ESS - Geosphere

What is a magma chamber?

The pocket beneath a volcano where magma collects.

Alfred Wegener is at the origin of?

The continental drift theory.

What is the slip? In terms of earthquakes.

- The amount of displacement on a fault. - Directly related to the amount of energy released that creates seismic waves in an earthquake.

What is viscosity?

A liquid's resistance to flow.

What are the two ways to make magma?

- Subducting lithosphere to sufficient depth such that heat and pressure melt rocks. - Reducing pressure on rocks in the upper mantle, which melts them and enable the magma to rise to the surface at, for example, divergent plate boundaries.

What is the Mercalli Intensity Scale?

- The Modified Mercalli intensity scale, descended from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. - Measures what we feel.

The average density of the Earth is 5.52 g/cm3 and the density of Jupiter is 1.33 g/cm3. Recall that density = mass / volume. (a) If the volume of Jupiter is about 1.4 x 10^33 cm3, what is the mass of the planet? Express your mass in kilograms (kg). (b) Why is the Earth about four times more dense than Jupiter even though Jupiter is about 11 times larger in size?

(a) mass = density x volume: (1.33 g/cm3) * (1.4 x 10^33 cm3) = 1.86 x 10^33 g = 1.86 x 10^30 (b) Jupiter (and the other gas giant planets) are made mostly of hydrogen and helium, which are light, gaseous elements. - The Earth is made mostly of heavy elements such as Fe, Mg, Si, O, Al, and other elements heavier than hydrogen and helium. - So even though Earth is much smaller than Jupiter, the abundance of heavy elements makes it more dense.

What is a Doppler Shift/Effect? How do we see it between Earth and stars?

- A Doppler Shift is how light changes for an observer. - We see a red shift when stars move away from Earth because the wavelengths are being stretched. - There is a blue shift of stars are moving towards Earth and wavelengths are compressing.

What is used to measure the magnitude of an earthquake?

- A seismograph, or seismometer, is an instrument used to detect and record earthquakes. - Generally, it consists of a mass attached to a fixed base. - During an earthquake, the base moves and the mass does not. The motion of the base with respect to the mass is commonly transformed into an electrical voltage. The electrical voltage is recorded on paper, magnetic tape, or another recording medium. - This record is proportional to the motion of the seismometer mass relative to the earth, but it can be mathematically converted to a record of the absolute motion of the ground. - Seismograph generally refers to the seismometer and its recording device as a single unit.

What is a volcano?

- A weak spot in the crust where molten material, or magma, comes to the surface. - An eruption of magma that rises from the upper mantle or crust and break through the surface

Why are radioactive isotopes used in medical imaging?

- All radioactive isotopes emit radiation (i.e., high-energy gamma or X-rays) when they decay, although the hazard associated with the radiation varies depending on the radionuclide. - In very small quantities, the radiation produced by some radioactive isotopes is low enough to be used in medicine. - The radiation produced by the isotope can be tracked and turned into an image.

What is dark matter?

- An unknown substance which holds galaxies together, but doesn't emit any electromagnetic radiation. - Universe is expanding at an accelerating rate because of dark matter, because it is a gravitational force that repels rather than attracts.

What are the main planetary features of early Earth at the time of the origin of life? (Archean Era)

- Archean Era ~4.0-2.5 b.y. ago: The longest time period, early life began to form during this time. - Continents and other areas began to take shape. - There was still a lack of free oxygen before 2.7 b.y. ago, meaning early life didn't rely on oxygen as heavy. Oxygen was mainly taken up in the form of H2O (Water). - The Sun during this time was 30% less bright as it is today, enough of a reduction in solar radiation to freeze water; however, evidence shows that life existed at this time. - Scientists believe that a naturally high level of Co2 and Methane gases contributed to a concentration of greenhouse gases and warming. - Another prediction for why water did not freeze is that the large masses of water during this time were able to absorb more heat, keeping the temperatures up.

How can we find the isotope number of an element? i.e., find how many protons, neutrons, and electrons are in the element.

