oce test one study guide

biological oceanography

the study of life in the oceans

geological oceanography

the study of the ocean floor

chemical oceanography

the study of the composition of seawater

physical oceanography

study of the motion of water in the ocean

ocean engineering

study of how to design/build things at sea

what is one major challenge of oceanic research?

it is very expensive

why is earth called the blue planet?

due to the abundant amount of water on its surface

how much of the earth’s surface is ocean water?

about 70%

what is the “water sphere”?

the southern hemisphere because it is mostly water

the world’s oceans

Atlantic, Pacific, Indian, Arctic

What is the largest ocean?

Pacific

What is the shallowest ocean?

Arctic

What is the smallest ocean?

Arctic

observation

the act of knowing and recording something

hypothesis

an educated guess as to what will happen during your experiment

theory

a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment

law

a statement that describes an observable occurrence in nature that appears to always be true

what is the difference between a theory and a law?

a law is the description of an event, while theory is the explanation for that event

What were early oceanographers classed as?

explorers

Why were oceans important to early civilizations?

They were essential for livelihood (transportation, knowing rain helps maintain crops and food)

Phoenicians

the first explorers, middle eastern society (lebanon, syria, etc), understand currents and water approaching land

Arab traders

1500-500 BC, traded all across Indian Ocean, East Africa, India, etc., learned about sea faring through traveling

Polynesians

1500 BC, originated from South Asia, India, over to Australia, begin to strike out across South Pacific ~1000 BC, courageous, hoping to run into land. boats made out of local materials, exploring and learning how to fish across Pacific Ocean. star structures using sticks, shells, rocks

Why did explorers need to stay close to land?

in order to see where they are navigating and to be closer to supply, know where you are and tell people how to get there, orally share information

The use of stars for navigation

ancient Polynesians used star maps for navigation, use how the seasons change as a guide

Aristotle’s discoveries

studies of the currents, determined that we have a hydrologic cycle (water is evaporated from oceans, then will condensate, and later precipitate), first to start thinking about the ocean as a science (cataloged animals and plants, figured out that oceans occupy the deepest parts of the Earth’s surface

Eratosthenes’ contribution

: Egyptian scientist, used geometry to determine the actual size of the Earth and the fact that it was spherical

Pliny the Elder’s contribution

(23-79 AD) proposed that the phases of the moon were related to the ocean/tides, detailed the currents moving through the Straits of Gibraltar (passageway between Spain & Morocco)

Ptolemy

(127-151 AD) drew detailed maps of known world, put  latitudes and longitudes on the map, published the first atlas, and the flaw in his map = he used the wrong radius of the Earth (made locations too close together). later consequence = Columbus (1492) thought he was in indigenous but was actually in San Salvador Island

Middle Ages

dark time for science, little discovery, but advances in ship building, use of compasses (aid navigation), Vikings came to Greenland and Newfoundland from Norway, Denmark, Iceland, Sweden – didn’t stay but settled in eastern part of North America but left because of changing climatic conditions. Arab explorers continue and describe winds and currents during monsoons, established more efficient trade routes throughout the Indian Ocean. Dark Ages was a bad time for science, but Black Death proved its importance and influenced Renaissance, Enlightenment (Europe/China), Age of Exploration (1400s)

Ming Dynasty

Emperor Zheng sent fleet of 300 ships across Pacific and Indian Oceans = largest expedition ever, perhaps reached North America but not a lot of permanent remnants

Who were European explorers funded by? (15th/16th century)

the governments

Dias

sailed around tip of Africa, Indian Ocean

Columbus

(1492) sailed through the Bahamas from Spain (thought that he was in India but was actually San Salvador Island)

Vespucci

: new world named for Americo Vespucci, Italian explorer, sailed to Americas and recognized South America as separate continent

Balboa

1500s, from Spain, crossed the Isthmus of Panama, named Pacific Ocean

Magellan

1519, first circumnavigation of the globe, sets out from Portugal and goes all the way around, ended up in conflict with locals (internal warfare), Magellan killed in Malaysia, but his expedition fleet/ships made it back to Portugal

Charts and navigation

allowed people to know where they were going, break maps up into latitude and longitude (latitude runs east/west, longitude runs north/south)

