All Module Notes (Geoscience 115)
All Module Notes (Geoscience 115) Geoscience 115
Popular in Science Behind the News- The World Around Us
Popular in Geology
This 29 page Bundle was uploaded by Hannah James on Thursday September 10, 2015. The Bundle belongs to Geoscience 115 at University of Wisconsin - Madison taught by Philip Brown in Spring 2014. Since its upload, it has received 114 views. For similar materials see Science Behind the News- The World Around Us in Geology at University of Wisconsin - Madison.
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Date Created: 09/10/15
Earthquakes Where Why and Predictions 0 The Past ten years have been very active for earthquakes O O O 2014 2013 2012 Quiet with only 11 quakes with a magnitude above 70 Largest 82 off the coast of Chile April 1st 19 quakes above 70 2 above 80 Largest 83 in Sea of Okhotsk of Japan 17 quakes above 70 average of last decade Caused 768 deaths 2nd lowest total for decade Largest 86 off the coast of Sumatra April 11th 2011 Largest 90 in Tohoku Japan on March 11th 20000 deathsnuclear disaster 0 No other quakes with magnitudes above 8 0 Largest in US 58 in Virginia on August 23rd 2010 2009 Largest 88 offshore of Chile on Feb 27th 0 70 in Haiti on January 12th 230000 deaths had most impact 0 Nearly two dozen more powerful than this quake in the year 17 quakes above 70 but one of the least deadliest years Largest 81 in S Pacific Killed 200 with a tsunami 0 One day later 76 in Indonesia caused 1700 deaths 2008 2007 2006 2005 Largest 79 on May 12th in Sichuan China that killed 90000 Most impact was an 80 in Peru that killed 500 Largest 84 in Sumatra Deadliest was a 63 beneath Java on May 26th that killed 6000 Notable quake 67 on Oct 15th beneath Hawaii Largest 83 in NW Pacific on Nov 15th Deadliest was a 76 in Pakistan on Oct 8th 86000 deaths Largest 87 in March off of Sumatra changed the coastline dramatically 2004 Dec 26th a 90 caused the deadliest tsunami in recorded history 0 Off the coast of Sumatra and devastated Indonesia Thailand etc 0 Major earthquakes in history 0 Japan 90 2011 In the days before the quake there were several earthquakes above 70 very close to the eventual epicenter of the big quake 0 Epicenter the spot on the Earth39s surface directly above the underground focus of the earthquake I Scientists can t predict whether the quakes were bleeding off strain to keep a large quake from happening or if they were foreshocks 0 Strain the change in the shape or size of an object when it is deformed by stress I Half an hour after the quake a 79 occurred 400km from the epicenter but scientists don t know why I Quake created the tsunami that did most of the damage 0 Haiti 70 2011 I One of the strongest quakes in the last 250 years 0 Epicenter on 15 miles west of the capital of Haiti 0 180000 homes gone leaving 15 million homeless 0 Turkey 74 1999 I Aug 17th one of strongest in the century and hit a heavilypopulated area 0 Many multistory buildings collapsed killed 15000 I Occurred along a fault line I Indications that quakes were getting closer to Istanbul 12 million people I Only 65 miles from epicenter of quake which is above the focus 0 Focus The actual location within the crust where the earthquake occurs Compare to 39epicenter39 I Turkey is very dangerous in terms of earthquakes 0 What are earthquakes and their parts 0 Richter scale is logarithmic 80 quake has 10 times as much ground motion and 30 times as much energy as a 70 0 Two types of waves released by a quake with different types for each I Body waves travel through the earth 0 PWaves primary waves fast seismic waves that can travel through solids liquids and gases 0 Compressional wave like a sound wave motion of particles is forward and back in the same direction as the wave 0 8waves secondary waves slower and can only travel through solids O Shear wave motion of the particles is perpendicular to the motion of the wave itself I Surface waves travel along or just below the surface 0 Rayleigh R waves similar to water waves in that the ground moves in a vertical path parallel to the wave movement 0 Love L waves shear waves where movement back and forth is confined to a horizontal plane on the surface 0 Earth s crust is made of 7 large and 10 smaller tectonic plates that oat on the mantle 0 Movement is the result of mantle movement due to convection I Convection Currents Warm material in a uid rises towards the surface cools and then descends again to be reheated O The rock of the plates then slips grinds and crunches as the plates move occurs at fault zones between plates 0 There are three kinds of plate boundaries 0 continental drift plate tectonics involves a lot of complicated motion 0 Tamest is in the ocean when the plates move away from each other I These are divergent plate boundaries 0 Divergent Boundary Spreading Center where new crust is being created as the old crust on each side moves away as if on a conveyor belt I Don t produce large quakes because motion is constant cmyear 0 Motion where one plate moves laterally and against one another sliding I There are transform plate boundaries strikeslip faults 0 Transform Fault a special kind of 39strike slip39 fault that involves horizontal offset of a spreading center or ridge 0 Sometimes plates are moving directly at each other I These are convergent plate boundaries 0 Convergent Boundary two plates are moving towards each other forcing subduction collision or lateral movement 0 Subduction zone one plate slides under the other back into the mantle O Collision zone plates hit each other 0 Designer of the theory of tectonic plates Alfred Wegener 1912 15 0 Also named Pangea 0 There is no way to predict earthquakes science isn t available to us 0 Safe buildings 0 Reinforced concrete buildings are cheap and strong but are very dangerous in an earthquake I Many say the biggest issue is not design but construction 0 EX in Turkey they used sea sand which is detrimental to concrete and rusts steel reinforcement rods 0 The key to safe buildings is vertical columns they prevent collapase 0 Goal of contractors is not to create buildings that will remain 100 intact but to make ones that will stay standing to people can get out possible to rebuild later 0 Other changes aim to reduce the movement between floors of a building I Shear walls built between columns help stiffen the building I Dampers are giant shock absorbers between columns and beams 0 New building type that is better confined masonry construction builds walls first and then beams and columns which