- Atomic Mass: Protons + Neutrons - Atomic Number: Just Protons - If the element is neutral, this makes the processes easy. The protons and electrons will be equal, while the neutrons will be (atomic mass - atomic number). - Example: What is the composition of a neutral element with an atomic number of 80 and atomic mass of 202? 202-80 = 122 , So: 80 Protons 80 Electrons 122 Neutrons

What are the chemical layers of the Earth?

- Crust: ~0-40 km in depth. 0.4% of Earth's mass. - Mantle: 40-2900 km in depth. 67.1% of Earth's mass. - Core: 2900-6370 km in depth. 32.5% of Earth's mass.

What affects earthquake aftermath damage?

- Earthquake aftermath damage can include fires, landslides, tsunamis. - Building and road construction practices can reduce or stop these affects.

What happens during radioactive decay?

- Energy is released. - The atom may change its atomic mass. - The nucleus of an atom spontaneously changes.

What is exponential decay/growth (radioactive dating and age dating)?

- Exponential Growth is growth whose rate becomes ever more rapid in proportion to the growing total number or size. - Exponential Decay is the opposite, decay slows as time passes. - Radioactive isotopes experience radioactive decay, where as half-lives pass, they decay slower. - Radioactive dating and age dating are both similar ideas, which state that we can use this decay to measure half-life of an elements to get precise ages of a mineral or rock.

What are foreshocks, mainshocks, and aftershocks?

- Foreshocks: Smaller magnitude earthquakes preceding the mainshock. - Mainshock: The largest magnitude earthquake. - Aftershock: Earthquakes that proceed the mainshock that can last for hours, days, weeks. - There is always a mainshock followed by aftershocks, but sometimes foreshocks don't occur.

Why do we think that our current atmosphere is of "secondary" origin (i.e., not the same composition as the atmosphere during the earliest stages of Earth history)?

- Heavy bombardment of Earth before ~3.9 b.y. would likely have driven off the atmosphere. - Geologic and isotopic evidence also indicates that there was no O2 in the earliest atmosphere.

What would happen to the ocean if the Earth received a huge impact compared to a medium impact. Where could life possibly survive from a huge impact?

- Huge impact vaporizes oceans. - Medium impact changes oceans chemistry. - Life might survive below the ground surface for a huge impact.

What is the hypocenter? What is the epicenter?

- Hypocenter: Location below the Earth's surface where earthquake starts. - Epicenter: Location directly above hypocenter on surface of the Earth.

What are hazards caused by active volcanoes?

- Lava flow - Acid rain - Volcanic bombs - Pyroclastic flow

What are the mechanical layers of the Earth?

- Lithosphere: ~0-100 km in depth. Strong, rocky outer shell of the solid Earth that comprises the thin crust and uppermost mantle. Forms the tectonics plates. - Asthenosphere: Weak, ductile layer of mantle beneath the lithosphere that deforms to accommodate the horizontal and vertical motions of plate tectonics. - Mesosphere (deep mantle): ~400-2900 km in depth. Mantle beneath the astehnosphere. - Outer core: ~2900-5150 km in depth. Liquid shell composed mainly of molten iron. - Inner core: ~5150-6370 km in depth. Inner sphere composed primarily of solid iron (a little nickel).

What is carbon dioxide?

- Major greenhouse gas - Is a colorless, odorless gas consisting of molecules made up of two oxygen atoms and one carbon atom. Carbon dioxide is produced when an organic carbon compound (such as wood) or fossilized organic matter, (such as coal, oil, or natural gas) is burned in the presence of oxygen.

How can we determine the age of rocks and minerals?

- Minerals contain very small amounts of naturally occurring radioactive isotopes (same protons, different neutrons) of elements, some that can take billions of years to decay. - When these isotopes are trapped in minerals as they crystallize, they act as atomic time-keepers.

What are five requirements for a substance to be called a mineral?

- Must be a solid under normal Earth conditions - Must be naturally formed, not man-made (plastic is not a mineral) - Must be inorganic (not coming or made of living things, such as coal, which is made from plants) - Must have a special chemical composition, meaning minerals are made up of chemical elements (fixed chemical formula) - Must have a characteristic crystal structure, that is , an orderly internal arrangement of atoms. All physical properties of a mineral result from the mineral's internal arrangement of atoms.

What kind of plate boundary is found at Hawaii?

