- represents the largest volume of freshwater available to humans
- 14% of freshwater is groundwater
- dissolving action of groundwater produces caves, caverns, and sinkholes
- serves as an equalizer of streamflow; dissolves rock
- the percentage of the total volume of rock that consists of power spaces
- openings called pore spaces
- sediment is usually porous
- permeable rock sediments that transmit groundwater
- "water carriers"; water bearing layers
ex. sand, gravel
aquitards- impermeable layers that hinder/ prevent water movement
What is the importance of groundwater as a resource and as a geologic agent?
- Provides freshwater for drinking etc.
What is groundwater, and how does it move?
- groundwater movement is usually slow
What are some environmental problems associated with groundwater?
- overuse by intense irrigation
- land subsidence caused by groundwater withdrawal
- contamination by pollutants (pesticides, etc)
What percentage of freshwater is groundwater? (p.94)
- intermittent hot springs (warmer than avg air temp)
a hole bored into the zone of saturation to remove groundwater
- applied to any situation in which groundwater rises in a well above the level where it was initially encountered
- landscapes that have been shaped by groundwater
hang from caverns
formations that develop from floor to ceiling in caves
What primary factors determine the nature of volcanic eruptions? How do these factors affect a magma's viscosity?
- Primary factors include magma's temperature, composition, and amount of dissolved gases it contains.
- The viscosity of magma is relate to its silica content.
What materials are associated w/ a volcanic eruption?
- Lava flows (pahoehoe and aa flows); gases (water vapor); pyroclastic material (pulverized rock fragments)
What are the eruptive patterns and characteristic shapes of the three groups of volcanoes generally recognized by volcanologists?
- Shield cones: domed volcanoes built primarily of fluid
- Cinder cones: steep slopes composed of pyroclastic material
- Composite cones (stratovolcanoes): large, interbedded lavas and pyroclastic deposits.
What criteria are used to classify intrusive igneous bodies? What are some of these features?
- Classified according to their shape, their orientation w/ respect to the host rock
can be shaped either discordant or concordant
What is the relation between volcanic activity and plate tectonics?
- MOST VOLCANOES ARE ASSOCIATED W/ PLATE BOUNDARIES. ACTIVE AREAS OF VOLCANISM ARE FOUND ALONG OCEANIC RIDGES WHERE SEAFLOOR SPREADING IS OCCURING (DIVERGENT PLATE BOUNDARIES) OR IN THE VICINITY OF OCEAN TREANCHES WHERE ONE PLATE IS SUBDUCTED BENEATH ANOTHER (CONVERGENT).
Mid Ocean Ridge
- linear swell of elevated seafloor
- here we find faulting, earthquakes, high heat flow, and volcanism
- deep flat features consisting of thick accumulations of sediment buried on the ocean floor
- atlantic ocean has more than pacific
- steep zone that marks the boundary between continental crust and oceanic crust
Continental Rise- slope merges into a more gradual incline
- submerged sloping surface extending from shoreline toward deep ocean basin
- contain important mineral deposits, reservoirs of natural gas
- source of food; fishing
What is the extent and distribution of the world's oceans?
- 71% of earth's ruface is dominated by oeans
- souther hemisphere (water hemisphere) 81% water
- pacific ocean has greatest depth
What are the principal elements that contribute to the ocean's salinity? What are the sources of these elements?
- salinity proportion of dissolved slats to pure water; usually between 35-37%
- principal elements: chlorine, sodium.
- primary sources: chemical weathering of rocks and volcanic outgassing
What techniques are used to map the ocean floor? (Ocean Bathymetry)
- echo sounders and multi beam sonars which bounce sonic signals off the ocean floor and can take pictures and determine depth
- satellite measurements too
How does a passive continental margin differ from an active continental margin?
- passive continental margins are NOT areas of convergence
- active continental margins are areas of convergence (where 1 plate moves beneath another)
What are the major features of the deep ocean basin? How are mid-ocean ridges related to seafloor spreading?
- deep ocean trenches (deepest parts of ocean)
- abyssal plains (level regions of sediment)
- seamounts (volcanic peaks underwater)
- oceanic plateaus
island of coral that encircles a lagoon partically or completely
- moves currents to the right in N. hemisphere and to the left in S. hemisphere as a result of earth's rotation
- influences the movement of ocean waters
- vertical water movements
- rising of cold water rom deeper layers to replace warmer surface water
- brings concentrations of dissolved nutrients, (nitrates and phosphates) to the ocean surface
- coastal upwelling- along west coasts of continents
** coastal winds and coriolis effect cause water to move away from shore
- derive their enegy and motion from wind
- influenced by wind speed, length of time wind has blown, and fetch (distance wind has traveled across open water)
- ocean drift that moves parallel to the shore
-move fine suspended sand and roll larger sand and gravel to oceans bottom.
