GEOL 160 exam 2

latent heat of boiling

After the change from ice to liquid water has occurred at 0°C (32°F), additional heat raises the water temperature. As it does, it takes 1 calorie of heat to raise the temperature of the gram of water 1°C (or 1.8°F). Therefore, another 100 calories must be added before the gram of water reaches the boiling point of 100°C

where are regions of high and low pressure created?

Atmospheric pressure is 1.0 atmosphere2 (14.7 pounds per square inch) at sea level and decreases with increasing altitude. Atmospheric pressure depends on the weight of the column of air above. For instance, a tall column of air produces higher atmospheric pressure than a short column of air. the tall column of air at sea level means air pressure is high at sea level and decreases with increasing elevation. Changes in atmospheric pressure cause air movement as a result of changes in the molecular density of the air. A column of cool, dense air causes high pressure at the surface, which will lead to sinking air (movement toward the surface and compression). A column of warm, less dense air causes low pressure at the surface, which will lead to rising air (movement away from the surface and expansion). In addition, sinking air tends to warm because of its compression, while rising air tends to cool due to expansion.

hyrdogen bonding

Attraction between positive and negative ends of water molecules to each other or other ions Weaker hydrogen bonds form between adjacent water molecules, and stronger covalent bonds occur within water molecules. In water, the positively charged hydrogen area of one water molecule interacts with the negatively charged oxygen end of an adjacent water molecule, forming a hydrogen bond Hydrogen bonds are weaker than covalent bonds but still strong enough to contribute to: -Cohesion (molecules sticking together) -High water surface tension -High solubility of chemical compounds in water -Unusual thermal properties of water -Unusual density of water

distribution of solar energy

Concentrated solar radiation at low latitudes (high angle of incidence and low surface area covered by sunlight) Solar radiation more diffuse at high latitudes (low angle of incidence and greater surface area covered by same amount of sunlight) atmosphere absorbs radiation, thickness varies with lattitude these differences in temperature causes widespread convection in the atmosphere

Arctic and Antarctic Circles

Daily heating of Earth influences climate in most locations Exceptions to this pattern occur north of the Arctic Circle (66.5 degrees north latitude) and south of the Antarctic Circle (66.5 degrees south latitude), which at certain times of the year do not experience daily cycles of daylight and darkness. For instance, during the Northern Hemisphere winter, the area north of the Arctic Circle receives no direct solar radiation at all and experiences up to six months of darkness. At the same time, the area south of the Antarctic Circle receives continuous radiation ("midnight Sun"), so it experiences up to six months of light. Half a year later, during the Northern Hemisphere summer (the Southern Hemisphere winter), the situation is reversed.

the coriolis effect

Deflects path of moving objects from viewer's perspective (to the right in Northern Hemisphere, to left in Southern Hemisphere) this is due to Earth's rotation Is zero at equator and greatest at poles Change in Earth's rotating velocity with latitude: -0 km/hour at poles -More than 1600 km/hour (1000 miles/hour) at the equator The greatest effect is on objects that move long distances across latitudes

boundaries between wind belts

Doldrums or Intertropical Convergence Zone (ITCZ): -The boundary between the two trade wind belts along the equator -air rises -very little horizontal air movement -precipitation Horse latitudes: -The boundary between the trade winds and the prevailing westerlies, centered at 30 degrees north or south latitude. -Sinking air in these regions causes high atmospheric pressure and results in clear, dry, and fair conditions, as well as surface winds that are light and variable -very little horizontal air movement Polar fronts (roaring 60s): -The boundary between the prevailing westerlies and the polar easterlies at 60 degrees north or south latitude -air rises -a battleground for different air masses, so cloudy conditions and lots of precipitation are common here -lots of horizontal air movement, with roaring winds (hence the name)