Harrison’'s contribution

developed time at sea, time plot to develop latitude/longitude, determine where you are in the world by what time it was (angle of sun). however, time pieces at sea were not completely accurate, ships misjudged and ran into reefs etc. British gov (1700s) gave grant Harrison for developing accurate sea time piece (coronagraph). determine longitude and help accurate calculations. 

cook’s contribution

(1768-1779) sailed Pacific using Harrison’s clock and maps lat/long of coastline to make accurate maps of area for the first time, measures depths, winds, currents, temperatures. one of the first oceanographers

Franklin and the North Atlantic current

trades, science research, studies currents, credited with first proper map of the Gulf Stream (fast moving stream that goes over to Europe and then comes back)

Maury’s contributions

(19^th Century) US Navy, founded naval depot, collected data from ships from all over world to make charts of currents and winds. used this info to cut down sailing times. published first oceanography book (1855), many say he was one of the first oceanographers

Darwin

cataloging ocean organisms, become basis of his evolution theories

Forbes

catalogs marine organisms in England and Mediterranean Sea, collects samples and different depths and proposes diff groups of animals live at diff depths of the ocean

Ross’ contributions

finds there in fact is life at depths of ocean (contradicts Forbes), similar creatures at different parts of the oceans

Muller’s contributions

microscopic plants & animals under the microscope (later named plankton)

Challenger expedition

first true oceanographic cruise, 3 ½ year expedition, sparked public interest by putting strange looking creatures on board to spark interest in funding, collected deep water samples, investigated deep water motion, measured temperatures, collected biological and geological samples, lead to an interest in the exploration of the ocean. uses data to describe why and how the ocean works

Nansen’s experiment with the Fram

(late 1800’s) investigated how certain ocean currents moved in the Arctic, had his ship (Fram) reinforced and frozen into the ice, drilled into ice to make temperature and depth measurements, made advances in technology that improved ocean order

Kelvin’s contribution

(late 1800s) invents time predicting machine and timetables that combined astronomical predictions with tidal theory

Amundsen’s contributions

Norwegian explorer, works his way through Northwest Passage, confirms location of the magnetic pole, becomes first to reach the North Pole, (1910) starts putting thermometers in a nonsense bottle (water sample bottle that was put below the ocean to get a sample contaminated by surrounding water)

eco sounding

sending sound signal to the bottom of the ocean and bouncing it back up (know how long it takes for water to travel through sound)

Why did oceanographic exploration take hold again in the 1940s?

due to WWII and need to get to remote locations quickly, needed to predict conditions for amphibious landing in WWII and chart beaches and harbors from the air, need to know how explosives behave and find enemy submarines, many oceanographers work for gov instead of private research

What technological advances came from the 1940s exploration?

radar, better sonar, temperature & depth records, money for more research and education

What the Glomar Challengere was for in the 1960s

(now JOIDES ship does the same): deep sea drilling into the sea floor to see what it was composed of and how deep they could get, used computers so data can be analyzed while still at sea and modify sampling based on trends in data

The significance of satellites

(since 1970s) aided exploration, measure surface height, wind speeds, ice cover, cloud cover, oil spill, abundances, and temperatures remotely. different satellites take different amounts of time and money, can also be put on ISS (space)

contribution of submarines

can go to depths of the ocean that humans cannot. most famous: alvin (35000 ft deep been to bottom of marianas trench)

ROVs

remotely operated vehicle, can stay at bottom of the ocean because no humans requiring oxygen. can gather data, collect samples, etc. can be used to find things & send down subs

What are “water reservoirs”?

the hydrologic cycle

What percentage of earth’s water is in the oceans?

71%

What is the second water largest reservoir, and about what percentage of earth's water is in it

Atlantic Ocean, 2%

What is the third largest water reservoir?

Indian Ocean

Basics of the hydrologic cycle

evaporation, condensation, precipitation

What is the source of energy for the hydrologic cycle?

the sun

radiometric dating

establishing how old something is based on the presence of a radioactive isotope within it

half-life

the amount of time it takes for half of the atomic nuclei of a radioactive sample to decay

geological timescale

way to subdivide time, tied to what lived during that time period (eon, era, period, epic/age)

What do scientists consider the age of the earth to be?

about 4.5 billion years

Precambrian eon

Precambrian is the time period before complex life forms

Phanerozoic eon

the time period with visible life forms (only 10% of history with complex life forms)