confine the walls securely Volcanoes What is inside the Earth and where is it coming out 0 Volcanoes often alter the shape of Earth s surface 0 January 2014 Mt Sinabung in Sumatra Indonesia erupted killed 14 O 2011 Not many eruptions but ash clouds from remote volcanoes sometimes affected modern life I Puyehue in Chile had dust clouds that circled the globe in S hemisphere O 2010 Eruption of Eyj afj allajokull in Iceland erupted under snow and ice and created ash cloud that disrupted air traffic for weeks 0 Recent eruptions O 1996 Mt Pavlov in Anchorage Alaska came to life with earthquakes that stirred the underground magma I Steam plumes and an ash clouds followed lava fountains upward spray of lava caused by the pressure of magma below it and two lava ows were still active months later 0 The Smoking Mountain I Popocatepetl located in Mexico is continuously active today wish steamash eruptions earthquakes etc 0 Awoke in 1995 has been quietly active since I A catastrophic eruption would be dangerous for millions 0 Volcanoes show us that Earth is alive 0 Earth is tons of hot molten rock covered by layers of cool rock I Hot rock is trying to find its way to the surface hence volcanoes I Hot rock has lots of energy so it creates steam explosions etc 0 Volcanoes have peculiar distribution 0 Most are located around edge of the Pacific Ocean Ring of Fire I This area is where tectonic plates collide heavier ocean ones sink beneath crust ones so it s one big subduction zone I Origin of lava ow is often 100km below a subduction zone I Sinking ocean crust contains hydrous minerals contains either H20 or OH in its structure and water in the pores in the rock that is under lots of pressure 0 This hot highpressure water is released and ows through the hot rock in the upper mantle and lower crust partially melting it and making it now magma rise through the crust O The lower you go the hotter magma gets 0 The upper mantle is thought to be the source of magma columns that feed volcanoes O Magma gathers in the magma chamber a few km below the surface pressure in the chamber increases until eruption causes it to decrease I Upward ow of magma can take many forms depends on chemical composition of magma and local geology 0 Making predicting eruptions difficultcomplicated 0 Forecasting volcanic eruptions is an inexact science 0 0 Issue is simple false alarms created cryingwolf effect I Cause a refusal to evacuate making a fatal mistake Forecasting depends on data such as the chemical nature of gases emitted changes before an eruption the slope of the land re ects subsurface magma movement etc I Issue is not gaps in science but lack of moneyequipment and people to gather data between eruptions 0 This baseline data can help identify changes before eruptions 0 Volcanic landscapes show how they change the Earth 0 Calderas large circular depressions surrounded by steep cliffs form when magma chamber empties and the surface above it collapses larger than a crater Crater circular depression at the top of a volcano through which gases lava etc are extruded I Crater Lake National Park is actually a caldera Lahar occurs when volcanic ash meets ice snow or liquid water and produces a torrential mud ow I 1985 lahars triggered by melting glaciers in Nevada del Ruiz Colombia buried the town of Armero killed 25000 I 1992 Mt Pinatubo in the Philippines released lahars but warnings prevented many deaths I Can also occur after eruptions loose ash mobilized by rain Pyroclastic ows incandescent ash and gas that ow downhill rapidly I 1902 Mt Pelee erupted with a ow killing 29000 I Hot gases reduce friction and allow the fat motion 0 After ow cools and stops material cools and forms an ash ow tuff if deposited material is thick enough the pumice and glass shards compress and form rock called welded tuff Phreatic Explosions when volcanic heat makes steam that explodes into the air Shield Volcano a volcano with multiple vents where lava ows without exploding I Ex Mauna Loa in Hawaii I Extremely uncommon because they form over a hot spot weak place in Earth s crust where magma rises to the surface not a subduction zone O Seamounts underwater volcanoes that form over a midocean ridge or a hot spot I As Pacific Ocean plate passes over hot spots it causes a new volcano I As the plate drifts away volcano stops erupting and new ones are made 0 Pillow Lava Forms during a slow underwater lava ow I As outside of ow cools it becomes elastic and the structure in ates with hotter uid lava from the inside 0 Increased pressure causes the lava to break through the crust and form an adjacent or overlying mass another pillow 0 Is a sign that an area was underwater during the formation of volcanic rocks 0 Columnar Joints Form during the cooling of volcanic rock ow contracts while cooling and forms fractures that produce a polygonal sixsided pattern I Below the surface these joints for parallel columns of igneous rock 0 Hot SpringsGeysers often get energy from heat contained in recently formed igneous rock which can be associated with a still molten magma chamber I Ex Old Faithful 0 Geothermal Power Plants Electricity generating stations that get energy by tapping hot water in underground rocks commonly heated by magma I Often located along the Ring of Fire 0 Flood Basalts are as if Earth spring a giant leak O Basalt is a common igneous rock that forms quick owing lava all the sea oors in the world are underlain by basalt 0 Flood basalts arise when lava oozed from a fissure in the Earth and ooded the landscape basalt makes the lava ow fast and far up to lOOkm per hour I This lack of viscosity thickness allows it to form these massive land provinces 0 Are interesting because past ones correlate with periodic extinctions in the fossil record I Evidence for these oods causing extinctions are mixed 0 EX one occurred when dinosaurs were wiped out but there is also strong evidence for a cometmeteor around that time 0 This process is occurring right now MidAtlantic Ridge 0 California has many volcanic effects to worry about 0 Long Valley Caldera has seen recent activity magma chamber is filling O Mammoth Mountain I Massive output of C02 which indicates resurgent magma 0 Largest Eruption in History 0 Aug 26th and 27th 1883 Krakatau in Southeast Asia erupted and sounded like a cannon up to 600 km away could be detected 4500 km away I Lofted 20 cubic km of rock into the ATM smoke and ash column 26 km above Earth s surface caused tsunamis that killed 36000 I Obliterated 23 of the 11 km island of Krakatau and darkened