The Oceans Exam 1
Biosphere
the zone of life on Earth → the global sum of all ecosystems
New Theory on Creation of Earth's Moon
Moon was produced by head on collision between Earth and Theia about 100 million years after Earth was formed
Charles Darwin (1809-1881)
- 5 year voyage aboard the HMS Beagle 1831-1836 - Theories of Coral Atoll Formation and Organic Evolution - 1859 → Publication of: "On the Origin of Species"
Origin of the Oceans
- As a result of density stratification, water for the oceans is outgassed from inside the Earth - Early in Earth's history, widespread volcanic activity released large amounts of water vapor and small quantities of other gases - As Earth cooled, water vapor condensed into clouds and fell to Earth's surface, where it accumulated to form the oceans
Captain James C. Cook's Expeditions: 1768-1779
- Began the voyaging for science - Major contribution of Cook's voyages: invention of the chronometer → clock or watch that wasn't affected by the waves and motion of the sea - 3 scientific voyages: one mission was to map the path of Venus between the Earth and the Sun in order to calculate the distance between the Earth and the Sun - Looked for Antartica and never found, but did find the Hawaiian Islands - He was considered an oceanographer, anthropologist and naturalist
Atmospheric Energy transfer
- Conduction → the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material: 1. the process by which sound waves travel through a medium 2. the transmission of impulses along nerves - Convection → the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in the transfer of heat - Radiation → the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization
Origin of the Atmosphere
- Density stratification caused Earth's early atmosphere (water vapor and carbon dioxide) to be outgassed from inside the Earth - the initial atmosphere was rich in hydrogen and helium - Earth's present atmosphere is rich in nitrogen and oxygen - overtime the composition of the atmosphere changed due to photosynthesis (releases oxygen to the atmosphere)
The Earth
- Earth consists of a series of concentric layers or spheres which differ in chemistry and physical properties - Three spheres surround the rocky portion of the Earth: 1. the atmosphere → the gaseous envelope that surrounds the Earth- mainly a mixture of nitrogen and oxygen 2. the biosphere → all living and non-living organic matter 3. the hydrosphere → the total amount of water on a planet. the hydrosphere includes water that is on the surface of the planet, underground, and in the air. a planet's hydrosphere can be liquid, vapor or ice
The Nebular Hypothesis
- Huge cloud of gas and space dust (nebula) began to contract about 4.6 billion years ago: 1. most of the material is gravitationally swept toward the center producing the sun 2. small eddies are created by circular motion 3. In time, most remaining debris forms the planets and their moons -aka big bang
The Challenger Expedition
- Led by Sir Wyville Thomson - Measured chemical composition of seawater and studied distribution of life forms at all depths - HMS Challenger December 21, 1872-1876 - Recognized as the first major expedition that was solely devoted to marine science - The deepest place on Earth is the Challenger Deep (35,798 feet) in the Marianas Trench → named after the expedition that discovered it - Challenger's contributions to oceanography and marine science were great - discovered over 4,700 new species to new habitats not previously thought to hold life - NASA named one of its orbiters in its honor
United States Exploring Expedition 1838-1842
- One of the most important scientific expeditions launched by the US was the US Exploring Expedition → also referred to as the Wilkes Expedition after its commander, Charles Wilkes - In addition to its surveying many parts of North and South America, this expedition found the elusive southern continent → Antarctica
Origin of the Solar System and Earth
- Protoplanets were created from the nebula - Protoearth was initially homogeneous: - Larger in size - Had lots of volcanic activity - No continents or oceans - No life
Robert Boyle (1627-1691)
- Studied the relation of water temperature, salt content (salinity) and pressure to the water depth - "Father of Chemical Oceanography"
New technology for Probing the Sea
- Submersibles are useful for the close examination and sampling of the fauna, sediment, and rock of the deep sea - The TOPEX/Poseidon satellite launched by NASA in 1992 has provided detailed, accurate data on the level of the sea surface -Undersea Robots
The Earth's Structure by Chemical Composition
- The Earth's rocky layers classified by chemical composition layers are: the crust → granite with basaltic rock the Mantle
The Oceanography Exposion
- Too many explorations to list - the great increase in the exploration of oceanography and marine science in general stemmed in large part from the industrial revolution with the evolution of scientific and technological advancements - Three expeditions stand out: 1. The German Meteor Expedition 2. Atlantis 3. The HMS Challenger II
Matthew F. Maury
- US Naval officer Matthew Maury was among the first to envision a worldwide pattern for surface winds and currents - produced instructions for making long distance sailing more efficient by working with the prevailing currents and winds - systems for recording oceanographic data from vessels adapted worldwide - 1855: compiled and standardized wind and current data from US Navy ship logs (enormous undertaking) - Published "The Physical Oceanography of the Sea"
Atmosphere
- gaseous layer that covers entire surface of Earth - Based on temperature the atmosphere is divided into four layers: 1. troposphere 2. stratosphere 3. mesosphere 4. thermosphere - 2 gases make up bulk of atmosphere → 78% nitrogen, 21% oxygen - biological importance because oxygen and carbon dioxide content - heat retention; protection from solar radiation - energy transferred between Earth's surface and the atmosphere via conduction, convection, and radiation
Cook's Expeditions
- mapped many unknown islands - determined outline of the Pacific ocean - Sampled ocean properties → studied geography, geology, biology, currents, tides, water temperatures for all oceans - modified shipboard diet to eliminate scurvy - used John Harrison's chronometer t determine longitude
Hydrophere
- oceans, lakes, rivers, groundwater, snow, ice - oceans contain 90% of free water on Earth - but surface water accounts for 10% of total water on the planet - remaining 90% is chemically bound in geological features
Track of the Magellan Expedition 1519-22
-Departed Sevilla, Spain: - September 20, 1519 - 5 ships - 230 men -Returned Seville, Spain: - September 6, 1522 - One Ship - 18 men - lost 80% of ships - lost > 90% of men
Polar Region Explorers
-Sir James Ross (Antarctic) and his uncle Sir John Ross (Arctic) - samples of bottom dwelling life
The Birth of Marine Science (late 1600s-1900)
1. Britain began to compete with France and Spain for global conquest 2. Realized the importance of understanding the global ocean 3. Royal Navy launched voyages to explore, map, and project British presence around the world 4. Crew included scientists and naturalists as well as sailors
Atmosphere layers
5) Atmosphere merges into space in the extremely thin exosphere. Upper limit of atmosphere 4) Thermosphere- layer with auroras. Also where space shuttles orbit. 3) Mesosphere is where meteors burn up. 2) Stratosphere- jet aircraft here- it is very stable. Ozone layer absorbs harmful rays from the Sun. 1) Troposphere- contains half of Earth's atmosphere. Weather occurs here. Earth's Surface.
