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Monday, 2 November 2015

AMAZING EARTH SCIENCE FACTS

AMAZING EARTH SCIENCE FACTS
 
SCIENTIFIC INVESTIGATION & THE NATURE OF SCIENCE 

·         A hypothesis is a prediction about a problem that can be tested.
·         A variable is a changeable factor in an experiment.
·         Constants are factors that are the same.
·         Scientific theories are systematic sets of concepts that offer explanations for observed patterns in nature. Any valid scientific theory has passed tests designed to invalidate it.
·         There can be more than one explanation for any phenomena.
·         Scientific laws are generalizations of observational data that describe patterns and relationships.
 
 
·         Density = mass/volume      
·         The SI Units for Density are : grams/cm3 or g/mL
·         Volume for irregular objects is found by water displacement.
·         Water is most dense as a liquid.   Density =  1 g/mL
·         Warm (air, water, magma) rises because it is less dense. Cold Sinks.
·         As pressure increases so does density.
·         The same substance has the same density. As mass increases so does the volume.
 
 
·         The altitude of Polaris equals your Latitude.
·         Latitude lines run east to west, but are measured north and south of the Equator.
·         Longitude lines run north to south, but are measures east and west of the Prime Meridian.
·         The closer the Contour Lines, the steeper the slope of the land.
·         Contour lines form V's and point upstream of rivers, streams, and creeks.

 

EARTH AND SPACE SYSTEMS

·         Ground water layers from the surface down would include zone of aeration, water table, & zone of saturation.
·         An Aquifer is a layer of rock that transports groundwater freely.
·         A spring is an area where the water table reaches the land's surface.
·         The Water cycle includes the processes of evaporation, condensation, precipitation, and runoff.
 
 
·         We have 2 high Tides and 2 Low tides each day.
·         Tides are caused by the gravitational pull of the Earth, Moon, and the Sun.
·         Surface currents move warm water toward the poles and cold water toward the equator.
·         Upwelling brings cold, nutrient rich water from the bottom of the ocean to the surface.  This is rich in biological activity.
·         Most waves are generated by wind.
·         Sea level rises when ice caps melt.
·         Features of the seafloor that are related to plate tectonic process include mid-ocean ridges and trenches. Other major topographic features are continental shelves, continental slopes, abyssal plains, and seamounts.
 
 
·         Weather describes day-to-day changes in atmospheric conditions.  Climate describes the typical weather patterns for a given location over a period of many years. 
·         Major factors affecting climate are latitude, elevation, proximity to bodies of water, and position relative to mountains.


·         Areas near the Equator receive the most direct radiation.·         Clouds form when air is at or below its dew point and condensation nuclei are present.
·         A psychrometer measures humidity in the air. A barometer measures air pressure.
·         High pressures bring cool and dry weather: Low pressures bring warm and wet weather.
·         Wind is due to uneven heating that causes air pressure differences. The Coriolis effect causes deflections of the atmosphere due to the rotation of the Earth. 
·         Convection in the atmosphere is a major cause of weather.
·         Wind blows from high to low.
·         Cold fronts move quickly and produce heavy rain and thunderstorms at the front. Warm fronts move slow and produce miles and miles of clouds and light rain ahead of the front.
·         The highest pressure is found at sea level. High pressure systems move clock-wise and outward. Low pressure systems move counterclockwise and inward.
·         U.S. weather is dominated by prevailing westerlies. Weather moves west to east.
·         A tornado is a narrow, violent funnel-shaped column of spiral winds that extends downward from the cloud base toward Earth.  
·         A hurricane is a tropical cyclone (counterclockwise movement of air) characterized by sustained winds of 120 km/h (75 mph) or greater.