- No plate boundary! - Plate motion over the stationary Hawaiian hotspot is recorded in extinct volcanoes on the ocean floor.

What is the Hadeon Era?

- Only life on Earth for first several billion years was single-celled. - We don't know exactly what Earth was like during this time, but through other clues we can make an estimate. - Hadeon Era ~4.6-4.0 b.y. ago: Era after the moon-forming impact. Earth was a molten ball that began to cool.

What is the composition and organization of our solar system?

- Planets 0.15%, Sun 99.85% - Terrestrial or "rocky planets" are first four (Mercury, Venus, Earth, Mars). - Jovian or "gas giants" are outer five (Jupiter, Saturn, Uranus, Neptune, Pluto).

What is the difference between the Richter Scale and MMI (Modified Mercalli Intensity Scale)?

- Richter scale measures the energy released in the form of a magnitude. - MMI is a measure of how much we feel the earthquake (shaking feeling).

What is an earthquake?

- Rocks under stress that suddenly fail along a fault in the Earth rupture and movement of rocks releasing energy generates seismic waves that we feel (shaking). - Earthquakes are occurring continually in the Earth's crust, but we only feel a small portion of them.

What is the Moon-Forming Impact?

- Says there was a Mars-sized collision with Earth about 4.51 bibliomaniac years ago. - Earth melted to the core. - Sped up Earth's rotation and tilted it 23 degrees. - The cause for seasons. - Ejected material was caught in Earth's gravitational field, creating the Moon.

Give two major differences between conditions on early Earth (before ~3.8 b.y.) and present-day Earth.

- Solar luminosity was about 25-30% less than present day. - Surface temperature was probably higher than present day (although we don't know by how much). - There was no (or very low) free oxygen (O2) in the atmosphere. - There was no (or very low) ozone (O3) in the stratosphere, and thus likely more ultraviolet (UV) radiation at the surface. - The amount of carbon dioxide (CO2) in the atmosphere was probably higher than present day. - There was a higher frequency of bolide (meteorites, asteroids, etc.) impacts. - Heat flow from the Earth's interior was higher (but not higher enough to compensate for lower solar luminosity.

What are the main differences between Early Earth (~4.5-3.8 b.y.) and Present Day Earth?

- Solar luminosity was ~30% less. - Geochemical evidence suggests surface temperatures on average were higher than today. - No free O2 molecules. High concentration of greenhouse gases. - No O2 meant no O3 (Ozone). More ultraviolet radiation hit Earth's surface. - Higher frequency of meterorite and asteroid hits until ~3.9 b.y. - Heat flow from Earth's interior was higher.

The most abundant isotope of mercury (Hg) has an atomic number of 80 and an atomic mass of 202. How many protons, neutrons, and electrons does a neutral (i.e., uncharged) atom of Hg-80 have?

- The atomic number is equal to the number of protons; therefore mercury has 80 protons. - The number of Neutrons = Atomic mass - atomic number: 202 - 80 = 122 neutrons - If the element is neutral, then the number of protons= the number of electrons: 80 protons = 80 electrons

What is a half-life?

- The consistent time it takes for half of the atoms of a radioactive parent isotope to convert to stable atoms of its daughter isotope. - Absolute age can be determined from half-life. - Can use Uranium and Potassium isotopes to date the age of the Earth. - Carbon14 is used to date living things, but has a short life-span.

How do earthquakes and volcanoes differ?

- The generation and movement of magma in the Earth prior to a major eruption can often be detected, as where earthquakes are typically undetectable. - Eruptions may last from days to months rather than seconds to minutes of an earthquake.

What is the Big Bang Theory?

- The idea that all matter and energy in the universe began in an unimaginably dense state, and then space itself began expanding. - Before the Big Bang, there was nothing (no time). - Not an explosion, an instantaneous appearance of time and space. - Estimated to have happens 13.7 billion years ago.

How can we find the earthquake focus?

- The larger the distance between P-waves and S-waves means there is a larger distance from the station measuring the waves to the actual earthquake focus. - This only gives a distance, meaning the focus could be anywhere within the radius of that distance. - By using three stations, the 3 radii will intersect at one point, marking the earthquake focus.

What is triangulation?