the sky for dozens of km around I Located on a subduction zone allowing for the power of the explosion 10000 times that of the Hiroshima bomb 0 Allowed scientists to observe new island colonization after the eruption I Species could get there by air passive transport oating sea oating or animal hitchhiker 0 Prof Ian Thornton wrote a book and talks about the colonization 0 Paricutin 1943 Central Mexico 0 Able to witness the building of the volcano from the ground up Geoscience Module 5 Asteroids and Us Coming Soon The Ultimate extinction machines 0 Valentine s Day 2001 The NEAR Shoemaker spacecraft Near Earth Asteroid Rendezvous landed on the asteroid Eros 0 Observed the asteroid s structure composition gravity and magnetic field for over a year before landing 0 February 22nd 2001 New evidence was found indicating a meteorite or comet in the extinction that marks the PermianTriassic boundary 0 Most asteroids orbit in a circular orbit between Mars and Jupiter 0 They often crash into each other and grind each other to bits Puny but Potent 0 The gravitational effects of planets can occasionally cause an asteroid s orbit to become more eggshaped 0 As the orbit becomes elliptical it could lead to a crosscollision with Earth s orbit or Earth itself 0 Small bits of asteroid that experience these effects could become meteors that brighten our night sky Disaster Flick 0 Most asteroids and comets don t come into contact with Earth 0 But they can effect Earthly events because of the kinetic energy from their enormous speeds 0 Kinetic Energy 12 mass velocity 2 I So a large impact could contain more energy than all the nuclear weapons ever produced The Last BIG One 0 65 million years ago Mass extinction marked the end of the Cretaceous Period and the beginning of the Tertiary Period commonly called the KT boundary 0 The direct cause of the extinction is not known but many predict climate change Too Hot in the hot Tub 0 The global warming of the mass extinction was most likely cause by a major volcanic event 0 The release of greenhouse gases C02 etc 0 Scientists looked at rocks from this time period and found rare materials such as iridium 0 It s possible that extraterrestrial materials were deposited by asteroids that crashed to Earth You Going to Prove That 0 One layer of cosmic dust doesn t prove an asteroid caused the extinction but there is other evidence too O The KT boundary contains shocked quartz crystals with microscopic laminations formed by fast highpressure metamorphism of the mineral change in structurecomposition of a rock by heat or pressure I This quartz is only found at two places on Earth ground zero of atomic bomb explosions and meteor impact craters 0 Boundary also contains soot that comes from a large mass of burning trees and plants 0 If there was an asteroid shouldn t there be an impact scar 0 There is in the Caribbean Sea 1 km beneath younger sediments is the Chicxulub crater I Largest of its kind on Earth 180 km in diameter Ready for another Barney joke 0 Evidence now favors a large meteor striking Earth 65 million years ago 0 Impact of a 1015 km meteor would ve cause a hot shockwave to spread all across North America I Heat wave would ve scorched everything in its path and vast clouds of dust afterwards would ve cooled the planet to extreme temperatures Ouch I Some scientists are still not convinced 0 Although a meteor could ve wreaked havoc at this time can it be directly linked to the widespread global extinction 0 There is evidence that a single catastrophic event was not enough to cause the extinction I Many paleontologists believe that a gradual extinction was already taking place 300000 years before the meteor 0 It s possible that volcanoes were emitting greenhouse gases that were increasing temp of Earth and killing off organisms and then the meteor hit and delivered the final blow to speed up the mass extinction of the dinosaurs O This extinction did however allow other more adaptable mammals to thrive with the dinosaurs gone Company Coming 0 The moon gives more evidence for a meteor crash 0 It s obvious the moon has been struck by many types of interplanetary objects I And the leading theory of the moon s formation was that it was ejected from Earth after it was struck from an angle by a piece of debris the size of Mars in the first 50100 million years of its life I Asteroids in the asteroid belt often crash into each other while orbiting so finding one larger than 1 km is rare 0 While asteroids that depart the belt can be dangerous to Earth they are eventually pulled by the sun s gravity into fiery oblivion A Striking Possibility I The odds of an asteroid s collision with Earth are rare 0 Space it too big for these objects to be a common threat 0 However since most asteroids are unknown the assurance against a collision is not ironclad 0 Approx 1500 to 200 asteroids larger than 1 km in diameter are orbiting near Earth most are not identified I This fact has spawned an asteroidsearch industry to find NEOs Near Earth Objects 0 NASA has a budget of 3 million for its asteroid search Searchin Searchin Gotta find a place to hide I Asteroids are hard to see 0 They re ect little light and are always on the move so you have to scan the same patch of sky to look for changing objects against the static background of stars I Some researchers look for light in the visible or infrared bands I Others use radar to bounce radio waves off the asteroids and rea the return signal uses the Doppler Effect to determine its distance from Earth 0 Efforts I LINEAR Lincoln Near Earth Asteroid Rsesearch is a satellite tracking telescope that can see the entire sky in 12 nights I When it began in March 1998 LINEAR saw 13 new near Earth objects 0 However asteroids and comets are constantly coming into view and the telescope still cannot see faint be possible destructive asteroids I The Catalina Project by U of Arizona has worked for the past 12 years to identify unknown asteroids Don t Wanna Live there but a great place to visit 0 Scientists have no visited asteroids 0 The spacecraft Galileo took pictures of asteroids Ida and 951 Gaspra O 27 June 1997 NEAR took pictures of 253 Mathilde a main belt asteroid O 7 planned missions to visit and even return samples from 26 asteroids over the next 13 years A little knowledge Dangerous 0 What could we do if an asteroid did threaten the Earth 0 Smashing a housesized piece of basalt into a 17 km asteroid would do nothing and no one knows how to accelerate an object to asteroidblasting speed 0 We need alternatives