·         Solstices occur when the sun is at its most Northern or Southern Point.  During the summer solstice, the Sun is over the Tropic of Cancer and during the winter solstice the Sun is over the Tropic of Capricorn. Summer Solstice is June 21st (longest day) when the Earth is tilted toward the Sun.   Winter Solstice is December 21st (shortest day) when the Earth is tilted away from the Sun. 
·         Equinoxes occur when the sun is directly over the equator.  Spring is March 21st and Fall is September 22nd (12 hours of daylight and 12 hours of darkness).
·         The Earth is closer to the sun in the winter.
  • The Earth rotates W to E (prograde rotation) once in 24 hours.  The Earth revolves counterclockwise around the sun once in 365.25 days.
  • The Earth is the 3rd planet from the Sun.
  • The Moon has phases because of reflected sunlight and the angle at which we view it.
  • Solar eclipses occur when the Moon blocks sunlight from Earth’s surface, while lunar eclipses occur when Earth blocks sunlight from reaching the Moon’s surface.
  • Two types of planets-- Inner (rocky) and Outer (gaseous)
  • Pluto is a dwarf planet and is part of the Kupier Belt.
  • Venus’ atmosphere is mostly CO2 and very dense.
  • Comets are known as dirty snowballs in space and originate in the Kupier Belt or Oort cloud. The tail is the result of the solar wind and points away from the sun.
  • Asteroids are rocky or metallic iron objects with origins between Mars and Jupiter.
  • A meteoroid is debris located outside Earth’s atmosphere. A meteor is debris located within Earth’s atmosphere. A meteorite is debris that has broken apart into smaller pieces before reaching Earth’s surface.
  • AU= astronomical unit, the distance between the Earth and Sun.  We measure planet distances in AU's.
·         Apollo 11 was the 1st manned landing on the moon. Neil Armstrong was the 1st man on the Moon.

EARTH MATERIALS AND PROCESSES

·         A mineral is found in nature, inorganic, solid, with a definite chemical composition and structure.
·         Major elements found in Earth’s crust are oxygen, silicon, aluminum, and iron. 
·         The most abundant group of minerals is the silicates, which contain silicon and oxygen. Some common silicates include feldspar and quartz.
·         The carbonate group of minerals is composed of the compound CO3. Some common carbonates are calcite and dolomite.
·         The oxide group of minerals is composed of oxygen and a metal. Some common oxides include hematite and magnetite.·         Igneous rocks are classified by composition and texture.
·         Igneous Rocks are produced by the cooling of magma or lava.
·         Fast cooling = Extrusive - Texture includes small mineral grains, glassy, air holes present.  Examples are Pumice, Basalt, and Obsidian
·         Slow cooling = Intrusive- Texture includes coarse or large mineral grains.  Granite is an example
·         Metamorphic rocks are formed by heat and pressure.
·         Metamorphic include foliated (banded) and non-foliated.
·         Foliated rocks are slate, schist, gneiss. Non-foliated include marble and quartzite.
·         Limestone morphs (changes) into marble.   Sandstone morphs into quartzite.
·         Sedimentary rocks form from rock fragments, organic material, or chemical precipitation.
·         Sedimentary rocks are found in flat layers or strata. Fossils are found in these layers.
·         Sedimentary subclasses include clastic, organic, and chemical.
·         Limestone is formed both chemically and organically.
·         Clastic rocks are made of fragments- Conglomerate, sandstone, and shale.
 
 
·         The Coastal plain is the flattest area underlain by all types of sediments produced by the erosion of the Appalachian Mountains and Piedmont. Fossils are abundant here.
·         Piedmont is underlain by igneous and metamorphic rocks produced by ancient volcanoes. Separated by a fall line from the Coastal plain.
·         Blue- Ridge- igneous and metamorphic rocks are the oldest in the State
·         Valley and Ridge- long parallel ridges composed of folded and faulted rocks that occurred during the collision of Africa and North America during the Paleozoic.  In the Valley and Ridge, karst topography & fossils are abundant.
·         Appalachian Plateau is underlain by sedimentary rocks. The area is actually a series of plateaus separated by fault and erosional down-cut valleys. Coal resources are found here. 
 
