NEO observation programs utilize telescopes with digital imaging devices. - Astronomers take three to five images of a given area of the night sky at intervals of 10 to 60 minutes. - Computer software is then used to compare the images to identify fast-moving objects - Programs such as Spacewatch and NEAT identify NEOs of diameters greater than a few hundred meters at least 100 years before possible impact

Describe the main soil horizons

- O (organic) - A (organic and mineral) - E (Zone of Leaching— layer that's leached of iron-bearing components, light in color(inorganic)) - B (zone of accumulation) - Bt (enriched with clay minerals) - Bk (accumulation of calcium carbonate, May fill spaces between soil particles but does not dominate structure of horizon) - K (structure is dominated by calcium carbonate) - C (Lies directly over the unaltered parent material) - R (Unaltered parent material, consolidated bedrock that underlies the soil)

Resonance

- Occurs when a wave reflecting from one shore is superimposed on a wave moving in another direction. - Can increase storm surge as water sloshes back and forth in the enclosed or partially enclosed body of water - The net effect is an amplification of the surge

Explain how large caldera eruptions occur and why they are so dangerous.

- Occurs when calderas form due to collapse of the land surface or volcanic edifice following partial emptying of the magma chamber. - Unlike the passive formation of a caldera on a shield volcano, this inward collapse causes an explosive release of magma and volatiles that still remain in the magma chamber

Describe how Earth's energy balance works.

- Once electromagnetic energy from the sun reaches Earth, it's redirected, transmitted, or absorbed by the atmosphere, ocean, or land - Energy is either reflected or scattered in different directions - Emission (Earth absorbs and then emits longer wavelengths back to sun) - Transmission ( Energy passing through the atmosphere)

Channelization

- One flood control tactic - Straightening, deepening, widening, clearing, and/or lining existing stream channels

Six major mass extinctions

- Ordovician, 446 mya, continental glaciation in Southern Hemisphere - Permian, 250 mya, volcanoes causing global warming and cooling - Triassic-Jurassic boundary, 202 mya, volcanic activity associated with breakup of Pangaea - Cretaceous-Paleogene boundary (K-Pg boundary), 65 mya, Asteroid impact - Eocene period, 34 mya, plate tectonics - Pleistocene Epoch, initiated by airburst (?), continues today caused by human activity

What are the major permanent and variable gases in the atmosphere?

- Permanent gases are nitrogen and oxygen, smaller amounts of argon - water vapor, and carbon dioxide are the main variable gases

What was the cause of the Peshtigo Fire in 1871, and why was it such a catastrophe?

- Peshtigo was an area of extensive timber harvesting, and a lot of slash (small bits of wood and waste matter left from logging activities) remained on the ground - Was driven by extremely high winds and fed by abundant fuel - 1500-2500 people killed - Slash-and-burn method used to clear land for crops. -The railroad was also expanding and, to prepare the area for the tracks and facilities, more trees had to be cut down and burned. - Often, the cut wood was on the railroad's right-of-way and workers who were cutting trees and removing brush left it lying by the tracks. - This created a fire hazard as coal-fired steam locomotives moving by could release sparks that could start a fire. - Fire was human caused

Mass of the Universe

- Planets make up ~ 0.14% of our Solar System's mass. - Sun accounts for the other 99.85%!

What are the three types of energy? How do they differ from one another?

- Potential energy, kinetic energy, and heat energy - Potential energy is stored energy - Kinetic energy is the energy of motion - Heat energy is the energy of random motion of atoms and molecules - Heat energy is also energy transferred from one object to another due to temperature difference

Three phases of a wildfire.

- Preignition - Combustion - Extinction

Explain how processes in the preignition phase prepare plant material for combustion.

- Preignition involves heating and pyrolysis of fuel to drive off moisture and break down large carbon molecules into small ones. - The smaller molecules create a cloud of flammable gas directly above the fuel, which then ignites

Define prescribed burns, and explain why they are part of fire management.

- Prescribed burns reduce the amount of fuel and the likelihood of a catastrophic wildfire - Meant to counteract the dangers of wildfire suppression

Differentiate, with examples, the primary and secondary effects of flooding.

- Primary effects include injury, loss of life, and damage caused by currents, debris, and sediment to buildings, railroads, bridges, roads, and communication systems - Secondary effects include short-term pollution of rivers, hunger and disease, and displacement of persons who have lost their homes

How are soil erosion rates determined?