- created by breaking waves
- daily changes in elevation of ocean surface
- result from gravitational forces exerted on earth by the moon and sun
- most places experiences 2 high and 2 low tides / day
- can be used to generate electrical power by constructing a dam
- occur when the sun and the moon are aligned together
- produces "higher" high tides and "lower" low tides
occur twice a month during times when earth-moon-sun system is aligned
- describes the horizontal flow of water accompanying the rise and fall of tides
What forces create and influence surface ocean currents?
- the pattern of earth's major wind belts
- the positions of the continents
- the coriolis effect
What is the basic pattern of surface ocean currents in each major ocean basin?
- waves travel in a circular orbital motion
- they reach the coast and crash or break- creating surf
How do ocean currents influence climate?
-poleward moving warm ocean currents moderate winter temps (middle lat)
- cold currents are greatest during summer in tropical climates
What 2 factors are most significant in creating a dense mass of ocean water?
- density differences
What factors determine the height, length, and period of a wave?
- wind speed, length wind has blown, and fetch
What are some typical shoreline features produced by wave erosion and from sediment desposited by beach drift and longshore currents?
What is the difference between a submergent and an emergent coast?
emergent coasts- exhibit wave-cut cliffs and marine terraces
submergent coasts- display drowned river mouths (estuaries
How are tides produced?
- caused by the gravitational attraction of the moon and the sun
- 3 main patterns:
`. diurnal tidal pattern (1 high 1 low tide daily)
semidiurnal tidal pattern (2 high and 2 low tides daily)
mixed tidal pattern (usually 2 high and low tides of different heights daily)
What is weather? How is it different from climate?
- weather is the state of the atmosphere at a particular place/ time
- climate is a generalization of weather conditions for a particular area
What are the basic elements of weather and climate?
- air temperature
- type and amount of cloudiness
- type and amount of precipitation
- air pressure
- speed and direction of the wind
What are the major components of clean, dry air?
- clean air composed of nitrogen (78%) and oxygen (21%)
- air is diluted by water vapor, dust, co2, etc.
What is ozone and why is it important to life on earth? In what atmospheic layer is it concentrated?
- form of oxygen
- concentrated w/in a 30 mile range of the atmosphere
- important to life b/c of its ability to absorb uv radiation from the sun
How do pressure and temperature change from Earth's surface to the top of the atmosphere?
trophosphere- temp usually increases w/ increasing altitude; all important weather phenomena occur here
stratosphere- exhibits warming b/c of absorption of UV radiation by ozone
meosphere- lower temps
thermosphere- no well defined temp limit
What causes seasons?
- The earth's orientation in relation to the sun causes changes
- fluctuations in the sun angle and length of daylight brought by earth's orientation cause seasons
How is the atmosphere heated?
- By the sun which brings rays to earth's surface, some are bounced back into the atmosphere, and some remains to warm the earth
- ozone also bounces back suns rays
What causes temperature to vary from place to place?
- differences in the receipt of solar radiation due to latitude
- the unequal heating & cooling of land & water
- geographic location
- ocean currents
- refers to the state of the atmosphere at a given time/ place
- the "right now" weather
-Aggregate weather conditions based on observations or specific time periods;
- Accumulated over many years
Factors influencing climate & weather
- air temp
- type and amount of cloudiness
- type and amount of precipitation
- air pressure
- speed and direction of wind
- mixture of many gases
- 20% oxygen
- 78% nitrogen
- .9% argon
- .03% co2
- form of oxygen (03)
- created when a single oxygen atom colides w/ an O2 atom
- absorbs potentially harmful UV radiation from sun
- located in the stratosphere
the spinning of earth about its axis
rotates once every 24 hrs
movement of earth in its orbit around the sun
- energy possessed by a material arising from the internal motions of atoms or molecules
- when something is heated, its atoms move faster, which leads to an increase in heat content
- refers to quantity of energy present
- average kinetic energy of a materials atoms or molecules
- refers to intensity or degree of hotness
3 mechanisms of heat transfer
-the transfer of heat through matter by molecular activity; heat flows from higher temp to lower temp (metal good conductor, air, bad)
- transfer of heat by mass movement or circulation within a substance; water will turn over producing convective circulation (even distribution of heat)
- radiant energy readily travels through the vacuum of space; requires no medium to transfer
- rise in temp that earth experiences b/c certain gases remain trapped in the atmosphere; reradiated to earth
- can heat earth too much
Want to see the other 62 Flashcards in Test # 2?JOIN TODAY FOR FREE!