solar radiation and latitude

Earth is spherical, so the amount and intensity of solar radiation received at higher latitudes are much less than at lower latitudes. The following factors influence the amount of radiation received at low and high latitudes Solar footprint: -the different angle of incidence at high and low latitudes means that most of the time in the equatorial region, the Sun is directly overhead, and so at low latitudes, sunlight strikes at a high angle -This means solar radiation is concentrated in a relatively small area -Closer to the poles, sunlight strikes at a low angle, so in high latitudes, the same amount of radiation is spread over a larger area Atmospheric absorption: -Earth's atmosphere absorbs some radiation, so less radiation reaches Earth's surface at high latitudes, compared to low latitudes, because sunlight must pass through more atmosphere at high latitudes Albedo: -the albedo of various Earth materials varies depending on the material considered. -For example, thick sea ice covered by snow reflects back into space as much as 90% of incoming solar radiation, and so has a high albedo. -This is one of the reasons a larger proportion of radiation is reflected back into space in ice-covered high latitudes as compared to low latitudes, which lack substantial amounts of ice. -Other Earth materials such as ocean, soil, vegetation, sand, and rock have much lower albedo values than ice; the average albedo of Earth's surface is about 30% Reflection of incoming sunlight -the angle at which sunlight strikes the ocean surface determines how much is absorbed and how much is reflected -If the Sun shines down on a smooth sea from directly overhead, only 2% of the radiation is reflected, but if the Sun is only 5 degrees above the horizon, 40% is reflected back into the atmosphere -Thus, the ocean reflects more radiation at high latitudes than at low latitudes. Because of all these reasons, the intensity of radiation at high latitudes is greatly decreased compared with the intensity of radiation received in equatorial regions. Other factors influence the amount of solar energy that reaches Earth. For example, the amount of radiation received at a particular location on Earth's surface varies daily because Earth rotates on its axis, so the surface experiences daylight and darkness each day. In addition, the amount of radiation varies annually due to Earth's seasons,

earth's seasons

Earth's orbit is slightly elliptical Earth's axis of rotation is tilted 23.5 degrees with respect to plane of Earth's orbit Seasons are caused by the tilt of Earth's axis, not the distance from the sun. Vernal equinox: -known as spring equinox in northern hemisphere -About March 21 -Sun is directly overhead at the equator on equinoxes -during this time every place on earth experience equal lengths of night and day Summer solstice -About June 21 -Sun directly overhead at Tropic of Cancer (23.5 degrees north latitude) -N hemisphere summer -S hemisphere winter Autumnal equinox -known as the fall equinox in the northern hemisphere -About September 23 -Sun directly overhead at the equator on equinoxes Winter solstice -About December 21 -Sun directly overhead at Tropic of Capricorn (23.5 degrees south latitude) -N hemisphere winter -S hemisphere summer

seawater density

Freshwater density = 1.000 g/cm3 Ocean surface water =1.022 to 1.030 g/cm3 the ocean is layered according to density

surface salinity variation by latitude

High latitudes: -Low salinity -Abundant sea ice melting, precipitation, and runoff Low latitudes near equator: -Low salinity -High precipitation and runoff Mid latitudes: -High salinity -Warm, dry, descending air increases evaporation

boiling and condesnation points

If enough heat energy is added to a liquid, it converts to a gas. The temperature at which boiling occurs is the substance's boiling point. If enough heat energy is removed from a gas, it condenses to a liquid. The highest temperature at which condensation occurs is the substance's condensation point, which is the same temperature as the boiling point boiling point = condensation point = 100°C (212°F). boiling point of water is unusually high water boils at relatively high temperatures because additional heat energy is required to overcome its hydrogen bonds and van der Waals forces.

freezing and melting points

If enough heat energy is added to a solid, it melts to a liquid. The temperature at which melting occurs is the substance's melting point. If enough heat energy is removed from a liquid, it freezes to a solid. The temperature at which freezing occurs is the substance's freezing point, which is the same temperature as the melting point freezing point = melting point = 0°C (32°F) freezing point of water is unusually high water melts at relatively high temperatures because additional heat energy is required to overcome its hydrogen bonds and van der Waals forces.

continental effect

Land areas have greater range of temperatures from day to night and during different seasons

Three distinct water masses based on density

Mixed surface zone (above thermocline) -zone is mixed by waves and currents so we don't see variations in temperature, pressure, or density Upper water/transition zone (thermocline, pycnocline, and halocline) deep water/deep zone (below thermocline to ocean floor)

water

Most abundant substance on Earth's surface H2O — polar liquid (H+OH- Exists in 3 phases on Earth Essential for life (you are 55-78% water)

freshwater vs seawater

Most dissolved solids in the ocean come from river discharge (stream run-off). But, the dissolved components in freshwater and seawater are very idfferent Ions with short residence time (aka a residence time less than 100 years) are in low concentration in seawater ions with long residence time are in high concentration in seawater. for example Na+ and Cl- (which have a residence time of 260 million years). ions with long residence time are removed from the ocean through evaporation and recycling at subduction zones (convergent plate boundaries).

earth's rotation

Objects at Earth's Equator rotate faster than objects at Earth's poles

marine effect

Oceans moderate temperature changes from day to night and during different seasons