- Rates of soil erosion are measured in volume, mass, or weight of soil that's removed from a location in a specified time and area - Erosion rates vary with the engineering properties of the soil, land use, topography, and climate

What is viscosity and what determines magma viscosity?

- Resistance to flow in fluids - Greater amounts of silica make it more difficult for magma to flow - Higher volatile content, silica content, and cooler temperatures make magma more viscous

Explain how human activity in Rio de Janeiro has resulted in devastating landslides.

- Rio de Janeiro has many granite cliffs and lots of rainfall - Many of the slopes were logged for lumber and fuel and to clear land for agriculture - a lack of building sites on flat ground led to increased urban development on slopes. - The removal of additional vegetative cover and the construction of roads led to building sites at higher elevations. - Excavations cut the base of many slopes and severed the soil cover at critical points - Placing fill material on slopes to expand the size of building sites increased the load on already unstable land

How do slumps (rotational slides) differ from soil slips and rock slides (translational slides)?

- Rotational slides, or slumps, have curved slip surfaces - The rotational sliding tends to produce small topographic benches, which may rotate and tilt in an upslope direction - Translational slides generally have planar slip surfaces - In translational slides, material moves along inclined slip planes within and parallel to a slope

Cinder Cones

- Scoria (the name for vesicular mafic volcanic rock) forms when basaltic magma with intermediate amounts of volatile content is explosively ejected, cools and falls to the ground - Conical shape of the volcano comes from the accumulation of scoria around the vent— Cinder cones also called scoria cones - Strombolian type eruptions

What is the difference between sensible heat and latent heat?

- Sensible heat is heat that may be sensed or measured by a thermometer - Latent heat is the amount of heat either absorbed or released when a substance changes phase

What is a blizzard? How does a blizzard develop?

- Severe winter storms where large amounts of falling or blowing snow are driven by high winds to create low visibilities for an extended period of time -

Describe how seismic activity can indicate a forthcoming volcanic eruption.

- Shallow earthquakes and tremors are produced below a volcano as upward-moving magma fractures the surrounding rock and gas bubbles in the magma form and burst

Differentiate between simple and complex craters

- Simple craters are typically small, a few kilometers in diameter - Complex impact craters experience the same processes of simple craters, but the shape of a larger, complex crater is different - During a period of seconds to several minutes following impact, complex craters grow to sizes up to more than 100 km (~60 mi.) in diameter. - In these craters, the rim collapses more completely, and the central crater uplifts following the impact

List the five main effects of subsidence and soil volume changes

- Sinkhole formation (Florida) - Changes in groundwater conditions - Melting permafrost (Alaska, Russia) - Coastal Flooding (New Orleans) - Loss of Wetlands (New Orleans)

Instrumental Record

- Starting about 1880, temperature measurements were made at various locations on land and in oceans - Today, temperature is measured at about 7000 stations around the world. - The concentration of carbon dioxide in the atmosphere has been measured since about 1960. - Accurate measurement of the production of solar energy has been taken over the past several decades

Explain the causes and effects of storm surges. What will cause a storm surge to increase?

- Storm surge is the local rise of sea level that results from water pushed toward the shore by the winds that swirl around a storm - As winds grow stronger, the water level rises, with the height of the water proportional to the square of the wind speed - Low atmospheric pressure in the storm pulls up the sea surface. - For every millibar that atmospheric pressure drops, the sea surface rises 1 centimeter - Higher storm surges can develop when coastal water depth gets shallower toward shore-- Water piles up

Both stratovolcanoes and lava domes form in the same tectonic setting and have similar composition, but why do they have different explosive behavior?

- Stratovolcanoes have high water content because they form above subduction zones where magma formation is caused by addition of volatiles. - The high-volatile content of these volcanoes means that eruptions can be extremely explosive - Lava domes form in the vent of a stratovolcano after an explosive eruption. - Formed in the same place (subduction zones), mixed with lots of water, high viscosity - HOWEVER, the volatile content of the magma gets expended during the stratovolcano eruption - The high-viscosity lava is degassed, has a low volatile content

What are mesoscale convective systems?

- The MCS is the most common of the three types - Large clusters of self-propagating storms in which the downdraft of one cell leads to the formation of a new cell nearby. - Unlike many single-cell, air-mass thunderstorms that last for less than an hour, these storms can grow and move for periods of 12 hours+.