A lively alternative I Asteroids are worth studying because they are our best chance at viewing the composition of the primordial solar system 0 85 of meteors that have crash landed to Earth are identical to the makeup of Earth s mantle 15 have the iron and nickel of Earth s core I This is similar to the 8020 volume ratio of mantle to core on Earth I When Earth was first forming asteroids and comets were bombarding the Earth so often that life could never have survived 0 Only after 38 billion years when the bombardment tapered off did the water and organic molecules that make up the building blocks of life appear Friend of Foe 0 The bombardment may have suppressed life for a time but it may also have provided the water and carbon molecules needed for life to begin I Comets and asteroids are still crashing to Earth and they contain around 10 of organic molecules 0 While most burn up and disintegrate or at least become hot enough to kill all the organic molecules the right size meteor could ve made it to Earth with its organic molecules intact Shock Therapy 0 These extraterrestrial objects could ve also provided the energy needed for complex organic molecules to form 0 Earth s atmosphere used to contain large amounts of CH4 N2 and H20 I The organic molecules necessary for life are larger versions of these whose development requires energy in the form of heat I These impacts could ve formed the first organic molecules Spacy Spin Doctor 0 Scientists view asteroids as remnants of the protoplanetary disk which was the disk of gas and dust that formed the sun and planets 46 billion years ago 0 When large objects coalesced some dregs remained These dregs became asteroids and now orbit between Mars and Jupiter 0 The asteroid belt divides the solid planets Mercury Venus Earth Mars and the gas planets Jupiter Saturn etc I The nature of asteroids remains unclear are they solid or agglomerations of rock gas and dust 0 Results from a J PL Jet Propulsion Laboratory team show that one asteroid 1998 KY26 is solid rock 0 Radar data on the asteroid showed it must be monolithic formed of a single type of rock and must have tensile strength ability to resist stretching I The reasoning is that asteroids have very weak gravity and a debris pile would selfdestruct by centrifugal force if it were to rotate faster than every two hours this asteroid rotates in less than 11 minutes All Together Now 0 Proof that asteroids are solid links them to meteorites which are also solid rock and which presumably originated in asteroids 0 Until now there has been no proof that asteroids had the same solid construction as meteorites 0 How did the protoplanetary disk fuse into solid rock 0 Planets have enough radioactive decay and mass to make and retain this fusion I But in the freezing asteroid belt heat for fusion may have come from the rapid decay of radioactive isotopes like aluminum26 during the first billion years of the solar system I It could ve also come from solar wind and planetary magnetism 0 Studies of meteorites found that they came from rocks that cooled at the rate expected for objects at least 100 km in diameter 0 This means that original asteroids were much bigger and their smaller size now is a result of continual collisions in orbit I Several moons in the solar system may be leftover asteroids 0 There is evidence that some asteroids had liquid water near their surfaces early in history 0 Today temperatures of the asteroid belt are 260 degrees Celsius I Because of the heating mechanisms stated above the belt would ve been much hotter earlier in history and was apparently hot enough to melt ice without immediately evaporating water Orbital Oddities 0 Distinctions used to be neat asteroids were rocks comets were dirty snowballs 0 But new data is making the distinctions murky a class of 3 objects that were originally called comets may be asteroids 0 Like all comets these three things have tails I But they each lack a coma I By analyzing the tails it became apparent that the bodies had been blasted by an impact which shook loose some dust which slowly expanded to become the tail 0 So the comets were actually asteroids 0 This data shows that asteroids suffer cataclysmic collisions that form families of smaller asteroids and that collisions that gouge their surfaces stir up dust and debris without necessarily busting them apart I This hints towards major diversity for comets and asteroids Like Chaotic 0 Why are most asteroids stuck in orbit while only a few escape and cross Earth s orbit 0 Some asteroids become pulled by Jupiter s gravity making their orbit more elliptical eggshaped I Eventually they would start crossing Earth s orbit A Temporary Asteroid 0 Asteroids are only temporary once they cross Earth s orbit because the sun s graVity pulls them in 0 But if asteroids are supposed to be temporary then Jupiter s graVity cannot solely explain the number of asteroids that cross Earth s orbit Brother can you spare a planet 0 Original computer simulations of asteroid orbits ignored the pull of the inner planets 0 But adding their pull to the simulations made more asteroids cross Earth s orbit and made the number more similar to actual calculations 0 Mars with only 14 of Jupiter s graVity plays a major role in asteroid orbits O Explanation could be chaos means that small perturbations disturbances can cause large changes in orbits Module 6 Amber Old Air and DNA 0 Nature s Preservative 0 Produced when resin called sap or pitch hardens to a solid that excludes airwater I The resin is produced by trees as a defense mechanism against insects I The resin is sticky and traps insects small lizards owers etc 0 This organisms show details chemistry and 3dimensional structure that can t be replicated in records of the past fossils etc 0 Amber not only excludes air and water but also contains preservative chemicals 0 Pine trees are some of the biggest producers of pitch in the temperate zone regions of the globe with distinct summer and winter 0 In the tropic zone the genus hymenaea are owering trees that produce large amounts of pitch 0 Only a few pieces of amber actually bear life I Baltic amber Dominican amber bears life most often 1 in 100 pieces I In 2010 a new source of amber was found in Ethiopia it was amber from the Cretaceous period when the first owering plants arrived and was some of the only amber to be found in the southern hemisphere from this time period Every once in a while an arthropod would get stuck in resin too usually have 0 segmented bodies exoskeletons and