- The process of using angles from control points to determine the position of a place whose location is unknown. - In earthquakes, we use three stations to create a pinpoint of earthquake focus.

What is elastic rebound?

- The sudden return of deformed rock to its undeformed shape. - Says that stress builds up along a fault when the fault is locked. When the rock fails and the fault ruptures, the stress is reduced as energy is released. - Over time, stress builds up again and another earthquakes happens.

What is the Nebular Hypothesis?

- Theory for origin of the solar system. - Slowly revolving cloud of dust, ice, and gas (the primordial nebula) began to contract and eventually formed into a disk. As the disk collapsed and began to spin faster, most of its mass localized at the center and grew hotter, eventually becoming the sun. - As the primordial nebula flattened into a disk and most of its mass gravitated to the center, small chunks of matter further from the middle of the disk (called planetesimals) began to collide and to attract dust and rock to eventually grow into planets and moons. - This explains why the planets all revolve in nearly circular orbits, moving in the same direction and same plane. - In turn, the theory shows why the inner, or terrestrial, planets are rocky while the outer, Jovian, ones are gaseous, owing to the abundance of ice and gas as planet-forming elements in the outer fringes of the disk. - https://sciencing.com/primordial-nebula-4353.html

Why do we have seasons on Earth?

- We think that the Moon-forming impact was large enough to knock the Earth off of its vertical rotational axis. - Because of the current tilt of Earth's axis (~23°), slightly more solar radiation reaches either the northern hemisphere or the southern hemisphere in summer.

Are earthquakes logarithmic?

- Yes, each increment of the magnitude scale is an earthquake 10 times larger. Magnitudes are measured 10^(magnitude) - How many times larger is a magnitude 9 earthquake than a magnitude 7 earthquake? Divide magnitude 9 by magnitude 7 to subtract the exponents. 10^9 / 10^7 = 10^2 = 100 times larger.

What are shallow focus, intermediate focus, and deep focus earthquakes? What boundaries cause them?

-Convergent boundaries cause shallow, intermediate, and deep focus earthquakes as the oceanic plate is subducted under. -Transform boundaries cause shallow and intermediate focus earthquakes. Shallow focus: - Crustal earthquakes, occur near the surface. - Cause for the majority of large spread, destructive earthquakes; however, most are of magnitudes smaller than what we feel. Intermediate focus: - Between shallow and deep focus. Deep focus: - Intra plate earthquakes, caused by collision of plates. - Occur by oceanic plates after they are subducted.

What affects the shaking intensity you feel in an earthquake?

-Distance from earthquake focus. - Earthquake depth and seismic wave propagation through the Earth. - Rock types: Soft, water-filled sediments shake more; Hard bedrock shakes less. - Whether or not ground failure occurs (liquefaction, ground rupture).

What is liquefaction?

-The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud - Acts similar to when you feet move through sand when standing on the coastal water.

What is the age of the universe?

13.7 billion years old.

What is a fault?

A break in the earth's crust.

What is a pyroclastic flow?

A dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing downslope at great speed.

What is a debris flow?

A mudflow with many large rocks.

What is the Richter scale?

A scale that rates an earthquake's magnitude based on the size of its seismic waves.

What are fumaroles?

An opening in a planet's crust which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrogen chloride, and hydrogen sulfide. The steam forms when superheated water condenses as its pressure drops when it emerges from the ground.

What are minerals?

Building blocks of rocks of which the geosphere is made.

What are the general compositions of the Earth?

Core: - Inner Core is solid iron with little nickel - Outer Core is molten iron Mantle: - Mainly oxygen, silicon, and magnesium Crust: - Mostly oxygen and silicon

Describe the Transform sub-boundaries.

Crust not created or destroyed for both. Continental: - At transform faults, plates slip horizontally past each other. -Example: San Andreas Fault Mid-Ocean Ridge: - Mid-ocean ridges are typically offset by transform faults.

What are the three types of plate tectonic boundaries? What are their sub-boundaries? What are the relative plate motions associated with each plate tectonic boundary?

Divergent boundaries: - Oceanic spreading center - Continental rift zone Spread apart leaving gap for magma to flow up into a high point. Convergent boundaries: - Ocean-continent collision - Ocean-island arc collision - Continent-continent collision Collide, ocean plate goes up continent plate, or if two oceans plates, the denser of the two. Transform boundaries: - Continental - Mid-ocean ridge Slide past each other.