Which flood caused the most deaths? Which caused the greatest economic loss? Can you make any generalizations about zone 1 and zone 2 floods?

- The Rapid City, South Dakota (flash flood) of 1972 caused the most deaths - The Mississippi River and tributaries flood of 1993 cost the most

What is the relationship between the downslope force and normal force?

- The downslope force or driving force (D) is parallel to the slope of the potential slip plane - the normal force (N) is perpendicular to the slip plane - The resisting force is proportional to the magnitude of the normal force, which adds frictional resistance onto the surface of the plane - As the slope angle (Θ) increases, N decreases and D increases proportionally

What is electromagnetic energy? How are the different types of electromagnetic energy distinguished?

- The energy emitted from the sun - This energy travels through the vacuum of space at the speed of light - Distinguished by their wavelengths

Why was the evacuation prior to the Mount Pinatubo eruptions so successful?

- The evacuation of 60,000 people prior to the 1991 eruption of Mount Pinatubo was successful because the Philippine government educated people about the dangers of violent ash eruptions with debris flows. - A video depicting these events was widely shown before the eruption, and it helped convince local officials and residents that they faced a real threat

Why did the Indonesian fires of 1997-1998 have such a widespread impact?

- The impact on tropical forest ecosystems, biodiversity, and the atmosphere was so severe that some observers called them a global natural disaster - Fires released so much smoke that much of Indonesia and neighboring Malaysia and Singapore were blanketed in smog - Many people developed chronic respiratory, eye, and skin ailments. - Schools and businesses forced to close for days to weeks - Premature deaths were blamed on the poor air quality - Crash of a Garuda Airlines jet into a mountainside in northern Sumatra, killing all 234 people on board due to lack of vision - Death of Orangutans who had to flee from forests

Paleo-proxy record

- The instrumental record is short-- as a result, there was a need to extend the record back further. - Proxy data refers to data that are not strictly climatic but can be correlated with climate - Proxy data includes natural records of climate variability, as indicated by tree rings, ocean sediments, ice cores, fossil pollen, corals, and carbon-14

What are global climate models, and why are they important?

- The mathematical models used by scientists to study climate and climate change - They depict the flow of surface water and groundwater, erosion and deposition of stream sediment, and global circulation of water in the ocean, air and atmosphere - Today, global climate models provide guidance on regions that could be relatively wetter/drier and hotter/colder in the future

How does topography influence a wildfire?

- The moisture content of fuel is influenced by its location on the landscape - Slopes exposed to winds have drier vegetation than slopes sheltered from the wind and are more prone to combustion - In mountainous areas, winds circulate up canyons in daytime, providing an easy path for wildfires - Fires burning on steep slopes can preheat fuel upslope from the flames - Slope makes it easier for a fire to move up and spread more rapidly (or down if aided by winds)

What are supercells?

- The most damaging of all severe thunderstorms - Defined by the presence of an upward spiraling column of air—vertical axis rotation—known as a mesocyclone

What part of the United States has the greatest volcanic hazard, and why?

- The mountainous regions of the Pacific Coast and at Yellowstone - Volcanoes are intimately related to plate tectonics and most occur along the Ring of Fire surrounding the Pacific Ocean basin - Yellowstone is hot spot activity

Karst Topography

- The name given to a common type of landscape in the United States and in many other parts of the world. - Subsidence results from chemical weathering, the dissolution of rocks beneath the land surface - Dissolution occurs as surface water or groundwater percolates through rock that is easily dissolved - Water becomes acidic when soil/bedrock is mixed with decaying plants or animals (because they release carbon dioxide in the same way humans do, making water acidic) erodes faster

Define flooding

- The natural process of overbank flow

Extinction

- The point at which combustion, including smoldering, ceases. - When there is no longer sufficient heat and fuel to sustain combustion, the fire is considered extinct.

Explain how the risk of dying from an asteroid impact is greater than the risk of a car accident.

- The probability of being killed by an impact catastrophe at the global level is approximately 0.01% to 0.1% - The probability of being killed in a car accident is ~0.008% - The risk is so high because it would be a global catastrophe, but it's just an average - T risk is spread out over thousands of years.

What is the safety factor, and how is it defined?

- The ratio of the resisting forces to the driving forces - If safety factor is greater than 1, the resisting forces exceed the driving forces and the slope is considered stable - If safety factor is less than 1, the driving forces exceed the resisting forces and slope failure is expected

What is a drainage basin?