January Atmospheric Pressures and Winds

Overall patterns mimic theoretical wind belts Wind patterns are more complex in reality due to: -Tilt of Earth's axis and seasons -Lower heat capacity of continental rock vs. seawater -Uneven distribution of land and ocean

energy resources from biogenous sediment

Petroleum: -Ancient remains of microscopic organisms (primarily diatoms) deposited on the continental shelf and slope. -More than 95% of economic value of oceanic nonliving resources -More than 30% of world's oil from offshore resources -Future offshore exploration will be intense -Potential for oil spills Gas Hydrates: -High pressures squeeze chilled water and gas into icelike solid -resemble ice but burn when lit -Methane hydrates most common -Most deposits are on continental shelf -Gas hydrates may be largest store of usable energy in organic carbon form. • -Rapidly decompose at surface pressures and temperatures -Release of sea floor methane may alter global climate. -Warmer waters may release more methane -Methane release may cause underwater slope failure (which is a tsunami hazard)

high and low pressure zones

Rising and descending air from cells generate high and low pressure zones High pressure zones -at 30 degrees latitude, a column of cool, dense air moves toward the surface and creates high pressure. -The descending air at about 30 degrees north and south latitude creates high pressure zones called the subtropical highs. -at 90 degrees latitude descending air at the poles creates high-pressure regions called the polar highs. -Descending air is quite dry, and it tends to warm under its own weight, so these areas typically experience dry, clear, fair conditions. Low pressure zones -A column of warm, low-density air rises away from the surface and creates low pressure. -rising air creates a band of low pressure at the equator (the equatorial low) and at about 60 degrees north and south latitude (the subpolar low) -The weather in areas of low pressure is dominated by cloudy conditions with lots of precipitation, because rising air cools and cannot hold its water vapor.

resources from lithogenous sediment

Sand and gravel used as: -aggregate in concrete -fill material in grading projects -on recreational beaches Some offshore sand and gravel deposits are rich in valuable minerals. for example: -diamonds are recovered from gravel deposits on the continental shelf offshore africa and australia -sediments rich in tin have been mined offshore asia -platinum and gold have been found offshore gold mining areas worldwide -some florida beach sands are rich in titanium

pure water vs seawater

Seawater has a higher boiling point, lower freezing point, and a higher density

latent heat of evaporation

The conversion of a liquid to a gas below the boiling point is called evaporation. At ocean surface temperatures, individual molecules converted from the liquid to the gaseous state have less energy than do water molecules at 100°C (212°F). To gain the additional energy necessary to break free of the surrounding ocean water molecules, an individual molecule must capture heat energy from its neighbors. In other words, the molecules left behind have lost heat energy to those that evaporate, which explains the cooling effect of evaporation. It takes more than 540 calories of heat to produce 1 gram of water vapor from the ocean surface at temperatures less than 100°C (212°F). More heat is required because more hydrogen bonds must be broken. At higher temperatures, liquid water has fewer hydrogen bonds because the molecules are vibrating and jostling about more.

global wind belts

The lowermost portion of the circulation cells (the part that is closest to the surface) generates the major wind belts of the world. these wind belts drag ocean water, creating currents trade winds (the trades): -flow from the poles to the equator -The masses of air that move across Earth's surface from the subtropical high-pressure belts toward the equatorial low-pressure belt -In the Northern Hemisphere, the northeast trade winds curve to the right due to the Coriolis effect and blow from northeast to southwest. -In the Southern Hemisphere, the southeast trade winds curve to the left due to the Coriolis effect and blow from southeast to northwest. -warm -fairly consistent (15 to 20 mph) prevailing westerly wind belts (westerlies): -from 30-60 degrees latitude -flow from the equator to the poles -Some of the air that descends in the subtropical regions moves along Earth's surface to higher latitudes as the prevailing westerly wind belts -because of the Coriolis effect, the prevailing westerlies blow from southwest to northeast in the Northern Hemisphere and from northwest to southeast in the Southern Hemisphere -inconsistent (5 to 30 mph) polar easterly wind belts: -from 60-90 degrees latitude -flow from the poles to the equator -Air moves away from the high pressure at the poles, too, producing the polar easterly wind belts. -The Coriolis effect is maximized at high latitudes, so these winds are deflected strongly. -The polar easterlies blow from the northeast in the Northern Hemisphere, and from the southeast in the Southern Hemisphere. -When the polar easterlies come into contact with the prevailing westerlies near the subpolar low pressure belts (at 60 degrees north and south latitude), the warmer, less dense air of the prevailing westerlies rises above the colder, more dense air of the polar easterlies. -cold -15 to 40 mph

global thermostatic effects of water's properties

These effects of water include the unique properties of water that act to moderate changes in global temperature, which in turn affect Earth's climate. For example, the huge amount of heat energy exchanged in the evaporation- condensation cycle helps make life possible on Earth: -The Sun radiates energy to Earth, where some is stored in the oceans -Evaporation removes this heat energy from the oceans and carries it high into the atmosphere. -In the cooler upper atmosphere, water vapor condenses into clouds, which are the source of precipitation (mostly rain and snow) -When precipitation occurs, it also releases water's latent heat of condensation. -this cycle of evaporation and condensation removes huge amounts of heat energy from the low-latitude oceans and adds huge amounts of heat energy to the heat-deficient higher latitudes. -In addition, the heat released when sea ice forms further moderates Earth's high-latitude regions near the poles.