 
·         The Earth consists of a solid Inner core( Fe & Ni), A liquid outer core( Fe & Ni), a plastic- like mantle (Si, O, Fe, Ni) and a thin rocky crust (Si & O)
·         The lithosphere is the crust and upper mantle.
·         Ocean Crust is thinner, younger, & denser than continental crust.  Oceanic crust is made of basalt and continental crust is made of granite.
·         Convection currents move tectonic plates.  Hot material rises, cools, becomes denser and sinks.
·         Convergent Boundaries are colliding plates which cause folded or thrust faulted mountains, subduction zones (volcanoes & trenches).  Reverse faults are produced from this movement.
·         Divergent boundaries are dividing plates and cause Sea- Floor Spreading, Mid- Ocean Ridges, Rift Valleys, & Volcanoes. Normal faults are produced from this movement.
·         Transform boundaries slide past each other and strike slip faults and Earthquakes are produced.
·         Earthquakes can result with any plate movement.
·         A volcano is an opening where magma erupts onto Earth’s surface. Most volcanic activity is associated with subduction, rifting, or seafloor spreading 
·         Hot Spots are not related to plate movement.
·         A fault is a break or crack in the Earth's Crust where movement has occurred.
·         Appalachian Mountains are folded mountains.
·         An Ocean plate will always sink under a continental plate because it is denser.  This is called subduction.
·         3 seismic stations are needed to find the epicenter of an Earthquake.
·         P waves travel the fastest and reach the Seismic station first. P waves travel through solids and liquids. P waves slow down and bend when they hit the liquid outer core.
·         S waves do not travel through liquids.
 

·         Weathering is the process that rocks are broken down by water, air, and organisms.
·         Chemical weathering occurs in warm, humid climates.
·         Mechanical weathering occurs in cold climates--- ice wedging.
·         Karst topography is developed in areas underlain by carbonate rocks, including limestone and dolomite. Included features like caves and sinkholes and forms when limestone is slowly dissolved away by slightly acidic groundwater.
·         Erosion is the process by which Earth materials are transported by moving water, ice, or wind. Gravity causes all these to happen.
·         Streams and moving water are the major agents of erosion.
·         Deposition is the dropping or settling out of sediment by wind, ice, or moving water.
·         High Erosion = high relief areas       High deposition = low relief areas
·         Large particles settle out first.  Sediment size from largest to smallest- breccia, sand, silt, clay.
·         Permeability is a measure of the ability of a rock or sediment to transmit water or other liquids.   Water does not pass through impermeable materials.As particle size increases, permeability increases.
·         Soil Evolution starts with the weathering of bedrock.  Organic material must be present in order to have Soil.
·         Soil profile consists of 3 horizons:
                        A- Top Soil (most evolved)
                               B-  Less humus, leaching from A     
                               C- Weathered Rock
 

COSMOLOGY, ORIGINS, AND TIME

·         A fossil is the remains, impressions, or other evidence of a former existence of life preserved in rock.
·         Virginia's fossils are mostly marine and are from all Era's in history. Fossils are found mainly in the Coastal Plain, Valley & Ridge, and Appalachian Plateau provinces.
·         Law of Superposition states that the oldest rocks are found on the bottom of strata and the youngest on top of strata.
·         Law of Cross-cutting relationships states that an igneous intrusion is younger than the layers it cuts across.
·         Fossils, Superposition, and Cross-cutting are used to determine relative ages.
·         Relative ages are placing events in sequence without assigning exact numerical ages.
·         Absolute time places a numerical age to an event.
·         Radioactive decay or half-life is used to determine the absolute age of rocks.
·         Uranium dating is used to find the ages of the oldest rocks.  Carbon-14 is used to find the ages of human artifacts.
·         The Earth is about 4.6 billion years old.
·         Unconformities are missing rock layers usually a result of erosion.
·         Eons are the largest division of geologic time.  The eons are divided into eras, and the eras are divided into periods.  We are in the Phanerozoic eon, the Cenozoic era, and the Quaternary period.