- The region drained by a single stream or river - Each stream has its own drainage basin or watershed that collects rain and other precipitation

Why is wildfire necessary for some plants and animals?

- The removal of some species from fires reduces competition for moisture, nutrients, and light, allowing the surviving species as well as new species to thrive. - In species that depend on fire for reproduction, a wildfire may trigger the release of seeds or stimulate flowering

How is the risk of extraterrestrial impact determined?

- The risk of an event is related to the probability that it will occur and to consequences should it take place - Predictions of likelihood and type of future impacts contain enormous statistical uncertainty - The risk of dying from a large impact or airburst is considerably greater than risks we normally face in life (but is calculated over a huge period of time)

What are the two main variables used to define climate zones? What other factors influence climate in a region?

- The simplest classification is by temperature and precipitation - Two places can have same average temp. but very different ranges in temperature (San Diego and El Paso, Texas) - Extreme seasonal patterns - Temp. and precipitation can be affected by currents, mountain ranges, and plateaus.

Why is the study of carbon dioxide in the atmosphere so important?

- There are CO2 measurements from the instrumental record that extend back through measurements from trapped air in glacial ice - There's a positive correlation between CO2 in the atmosphere found in ice cores to the paleo-temperature record. - CO2 levels have corresponded closely to air temperature for more than 410,000 years - Records from other ice cores show similar patterns older than than 800,000 years

What is the argument for and against the 2003 Healthy Forests Restoration Act?

- Those in support think the new procedure will reduce the risk of catastrophic fires around national forests, save lives of forest residents and firefighters, and protect wildlife, including endangered species - Those against argue that large-scale logging will be promoted far from communities at risk from wildfire and damage our forests. They further argue that the best approach to minimizing risk from wildfire is through the selective removal of vegetation around communities and homes

Define soil

- To soil scientists, it is solid earth material that's been altered by physical, chemical, and organic processes such that it can support rooted plant life. - To engineers, soil is any solid earth material that can be removed without blasting.

Describe several sources of paleo-proxy climate data.

- Tree rings - Sediments - Ice Cores - Ice cores from glaciers often contain small bubbles of air deposited at the time of the snow. - The composition and ratio of past atmospheric gases preserved in the ice may be studied - Ice cores also volcanic ash and dust, which can provide proxy data to assist in evaluating climate change - Pollen - Corals - Carbon-14 - Carbon Dioxide

Where are tropical cyclones most common, and why?

- Tropical cyclones form over warm tropical or subtropical ocean water, typically between 5° and 20° latitude - They are not associated with fronts (boundaries between warm and cold air masses) and have warm central cores - They derive energy from warm ocean water and the latent heat released as rising air condenses to form clouds (latent heat of condensation)

How might processes involved in urbanization increase or decrease the stability of slopes?

- Urbanization and development will expand in landslide-prone areas. - Tree cutting will continue in landslide-prone areas. - Changing global climate patterns will result in regional increases in precipitation (inducing landslides)

Smoldering Combustion

- Volatile gases are removed from the fuel, woody materials continue to decompose through pyrolysis, and carbon and ash begin to blanket new fuel. - This blanket of noncombustible material hinders flaming combustion and lead to smoldering combustion instead. - Takes place at lower temperatures - Does not require rapid pyrolysis for its growth. - The ultimate product is charcoal.

How is a volcanic crater different than a caldera?

- Volcanic craters are caused by explosive extrusion of volcanic material during an eruption - Calderas form by the inward collapse of the volcano top due to removal of magma from the subsurface

Three basic atmospheric conditions that are required to produce a thunderstorm:

- Warm humid air is available in lower atmosphere to feed clouds and precipitation and provide energy to the storm as it develops. - A steep vertical temperature gradient must exist in the environment such that the rising air is warmer than the air it moves through. - An updraft must force moist air up to colder levels of the atmosphere.

What are the major gases emitted in a volcanic eruption? How can they be hazardous?

- Water vapor(H20), carbon dioxide (C02), carbon monoxide (CO), sulfur dioxide (SO2), and hydrogen sulfide (H2S) - Water and carbon dioxide make up more than 90 percent of all emitted gases - Toxic concentrations of these gases are rare, but a huge carbon dioxide cloud rose from a volcano in Cameroon and suffocated 2000 people - Sulfur dioxide can also react in the atmosphere to produce acid rain - Toxic concentrations of chemicals emitted as gases may be adsorbed by volcanic ash that falls onto land. - These chemicals have contaminated the soil and have been absorbed by plants that are eaten by people and livestock

What are the five main tools used to predict hurricanes and extratropical cyclones?

