Lecture 1 - Planetary - Physical Geology.pdf

General Geology Planetary and Physical Geology H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY What is Geology? study of the earth, its composition, structure, and history and the processes that shaped the earth of the past and those that would continue to mold the earth of the present. H.D.A...

General Geology Planetary and Physical Geology H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY What is Geology? study of the earth, its composition, structure, and history and the processes that shaped the earth of the past and those that would continue to mold the earth of the present. H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY Hypothesis a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation Model hypothesis expressed as a visual or statistical simulation or as a description by analogy of phenomena or processes that are difficult to observe and describe directly Theory the widely accepted explanation for a group of known facts. A theory is a hypothesis that has been elevated to a high level of confidence by repeated confirmation through testing and experimentation; serendipity – finding something of a value purely by chance H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY Branch of Geology Two main division of Geology 1. PHYSICAL GEOLOGY examines Earth’s composition and processes occurring on and beneath its surface. 2. HISTORICAL GEOLOGY examines origin of the Earth origin of life and changes in Earth and life through time; deals with the layered rock record and fossils H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY Branch of Geology 1. PHYSICAL GEOLOGY ⮚ Volcanology ⮚ Seismology ⮚ Environmental Geology ⮚ Engineering Geology ⮚ Mining Geology ⮚ Petroleum Geology ⮚ Mineralogy ⮚ Petrology ⮚ Seismology ⮚ Geomorphology ⮚ Geophysics ⮚ Geochemistry ⮚ Planetary Geology H.D.A.Reyes Correlations 1 2. HISTORICAL GEOLOGY ⮚ Paleontology ⮚ Stratigraphy ⮚ Geochonology INTRODUCTION TO GEOLOGY ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ Concepts and Principles in Geology Theophrastus – Interpretation of fossils (372-287 BC) Shen Kua – Land Formation: Erosion of the mountains by deposition of silt (1031-1095) Georgius Agricola – First systematic treatise about mining and smelting work (De Re Metallica Libri XII, 1556) Jean-Etienne Guettard and Nicolas Desmarest – first Geologic maps; first observation of the volcanic origins of parts of France George Cuvier and Alexandre Brongniart – Stratigraphic succession of earth layers Alfred Wegener and Arthur Holmes – Continental Drift Theory Harry Hess – Theory of seafloor spreading William Morris Davis – Davisian geomorphology or Davis’ Theory. Cycle of Erosion Model. H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY Concepts and Principles in Geology ▪ Nicolas Steno - Three defining principles of stratigraphy ⮚ Law of Original Horizontality – Beds were deposited nearly horizontal due to gravitational pull. ⮚ Law of Superposition – The younger strata lies at the top of older strata. ⮚ Law of Lateral Continuity – Strata is deposited laterally until the sediment supply last or encounter any geologic barrier Law of Cross-cutting relationship - it was first established by Nicolas Steno, then later formulated by James Hutton and embellished upon by Charles Lyell. Law of Inclusion – Proposed by Charles Lyell: the rocks that was included is relatively older than the body that includes it. Law of Faunal Succession – William Smith: Ordering strata by examining the fossils contained in them H.D.A.Reyes Correlations 1 INTRODUCTION TO GEOLOGY Concepts and Principles in Geology • James Hutton – (1726-1797) – Scottish medical man, farmer, geologist, the “father of modern geology” ⮚ Plutonism (James Hutton) - rocks were formed by emplacement and solidification of lava from volcanoes ⮚ Neptunism (Abraham Werner) - rocks had settled out of a large ocean whose level gradually dropped over ⮚ Catastrophism (coined by William Whewell, proposed by Baron Georges Cuvier) - the Earth has been affected in the past by sudden, short-lived, violent events, possibly worldwide in scope ⮚ Uniformitarianism (coined by William Whewell, formulated by James Hutton, and popularized by Sir Charles Lyell) - assumption that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe: “The present is the key to the past.” ⮚ Actualism - many process that happened in the past are similar or identical to processes that happen today, but not necessarily at the same rate. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Big Bang Theory o contends that the Universe originated from a cosmic explosion (origin unknown) that hurled matter in all directions 15 and 20 billion years ago at incredible speeds began to cool and condense into the first stars and galaxies. o First proposed by the Belgian priest Georges Lemaître in the 1920s o Edwin Hubble justified Lemaître’s theory through observations that the Universe is continuously expanding; galaxies are moving away from each other H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Nebular Theory o Is an explanation for the formation of solar systems. The word “nebula” is Latin for “cloud,” and according to the explanation, stars are born from clouds of interstellar gas and dust. The transition from an undifferentiated cloud to a star system complete with planets and moons takes about 100 million years. According to this theory, our own solar system formed about 4.6 billion years ago, and others are forming today in distant nebulae H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Planetesimal Theory ⮚ Put forth by Viktor Safronov in 1941, explains planet formation in the early solar system from accretion of small bodies, growing in size as gravity attracted more and more objects. As the small bodies orbit, their gravity is very weak and they must rely on nongravitational forces to stay together, such as radiation pressure and the emission of thermal photons. ⮚ Growth of the small planetesimal caused the strength of its gravity to increase. Growth to approximately one km in size allowed the gravity of planetesimals to attract objects to them, increasing their size to seeds for planetary formation. ⮚ Collisions were common during the formation of the solar system and planets. Planetesimals continually collided and destroyed each other, but some planetesimals were able to withstand the impacts and grow, eventually forming into planets. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Universe – The totality of space and time – past, present, and future Galaxies – An enormous collection of heavenly bodies held together by gravitational attraction. Each galaxy is light year apart from each other. Light year – the distance traveled by light in one year Speed of Light – 3x10^5 km/sec 1 light year = 9.4x10^12 km H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY Evidence for the expansion of the Universe ✔ There is evidence that the universe is expanding, based on the study of light signals ✔ The light signal from a galaxy is separated into its component wavelengths by passing through a prism device called a spectroscope ✔ The result is a broad play of colors called a spectrum. Each gaseous element emits a characteristic wavelength; thus, they can be identified. ✔ Comparing the spectra of galaxies to that of the Sun as reference, the spectral lines of the galaxies are displaced towards the long-wave end of the spectrum – the red end. This phenomenon is called the red shift. This is evidence that galaxies are moving apart. Therefore, the universe is expanding. ✔ The magnitude of a red shift is directly proportional to the velocity with which the source is receding from the observer. ✔ Galaxies displaying the greatest red shifts are also the farthest from the Earth. ✔ The fastest or most distant galaxies are receding at velocities close to the speed of light. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Sun The Solar System ⮚ The largest object in the solar system (99.8%) ⮚ The surface of the Sun, called the photosphere, is at a temperature of about 5800 K. Sunspots are "cool" regions, only 3800 K (they look dark only by comparison with the surrounding regions). Sunspots can be very large, as much as 50,000 km in diameter. Sunspots are caused by complicated and not very well understood interactions with the Sun's magnetic field. ⮚ A small region known as the chromosphere lies above the photosphere. ⮚ The highly rarefied region above the chromosphere, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K. ⮚ Yellow Dwarf star H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Asteroids - Are rocky, airless worlds that orbit our sun, but are too small to be called planets. Tens of thousands of these minor planets are gathered in the main asteroid belt, a vast doughnut-shaped ring between the orbits of Mars and Jupiter. Stars - A luminous sphere of plasma held together by its own gravity. Super Nova an astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion. H.D.A.Reyes Correlations 1 Planetary Geology and Earth's System • • • Comet - are icy bodies in space that release gas or dust. Meteor - known colloquially as a "shooting star" or "falling star", is the visible passage of a glowing meteoroid. Meteorite - a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon The Solar System Source:http://astrobob.areavoices.com/2017/08/30/s ee-florence-one-of-largest-near-earth-asteroids-zipby-earth/ Source:http://zeenews.india.com/space/skywatchers -can-enjoy-a-dazzling-meteor-shower-this-week2064586.html Source:https://www.dkfindout.com/uk/space/s olar-system/comets/ Source:http://www.arizonaskiesmeteorites.com/AZ _Skies_Links/Meteorite_Photos/Stony_Irons/Pallas ites/index.html PLANETARY GEOLOGY The Solar System What is the Brightest star you see in the sky? Sirius, “Dog Star” What is The largest star? VY Canis Majoris A blue supergiant that is the brightest star in the constellation Orion. Rigel Star Bright red star in the Orion which is nearing to its end. Betelgeuse H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Planets - a celestial body moving in an elliptical orbit around a star. 1. Terrestrial planets – relatively small, dense, rocky planets closest to the Sun (Mercury, Venus, Earth, Mars) – and their satellites, and a belt of asteroids, which are small, planet-like bodies in orbit beyond mars. 2. Jovian planets – large, low density planets farthest from the Sun (Jupiter, Saturn, Neptune, Uranus and their satellites) whose outer layers are composed mainly of frozen or liquid hydrogen, helium, ammonia and methane. Comets – Jan Oort, a Dutch astronomer, showed in 1950 that comets form a diffuse spherical cloud located in the far reaches of the Solar System. Some comets periodically swoop toward the Sun and retreat again. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Criteria of a planet: ❑ is in orbit around the Sun ❑ has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape ❑ has cleared the neighborhood around its orbit. ❑ not massive enough to induce thermonuclear fusion, thereby, making it a star. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Haumea Source: http://deskarati.com/2013/10/17/scale-model-of-the-solar-system/ H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Natural Satellites • Moon - is any celestial body in space that orbits around a larger body Planet No Mercury 0 Venus 0 Earth 1 Luna Mars 2 Phobos and Deimos Jupiter 79 Ganymede(Largest moon), Callisto, Io, Europa, etc. Saturn 82 Titan, Rhea, Iapetus, etc. Uranus 27 Titania, Oberon, Umbriel, Ariel, Miranda, etc. Neptune 14 Triton, Proteus, Nereid, etc. Pluto 5 Charon, Hydra, Nix, Kerberos, Styx Source: http://www.go-astronomy.com/planets/planet-moons.htm H.D.A.Reyes Correlations 1 Names PLANETARY GEOLOGY The Solar System • • • • Mercury The fastest planet, zipping around the Sun every 88 Earth days. Mercury spins slowly on its axis and completes one rotation every 59 Earth days. Mercury has a central core, a rocky mantle and a solid crust. Instead of an atmosphere, Mercury possesses a thin exosphere made up of atoms blasted off the surface by the solar wind and striking meteoroids. Mercury's exosphere is composed mostly of oxygen, sodium, hydrogen, helium and potassium. H.D.A.Reyes Correlations 1 Source: https://phys.org/news/2015-02-important-planet-mercury.html PLANETARY GEOLOGY The Solar System Venus • The hottest planet in our solar system with surface temperatures hot enough to melt lead due to its thick atmosphere traps heat in a runaway greenhouse effect. • Glimpses below the clouds reveal volcanoes and deformed mountains. • Venus has