Molecule

Two or more atoms held together by shared electrons smallest form of a substance

water's global thermostatic effects

Water's properties moderate temperature on Earth's surface. For example, because of water's high heat capacity, equatorial oceans do not boil and polar oceans do not freeze solid The heat energy exchanged in evaporation condensation cycle makes life possible on Earth

Coring

a hollow steel tube with a heavy weight on top that is thrust into the seafloor to collect cores (cylinders of sediment and rock) advantages: -It's considerably less expensive and time-consuming than drilling -unlike dredging, the gravity corer can sample below the surface, it lets you sample the upper 30-50 ft of the seafloor and subsurface sediments. disadvantages: -depth of penetration is limited.

pycnocline

abrupt change of density with depth separates ocean layers with different density only develops at low latitudes (high latitudes are isopycnal)

thermocline

abrupt change of temperature with depth separates ocean layers with different temperature only develops at low latitudes (high latitudes are isothermal)

Heat

amount of energy transferred from one body to another due to temperature differences. It is proportional to the kinetic energy of molecules

Drilling

an international effort, can sample more than 23,000 ft beneath seafloor advantages: -able to sample much deeper beneath the seafloor (which is ideal for many scientific questions), disadvantages: -incredibly expensive and time-consuming.

angle of incidence

angle of the sun hitting sea surface lower angle of incidence = greater reflection of incoming sunlight

temperature variation with depth

at low latitudes, temperature decreases with depth at high latitudes, temperature is isothermal (consistently low throughout) the deep ocean has a consistently low temperature globally

Residence Time

average length of time a substance remains dissolved in seawater controlled by how readily it is used in biological and chemical processes (the more readily it is used, the shorter the residence time) for example: -Chloride and Sodium (Cl and Na) are toxic to many life-forms, so they aren't readily removed from the ocean (which is why they have a long residence time and why the ocean is salty) -Fe and Al are removed very quickly through biological processes (which is why they have a short residence time) -some ions (Fe, Mn, C) are easily incorporated into hydrogenous sediment (hencethe short residence time) -other ions (Ca, Si, P) are used by marine life (hence the short residence time)

If there is a net annual heat loss at high latitudes and a net annual heat gain at low latitudes, why does the temperature difference between these regions not increase?

because of atmospheric cirulcation. heat circulates in the atmosphere and helps to keep global temperatures more moderate because heat moves from regions of heat gain to regions of heat loss

atoms

building blocks of all matter Number of protons distinguishes chemical elements

convection cell

composed of the rising and sinking air moving in a circular fashion, similar to the convection in Earth's mantle Temperature has a dramatic effect on the density of air. At higher temperatures, air molecules move more quickly, take up more space, and density is decreased. Thus, the general relationship between density and temperature is: -Warm air is less dense (and can hold more moisture because it's less dense) so it rises (as it rises it expands and cools because there is less atmosphere above pushing downward) -Cool air is more dense (and can't hold as much moisture), so it sinks (as it sinks it compresses and warms)

clouds

cooling, rising air, with enough water vapor, forms clouds

pelagic (oceanic) sediments

deposits found in the deep ocean basins. Dominated by biogenic oozes and fine grained lithogenous materials like silts and abyssal clays Even though they are far from land, deep abyssal plains contain thick sequences of abyssal clay deposits composed of particles transported great distances by winds or ocean currents and deposited on the deep-ocean floor these deposits also contain: -microscopic biogenous materials that form oozes (siliceous - cold water, calcareous - warm water) -manganese hydrogenous sediment -microscopic cosmogenous sediment mixed in.

neritic sediments

deposits that are found on the margins of the major continental landmasses and islands (nearshore). these deposits are generally coarse grained. Dominated by lithogeneous sediments: -coarse lithogenous materials like sands accumulate rapidly on the continental shelf, slope, and rise -Examples of lithogenous neritic deposits include beach deposits, continental shelf deposits, turbidite deposits, and glacial deposits. also can containt: -macroscopic manganese materials like shells and corals -evaporite hydrogenous sediment -microscopic cosmogenous sediments mixed in beach deposits: -Beaches are made of whatever materials are locally available -Beach materials are composed mostly of quartz-rich sand that is washed down to the coast by rivers but can also be composed of a wide variety of sizes and compositions -This material is transported by waves that crash against the shoreline, especially during storms. turbidity deposits: -turbidity currents are underwater avalanches that periodically move down the continental slopes and carve submarine canyons -Turbidity currents also carry vast amounts of neritic material -This material spreads out as deep-sea fans, comprises the continental rise, and gradually thins toward the abyssal plains. -These deposits are called turbidite deposits and are composed of characteristic layering called graded bedding