- Weather Satellites: - Most valuable tools for hurricane detection - Satellites can detect early warning signs of hurricanes long before the storm actually begins - Aircraft: - special planes are flown directly into a hurricane to gather data - Doppler Radar Systems - Weather Buoys - Computer Models

What role do mass wasting and erosion play in the mining of precious earth materials, such as gold and diamonds?

- Weathering frees minerals from rocks, and mass wasting transports the minerals downslope. - Heavier minerals, particularly gold and diamonds, can be concentrated at the base of the slope and in adjacent streams. - Gold and diamonds have been mined from colluvium and debris flow deposits

Define wildfire.

- Wildfire is a self-sustaining, rapid, high-temperature biochemical oxidation reaction that releases heat, light, and other products. - This reaction requires three things— fuel, oxygen, and heat

How has the nature of wildfires and human interaction changed over geologic and historic time?

- Wildfires date back more than 350 million years when trees evolved - Wildfire behavior changed drastically 20 million years ago, when grasses evolved - Grasses provided a new type of fuel that grew quickly and could sustain more frequent fires - Then, about 11,500 years ago (the beginning of the Holocene Epoch), climate warmed after the last major glacial advance and wildfire behavior intensified again - Natural fires started by lightning strikes and volcanic eruptions allowed early humans to harness fire for heat, light, and cooking, which helped human populations spread across continents - The ability to use fire for cooking and for warmth allowed humans to expand their diet and settle in colder areas

Describe the differences among force, work, and power

- Work is the force times the distance over which it is applied - Work is measured in joules - Power is the rate at which work is done - Power is energy (joules) divided by time - Force is energy exerted (push pull?, energy it takes to move something?)

Why are downstream zone 2 floods potentially so dangerous?

- Zone 2 floods cover a wide area and are usually produced by long storms that saturate the soil and produce increased runoff - This kind of flood is characterized by the downstream movement of the flood crest (the peak height of the floodwaters) - Large rise and fall of discharge at a particular location

Three Major Heat-Transfer processes

- conduction, convection, and radiation - Conduction = heat transfer through a substance by atomic or molecular interactions (least important in the atmosphere) - Convection = transfer of heat by the mass movement of a fluid, such as water or air - Radiation is wavelike energy that emitted by any substance that possesses heat

What are the three requirements for fire to start and for combustion to continue? What happens when one of these requirements is removed?

- fuel, oxygen, and heat - If any one of the three requirements of this triangle is removed, the fire goes out

Explain how timber harvesting, specifically clear-cutting, affects the occurrence of landslides

- logging on weak, unstable slopes increases landslide erosion by several times compared to slopes not logged

P Waves

- primary or compressional waves - Move fast with a push/pull motion - Can move through solid, liquid and gas - It is possible to hear them

What are three major causes of hurricane damage? Which is typically the most deadly?

- storm surge, high winds, and heavy rains - Storm surge causes the greatest damage and contributes to 90% of all hurricane-related fatalities

Explain the various hazards linked to a large extraterrestrial impact in the future

- tsunamis, wildfires, earthquakes, mass wasting, climate change, and, possibly, volcanic eruptions - Major extinctions of life caused by increased melting of lava, huge basaltic flow, unstable earth mantle

What are the three ways that vegetation affects slope stability?

1. Vegetation provides cover to cushion the impact of rain, retarding surface erosion. 2. Plant roots add strength and cohesion to slope materials. They anchor soil and unconsolidated material, increasing a slope's resistance to landsliding 3. Vegetation also adds weight to a slope (instability)

What is the approximate abundance of water on the Earth?

<0.2%

What are some adverse effects of channelization?

> Draining wetlands affects plants and animals by eliminating habitats necessary for the survival of certain species > Cutting trees eliminates cover for fish and exposes the stream to sun, which damages plant life and heat-sensitive aquatic organisms. > Cutting floodplain hardwood trees eliminates many animal habitats (while increasing erosion) > Straightening/modifying the stream bed destroys the diversity of flow patterns and breeding areas for aquatic life, while changing peak flow.

What are the major factors that influence the damage a flood causes?