a central core, a rocky mantle and a solid crust. Source: https://cosmosmagazine.com/space/venus-may-have-hosted-liferesearchers-say H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System • • • • • Venus Venus' atmosphere consists mainly of carbon dioxide, with clouds of sulfuric acid droplets. The highest mountain on Venus, Maxwell Montes, is 20,000 feet high. Alta Regio - a complex dome of shield volcanoes. Thetis Regio - a highland plateau created by crustal compression Chasmata - prominent canyons Source: https://cosmosmagazine.com/space/venus-may-have-hosted-liferesearchers-say H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Earth • Earth is the third planet from the Sun and the fifth largest in the solar system. • the biggest of the terrestrial planets Source: https://titan.uio.no/node/1749 H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Mars • Mars is one of the most explored bodies in our solar system, and it's the only planet where we've sent rovers to roam the alien landscape. • The Egyptians called it "Her Desher," meaning "the red one.“ • It is frequently called the "Red Planet" because iron minerals in the Martian dirt oxidize, or rust, causing the surface to look red. Source: https://space-facts.com/mars/ H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Mars • A large canyon system called Valles Marineris is long enough to stretch from California to New York—more than 4,800 km. This Martian canyon is 320 km at its widest and 7 km at its deepest. That's about 10 times the size of Earth's Grand Canyon. • Mars is home to the tallest shield volcano in the solar system, Olympus Mons. It's three times taller than Earth's Mt. Everest with a base the size of the state of New Mexico. • Alba Patera is the largest volcano in terms of base diameter. H.D.A.Reyes Correlations 1 Source: https://space-facts.com/mars/ PLANETARY GEOLOGY The Solar System Ceres • Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter and the only dwarf planet located in the inner solar system. • Ceres is so much bigger and so different from its rocky neighbours that scientists classified it as a dwarf planet in 2006. • Ceres is one of the few places in our solar system where scientists would like to search for possible signs of life. Ceres has something a lot of other planets don't: water. H.D.A.Reyes Correlations 1 Source: https://solarsystem.nasa.gov/planets/dwarfplanets/ceres/overview/ / PLANETARY GEOLOGY The Solar System Jupiter • The largest planet in the solar system – more than twice as massive as all the other planets combined. • Jupiter's stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium. • Jupiter’s iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years. Source: https://www.slashgear.com/scientists-discover-12-new-jupitermoons-describe-one-as-an-oddball-17537978/ H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Jupiter • On Jul. 17, 2018, scientists announced they had discovered 12 new moons orbiting Jupiter. That raised Jupiter’s total number of moons to 79—the most of any planet in the solar system. Fiftythree of the moons are confirmed and named; the other 26 are awaiting official confirmation of discovery before they are named. • Jupiter also has several rings, but unlike the famous rings of Saturn, Jupiter’s rings are very faint and made of dust, not ice. H.D.A.Reyes Correlations 1 Source: https://www.slashgear.com/scientists-discover-12-new-jupitermoons-describe-one-as-an-oddball-17537978/ PLANETARY GEOLOGY The Solar System • • • • Saturn Saturn is the sixth planet from the Sun and the second largest planet in our solar system. Adorned with a dazzling system of icy rings, Saturn is unique among the planets. Surrounded by more than 82 known moons. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium. At Saturn's center is a dense core of metals like iron and nickel surrounded by rocky material and other compounds solidified by the intense pressure and heat. It is enveloped by liquid metallic hydrogen inside a layer of liquid hydrogen—similar to Jupiter's core but considerably smaller. H.D.A.Reyes Correlations 1 Source: https://solarsystem.nasa.gov/planets/saturn/overview/ PLANETARY GEOLOGY The Solar System Uranus • Uranus is very cold and windy. The ice giant is surrounded by 13 faint rings and 27 small moons as it rotates at a nearly 90-degree angle from the plane of its orbit. This unique tilt makes Uranus appear to spin on its side, orbiting the Sun like a rolling ball. • The first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star. • Uranus gets its blue-green color from methane gas in the atmosphere. H.D.A.Reyes Correlations 1 Source: https://solarsystem.nasa.gov/planets/uranus/overview/ PLANETARY GEOLOGY • • • • The Solar System Neptune Dark, cold and whipped by supersonic winds, ice giant Neptune is the eighth and most distant planet in our solar system. Sometimes Neptune is even farther from the Sun than dwarf planet Pluto. Pluto's highly eccentric, oval-shaped orbit brings it inside Neptune's orbit for a 20-year period every 248 Earth years. This switch, in which Pluto is closer to the Sun than Neptune, happened most recently from 1979 to 1999. Pluto can never crash into Neptune, though, because for every three laps Source: https://solarsystem.nasa.gov/planets/neptune/overview/ Neptune takes around the Sun, Pluto makes two. This repeating pattern prevents close approaches of the two bodies H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Neptune • Neptune's atmosphere is made up mostly of hydrogen and helium with just a little bit of methane. • Neptune is our solar system's windiest world. Despite its great distance and low energy input from the Sun, Neptune's winds can be three times stronger than Jupiter's and nine times stronger than Earth's. • In 1989 a large, oval-shaped storm in Neptune's southern hemisphere dubbed the "Great Dark Spot" was large enough to contain the entire Earth. That storm has since disappeared, but new ones have appeared on different parts of the planet. H.D.A.Reyes Correlations 1 Source: https://solarsystem.nasa.gov/planets/neptune/overview/ PLANETARY GEOLOGY The Solar System Pluto • Pluto is a complex and mysterious world with mountains, valleys, plains, craters, and maybe glaciers. Discovered in 1930, Pluto was long considered our solar system's ninth