jointed limbs I It has been known that resin seals wounds and repels insects but recently scientists have discovered a much more complex interaction with resin 0 Resin contains 30 to 40 compounds which I Repel insects or attract them I Attract parasites of herbivorous insects that eat the insects who eat the trees I Contain chemicals that kill pathogenic fungi carried by bark beetles 0 Why is amber important 0 Entomology study of bugs Amber shows what species used to look like where they used to live etc I This gives information about climate migration patterns environmental conditions etc 0 Genetic information DNA extracted from amber can show the relationship and changes to DNA over the years 0 Whole organisms some whole organisms have been recovered from amber I Questions scientists have 0 Does amber accumulate gradually or suddenly 0 What kind of stuff doesn t get trapped in amber 0 Are there other unrecognized preservatives in nature 39 Some preservatives that aren t as good as amber fossils freezing dehydration silicification of wood and peat bogs 0 How real are the results 0 Scientists wonder if they can get samples of old atmospheres from amber 0 There are small bubbles in amber that scientists sucked the air out of and determined that they could sample gases from old atmospheres from them 0 But the data is inconclusive on whether this method is sound and accurate for predicting the atmospheres of the past 0 Scientists cannot yet create life from cells trapped in amber 0 But Raul Cano reanimated bacteria that survived as spores in the gut of a bee trapped in amber He tried to avoid contamination that would make current bacteria grow and corrupt the experiment but it can never be sure that the bacteria was actually reanimated Geosci 115 Module 7 Life in Extreme Environments 0 Mendel founder of modern genetics 0 Leeunhoek first to observe singlecell organisms 0 Scientists have long believed that life could only exist in normal conditions 0 But organisms called extremophiles are organisms that live in harsh conditions 0 Scientists cannot agree how to classify life 0 Biologist Lynn Margulis uses 5 kingdoms I Monera prokaryotes more biodiversity that the rest of life altogether I Protoctista eukaryotic microbes products of bacterial symbiosis bacteria living together and relying on each other 0 Algae ciliates and other microbes that don t fit in other categories I Fungi sporeforming molds yeasts and mushrooms I Plantae maternally retained embryoformers I Animalia animals product of an egg fertilized by swimming cellsperm 0 Taxonomy the grouping of organisms was traditionally done by appearance because it was believed that similar appearances showed similar ancestry 0 But microbes create and issue for this process 0 In the 1970 s Carl Woese employed RNA sequences from ribosomes 0 RNA changes slowly and randomly over millennia I So more variation between organisms means a more remote common ancestor and greater evolutionary distance between them 0 An advantage is that not to analyze organisms scientists only have to extract DNA or RNA not grow the organism which is good because scientists do not know the conditions in which all organisms grewgrow O Woese classified life into three domains I Archaea Ancient prokaryotes I Bacteria More modern prokaryotes I Eucarya All organisms w a nucleus eukaryotes plants fungi animals 0 Recently the first DNA sequences and Archaea bacteria have been coded 0 These showed many characters that hadn t been found before and also reinforced that Archaea bacteria are more closely related to eucarya than bacteria 0 The tree of life is extremely complicated and there s lots of confusion about its organization 0 Some suggest another domain exists others say there needs to be one common ancestor etc 0 The more questions are answered the more questions are raised 0 Thomas Brock first found organisms living in hot temperatures in the 1960 s in Yellowstone National Park I Organisms that live at high temperatures are called thermophilic organisms O Grow best between 45 degrees Celsius 113 F and 80 degrees Celsius 176 F O Hyperthermophiles grow best at temperatures higher than this 0 Only prokaryotes from Bacteria and Archaea have been found at these temp and most thermophiles are from Archaea 0 Life in extreme temperatures because species enjoy having a niche all to themselves I DNA and like molecules are usually heatsensitive it is unclear why those of thermophiles are not 0 Possibly because they have more GC than AT bonds of which GC are stronger because they have triple bonds I They also seem to have slightly different chemical compositions which in proteins and other molecules can make them stronger and more heat resistant 0 It is now suggested that organisms evolved downtemperature and were once more related to thermophiles 0 Scientists have not found the upper limit of temperature for life but some speculate it is between 113 and 150 degrees Celsius Lake Vostok is found miles under the Antarctic ice sheet and it was discovered that life exists there 0 This means that in the similar situation on Jupiter s moon Europa life could exist 0 Psycrophilesz coldloving organisms I Grow best around 15 Celsius 59 F but can t grow over 20 Celsius 68 F can also live in temperatures colder than this 0 Have a large impact on global cycles of elements such as carbon because of their abundance I Most of our earth is deep oceans which are cold Hence the high number of psycrophiles Organisms that live in acid are acidophilic 0 Most normal environments are between pH 5 and pH9 prime is pH 7 0 Acidophiles require a pH of 7 inside their cells but a pH of 5 or lower outside their cells 0 Because they can live in toxic metal and eat damaging chemicals like pyrite acidophiles are often used to clean up manmade environmental disasters such as minerock drainage etc In 1996 a meteorite in Antarctica was discovered to be from Mars and possibly a fossil O Polycyclic aromatic hydrocarbons PAHs organic molecules associated with life on Earth were found in the rock and were more concentrated towards the center of it making contamination from Earth rock less likely Rock also contained carbonate molecules which are associated with life Shapes resembling life were also found 0 However there is still no concrete evidence for life on mars no lifefossils have 00 been recorded on the actual planet 0 Scientists know it is from mars because of the meteorite s oxygen isotopic composition different number of neutrons from regular oxygen 0 In recent years the case