> Land use on the floodplain > Depth and velocity of floodwaters > Rate of rise and duration of flooding > Season of the year in which flooding takes place > Quantity and type of sediment transported and deposited by floodwaters > Effectiveness of forecasting, warning, and evacuation

Describe the three zones of a river system

> Zone 1: The zone of water and sediment production, also called the zone of production. This is generally in the upper parts of the system where topography is steeper and more precipitation falls. Water velocity is fast, and downcutting and erosion occur. Channels may be in steep-sided, V-shaped valleys with waterfalls and rapids controlled by hard rocks. > Zone 2: The zone of transport, where water and sediment are conveyed by a river with a broad valley and floodplain, created as the river moves laterally rather than downcutting a steep valley. Sediment is frequently deposited in river bars or on the floodplain, but such deposition is temporary in the history of a river. The channel pattern may be braided or meandering or some combination of both. > Zone 3: The zone of deposition, where water velocity slows near base level and sediment is deposited. This may be an alluvial fan, lake, or, more commonly, a delta.

Name the factors that affect driving and resisting forces on slopes, and explain how these are interrelated.

> type of earth materials > slope angle and topography > climate > vegetation > water > time

What is an endemic disease?

A continuous presence of a disease in a given geographic area

What is dry ravel?

A gravity-driven process that moves a large volume of sand, gravel, and organic material stored upslope of brush vegetation before the fire downslope in dry weather following a wildfire

Define airburst

A meteoroid entering the atmosphere at about 85 km (~53 mi.) above Earth's surface that becomes a meteor and emits light and then explodes in the atmosphere at an altitude between 12 and 50 km (~7 and 31 mi.),

What are stromatolites?

A small rocky mound built up of layers of cyanobacteria and trapped sediment

What is an outbreak?

A sudden explosion of cases, usually very short-term and in a more restricted area or group than epidemics

Tornado

A violently rotating column of air associated with extreme horizontal winds

Define alluvial fan and delta.

Alluvial Fan: - a fan-shaped deposit on land formed in Zone 3 - Triangular or irregularly shaped deposit (also zone 3) - Floods on Alluvial fans and deltas are particularly hazardous because of uncertain and changing flow paths

What is punctuated uniformitarianism?

Although uniformitarianism explains the long geologic record of gradual mountain building, canyon erosion, and landscape construction, periodic catastrophic events do occur and can cause mass extinctions.

What is a pandemic?

An excess number of cases in many countries at the same time (i.e., worldwide epidemics)

What is the basic requirement that a storm must meet to be given a name?

An official name is assigned once the maximum winds of a tropical depression exceed 63 km (~39 mi.) per hour and it becomes a tropical storm.

Why does atmospheric pressure decrease with increasing altitude?

Atmospheric pressure is greater at sea level than at the top of a mountain where there's less air (fewer gas molecules)

Describe the primary and secondary effects of volcanic eruptions

Primary Effects: - Lava flows, pyroclastic activity such as ash fall, pyroclastic flows and lateral blasts, and release of volcanic gases Secondary Effects: - Debris flows, mudflows, landslides or debris avalanches, floods, fires, and tsunamis

What are some differences between viral and bacterial infections and diseases?

Bacterial Disease: - any of a variety of illnesses caused by bacteria - Most (>90%) bacteria are harmless or even helpful - Living, and localized (affects only one small area of the body) - Viruses: - microscopic organisms that exist everywhere on earth - NOT living, and systemic (bloodstream, whole body) - They can infect animals, plants, fungi, and even bacteria - A virus may have an effect on one organism, but a different effect on another - Viruses consist of genetic material, RNA or DNA, surrounded by a coat of protein, lipid (fat), or glycoprotein. - Viruses cannot replicate without a host, so they are classified as parasitic.

Catastrophism

Based on Archbishop Ussher's "young Earth" belief, early earth scientists were forced to conclude that most of the processes that formed our planet were catastrophic in nature

What are meteorites and comets made of?

Comets: - Frozen water and/or carbon dioxide form an icy core that is surrounded by rock fragments and dust-- "dirty snowball." Meteorites: - Stony, metallic, or carbonaceous (containing carbon) composition

List the following types of electromagnetic energy in order from shortest wavelength to longest wavelength: radio waves, ultraviolet radiation, gamma radiation, visible light, infrared radiation, X-rays, and microwaves.

Cosmic rays, gamma rays, X-Rays, UV radiation, Visible light, Infrared radiation, Microwaves, Radio waves

How is color related to energy absorption?