planet. But after the discovery of similar intriguing worlds deeper in the distant Kuiper Belt, icy Pluto was reclassified as a dwarf planet. • Pluto is orbited by five known moons, the largest of which is Charon. Charon is about half the size of Pluto itself, making it the largest satellite relative to the planet it orbits in our solar system. Pluto and Charon are often referred to as a "double planet”. • 2377 km - diameter H.D.A.Reyes Correlations 1 Source: https://www.sporcle.com/blog/2018/04/what-is-pluto-and-is-plutoa-planet/ PLANETARY GEOLOGY The Solar System Pluto • Is Pluto a Planet? NIETHER ✔ Terrestrial planets are made up (mostly) of metal (iron) and rocks (silicates) and it has too small of a density to be considered a terrestrial planet. ✔ Jovian planets are giant gas balls not unlike the SUN although they have a small rocky central core. Pluto is a rock ice planet---more like Europa, a satellite of Jupiter. ✔ Pluto is made up of rock, and ice, and no gas. H.D.A.Reyes Correlations 1 Source: https://www.sporcle.com/blog/2018/04/what-is-pluto-and-is-plutoa-planet/ PLANETARY GEOLOGY The Solar System H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Rotation of planets with their respective axis H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Rotation of planets with their respective axis 39 Source: https://i.pinimg.com/originals/ a2/de/33/a2de33efa88833c8a0 7f449f715978f4.gif PLANETARY GEOLOGY The Solar System From smallest to largest MMVenusJ H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System From smallest to largest Source: https://cdn.britannica.com/93/95393-050-5329EE11/planets-distance-order-Sun.jpg H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Solar System Density H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Last Portion of the Solar System • • Oort Clouds The Oort Cloud is believed to be a thick bubble of icy debris that surrounds our solar system. In 1950, Dutch astronomer Jan Oort first proposed the idea of this sphere of icy bodies to explain the origins of comets with that take thousands of years to orbit the Sun. These are called long-period comets and most have been seen only once in recorded history. More frequent visitors to the inner solar system are called shortperiod comets. The Oort Cloud was named for Oort. H.D.A.Reyes Correlations 1 Source: https://solarsystem.nasa.gov/solar-system/oort-cloud/overview/ PLANETARY GEOLOGY Astronomical Terms to Remember • Black hole - A concentration of mass so dense that nothing — not even light — can escape its gravitational pull once swallowed up. Many galaxies (including ours) have supermassive black holes at their centers. • Eclipse - An event that occurs when the shadow of a planet or moon falls upon a second body. ❑ Solar eclipse occurs when the Moon’s shadow falls upon Earth, which we see as the Moon blocking the Sun. ❑ When Earth’s shadow falls upon the Moon, it causes a lunar eclipse. Source: https://www.skyandt elescope.com/observin g/red-moon-meetsred-planet-for-lunareclipse/ H.D.A.Reyes Correlations 1 Source: https://www.nissanof melbourne.com/blog/w hen-is-the-solareclipse-in-melbournefl/solar-eclipsediagram_b PLANETARY GEOLOGY Astronomical Terms to Remember • Equinox - The two times each year, near March 20th and September 22nd, when the Sun is directly overhead at noon as seen from Earth’s equator. On an equinox date, day and night are of equal length. • Solstice - The two times each year, around June 20th and December 21st, when the Sun is farthest north or south in the sky. Source: https://www.weather.gov/cle/seasons ❑ At the summer solstice, the day is longest and the night is shortest, and vice versa at the winter solstice. • Parallax - The apparent offset of a foreground object against the background when your perspective changes. At a given instant, the Moon appears among different stars for observers at widely separated locations on Earth. Astronomers directly calculate the distance to a nearby star by measuring its incredibly small positional changes (its parallax) as Earth orbits the Sun. H.D.A.Reyes Correlations 1 Source: https://www.gaia.ac.uk/science/parallax PLANETARY GEOLOGY Astronomical Terms to Remember • Apogee - the farthest point from the earth. • Perigee - the closest point to the earth and it is in this stage that the moon appears larger. ❑ The apogee and perigee of the moon have an effect on the tides here on Earth. When the moon is at apogee, the furthest distance from the Earth, it has less gravitational pull which, along with other factors that influence the tides, can contribute to lower tides or lower variation in the high/low tide level. When the moon is at perigee, closer to the Earth, there is much more gravitational pull which contributes to the opposite effect: higher tides or greater variation in the high and low tide. H.D.A.Reyes Correlations 1 Source: https://www.universallifetools.com/2017/01/super-moonsmeaning-spiritual-micro-moons-2017/ PLANETARY GEOLOGY Astronomical Terms to Remember • The Earth is closest to the Sun, or at the perihelion, about 2 weeks after the December Solstice, when it is winter in the Northern Hemisphere. • Conversely, the Earth is farthest away from the Sun, at the aphelion point, 2 weeks after the June Solstice, when the Northern Hemisphere is enjoying warm summer months. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY Astronomical Terms to Remember • The penumbra is a half-shadow that occurs when a light source is only partly covered by an object – for example, when the Moon obscures part of the Sun's disk. • Umbra – the shadow's dark center portion. • Antumbra – the lighter part of the shadow that begins where the umbra ends. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY • • • • • • • The Moon The fifth largest moon in the solar system. Earth's moon is the only place beyond Earth where humans have set foot. It is one of the responsible things why we have tides. Radius - 1,737.5 km 384,400 km away from the Earth (The moon is slowly moving away from Earth, getting about an inch farther away each year) The moon makes a complete orbit courtesy of NASA around Earth in 27 Earth days and Photo Source: https://www.decodedscience.org/full-moons-crime-aka-lunareffect-real-deal-pseudoscience/41881 rotates or spins at that same rate. It appears to orbit us every 29 days. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY • • • • • The Moon It has a core, mantle and crust. The solid, iron-rich inner core is 240 km in radius. It is surrounded by a liquid iron shell 90 km thick. A partially molten layer with a thickness of 150 km surrounds the iron core. It has a crust with a thickness of 70 to 150 km Long ago the moon had active volcanoes, but today they are all dormant and have not erupted for millions of years. Photo courtesy of NASA Source: https://www.decodedscience.org/full-moons-crime-aka-lunareffect-real-deal-pseudoscience/41881 H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Moon • Equatorial Radius: 1737.5km • Density: 3.344g/cm3 • Inclination: 6.68 degrees • Age: 4.53 billion years Photo courtesy of NASA Source: https://www.decodedscience.org/full-moons-crime-aka-lunareffect-real-deal-pseudoscience/41881 H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY • • • • The Moon Lunar regolith - rubble pile of charcoal-gray, powdery dust and rocky debris that covers the moon due to series of impacts. The surface of the moon is characterized by regions named maria (Latin for seas), which are dark-colored basaltic lowland regions due to are impact basins that were filled with lava between 4.2 and 1.2 billion years ago. the lunar highlands representing older and much more cratered crust. courtesy of NASA The moon is one-sixth of Earth's, Photo Source: https://www.decodedscience.org/full-moons-crime-aka-lunarwhich is why in footage of effect-real-deal-pseudoscience/41881 moonwalks, astronauts appear to almost bounce across the surface. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Moon • How does the moon formed? Photo courtesy of NASA Source: https://www.decodedscience.org/full-moons-crime-aka-lunareffect-real-deal-pseudoscience/41881 H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY Earth’s Moon Formation of the Moon ⮚ The Fission Theory: This theory proposes that the Moon was once part of the Earth and somehow separated from the Earth early in the history of the solar system. ⮚ The Capture Theory: This theory proposes that the Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth. ⮚ The Condensation Theory: This theory proposes that the Moon and the Earth condensed individually from the nebula that formed the solar system, with the Moon formed in orbit around the Earth. Source: https://spaceplace.nasa.gov/review/all-about-the-moon/moon_rotation.en.gif 54 PLANETARY GEOLOGY The Earth and Moon Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no oxygen and so would have been toxic to most modern life including humans. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. A giant impact collision with a planet-sized body named Theia while Earth was in its earliest stage, also known as Early Earth, is thought to have been responsible for forming the Moon. Over time, the Earth cooled, causing the formation of a solid crust, and allowing liquid water to exist on the surface. H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY Earth’s Moon Formation of the Moon ⮚ The Giant Impactor Theory (sometimes called The Ejected Ring Theory): This theory proposes that a planetesimal (or small planet) the size of Mars struck the Earth just after the formation of the solar system, ejecting large volumes of heated material from the outer layers of both objects. A disk of orbiting material was formed, and this matter eventually stuck together to form the Moon in orbit around the Earth. This theory can explain why the Moon is made mostly of rock and how the rock was excessively heated. Furthermore, we see evidence in many places in the solar system that such collisions were common late in the formative stages of the solar system. This theory is discussed further below. Source: https://www.scienceabc.com/wp-content/uploads/2017/03/Moon-formation-imagerotation-earth-theia-celestial-fragments-space-universe_.jpg 56 PLANETARY GEOLOGY The Earth and Moon H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Earth and Moon H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Earth and Moon H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY The Earth and Moon H.D.A.Reyes Correlations 1 PLANETARY GEOLOGY Moonquake Lunar equivalent of an earthquake. Four Different Kinds of Moonquakes: 1. deep moonquakes about 700 km below the surface, probably caused by tides 2. vibrations from the impact of meteorites 3. thermal quakes caused by the expansion of the frigid crust when first illuminated by the morning sun after two weeks of deep-freeze lunar night 4. shallow moonquakes only 20 or 30 kilometers below the surface. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Atmosphere - the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ The lowest layer of the Earth’s atmosphere ⮚ It extends from Earth's surface to an average height of about 12 km, although this altitude actually varies from about 9 km (30,000 ft) at the poles to 17 km (56,000 ft) at the equator, with some variation due to weather. ⮚ The troposphere contains roughly 80% of the mass of Earth's atmosphere ⮚ The troposphere is denser than all its overlying atmospheric layers because a larger atmospheric weight sits on top of the troposphere and causes it to be most severely compressed ⮚ Nearly all atmospheric water vapor or moisture is found in the troposphere, so it is the layer where most of Earth's weather takes place. It has basically all the weather-associated cloud genus types generated by active wind circulation, although very tall cumulonimbus thunder clouds can penetrate the tropopause from below and rise into the lower part of the stratosphere H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: High-Level Clouds (Above 6 kms): ❑ Cirrus clouds are feathery, wispy formations made up of very minute ice crystals. Cirrus clouds reveal the presence of moisture at great heights and may indicate an onset of bad weather. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: High-Level Clouds (Above 6 kms): ❑ Cirrostratus clouds are high altitude clouds made up of tiny ice crystals. Cirrostratus clouds have a thin-layered formation through which the sun’s rays pass, creating a halo like an effect. They indicate a rainy spell. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: High-Level Clouds (Above 6 kms): ❑ Cirrocumulus clouds are also high altitude clouds but these are formed when two layers of clouds move in directions opposite to each other. They also indicate unsettled weather. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Middle-Level Clouds (Between 3-6 kms): ❑ Altocumulus Clouds are thick, fluffy, middle altitude clouds that are a patchy white and grey in colour. Though they look like cirrocumulus clouds. Altocumulus clouds indicate sunny spells. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Middle-Level Clouds (Between 3-6 kms): ❑ Altostratus Clouds are clusters of bluish-grey clouds indicate that there may be rain head H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Low-Level Clouds (Below 3 kms): ❑ Cumulus is thick low altitude clouds are usually puffy and have very distinct edges and a noticeable vertical development. They look like heaped up cotton and have interesting shapes. They indicate sunny weather. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Low-Level Clouds (Below 3 kms): ❑ Stratus clouds - These low altitude clouds are responsible for dull, gloomy, overcast days and they indicate rainy weather. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Multi-layered Clouds (Rainy Clouds): ❑ Nimbostratus clouds are considered as low clouds, Nimbostratus clouds are actually multilayered clouds, as their vertical extent goes well into the middle cloud region and they often have taller cumulonimbus clouds embedded with them, found at a height up to 2000m. These dark grey rain or snow bearing clouds cover the sky so completely that one cannot see the sun. They indicate a long spell of heavy rain or snow. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Troposhere ⮚ Type of clouds: Multi-layered Clouds (Rainy Clouds): ❑ Cumulonimbus clouds produce lightning, thunder, heavy rain, hail, strong winds and tornadoes. The tallest among all clouds, cumulonimbus clouds span all cloud layers and extend above 2000m. These clouds usually have large anvil-shaped tops, which form because of the stronger winds at the higher levels of the atmosphere. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Stratosphere ⮚ The atmospheric pressure at the top of the stratosphere is roughly 1/1000 the pressure at sea level. ⮚ It contains the ozone layer, which is the part of Earth's atmosphere that contains relatively high concentrations of that gas. ⮚ The stratosphere defines a layer in which temperatures rise with increasing altitude. This rise in temperature is caused by the absorption of ultraviolet (UV) radiation from the Sun by the ozone layer. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Mesosphere ⮚ Temperatures drop with increasing altitude to the mesopause that marks the top of this middle layer of the atmosphere. It is the coldest place on Earth and has an average temperature around −85 °C ⮚ Just below the mesopause, the air is so cold that even the very scarce water vapor at this altitude can be sublimated into polar-mesospheric noctilucent clouds. ✔ Noctilucent clouds also known as night clouds are tenuous cloud-like phenomena in the upper atmosphere. They are visible in a deep twilight. They are made of ice crystals. Noctilucent roughly means night shining in Latin ⮚ The mesosphere is also the layer where most meteors burn up upon atmospheric entrance. ⮚ It is too high above Earth to be accessible to jetpowered aircraft and balloons, and too low to permit orbital spacecraft. The mesosphere is mainly accessed by sounding rockets and rocket-powered aircraft. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Thermosphere ⮚ The temperature of the thermosphere gradually increases with height. Unlike the stratosphere beneath it, wherein a temperature inversion is due to the absorption of radiation by ozone, the inversion in the thermosphere occurs due to the extremely low density of its molecules. ⮚ The temperature of this layer can rise as high as 1500 °C (2700 °F), though the gas molecules are so far apart that its temperature in the usual sense is not very meaningful. ⮚ This layer is completely cloudless and free of water vapor. However, nonhydrometeorological phenomena such as the aurora borealis and aurora australis are occasionally seen in the thermosphere. The International Space Station orbits in this layer, between 350 and 420 km. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth :Atmosphere Exosphere ⮚ The exosphere is the outermost layer of Earth's atmosphere. It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km where it merges into the solar wind. ⮚ This layer is mainly composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen and carbon dioxide closer to the exobase. ⮚ the exosphere no longer behaves like a gas, and the particles constantly escape into space. These freemoving particles follow ballistic trajectories and may migrate in and out of the magnetosphere or the solar wind. ⮚ The exosphere contains most of the satellites orbiting Earth. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth : Hydrosphere ⮚ all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth : Biosphere ⮚ is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, geosphere, hydrosphere, and atmosphere. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of the Earth How those layers Formed? • Models for the Earth’s accretion and its differentiation into a primitive mantle and core. ❑ Homogeneous accretion ❑ Heterogeneous accretion ❑ Magma ocean model ✔ Differentiation A process by which random chunks of primordial matter were transformed into a body whose interior is divided into concentric layers that differ from one another both physically and chemically Occurred early in the Earth’s history when the planet got hot enough to melt ✔ Accretion The process of growth or increase, typically by the gradual accumulation of additional layers of matter H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of the Earth How those layers Formed? ❑ Homogeneous accretion (Ringwood,1979) ▪ 2-stage process: i) Accretion of a homogeneous or undifferentiate d proto-Earth and ii) Subsequent differentiation into a metallic core and silicate mantle H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of the Earth How those layers Formed? ❑ Heterogeneous accretion (Turkenian and Clark, 1969) ▪ Planet growth by simultaneous condensation and accretion of various compounds as the temperature fell inside an originally hot Solar Nebula H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of the Earth How those layers Formed? ❑ Magma ocean model ▪ Earth experienced large scale melting and developed one or more magma oceans late in its accretion ▪ Melting was probably caused by heating due to collisions among the accreting planetesimals, radioactive decay of short-lived nuclides and the greenhouse effect of the evolving atmosphere H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of the Earth How those layers Formed? ❑ Magma ocean model H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Layers Based on Composition (Geochemistry) The Crust consists of: 1) The continental crust - relatively light “granitic” rock that includes the oldest rock of the crust; generally richer in Na and K; thickness ranges from 30 to 80 km, sometimes attaining 100 km in some portions. 