cosmogenous sediment

derived from extraterrestrial sources origins: -Extraterrestrial "space dust" -Origin not well understood -come from asteroid collisions (spherule) or impacts with Earth and other rocky planets (tektite) composition: -when coming from asteroid collisions (composed of iron and nickel) -when coming from impacts with Earth and other rocky planets (silica rich) Texture: -when coming from asteroid collisions (spherules) -when coming from from impacts with Earth and other rocky planets (teardrop-shaped)

hydrogenous sediment

derived from material dissolved in water origins: -formed when changes in ocean water conditions cause dissolved materials to precipitate (or come out of solution). Changes in conditions include changes in temperature or pressure, or the addition of a chemically active fluids composition: -manganese nodules (hard lumps 5-20 cm in diameter that form on abyssal plains) -phosphates (nodules that form on the continental shelves at <1000 m water depth) -Metal Sulfides (metal deposits form at hydrothermal vents at mid-ocean ridges) -Evaporites (form wherever there are high evaporation rates combined with restricted ocean circulation)

lithogenous sediment

derived from preexisting rock material that originates on land from erosion, volcanic eruptions, or blown dust. found on most parts of the ocean floor, and can occur as thick deposits close to land origins: -rocks on land broken up and decomposed through weathering by water, temperature extremes, and chemical effects. transportation: -bits of rock are picked up (eroded) and transported and carried to the ocean by moving water such as streams, rivers, currents, and waves (streams are the primary source of lithogenous sediment to the ocean - flowing water carries sediment load [gravel, sand, silt, and clay] to the ocean) -wind (blows fine-grained dust [silt and clay] far out over the ocean, where these particles slowly settle to the ocean floor. Deposits tell about past atmospheric conditions) -volcanic eruptions (hurl tiny ash particles high into the atmosphere, where jet stream winds can carry them thousands of miles, where they eventually settle to the ocean floor. Sharp edges and irregularly shaped particles distinguish ash from other marine sediments) -glaciers (carry lots of sediment of all sizes [clay to boulder] to the ocean. Icebergs can act as a raft and carry sediment and boulders far into the ocean floor) -gravity (erosion of beach cliffs and coastal landslides cause large boulders and massive blocks of sediment to fall into the coastal ocean. Wave energy breaks down boulders into sand grains which are carried away by nearshore currents) -Turbidity currents (flow through submarine canyons, carrying lithogenous sediment from the shelf to the base of the slope where submarine fans form the continental rise) composition: -varies by what type of rock is being broken up -In southern California granite is being eroded, so sediments consists of lots of quartz, feldspar, and biotite -consists primarily of quarts because it is resistant to abrasion, extremely abundant, and extremely stable. -olivine (a volcanic mineral that causes green sand beaches in Hawaii) texture: -grain-size ranges from clay to boulders. -classified as boulders (largest), cobbles, pebbles, granules, sand, silt, or clay (smallest) -larger grains are harder to move, and are therefore deposited where energy is high (beaches) -smaller grains will transport further, deposited in low-energy environments (deep sea) -sorting (how uniform the grain size). sediment is poorly sorted in higher energy environments, and well sorted in lower energy environments -rounding (as grains travel, they become rounder) neritic vs pelagic -neritic (nearshore - coarse lithogenous materials) -pelagic (open ocean - lithogenous abyssal clays)