Phanerozoic divisions

Paleozoic (old life), Mesozoic (middle life), Cenozoic (recent life)

origins of planets & earth

started as a cloud of dust and gas that contained all the elements, asteroids and comets formed other planets, over time particles grow and collide with space debris to become planets

What are the four factors that affect the evolution of earth?

melting, volcanos, distance from the sun, presence or absence of a plane

melting

caused differences between crust and earth as a whole

chemical composition of the mantle and crust

heavier elements (iron and magnesium) in the mantle and lighter elements (silicon and oxygen) in the crust

volcanoes

radioactive decay of elements emits heat, which allows volcanoes to form. gasses get released during volcanic eruptions, water vapor in the atmosphere eventually condenses and falls to earth, resulting in rivers/lakes/oceans

Where is earth wider?

Earth is wider around the equator than around poles

time zones

formed due to light and darkness at different times (distance from sun & equator)

distance from the sun

controls the state of the water present (liquid, gas, etc.), Know the true “reason for the seasons”: rotation & revolution, tilt of the earth’s axis, angle of sunlight

tropic of cancer

23 ½ degrees north latitude, vertical rays hit on June solstice

tropic of capricorn

23 ½ degrees south latitude

Arctic and Antarctic Circles

24hrs of dark (eternal night/new moon)

Equator

imaginary line equally distant from both poles, divides the northern and southern hemisphere

Summer and Winter solstices

December and June

Fall and Spring Equinoxes

March and September

Why and how length of day changes between seasons

tropic of Capricorn and tropic of cancer, summer and winter solstice

How did plants change Earth’s atmosphere?

through photosynthesis, they take up carbon dioxide and then release oxygen into the atmosphere

Prime Meridian

line drawn from north to south at 0 degrees longitude

Where is the equator?

0 degrees latitude

lines of latitude and longitude

equator is at zero, latitude and longitude lines are drawn horizontally and vertically on globe. longitude is measured through the prime meridian

globes vs. maps

maps were not re-producible for a long time, globe is totally accurate, maps have distortion but are more practical

What do earthquake waves tell us about the interior of the earth?

show that the earth’s interior consists of a series of concentric shells with a crust, mantle, liquid outer core, and a solid inner core

Alfred Wegener’s idea

Wegener came up with the continental drift and his idea was that the continents were not in the places had always been (they had moved)

evidence for Wegener’s idea

• fit of coastlines (particularly Africa and South America, coastlines all fit together, they split apart during Pangea)

• fossil similarities (Mesosaurus and Glossopteris: fossils from around the same time period were found in lands that were once together, same rocks were found all across South America, India, Antarctica, Australia, and Africa)

• glacial evidence (till, straitions: large bundles of ice and parts of glaciers that make grooves on the rock’s surface. usual for Antarctica but not for South America and Africa, proves that continents were together at the time)

• mountain ranges (rocks & mountains from different sides of earth were still similar)

Why was Wegener’s idea criticized?

no mechanism, no evidence of actual motion

How did new data revive Wegener’s ideas?

deep sea data from WW2, and by 1968 the theory of plate tectonics was accepted  

What were the new lines of evidence for Wegener’s ideas?

• mid-ocean ridges: where seafloor spreading occurred

• ages of sea floor: mid ocean ridges are the youngest part of the sea floor

• thickness of seafloor sediments: the thickest sediments were found at the edges of the contents, thinnest in the middle because it had not been around as long

• magnetic reversals: geomagnetic pole was pointing to the South Pole, when a rock cools it records the geomagnetic field at that time, allowing us to see seafloor spreading

• polar “wandering”: seemed two magnetic poles flipped from north to south and wandered all over the globe (European and North American paths), but the continents were moving not the poles

• earthquake and volcano patterns (pacific ring of fire): follow the plate boundaries

• hydrothermal vents and black smokers: hot water minerals are coming out into cold water causing them to solidify at the mid ocean ridge (evidence of heat flow at the mid-ocean ridge)

• hot spots: a mantle plume, plate moves over top of the hotspot and get increasingly older/younger

hot spots

a mantle plume, plate moves over top of the hotspot and get increasingly older/younger, comes from underneath up to the sea surface

asthenosphere

the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur

lithosphere

the rigid outer part of the earth, consisting of the crust and upper mantle

mantle

the region of the earth's interior between the crust and the core, believed to consist of hot, dense silicate rocks