·         The primitive atmosphere was mostly helium and hydrogen. After the Moon was formed, the early atmosphere contained mainly CO2, CO, and water vapor. 
·         The Earth's atmosphere is 21% Oxygen, 78% Nitrogen, and 1% trace gases.
·         Early photosynthetic life such as cyanobacteria (blue-green algae) consumed carbon dioxide and generated oxygen.
·         Human activities such as burning fossil fuels have increased CO2 levels.
·         High CO2 levels produce the Greenhouse effect.
·         CFC's (chlorofluorocarbons) are decreasing the ozone levels of the upper atmosphere


·         The Big-Bang explains the origin of the universe. The universe began as a dense sphere of gas and dust that expanded and condensed into galaxies. Red Shifts indicate the Universe is expanding outward.  This is used to support the Big Bang Theory.
·         The Solar Nebula Theory is our best current idea for the origin of the solar system.  It explains that the planets formed through the condensing of the solar nebula.
·         The mass of a star controls its evolution, lifespan, and ultimate fate. Stars form from a cloud of gas and dust called a nebula.
  • A light year is the distance light travels in a year. We measure star and galaxy distances with light years.
·         The Sun consists largely of hydrogen gas and its energy comes from nuclear fusion of hydrogen to helium. Our Sun's life cycle is Nebulae, Protostar, Yellow Main Sequence Star, Red Giant, White dwarf and black dwarf.
·         We are located in the Milky Way Galaxy which is a spiral galaxy.
·         The 3 types of Galaxies are spiral, elliptical, and irregular.


EARTH RESOURCES AND HUMAN INTERACTIONS

·         Much of our knowledge of the solar system is a result of space exploration efforts. 
·         Technology has vastly improved how we explore space, such as telescopes, planetary orbiters, and landers/rovers.
·         Apollo 11 was the 1st manned landing on the moon. Neil Armstrong was the 1st man on the Moon.
·         The Hubble Space telescope has improved our knowledge and understanding of the Universe.
 
·         Ores are useful and profitable.
·         Common ore minerals are pyrite, magnetite, hematite, galena, graphite, and sulfur.
 
·         Virginia resources include limestone, coal, and gravel.
·         Renewable resources can be replaced by nature at a rate close to the rate at which they are used. Includes vegetation, water, and soil.
·         Nonrenewable are renewed very slowly or not at all. Includes coal, oil, and minerals.
·         The Earth's Water Supply is renewable but also finite.
·         Coal Evolution from softest to hardest- Peat, Lignite, Bituminous, Anthracite
·         In Virginia, major rock and mineral resources include coal for energy, gravel and crushed stone for construction, silica for electronics, zirconium and titanium for advanced metallurgy, and limestone for concrete.
 
·         Earth’s freshwater supply is finite. Geological processes, such as erosion, and human activities like waste disposal, can pollute water supplies.
·         The major watersheds in Virginia are the Chesapeake Bay, Gulf of Mexico, and North Carolina Sounds. 
·         Estuaries are areas where salt water mixes with fresh water.   An example is the Chesapeake Bay. This produces variations in salinity and high biological activity. Chemical pollution and sedimentation are great threats to the well-being of estuaries and oceans.
·         The oceans are environmentally and economically important.  The impact of human activities, such as waste disposal, construction, and agriculture, affect the water quality within watershed systems and ultimately the ocean.  Pollution and overfishing can harm or deplete valuable resources.

·         Human activities such as burning fossil fuels have increased CO2 levels.  The ability of Earth’s atmosphere to absorb and retain heat is affected by the presence of gases like water vapor and carbon dioxide. 
·         High CO2 levels produce the Greenhouse effect.
CFC's (chlorofluorocarbons) are decreasing the ozone levels of the upper atmosphere

More topics ..............




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