for life concerning this rock has weakened dramatically with further examination 0 The fossils of bacteria found were wrong because bacteria can t get that small 0 The PAHs could ve been from an early chemical on Mars as opposed to life 0 Also the amino acids found in the rock were the exact same as those in the ice during the time period that the meteorite landed so they re probably terrestrial Water water not everywhere Moon39s River In the past few years there have been several claims of water on Mars One from 2008 and one from February 2014 39 A report from December 2014 claimed that most of the water on Mars must have diSPCISCd after the first 56000 million years after Mars was formed 39 This module explained why we know of our moon39s water and why we care Liquid Gold on the Moon March 5th 1998 NASA announced the discovery of water on the moon Craters near the 1unar poles that can39t be seen from Earth seem to contain ice crystals 39 Anywhere else on the moon water would be vaporized from the intense sunlight during the day 39 Even if the report is correct the water would be spread across thousands of kilometers of terrain and the soil is at best 1 ice The ice only exists because those shadowed areas are 173 degrees Celsius Lunar Dreams 39 Scientists want to return to the moon for a closer look at the water and some Want to setup a camp on the moon to create bottle water out of the ice or even cheap rocket fuel 39 Why do we think there39s water on the mOOIl 39 In 1996 the Clementine satellite sent back images of possible water in 1988 the Lunar Prospector found traces of hydrogen and presumably water in the polar craters The Lunar Prospector was the inaugural satellite of the Discovery program 39 The goal of the program was to launch sma11 cheap satellites built from offtheshelf parts 0 After Prospector reached the moon the neutron spectrometer began signaling the presence of hydrogen atoms in the moon39s quotsoilquot which is asteroidchurned dust on the lunar surface It39s not the frigiditv it39s the humidity A neutron spectrometer measures the number of neutrons in atomic nuclei 39 That measures the neutrons formed when the moon is bombard d by cosmic rays energetic gamma rays from deep space When the Ray strikes the moon39s surface it loosens highenergy neutrons which may collide with other atoms in the soil and be bounced into space 39 These with enter the spectrometer which measures their energy As the neurons bounce they lose energy So their spectrumenergy depends on the history of their bounces When the spectrometer reads these neutrons and their spectrums it determines what kind of atoms they hit while in the lunar soil quotI See Hvdroaenquot 39 Because the Prospector observed hydrogen in the moon39s soil the ObViOUS Explanation iS that ice and water are underneath the moon39s crust Because hydrogen is so light it even has enough thermal energy to bounce in the space within the cold temperatures of the lunar craters So to be found on the moon it must be bound with other molecules water is the only option This makes some scientists certain of the water while others are still skeptical Just Gettin2 Started The process of looking at multiple hypotheses has just begun 39 Looking at the origin of this water could get a fingerprint to the early history of our s01af system This is not how to parallel park 0 Scientists decided to end the Prospector mission by crashing it into the crater to see if it would kick up a cloud of water ice but no ice was detected in the dust kicked up Where39s it From When the moon was blasted into space from earth it was way too hot to hold water So where did the water come from 39 The best guess has been cometS New Water on the moon from the sun 39 The hydrogen isotope values from the trace amounts of water in the lunar regolith quotsoilquot indicates that the water came from the solar wind meteorites How much water is in the lunar canteen Most of the water that reach the moon fell in sunny places and was boiled away and estimates indicate that only 1 300 to 500 million metric tons is still present on the moon But the water is spread out and is at maximum 1 of the soil by weight 39 So is it a source or just a curiosity 39 By decomposing the water into hydrogen and oxygen the compound could be made into combustible rocket fuel for astronauts But water at 1 of the soil concentration would not be an economically viable source Europa Orbiting incubm Europa has no disfiguring craters or scars that indicate age on a moon But this is not because it is young it is because the moon is resilient 39 This may be because it39s smooth surface rests on a giant subterranean ocean Did somebodv sav ocean 0 Because the moon is covered in frozen water and is not dense enough to be pure rock it indicates that the moon also contains water on the inside Too cold for swimming 0 Europa is warmed by the interaction of J upiter39s gravity and the gravity of other moons So the ocean is liquid water and may be as deep as 100 kilometers 39 The upper layer is probably slushy and the lower layer most likely contains lots of salt A living ocean near Jupiter Does this mean that the ocean contains life Europa is slightly smaller than Earth39s moon it39s oceans are 260 degrees Fahrenheit most of its density is in the center of the planet and it often experiences a rain of organic chemicals from comets and asteroids Does this add up to life No the fact that Life can live in extreme climates only proves that the possibility of life on Europa should be taken seriously 39 The moon seems to have the three components necessary for lifCZ organic mol cul s from comets heat and liquid water What39s so special about water anvwaL 39 All living things contain water 0 Water has polar molecules which means a body of water will stick to itself through cohesion 39 Waters high specific heat due to cohesion allows it to maintain a less varied climate near the coasts and it keeps temperature Within the range of where life is possible Water39s high specific heat also makes it so that lots of heat is required to turn the water into vapor heat of vaporization 39That39s some high guality H20quot Ice is less dense than water that39s why lakes freeze from the top down and fish can remain alive during the winter Water is also a very versatile solvent Because the water in our bodies can dissolve the molecules we need for life WC am 31316 to transport the nutrients we need all around our body What39s Next 39 The next logical step would be drilling a hole in the ice of