biogenous sediment

derived from the remains of hard parts of once living organisms origins: -Biogenous sediment begins as the hard parts (shells, bones, and teeth) of microscopic and macroscopic living organisms. -When these organisms die, their remains settle to the seafloor. -Classified as macroscopic (can be seen by the naked eye) or microscopic (most abundant). Macroscopic -skeletons of marine vertebrates like whale, dolphins, fish -clam and snail shells -coral reef fragments -marine life is concentrated in warm water above the continental shelf, so this is where most macroscopic biogenous sediment is found. Microscopic -microscopic organisms secrete tiny shells called tests. When the organisms die, these shells sink to the seafloor in a continuous "snowfall" of biogenous ooze (to be classified as biogenous ooze, must contain at least 30% biogenous test material by weight) -Phytoplankton are tiny photosynthetic plants that float in the upper sunlight portions of the ocean. -Zooplankton are tiny animals that float or swim weakly in the ocean Composition: -composed of either silica (SiO2) from diatoms and radiolarians or calcium carbonate (CaCO3) from foraminifers and coccolithophores. -Calcareous Ooze (deposits comprised of >30% of the tests of foraminifera, coccoliths, and other calcium carbonate [CaCO3] secreting organisms). Calcareous ooze lithifies to become chalk. -Siliceous Ooze (deposits comprised of >30% of the tests of diatoms, radiolarians, and other silica [SiO2] secreting organisms). Siliceous ooze lithifies to become diatomaceous earth texture: -macroscopic (can see with your eye) -microscopic (need microscope to see) neritic vs pelagic -neritic (nearshore - macroscopic biogenous sediment like shells and corals) -pelagic (open ocean - calcareous oozes, siliceous ooze) distribution (neritic deposits): -macroscopic materials (shells, corals) -microscopic carbonates in tropical waters, ex. great barrier reef in Australia, limestones distribution (pelagic deposits) -siliceous ooze, found beneath cold surface water in high latitudes. Upwelling brings deep, cold, nutrient rich ocean water to the surfce and high biological productivity. also found in sea floor beneath areas of upwelling, including along the equator. -calcareous ooze, found in sea floor beneath warm surface water in low latitudes. found at depths above 4500 m (15,000 ft) below sea level (which is the calcite compensation depth [CCD]). Above the CCD calcium carbonate is stable and is not dissolved. Below the CCD low temperature and high pressure conditions cause calcium carbonate to dissolve. also found in sea floor beneath warm surface water in low latitudes along the mid ocean ridge. distribution depends on 3 fundamental processes: -Productivity (surface waters with high biological productivity favor the formation of biogenous sediment) -Destruction (siliceous sediments will dissolve unless there is enough silica to saturate the ocean water. Calcareous sediments will dissolve in seawater at depths below the CCD) -Dilution (a high influx of lithogenous material will dilute biogenous sediment found in seafloor deposits to concentrations of <30%)

hydrologic cycle

describes the continual movement of water on, above, and below the surface of Earth. The movement of water through various components of the hydrologic cycle involves processes that recycle water among the ocean, the atmosphere, and the continents, illustrating that water is in constant motion between the different components (or reservoirs) of the hydrologic cycle. many of the processes of the hydrologic cycle affect seawater salinity. For example, river runoff into the ocean changes seawater salinity in that region. Of Earth's reservoirs, the vast majority of water at or near Earth's surface is contained in the ocean.

temperature

direct measurement of the average kinetic energy of molecules in a substance

water's three states of matter

exists as a solid, liquid, and gas at the earth's surface

movement of the atmosphere

global atmospheric circulation is the product of unequal heating of the earth's surface by the sun convection occurs because of this. Air always flows from high to low pressure. Cool, dense air sinks, causing higher surface pressure Warm, moist air rises, causing lower surface pressure Wind = moving air

latent heat of vaporization

greater than the latent heat of melting because: -To go from a solid to a liquid, just enough hydrogen bonds must be broken to allow water molecules to slide past one another. -However, to go from a liquid to a gas all of the hydrogen bonds must be completely broken so that individual water molecules can move about freely

specific heat

heat capacity per unit mass water's specific heat is far greater than that of many other substances. this makes the temperatures of the oceans relatively resistant to change, therefore allowing oceans to moderate the earth's total temperature range

hypothetical nonspinning earth

if the earth was not spinning on its axis but instead the Sun rotated around Earth, the Sun would be directly above Earth's equator at all times Because more solar radiation would be received along the equator than at the poles, the air at the equator in contact with Earth's surface would be warmed. This warm, moist air would rise, creating low pressure at the surface. This rising air would cool and release its moisture as rain. Thus, a zone of low pressure and much precipitation would occur along the equator. As the air along the equator rises, it reaches the top of the troposphere and begins to move toward the poles. Because the temperature is much lower at high altitudes, the air cools, and its density increases. This cool, dense air sinks at the poles, creating high pressure at the surface. The sinking air is quite dry because cool air cannot hold much water vapor. Thus, the poles experience high pressure and clear, dry weather. Air always moves from high pressure to low pressure, so air travels from the high pressure at the poles toward the low pressure at the equator. Thus, there are strong northerly winds in the Northern Hemisphere and strong southerly winds in the Southern Hemisphere. The air warms as it makes its way back to the equator, completing the loop (called a convection cell or circulation cell) However, the Earth rotates, so circulation is not so simple

salinity variation with depth

in low latitudes salinity decreases with depth in high latitudes salinity increases with depth Deep ocean salinity fairly consistent globally

density variation with depth

in low latitudes, density increases with depth in high latitudes density is isopicnal (high throughout) deep ocean density consistently high globally

decreasing salinity

involves adding fresh water to ocean processes that add fresh water include runoff, melting icebergs, melting sea ice, precipitation

increasing salinity

involves removing water from ocean processes that remove fresh water include sea ice formation and evaporation