Darker-colored surfaces have lower albedo (reflectivity) than lighter-colored surfaces

Describe the physical and chemical changes that cause rocks to melt.

Decompression Melting: - Occurs when the overlying pressure exerted on hot rock within the asthenosphere is decreased - Mainly occurs where the lithosphere is being stretched and extended Addition of Volatiles: - Volatiles are chemical compounds, such as water, carbon dioxide, and sulfur dioxide, that evaporate easily and exist in a gaseous state at Earth's surface - These chemical compounds lower the melting temperature of rocks by breaking chemical bonds within minerals - Magma formation due to the addition of volatiles occurs at subduction zones and is responsible for the "Ring of Fire" Addition of heat: - As magma rises in the mantle and through the crust, heat from deep within Earth is carried toward the surface and is transferred to the surrounding rocks - This heat causes cooler, shallower rocks to melt and this newly formed magma may become mixed with rising magma

Characterize a tornado in terms of wind speed, size, typical speed of movement, duration, and length of travel.

EF0-- (105-137 km/hr (~65-85 mph)), Light damage EF1-- 138-177 km/hr (~86-110 mph), Moderate damage EF2-- (178-218 km/hr (~111-135 mph)), Considerable damage EF3-- (219-266 km/hr (~136-165 mph)), severe damage EF4-- (267-322 km/hr (~166-200 mph)), Devastating damage EF5-- (More than 322 km/hr (More than 200 mph)), Incredible damage

Define Earth system science and describe its goals

Earth system science is about learning how the various components of the system— atmosphere, oceans, land, and biosphere—are linked on a global scale and interact to affect life on Earth. Goals: - To predict future changes that are relevant to society and people today. - Understand how Earth works, how it has evolved from a landscape of barren rock to the complex landscape it is today. - Apply that understanding to better manage our environment.

Convergent Plate Boundaries

Ex: Himalayas, Nazca plate boundary - compressive stress = force that pushes rocks together - "thrust faults" - subduction zone is a "mega-thrust" - Subduction recycles CO2 back into atmosphere. - Oceanic-continent, continent-continent, oceanic-oceanic - Continent-continent creates mountains (continental crust too buoyant to subduct!)

Divergent Plate Boundaries

Ex: Mid-atlantic ridge - tensile stress = force that pulls rocks apart - "rift valley"-- narrow oceanic basins form between separated continents - magmatism through fissures in continental crust (volcanoes)

Transform Plate Boundaries

Ex: San Andreas Fault - exist in oceanic and continental crust - Shearing stress - no volcanism!

How do burned vegetation and soil interact to repel water?

Extremely hot fires that scorch dry, coarse soil may leave a non-wettable, or water-repellent, layer—called a hydrophobic layer—in the soil

Difference between flash floods and downstream flooding

Flash Flooding: - Typically occur in zone 1; short but intense rainfall; arid environments Downstream flooding: - Occurs in zones 2&3, often occur with extended rainfall that saturates ground

What are the main natural service functions of flooding?

Floods provide fertile sediment for farming, benefit aquatic ecosystems, and in some cases help keep land above sea level

Link the types of fuel to wildfire behavior.

Ground Fires: - In forests, Ground fires burn in duff, decaying organic matter in the soil, drained or temporarily dry swamps and marshes and in thicker peat deposits below the soil Surface Fires: - Low-intensity surface fires burn grass, shrubs, dead and downed limbs, leaf litter, and other biomass Crown Fires: - Crown fires begin when a surface fire moves up trunks into limbs of trees through various layers of fuel

How do the chances of a Category 1 hurricane making landfall in the U.S. South (Florida-Georgia) compare with that in the Northeast (New York-Massachusetts)?

Hurricanes have a higher probability of striking on the gulf coast (Florida), but may move to the Northeast

What did the Miller-Urey experiment demonstrate?

It is possible to build up complex pre-biotic molecules from simple reducing gases

Why are flood losses so great in Asia?

Large populations living along rivers and the resulting land-use changes linked to a climate characterized by intense precipitation

Which North American regions are most vulnerable to wildfire?