What does a cross-section at a plate tectonic boundary look like? What geological processes happen at each boundary?

Divergent: - Rift valley forms as crust splits. - Frequent earthquakes along strike rift. - Magma and hot rock flows up. Forms new crust in the gap. - Volcanoes can also form where magma flows up. Convergent: - Buckles edge of one or both plates up into a mountain range. - Other plate bends down into a deep sea trench. - Volcanoes form parallel to plate boundary. - Earthquakes shake on both sides of the boundary. - Continental crust is cracked and oceanic crust is destroyed. Transform: - Fault-valley or undersea canyon. - Earthquakes happen as plate slide past each other and get stuck by friction. - No magma is formed, no volcanoes. Crust is crumbled and broken.

Active Volcanoes show warning signs.

Earthquake tremors, bulges or elevation changes, changes in gas chemistry.

The rate of decay of a radioactive element changes over time.

False

What magma is more viscous: basalt magma (oceans or felsic magma (continents)?

Felsic magma is more viscous because it traps more gas because it can't escape while underground.

What is the rock cycle?

Forces deep inside Earth and at the surface produce a slow cycle that builds, destroys, and changes the rocks in the crust.

What is the most common gas in magma?

H20 Water Vapor.

What are three families of rocks?

Igneous: - Formed by cooling and consolidation of magma. - Magma forms deep underground, vents through surface by a volcano to become lava, and eventually cool. Sedimentary: - Formed either by chemical precipitation of material carried in solution in sea, lake, or river water; or by the decomposition of mineral particles transported in suspension by water, wind, or ice. Metamorphic: - Either igneous or sedimentary rocks that have been changed as a result of high temperatures, high pressures, or both.

You observe a Doppler shift of light from a galaxy that is moving to lower energy. Would this appear as a red shift or a blue shift?

Lower energy = longer wavelength = lower frequency = red shift

What are volcanic bombs?

Lumps of lava thrown out by volcanoes.

What determines the physical appearance of a rock?

Mineralogy: - Refers to the relative proportions of a rock's constituent material. Texture: - Describes the sizes and shapes of a rock's mineral crystals or grains and the way they are put together.

What is magma?

Molten rock beneath the earth's surface. Turns to lava when it reaches the surface.

What is the inner core of the Earth made of?

Mostly iron with a little nickel.

Explain the formation of the solar system.

Nebular Hypothesis. - Sun formed from a large mass of collapsing gas within an interstellar cloud under gravitational forces. - Outer gases and dusts (small particles, liquids) compressed (accretion) in the hot disk. - Dusts and later planetesimals (denser material) compressed closer to the Sun (due to gravity forces) and have the rocky planets. - Accretion of gases of the outer parts have the Gas Giants. - All planets formed at the same time from same material as the Sun.

Describe the Convergent sub-boundaries.

Ocean-Continent Collision (Convergence): - When oceanic lithosphere is subducted, and a volcanic mountain belt is formed at the continental margin. Ocean-Island Arc Collision (Convergence): - Where oceanic lithosphere meets oceanic lithosphere, the denser (older) plate is subducted under the other; a deep sea trench and a volcanic island arc are formed. Continent-Continent Collision (Convergence): - When two continents converge, the crust crumbles and thickens, creating high mountains and a wide plateau. - No subduction.

What is more dense: continental crust or oceanic crust.

Oceanic Crust.

Describe the Divergent sub-boundaries.

Oceanic spreading center: - Rifting and spreading along a mid-ocean ridge creates new oceanic lithosphere. - Example: Mid-Atlantic Ridge Continental Rift Zone: - Rifting and spreading zones on continent are characterized by parallel rift valleys, isolationism, and earthquakes.

Which part of Earth is thought to be liquid?

Outer core.

What exactly makes up Earth's crust?

Oxygen and Silicon make up 70% of continental crust by weight. 10 other elements make up 30%: - aluminum - iron - calcium - magnesium - potassium - titanium - hydrogen - manganese - phosphorus These elements (abundant elements) make up 99.27% of the crust. All remaining elements (scarce elements) make up 0.77%. - Abundant elements are largely responsible for the composition of common materials on Earth.