marine sediment

loose grains rock, dust, skeletal fragments, shells, etc, that settle out of the water and collect on the ocean floor. provide a wealth of information about past conditions on Earth. As sediment accumulates on the ocean floor, it preserves the materials—and the conditions of the environment—that existed in the overlying water column. By carefully analyzing cylindrical cores of sediment collected from the sea floor and interpreting them, Earth scientists can infer past environmental conditions such as: -sea surface temperature -nutrient supply -abundance of marine life -atmospheric winds -ocean current patterns -volcanic eruptions -major extinction events -changes in Earth's climate -the movement of tectonic plates these sediments reveal that earth has had an interesting and complex history including mass extinctions, the drying of entire seas, global climate change, and the movement of tectonic plates. most of what is known of Earth's past geology, climate, and biology has been learned through studying ancient marine sediments

heat gained and lost by oceans

low lattitudes = more heat gained than lost high lattitudes = more heat lost than gained: -ice has a high albedo -low solar ray incidence

resources from hydrogenous sediment

manganese nodules and crusts: -Lumps of metal -Contain manganese, iron, copper, nickel, cobalt -Economically useful carbonates: -widely used in the construction industry, in the production of cement -commonly used medicinally as calcium supplements or antacids phosphorite: -phosphate minerals -Fertilizer for plants -Found on continental shelf and slope Evaporative salts: -Form salt deposits -Gypsum -used in drywall -Halite -common table salt

density

mass/unit volume The density of most substances increases as temperature decreases. Density increases as temperature decreases because the molecules lose energy and slow down, so the same number of molecules occupy less space. This shrinkage caused by cold temperatures, called thermal contraction, also occurs in water, but only to a certain point. As pure water cools to 4°C (39°F), its density increases. however, from 4°C down to 0°C (32°F) its density decreases. at these temperatures water stops contracting and actually expands, which is highly unusual The result is that ice is less dense than liquid water, so ice floats on water. This all happens because molecular packing changes as water approaches its freezing point. until water reaches 4°C, its density increases because the amount of thermal motion decreases, so the water molecules occupy less volume. When the temperature is lowered below 4°C (39°F), the overall volume increases again because water molecules begin to line up to form ice crystals. ice crystals are bulky, open, six-sided structures in which water molecules are widely spaced. Their characteristic hexagonal shape mimics the hexagonal molecular structure resulting from hydrogen bonding between water molecules By the time water fully freezes the density of the ice is much less than that of water at 4°C (39°F), the temperature at which water achieves its maximum density. Density increases with: -decreasing temperature (temperature is the greatest influence on density) -increasing salinity -increasing pressure Increasing pressure or adding dissolved substances decreases the maximum density temperature Dissolved solids also reduce the freezing point of water. Most seawater never freezes. Density increases with increasing pressure (this does not affect surface waters)

isopycnal

no density variation in water column

isothermal

no temperature variation in water column

salinity variations in the ocean

ocean salinity is a steady state condition in that the average amounts of various elements remains constant over time Open-ocean salinity varies between 33-38 o/oo. In coastal areas salinity varies more widely Brackish describes an influx of fresh water from rivers or rain that lowers salinity of water (examples: coastal marshes, wetlands, estuaries) Hypersaline describes high evaporation conditions For example: -Great Salt Lake salinity = 280 o/oo. -Dead Sea salinity = 330 o/oo. Salinity may vary with seasons (dry/wet).•

circulation cells

one in each hemisphere Hadley cells (tropical cells): -The greater heating of the atmosphere over the equator causes the air to expand, to decrease in density, and to rise. -As the air rises, it cools by expansion because the pressure is lower, and the water vapor it contains condenses and falls as rain in the equatorial zone. -The resulting dry air mass travels north or south of the equator. -Around 30 degrees north and south latitude, the air cools off enough to become denser than the surrounding air, so it begins to descend, completing the loop. These circulation cells (from 0 to 30 degrees latitude) are called Hadley cells Ferrel cells (mid-latitude cells): -In addition to Hadley cells, each hemisphere has a Ferrel cell between 30 and 60 degrees latitude . -these cells are not driven solely by differences in solar heating -Similarly to the movement of interlocking gears, the Ferrel cell moves in the direction that coincides with the movement of the two adjoining circulation cells. polar cells: -between 60 and 90 degrees latitude

albedo

percentage of incident radiation that is reflected back to space measured in 0 to 100% earth's albedo is about 30%

Subatomic particles

protons, neutrons, electrons

Halocline

separates ocean layers with different salinity develops at high and low latitudes

thermal contraction

shrinkage of most substances caused by cold temperatures

Dredging

simple grab from the seafloor surface advantages: -relatively quick and easy disadvantages: -often doesn't work right and the dredge can come up empty -samples aren't necessarily intact ebcause they get disrupted by the scoop -can only gather samples from the surface of the ocean floor.