2) The oceanic crust - composed of dark, dense volcanic rocks (basalt) with densities much greater than that of granite; more Fe-rich than the continental crust and thinner, ranging from 3 to 10 km in thickness; young and relatively undeformed by folding. The Mantle - surrounds or covers the core; constitutes the great bulk of Earth (82% of its volume and 68% of its mass); composed of iron and magnesium silicate rock. The Core - central mass about 7000 km in diameter; density increases with depth but averages about 10.78 g/cm3; constitutes only 16% of Earth’s volume but accounts for 32% of Earth’s mass; mostly composed of iron. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Internal Layers Based on Physical Properties Lithosphere - the strong rigid outer layer consisting of the crust and a portion of the upper mantle. Asthenosphere (“weak sphere”)- a major zone within the upper mantle where temperature and pressure are at just the right balance so that part of the material melts. The rocks become soft plastic in behavior and flowing like warm tar. The boundary between the lithosphere and the asthenosphere is distinct but does not correspond to a compositional change but due to a major change in the physical properties of the rock. It is as much as 200 km thick. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Outer Core - The outer core is a liquid layer 2270 km thick. It is the movement of metallic iron within this zone that generates Earth’s magnetic field. Inner Core - is a sphere having a radius of 1216 km. Despite its higher temperature, the iron in the inne rcore is solid due to the immense pressures that exist in the center of the planet. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth The Core Inner and Outer Core H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Mohorovicic Discontinuity (Seismic Moho) • Boundary between crust and mantle. • At this discontinuity, P wave increase from 7 to 8 km/sec • Disappearance of Feldspar Low Velocity Zone (LVZ) • 60-220 km • Seismic wave slightly slows down compared to the velocity from its top and bottom. • It slows down because of 1 to 10% partial melting of the mantle. • It varies in thickness depending on the local pressure, temperature, melting point, and availability of H2O Transition Zone • 410 to 660 km • Phase transition of olivine to spinel type structure • Transition of silicate. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth Transition Zone H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Layers of Earth H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics The Earth’s lithosphere floats on the denser, plastic asthenosphere beneath, and it rises and sinks in attempts to maintain equilibrium. • Tectonics – study of the origin and arrangement of the broad structural features of the earth’s surface (e.g., continents, mountain belts, island arcs, earthquake belts, faults, folds, etc.) . • Plate – a large, mobile slab of rock that is part of the earth’s surface. It may be made up entirely of sea floor (e.g., Nazca plate) or both continental and seafloor (e.g., North American plate). • Plate tectonics – the principle that the earth’s surface is divided into large, thick plates that move slowly and change size relative to one another. • Plate boundary – narrow areas of intense geologic activity where plates move away from one another, past one another or toward one another H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Plate Tectonics Theory ▪ ▪ Formulated by Alfred Wegener, in full Alfred Lothar Wegener, (born November 1, 1880, Berlin, Germany—died November 1930, Greenland), German meteorologist and geophysicist. More than 50 years passed before enough data were gathered to transform this controversial hypothesis into a sound theory that wove together the basic processes known to operate on Earth. Photos.com/Jupiterimages Source : https://www.britannica.com/biography/Alfred-Wegener H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics: Plate Boundaries Diverging Plate Boundary ▪ A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates. ▪ Constructive or Extensional Boundary 1. Continental extension 2. Continental rifting 3.Ocean spreading H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics: Plate Boundaries Converging Plate Boundary ▪ A region of active deformation where two or more tectonic plates or fragments of the lithosphere near the end of their life cycle. ▪ Destructive Plate Boundary ▪ Ocean-Ocean Convergence H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics: Plate Boundaries Converging Plate Boundary ▪ Ocean-Continent Convergence H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics: Plate Boundaries Converging Plate Boundary ▪ Continent-Continent Convergence 1. Ocean-continent convergence 2. Ocean closing 3. Continent-continent collision H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics: Plate Boundaries Transform Plate Boundary ▪ ▪ ▪ where one plate slides horizontally past another plate along a fault or a group of parallel faults. Conservative Plate Boundary the displacement along the fault abruptly ends or transforms into another kind of displacement MOR MOR H.D.A.Reyes Correlations 1 MORTrench Trench -trench PHYSICAL GEOLOGY Tectonics The Plate Tectonics Theory • Continental Drift – A hypothesis suggesting that the continents moved over the Earth’s surface. ⮚ Pioneered by