Europa and obserVing What was underneath Geoscience Module 9 Global Warming Pass the Ice 0 There are signs that we are on the verge of dangerousand possibly catastrophic warming 0 Possibly because of carbon emissions changing the atmosphere 0 Some scientists say that climate is less stable than we once predicted and changes rapidly on its own 0 Recent studies have found that then lower atmosphere has shown no temperature change in from the 70 s to the 90 s and the stratosphere cooled 06 degrees per decade 0 So how does the climate warm without the atmosphere warming scientists said we don t know 0 However a recent report negated this and showed that the atmosphere increased in temperature almost as much as the surface 0 While climate often varies slightly from year to year it has been shown that recent variations seem to be upward 0 The greenhouse effect starts with light and its wavelengths difference between adjacent waves 0 Hotter objects emit shorter more energetic wavelengths colder longer 0 Sun emits lots of UV and visible light wavelengths which are absorbed by earth I Some of it is reemitted back to space but the earth is cooler so it is long infrared wavelengths 0 While the sun s shorter wavelengths pierce the atmosphere the longer wavelengths from earth are trapped by greenhouse gases water vapor methane and carbon dioxide 39 Carbon emissions is increasing the levels of carbon dioxide in the atmosphere 0 Climate can change erratically 0 Data shows that in the younger days that followed the ice age 13000 years ago the climate cooled as much as 5 degrees in five years I This occurred in Greenland and it s unclear if it occurred in other areas 0 Evidence shows is occurred at least in Antarctica too O The temperature then suddenly cooled 39 Showed that this rapid warming occurred because of changes in ocean circulation 0 Melted fresh water from the area went into the ocean preventing the downturn of cold salty ocean water to the sea oor and disturbing the ow of heat to Greenland and Northern Europe 0 Scientists now consider land and ocean changes as well as atmospheric changes when discussing global warming 0 Changing forested area to farmland would greatly warm our climate 0 Deforestation would also greatly reduce rainfall because so much of is it caused by plant transpirationeVaporative cooling 0 So trends in plant life could better explain long term climate change in the past because atmosphere changes too rapidly to explain the long term variations Geoscience Module 10 Nor any drop to drink Groundwater is the underground water that fully saturates pores or cracks in soils or rocks 0 Groundwater is replenished by precipitation 0 Between the surface and the aquifer zone is the unsaturated zone where water first goes after precipitating It usually contains some water can be fully saturated right after rain or dry during a drought After water requirements for plants are satisfied the rest of the precipitation ows into the water table the top of zone below which the openings in rocks are saturated 0 Below the water table all the openings in rocks are full of water that moves through aquifers to streams wells or wherever the water is being withdrawn 0 Refilling of aquifers is slow because water ows slowly through unsaturated zone and aquifer Aquifers can be replenished artificially through two ways 0 I spread water over the land in pits and ditches that allow the water to infiltrate the water 0 2 construct recharge wells and inject water directly into an aquifer I More expensive but reasonable when the spreading method isn t possible 0 The type of rock surrounding an aquifer determines whether or not it is a good supply of water ex clay has few cracks for water to travel through but limestone has many so limestone makes a better aquifer that replenishes more quickly Aquifers vary in depth range and supply 0 The quantity of water a given type of rock will hold depends on its porosity a measure of pore space between the grains of rock or of cracks I If the grains are all about the same size or wellsorted the waterfilled spaces between the grains account for a large portion of the volume of the aquifer 0 Sand and gravel aquifers have well sorted grains so they hold and transmit larger quantities of water 0 If water is to move through a rock the pores must be connected I If the pores are connected and are large enough the rock is permeable I A rock without many pore space ex granite can only be permeable if it contains enough sizeable cracks or fractures 0 Nearly all rock formations are broken by parallel systems of cracks called joints caused by stresses in the Earth s crust 0 Natural processes ice freezing weathering heatingcooling causing expansion etc widen these cracks There is no relationship between the depth on an aquifer and it s water yield 0 After entering an aquifer water moves to lower lying places and is discharged into springs streams etc 0 Ground water in aquifers between layers of poorly permeable rock may be confined under pressure I If this water is tapped by a well the water will rise above the aquifer and ow out 0 These waters are under artesian pressure and are called artesian aquifers 0 The water level to which they rise in these wells is called the Dotentiometric surface A spring is occurs when an aquifer is filled to the point where it over ows onto the surface thermal springs occur where the water is hot often in areas of recent volcanic activity geysers are thermal springs that erupt Water shortage is greatest in equatorial countries often where population is rising 0 Countries with big issues I China increasing population contaminated water sources and over pumping farmers are going out of business without water and the country will have to import more food I India over pumping salination of water I Israel over pumping causing seafood to contaminate drinking water The Nile is a source of water for over ten countries including Egypt and it is likely that a water war could erupt soon 0 Ethiopia tried to build a dam in the Nile and Egypt strongly opposed it The Tigris and Euphrates rivers also supply many countries owing from Turkey to Syria and Iraq 0 Turkey has built dams to control the river limiting the irrigation of the other two Some countries Jordan and Israel have been cooperating over the water shortage to try and preserve their resources Charging for water would reduce consumption greatly as it has for farmers in some areas of America 0 But if farmers go out of business or grow more profitable crops it could lead