hydrogen bonds in water's three states of matter

solid: -in the solid state, water exists as ice -there are hydrogen bonds between all molecules -crystalline structure is 3 dimensional -intermolecular bonds are constantly being broken and reformed liquid: -in the liquid state, there are some hydrogen bonds -Intermolecular bonds are being formed and broken at a much greater rate than in the solid state. gas: -in the gaseous state, there are no hydrogen bonds -water molecules move rapidly and independrntly

Calorie

the amount of heat needed to raise the temperature of 1 gram of water by 1° centigrade

heat capacity

the amount of heat required to raise the temperature of 1 gram of any substance by 1° centigrade Water has a high heat capacity, it can absorb or lose much heat without changing temperature. The reason for water's high heat capacity is because it takes more energy to increase the kinetic energy of hydrogen-bonded water molecules than it does for substances in which the dominant intermolecular interaction is the much weaker van der Waals force. As a result, water gains or loses much more heat than other common substances while undergoing an equal temperature change. In addition, water resists any change in temperature The ocean's heat capacity moderates coastal temperatures The ocean's heat capacity also lessens Earth's total temperature range. The earth only has a 262°F total range, while the moon has a 496°F total range

physical properties of the atmosphere

the atmosphere is a combination of gasses, that we call air: - Mostly nitrogen and oxygen -also contains carbon dioxide, argon, and methane (significant for heat trapping properties) -also contains water, mostly from ocean surface evaporation not static, constantly changing shields the earth from things coming from space, protecting it from most impacts absorbs or reflects much of solar energy earth's atmosphere is layered based on temperature Troposphere is the lowest layer of atmosphere, where all weather occurs, extends from surface to about 12 km (7 miles) up Temperature decreases with altitude

latent heat of melting

the energy needed to break the intermolecular bonds that hold water molecules rigidly in place in ice crystals. The temperature remains unchanged until most of the bonds are broken and the mixture of ice and water has changed completely to 1 gram of water.

latent heat

the heat absorbed or released during change of state (involves breaking or forming hydrogen bonds) When water undergoes a change of state—that is, when ice melts or water freezes, or when water boils or water vapor condenses—a large amount of heat is absorbed or released. The amount of heat absorbed or released is due to water's high latent heats and is closely related to water's unusually high heat capacity. latent heat affects the amount of energy needed to increase water temperature and change the state of water.

water as a universal solvent

the polar nature of water allows it to dissolve nearly everything. Water molecules stick not only to other water molecules but also to other polar chemical compounds. In doing so, water molecules can reduce the attraction between ions of opposite charges by as much as 80 times. The electrostatic attraction between oppositely charged ions produces an ionic bond. For example, when solid NaCl is placed in water, the electrostatic attraction (ionic bonding) between the sodium and chloride ions is reduced by 80 times. This, in turn, makes it much easier for the sodium ions and chloride ions to separate. When the ions separate, the positively charged sodium ions become attracted to the negative ends of the water molecules, the negatively charged chloride ions become attracted to the positive ends of the water molecules and the salt is dissolved in water. This is why the ocean contains so much salt (110 quintillion pounds)

salinity

the total amount of dissolved solids in water including dissolved gases It excludes dissolved organic materials and suspended fine-grained sediments It is expressed as ratio of the mass of dissolved substances to the mass of the water sample. Expressed in parts per thousand (ppt) Typical ocean salinity is 35 ppt (o/oo) or 3.55% Major seawater components: -chloride (Cl-) -sodium (Na+) -sulfate (SO4-) -magnesium (Mg2+) -calcium (Ca2+) -potassium (K+) All of Earth's naturally occurring elements are contained in the seawater

heat, temperature, and changes of state of water

water has a high heat of vaporization (state/phase changes require lots of energy) in order to change phase, energy must be added for molecules to overcome molecular attractive forces. adding or removing heat causes a substance to change its state of matter. Forces Include: -hydrogen bonding -Van der Waals forces (relatively weak interactions that become significant only when molecules are very close together, as in the solid and liquid states, but not the gaseous state)

water's molecular structure

water has covalent bonds (bonds created by sharing electrons with other atoms) in water, these bonds form between two hydrogen (H) and one oxygen (O) atoms The water molecule is composed of one atom of oxygen and two atoms of hydrogen (H2O). The two hydrogen atoms, which are covalently bonded to the oxygen atom, are attached to the same side of the oxygen atom and produce a bend in the geometry of a water molecule. This geometry makes water molecules polar, which allows them to form hydrogen bonds with other water molecules or other substances and gives water its remarkable properties. water is a polar molecule (a molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end). As a result water molecules orient themselves relative to one another.