What are the three types of seismic waves?

P-waves (Primary Waves): - Compressional waves. - Move by compressing and expanding material (push and pull) in the direction the wave is traveling. - Travel the fastest out of all seismic waves. - Move faster than sound through solid rock 6-8 km/second. - Can travel through both solids and liquids. S-waves (Secondary Waves): - Shear waves. - Wave motion is perpendicular to the direction of wave travel (back/forth and up/down). - Travel at slower speeds through the Earth as p-waves, arrive after p-waves. - About half the speed of p-waves through rocks 3-4 km/second. - Can only travel through solids, not liquids. Surface waves: - Love or Rayleigh waves. - Go around the surface of the Earth. - Speed is less than s-waves. - Motion is either elliptical (similar to ocean waves, Rayleigh waves), or perpendicular (back/forth, Love waves), to the direction of wave travel.

What is a rock?

Rocks are formed either by the concentration of minerals or the cementation of non-mineral solid matter (i.e., obsidian, pumice, coal)

What are body waves?

Seismic waves that travel through the Earth's interior

Can volcanoes be explained through plate tectonics?

Similar to earthquakes, the location of active volcanoes and their styles of eruption are explained well withing frameworks of plate tectonic theory.

What is stress? In terms of earthquakes.

Stress is local force per unit area.

What two important factors determine whether volcanoes erupt violently?

The amount of gas trapped in the molten magma under pressure -As magma travels to the surface, pressure is reduce and gases are released, slowly or violently. Water vapor H20 make sup most volatile gas (70-95%). Viscosity of the magma (How freely it flows) - Mafic composition (i.e., basalt) less viscous. These are found in oceans, allowing pressure to escape more easy - Felsic composition (i.e., andesite or rhyolite) more viscous. These are found on land, pressure builds up as gases are trapped under the surface of the Earth. Less viscosity allows gas to escape as pressure releases during eruption. Thick viscosity traps gases, causing pressure until the gas explodes. - Gases only make up a small percent of the mass of magma, but they have a large effect on the amount of ash and volcanic materiel that explodes at surface.

What is Hubble's Law?

The faster a galaxy is moving, the farther away it is. V=H*d V - Velocity H - Hubble constant D - Distance

What is the continental drift theory?

The hypothesis that states the earth was once a super continent that divided and slowly drifted apart over millions of years.

Calculate the volume of the Earth's Core if the core is 32.5% of Earth's mass, the density of the Core is 11.5 g/cm^3, and the mass of the Earth is 6 * 10^27 g.

Volume = Mass/Density Density = Mass/Volume Mass = Volume * Density Vcore = Mcore /Dcore = (32.5% * (6 * 10^27g)) / (11.5 g/cm3) = 169.6 * 10^24 cm3

What is the style (flowing or exploding) of volcanic eruption based on?

Whether an eruption flows like a river or violently explodes is based on the composition of the magma and the concentration of volatile gases that are dissolved in the magma.

A rock was determined to be 1.5 billion years old by radiometric age dating. In the rock, the number of radioactive parent atoms measure was 125,000 atoms, and the number of daughter atoms was 875,000 atoms. a.) If you assume not no parent or daughter atoms were lost from the rock, how many half-lives have gone by? b.) What is the half-life of the radioactive isotope?

a.) Total atoms = 125,000 + 875,000 = 1,000,000 atoms 1st half-life: 1,000,000 / 2 = 500,000 atoms 2nd half-life: 500,000 / 2 = 250,000 atoms 3rd half-life: 250,000 / 2 = 125,000 atoms 3 half-life's went by. b.) The rock is 1.5 billion years old and 3 half-lives have gone by, so: 1.5 billion / 3 half-lives = 500 million years per half-life.

Name one measure or step that can be taken to lessen or minimize the destructive effect of an earthquake on humans and their built environment.

several answers; building construction most important

When did life emerged on Earth?

~3.8 billion years ago.

How old is the Earth?

~4.56 billion years old. Had to have formed before the moon-forming impact (3.8 b.y.) and around the same time as the formation of the solar system.