Large wildfires are most common in Alaska and the western contiguous United States

Washover Channels

Many overwash deposits form broad fans or deltas at the end of channels, as the storm surge cuts through the beach and dunes perpendicular to the shoreline

Forecast

Range of probability for event

Two types of sinkholes

Solutional sinkholes: - Form by dissolution on the top of a buried bedrock surface and are the more common type of sinkhole. - Dissolution occurs where downward infiltration of acidic groundwater becomes concentrated in holes created by joints and fractures. - In the formation of these sinkholes, groundwater is typically drawn into a cone above a hole in the limestone, like water being drawn into a sink drain. Collapse sinkholes: - Collapse sinkholes develop when surface or near-surface material collapses into an underground cavern. - As subsidence features, these sinkholes can develop into spectacular collapse structures.

Prediction

Specific date, time, and magnitude of event

Examples of Bacterial Diseases

TB, typhoid, cholera, diphtheria, bacterial meningitis, tetanus, bubonic plague, Lyme disease, salmonella, gonorrhea, and syphilis.

Why is there little risk of mass wasting in the Midwest and Great Plains region of the United States?

The Plains states are flatter and, therefore, relatively safe from landslides

Which areas of the United States and Canada have the highest risk for hurricanes?

The entire Gulf Coast from southern Texas to southern Florida and the Atlantic Coast from southern Florida northward through the coastal provinces of Canada

Define fire regime.

The fire regime is broadly defined to include: (1) the types of fuel that are found in plant communities (2) typical fire behavior as described by fire size, intensity, and amount of biomass removed (3) the overall fire history of the area, including fire frequency and recurrence interval

Was the impact from the 1988 wildfires in Yellowstone harmful or beneficial? Why?

The fires of 1988 did not destroy the park; they revitalized ecosystems through natural transformations that cycle energy and nutrients through soils, plants, and animals

Why does the wildfire risk shift from year to year?

The geographic region at greatest risk for wildfires shifts from year to year due to factors such as weather conditions and fuel availability

When was the greatest mass extinction in Earth's history?

The largest recorded mass extinction occurred near the end of the Permian Period, about 250 million years ago, when 80 to 85 percent of all living species died out

Regions with the highest risk of mass wasting

The mountainous areas of the West Coast, the Rocky Mountains, and the Appalachian Mountains

Why is the polar jet stream stronger than the subtropical jet stream?

The polar jet stream is stronger because it occurs along the boundary between cold arctic polar air masses to the north and warm subtropical and tropical air masses to the south (60 degrees latitude N)

How many named tropical storms preceded Hurricane Sandy in 2012?

The season tied for the third most active season on record and Hurricane Sandy became the second most expensive hurricane to hit the United States.

Explain the two primary ways that soils are classified.

Two separate systems of soil classification: - Soil taxonomy, used by soil scientists - Engineering classification, which groups soils by material types and engineering properties

Which of the following was NOT a result of the K-Pg (or K/T) Boundary mass extinction event?

Widespread wildfires were experienced on all Earth's continents

What are slope segments, and how do the common types of slope segments differ?

free face (cliff, hard granite), talus (accumulation of rockfall), upper convex, lower concave slopes (softer rock, thick vegetation) straight

Hypocenter

points where the strain energy stored in the rock is first released; fault begins to rupture

S Waves

secondary or shear waves - Move slower with an up/down motion - Can travel only through solids - cause no change in volume

What is an epidemic?

• An occurrence of new cases of disease in a population clearly in excess of normal expectation in that population • Usually describes short-term occurrences of infectious diseases

Lithosphere and Asthenosphere

• Earths crust and uppermost mantle are brittle, and elastic • Combined, they are the lithosphere • The underlying layer is the asthenosphere • Rocks there flow slowly under stress (but they are solid)

Continents versus Ocean Basins

• Ocean crust is less dense than continental crust • Ocean crust is also thinner • Ocean crust is young (< 200 million years old) • Continental crust is older (several billion years old)

Define mass extinction

• Sudden loss of large numbers of plants and animals relative to number of new species being added • Defines the boundaries of geologic periods or epochs • Usually involve rapid climate change triggered by plate tectonics, volcanic activity, or extraterrestrial impact

Uniformitarianism

• The present is the key to the past • Processes that are happening today have happened in the past

Examples of Viruses

• the common cold and different types of flu • measles, mumps, rubella, chicken pox, and shingles • hepatitis • herpes and cold sores • polio • rabies • Ebola, yellow fever, and Hanta fever • HIV, the virus that causes AIDS • Severe acute respiratory syndrome (SARS) • dengue fever, Zika, and Epstein-Barr • Some viruses lead to cancer e.g., human papilloma virus (HPV)