to food shortages In areas without water water vendors can charge ridiculous prices costing people almost all of their income Privatization of water seems like it would make water more available but it has failed before ex Cochabamba Conservation is the last oasis and can greatly reduce water consumption 0 Drip irrigation and low ow toilets both greatly conserve water 0 Reuse of wastewater is often employed in arid lands 0 Desalination of water would be the ultimate solution if it can be done economically 0 Global warming would cause sea levels to rise with more evaporation and precipitation but would overall change the hydrology of every river basin in the world 0 More snow melting will worsen the water shortages in many places especially Asia Geoscience Module 11 El Nino vs La Nina Recent El Nino events of 19971998 made many people global warming believers El Nino and La Nina are the two counterparts of the Southern Oscillation often shortened to ENSO El Nino Southern Oscillation O The Southern Oscillation is the cyclic warming and cooling of the eastern and central Pacific Ocean that has huge impacts on weather throughout the globe I El Nino warm episodes La Nina cold episodes The ENSO cycle can be viewed by using the ENSO index blue spikes are La Nina red spikes are El Nino events 0 This index combines sea level air pressure air and water temperature wind directionspeed and cloudiness above the tropical Pacific Event of El Nino was named because it often peaked in December was named after the baby Jesus What causes El Nino O The Sun s radiation warms the equator much more than the poles because of their direct angle on the equator yearround I The motion of the atmosphere is powered by the heat from the sun which evaporates sea water 0 The warm moist air rises from the equator and transfers heat towards the poles I Also dry cool air drops at the middle latitudes and is moved below back towards the equator 0 These motions create giant atmospheric loops called convection cells which transfer heat 3 in each hemisphere 0 While air is changing latitudes between the equator and poles Earth s rotation gives the atmosphere a slight push called the coriolis effect effect is dependent on speed and latitude of the moving object I Greatest at poles and almost nonexistent and the equator I Causes air to rotate to the right in the Northern Hemisphere and to the left in the Southern Hemisphere 0 EX a hunk of still air at the equator is actually moving 1000 miles an hour it s simply moving the same speed as earth s surface But as you move towards the poles earth moves slower and the air moves at the same speed so you get the appearance of the air being de ected to the right or left I The coriolis effect is often called a force but it really isn t once because it s only a perception as a result of the Earth s rotation Where the convection cells converge bands of prevailing winds and jet streams are created 0 Prevailing wind A wind that blows from one direction more frequently than any other during a given period such as a day month season or year I The easterlies westblowing prevailing winds at low latitudes are also known as the Trade Winds I Named after the direction from which they are blowing ex winds from west are westerly winds I Doldrums latitudes where winds are very mild 0 Jet stream A current of fast moving air found in the upper levels of the atmosphere Without El Nino a convection cell forms in the W Pacific above Australia called the West Pacific Warm Pool 0 Trade winds push surface water westward while the Sun heats it making the Warm Pool contain an enormous amount of energy with water s high specific heat the energy can be stored as heat energy in the warm pool I This area creates moisture which is carried around the globe and is released as thunderstorms I Controls the directions of jet streams an reinforces prevailing winds 0 As this warm water moves towards the W Pacific cooler deepsea water is drawn up to the surface in the E Pacific During El Nino the trade winds weaken and the warm water moves back towards the E Pacific evening the sea level in the E and W O The Warm Pool moves East as well and the upwelling of cool water in S America the E Pacific stops 0 When the Warm Pool moves east during El Ni o so does the weather it creates I This means that storms are being created in a different part of the ocean and prevailing winds jet streams are being distributed to different parts of Earth I The shift in position of thunderstorms changes the global atmospheric circulation changing global jet streams and thus global weather At the end of El Nino the trade winds pick up and the Warm Pool is moved back towards the east returning the earth to normal conditions 0 But once the trade winds have strengthened they tend to go past their normal speedstrength I When this happens more and more surface water gets pushed west meaning even larger amounts of cold water are drawn up off the coast of S America O This strong upwelling of water and cooling of the east Pacific the opposite of El Ni o is dubbed La Ni a O Eventually the trade winds will weaken again and the Pacific ocean will begin another cycle of warming and cooling oscillation between the two events occurs every 3 4 years El Nino may affect weather patterns also our economy and lives but it mostly contributes to weather s uncertainty cannot predict weather based on whether or not an El Nino event is taking place 0 Can cause oodshurricanes or extreme droughtsfires no prediction can be made for either New gathering of information about El Nino from satellites and computers help scientists predict and identify the weather changes 0 This allows them to warn people about upcoming droughts ooding etc I It can allow areas to prepare for the new weather plant droughtresistant crops repair irrigation ditches etc I However predictions aren t always accurate TOGA is an array of buoys across the Pacific rigged with scientific equipment that allows us to monitor sea temperature and conditions Are the increasing El Ni o s caused by global warming and the increase in greenhouse gases in our atmosphere 0 Some scientists argue that El Nino has actually caused some of the temperature increases in the N Hemisphere I So the changes to jet streams by El Nino have actually caused the temp change not global warming 0 However many say that global warming could be increasing the intensityextremity of El Nino thus at least causing the temperature changes indirectly
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