Ocean Exploration (2500BC-1700AD) Con't
Chinese: -200BC → 1500AD - East coast Asia, Indonesia, India, Arabian Coast, and Horn of Africa - Navigation: 1. coastal landmarks 2. celestial observations 3. charts and logbooks 5. COMPASS European age of discovery: -1400 →1700 - Linked Middle Ages and modern science era - famous european explorers: 1. Vasco de Gama 2. Ferdinand Magellan 3. Christopher Columbus 4. Amerigo Vespucci 5. John Cabot 6. Francis Drake
Planet "Earth" or Planet "Ocean"
Earth's Oceans: - 70.8% of Earth's Surface - Are interconnected ("world ocean") - Have huge size and volume - average depth = ~3,668 meter (12,034 feet) - area = 362 million miles squared - volume of seawater = 1.334 billion km cubed
Major Events in Earth's Development Con't
First multi-celled animals → 600 million years Nautilus → 500 million years Sharks → 500 million years Horseshoe Crab → 500 million years Devonian reef corals → 460 million years Tiktaalik (first vertebrate animal on land) → 375 million years Turtles → 215 million years First fossils of genus Homo → 2 million years
Ben Franklin
First ocean chart of the gulf stream (1786)
Sir Isaac Newton (1642-1727)
First to correctly explain tidal forces
R/V Atlantis
In 1931, the US ship launched the Atlantis: she was the first ship specifically designed and built for ocean studies. Served as Woods Hole Oceanographic Institution's major research vessel from 1931-1964
HMS Challenger II
In 1951, the HMS Challenger II began a two year voyage to measure the depths of the ocean. Its major accomplishment was surveying the deepest known point on Earth located at the Marianas Trench → discovered by the 1st Challenger
Earth's Internal Structure
In compositions, Earth is made up of 3 main spheres: 1. Crust= outmost layer is the very thin, brittle veneer of rocks 2. Mantle= middle, large sphere made of materials rich in Si, Fe, Mg 3. Core (inner and outer)= center, intensely hot Fe and Ni Mantle and core are about equal in thickness---but-- the distribution by Earth's volume is: Core= 15% Mantle= 84% Crust= 1%
Edward Forbes (1815-1854)
Maintained the ocean was lifeless at depths greater than 550 meters (1750 feet)
The Meteor Expedition (1925-27)
One of the major accomplishments of the Meteor Expedition, was the mapping of the Atlantic seafloor with echo-sounding technology
Ocean Exploration (2500BC- 1700AD)
Polynesian expansion: -2000BC → 900AD - Huge area of western Pacific - Navigation: 1. wind, wave, currents 2. celestial observations 3. stick charts (see image) 4. blind luck Phoenicians: - 2000BC → 500BC - Mediterranean & western Europe - Navigation: 1. Coastal landmarks 2. wind, wave, currents 3. celestial observations 4. crude charts Arabs and Africans: - 700 → 1300AD - Arabian coast, east Africa, Madagascar, India, Indonesia - Navigation: 1. Coastal Landmarks 2. celestial observations 3. waves and currents 4. charts and log books Vikings: - 800 → 1100AD - North Atlantic - Navigation: 1. coastal landmarks 2. celestial landmarks 3. waves and currents 4. charts and log books
Density stratification creates a layered earth
Protoearth experiences density stratification: - Density= how heavy something is for its size - density stratification causes high density material to sink while low density material rises 1. high density material = rock material and layers 2. low density material = gases
Ocean Exploration (2500BC-1600AD)
Southern Europeans: -1400 → 1700AD - Entire temperate and tropical world ocean - Navigation: 1. Coastal Landmarks 2. Celestial observations 3. charts 4. compass 5. logbooks - Vasco de Gama (Africa) - Caribbean
Ocean or Oceans
The global ocean is divided into five oceanic divisions: - Pacific ocean (biggest, getting smaller) - Atlantic ocean (getting bigger) - Arctic ocean (smallest) - Indian ocean - Southern ocean
Major Events in Earth's Development
about 5 billion years ago →big bang about 4 billion years ago → oceans form about 3 billion years ago → life forms about 2 billion years ago → the atmosphere is oxygen rich about 1.5 billion years ago → multicellular life forms