Alfred Wegener ⮚ Central idea - all the world’s continental crust had existed as a single landmass, he called Pangea (whole earth, later to be regarded as the supercontinent that existed between 200 and 300 million years ago) and that the continents we see today are the result of fragmentation. • Alexander du Toit (friend of Wegener) divided Pangea into: o Laurasia – North America, Greenland and Eurasia o Gondwanaland – South America, Africa, India, Australia, Antarctica • Weakness – lack of an adequate mechanism (they have not thought of Plate tectonics yet) H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics The Plate Tectonics Theory Evidences for Pangea ⮚ Jigsaw fit ⮚ Structural evidence (continuation of mountain belts and other geological Features) ⮚ Glaciers ⮚ Distribution of life forms ⮚ Similarity in Sedimentary records ⮚ Paleomagnetic Evidence H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics The Plate Tectonics Theory Evidences for Pangea H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Tectonics The Plate Tectonics Theory Evidences for Pangea • Paleomagnetism – the study of the Earth’s past magnetism as recorded at the time of their formation. • A compass needle will always point to the Earth’s magnetic North and South poles. If rotated vertically, it will form an angel with the horizontal plane, called magnetic inclination. • Magnetic minerals (e.g., magnetite) in lavas and sediments acquire the magnetic orientation characteristic of the latitude at which they are located. If continents were stationary, ancient rocks should have the magnetsim of the Earth’s present magnetic field. Actual evidence shows that this is not the case, leading to the conclusion that the rock (and the continent carrying it) moved after it formed. • By studying the changes of inclination of minerals in a sequence of rocks, we can determine the path of the continent through time. This path is called the apparent polarwandering curve H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Continents Major features of the continents: 1. Most continents are roughly triangular in shape. 2. They are concentrated in the Northern Hemisphere. 3. Although each may seem unique, all continents have three basic components: (a) a shield - large areas of highly deformed igneous and metamorphic rock (basement complex) (b) a stable platform or craton - extensive flat, stable regions of the continents in which complex crystalline rocks are exposed or buried beneath a relatively thin sedimentary cover (c) folded mountain belts – uplifted mountain ranges that are sites of tectonic convergence 4. Continents consist of rock that is less dense than the rock in the ocean basins. 5. The continental rocks are old, some as old as 3.8 billion years. 6. The climatic zone occupied by a continent usually determines the style and variety of landforms developed on it. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Continents H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor Major features of the ocean floor 1. Mostly basalt, a dense volcanic rock, and its major topographic features are somehow related to volcanic activity The oceanic crust, therefore, is entirely different from the continental crust. 2. The rocks are young in a geologic time frame; most are less than 180 million years old 3. The rocks have not been deformed by compression. 4. The major provinces of the ocean floor are a. Oceanic ridge - most striking and important feature on the ocean floor; extends continuously from the Arctic basin down the center of the Atlantic Ocean, into the Indian Ocean, and across the South Pacific; A huge, cracklike valley, called the rift valley, runs along the axis of the ridge throughout most of its length b. The abyssal floor - vast areas of broad, relatively smooth, deep-ocean basins on both sides of the ridge; lies at depths of about 4000 m; consists of: ⮚ Seamounts - isolated peaks of submarine volcanoes. ⮚ Trenches - the lowest areas on Earth’s surface; adjacent to island arcs or coastal mountain ranges of the continents. c. Continental margins - zone of transition between a continental mass and an ocean basin consisting of continental shelf and continental slope H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor ▪ Major Features of the Continents ❑ Continental Shelf ✔ It extends seaward from the shore. ✔ Because it is underlain by continental crust, it is considered a flooded extension of the continents. ✔ the width of the continental shelf is variable. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor ▪ Major Features of the Continents ❑ Continental slope ⮚ Here lies the boundary between the continents and the deepocean basins. ⮚ A relatively steep drop-off that extends from the outer edge of the continental shelf to the floor of the deep ocean Ocean depths are often expressed in fathoms. One fathom equals 1.8 m or 6 ft, which is about the distance of a person’s outstretched arms. H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor ▪ Major Features of the Continents ❑ Continental Rise ✔ Consists of a thick accumulation of sediments that moved downslope from the continental shelf to the deep-ocean floor. ✔ Formed at regions where trenches do not exist, the steep continental slope merges into a more gradual incline H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY The Ocean Floor H.D.A.Reyes Correlations 1 PHYSICAL GEOLOGY Selected References Lutgens, F., Tarbuck, E. and Tasa, D. (2012). Essentials of Geology Eleventh Edition. Upper Saddle River, New Jersey: Pearson Prentice Hall Gill, R. (2010). Igneous Rocks and Processes A Practical Guide. 9600 Garsington Road, Oxford: Wiley-Blackwell A John Wiley & Sons, Ltd., Publication. N. Ramos. Geology 11 Principles of Geology; Lecture Notes: The Planet Earth [Power Point Slides]. NIGS-UP Dilliman, Quezon City. B.D. Payot (2018). Geology 250 Igneous Petrology: Introduction [Power Point Slides]. NIGS-UP Dilliman, Quezon City. https://www.skyandtelescope.com/astronomy-terms/ http://www.moonconnection.com/apogee_perigee.phtml https://www.timeanddate.com/astronomy/perihelion-aphelionsolstice.html https://www.timeanddate.com/eclipse/penumbra-shadow.html https://edugeneral.org/blog/geography/different-types-of-clouds/ Disclaimer: Photos and illustrations credit to the owners H.D.A.Reyes Correlations 1